In vitro test for the quantitative determination of the catalytic activity of creatine kinase MB subunit (CK‑MB) in human serum and plasma on
Immunological UV assay
Sample and addition of R1 (buffer/enzymes/coenzyme)
Addition of R2 (buffer/substrate/antibody) and start of reaction.
Human CK‑MB is composed of two subunits, CK‑M and CK‑B which both have an active site. With the aid of specific antibodies to CK‑M, the catalytic activity of CK‑M subunits in the sample is inhibited to 99.6 % without affecting the CK‑B subunits. The remaining CK‑B activity, corresponding to half the CK‑MB activity, is determined by the total CK method. As the CK‑BB isoenzyme only rarely appears in serum and the catalytic activity of the CK‑M and CK‑B subunits hardly differ, the catalytic activity of the CK‑MB isoenzyme can be calculated from the measured CK‑B activity by multiplying the result by 2.
3‑2000 U/L (0.05‑33.4 µkat/L)
Determine samples having higher activities via the rerun function. Dilution of samples via the rerun function is a 1:3 dilution. Results from samples diluted by the rerun function are automatically multiplied by a factor of 3.
Limit of Blank | = 3 U/L (0.05 µkat/L) |
Limit of Detection | = 3 U/L (0.05 µkat/L) |
Limit of Quantitation | = 5 U/L (0.08 µkat/L) |
The Limit of Blank, Limit of Detection and Limit of Quantitation were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A2 requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the activity below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low activity samples.
The Limit of Detection corresponds to the lowest analyte activity which can be detected (value above the Limit of Blank with a probability of 95 %).
The Limit of Quantitation is the lowest analyte activity that can be reproducibly measured with a total error of 20 %. It has been determined using low activity CK‑MB samples.
Reference intervals strongly depend on the patient group regarded and the specific clinical situation.
< 25 U/L |
1. | CKmen | > 190 U/L |
CKwomen | > 167 U/L | |
2. | CK‑MB | > 24 U/L |
3. | The CK‑MB activity accounts for 6‑25 % of the total CK activity. |
< 0.418 µkat/L |
*calculated by unit conversion factor
1. | CKmen | > 3.17 µkat/L |
CKwomen | > 2.79 µkat/L | |
2. | CK‑MB | > 0.40 µkat/L |
3. | The CK‑MB activity accounts for 6‑25 % of the total CK activity. |
When myocardial infarction is suspected the diagnostic strategy proposals in the consensus document of European and American cardiologists should in general be followed.
If despite the suspicion of myocardial infarction the values found remain below the stated limits, a fresh infarction may be involved. In such cases the determinations should be repeated after 4 hours.
Maximum diagnostic efficiency of the CK‑MB determination will be obtained when a sequential sampling protocol is used and consideration is given to the time pattern of activity over a 6 to 48 hour period. When only CK‑MB activity is used, the diagnostic efficiency will be lower and will vary with the sampling time.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
The total CK activity of the specimen should be determined prior to performing the CK-MB assay. The amount of anti‑human CK‑M subunit antibody in the CK-MB reagent is sufficient for the complete inhibition of up to 4000 U/L CK‑M activity. If the total CK activity exceeds 4000 U/L, the specimen requires dilution because complete inhibition of the CK‑M subunit is no longer assured. In patients with a disposition to macro‑CK formation, implausibly high CK‑MB values may be measured in relation to the total CK, since the macroforms mainly consist of CK‑B subunits. As these patients have generally not suffered a myocardial infarction, additional diagnostic measures are necessary.
Criterion: Recovery within ± 10 % of initial value at a CK‑MB activity of ≥ 25 U/L.
Icterus:
Hemolysis:
Lipemia (Intralipid):
Adenylate kinase: Adenylate kinase (AK) may cause positive interference. Sources of AK in the blood are erythrocytes, muscle, and liver. In order to reduce AK interference to a minimum, AMP and Ap5A are included in the reagent. The AMP/Ap5A mixture causes 97 % inhibition of the AK from erythrocytes and muscle, and 95 % inhibition of the AK from liver.
Drugs: No interference was found at therapeutic concentrations using common drug panels.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on cobas c systems. All special wash programming necessary for avoiding carry-over is available via the cobas link. The latest version of the carry-over evasion list can be found with the NaOHD/SMS/SCCS Method Sheet. For further instructions, refer to the operator’s manual.
Analyzer(s) on which cobas c pack(s) can be used | |||
08057486190 | Creatine Kinase‑MB (150 tests) | System‑ID 2043 001 | cobas c 303, cobas c 503 |
Materials required (but not provided):
11447394216 | Calibrator f.a.s. CK‑MB (3 x 1 mL) | Code 20402 | |
05117003190 | PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 20391 | |
05947626190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 20391 | |
05117216190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 20392 | |
05947774190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 20392 | |
08063494190 | Diluent NaCl 9 % (123 mL) | System-ID 2906 001 |
CKMB2: ACN 20430
Ready for use
Reporting time | 10 min | ||
Wavelength (sub/main) | 546/340 nm | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 79 µL | – | |
R2 | 16 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 3.9 µL | – | – |
Decreased | 11.7 µL | 10 µL | 80 µL |
Increased | 3.9 µL | – | – |
For further information about the assay test definitions refer to the application parameters setting screen of the corresponding analyzer and assay.
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 8 weeks |
Calibrators | S1: H2O S2: C.f.a.s. CK‑MB |
Calibration mode | Linear |
Calibration frequency | Automatic full calibration Full calibration |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against the IFCC Method for Creatine Kinase
Representative performance data on the analyzers are given below. These data represent the performance of the analytical procedure itself.
Results obtained in individual laboratories may differ due to heterogenous sample materials, aging of analyzer components and mixture of reagents running on the analyzer.
Precision was determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP05-A3 requirements with repeatability (n = 84) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days). Results for repeatability and intermediate precision were obtained on the cobas c 503 analyzer.
Repeatability | Mean | SD | CV |
PCCC1a) | 42.9 | 0.380 | 0.9 |
PCCC2b) | 96.9 | 0.365 | 0.4 |
Human serum 1 | 16.0 | 0.358 | 2.2 |
Human serum 2 | 22.6 | 0.365 | 1.6 |
Human serum 3 | 190 | 0.779 | 0.4 |
Human serum 4 | 997 | 2.61 | 0.3 |
Human serum 5 | 1782 | 4.80 | 0.3 |
Intermediate precision | Mean | SD | CV |
PCCC1 FREFPreciControl ClinChem Multi 1 | 42.9 | 0.557 | 1.3 |
PCCC2 FREFPreciControl ClinChem Multi 2 | 96.6 | 0.712 | 0.7 |
Human serum 1 | 15.5 | 0.507 | 3.3 |
Human serum 2 | 22.3 | 0.560 | 2.5 |
Human serum 3 | 190 | 3.24 | 1.7 |
Human serum 4 | 997 | 11.1 | 1.1 |
Human serum 5 | 1784 | 28.1 | 1.6 |
The data obtained on cobas c 503 analyzer(s) are representative for cobas c 303 analyzer(s).
CK‑MB values for human serum and plasma samples obtained on a cobas c 503 analyzer (y) were compared with those determined using the corresponding reagent on a cobas c 501 analyzer (x).
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.014x − 1.73 U/L | y = 1.013x − 1.24 U/L |
τ = 0.964 | r = 1.000 |
The sample activities were between 4.90 and 1876 U/L.
CK‑MB values for human serum and plasma samples obtained on a cobas c 303 analyzer (y) were compared with those determined using the corresponding reagent on a cobas c 501 analyzer (x).
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.015x + 0.202 U/L | y = 1.023x + 0.108 U/L |
τ = 0.932 | r = 1.000 |
The sample activities were between 3.50 and 1970 U/L.
Creatine kinase (CK) appears as three isoenzymes which are dimers composed of two types of monomer subunits. The isoenzymes comprise all three combinations of monomers, M (for skeletal muscle derived) and B (for brain derived), as represented by the notations MM, MB, and BB.
Many organs contain CK, but the distribution of isoenzymes is different in each one. Skeletal muscle is very rich in the MM isoenzyme, while brain, stomach, intestine, bladder, and lung contain primarily the BB isoenzyme. The MB isoenzyme has been found in appreciable amounts (15 to 20 percent) only in myocardial tissue. Therefore, total serum CK activity is elevated in a number of diseases. This lack of specificity limits its diagnostic value. However, the striking difference in the CK isoenzyme patterns from different organs has made CK one of the most useful enzymes for diagnostic purposes in acute myocardial infarction. CK‑MB appears in serum reflecting its unique presence in myocardial tissue. It is in supporting the diagnosis of suspected myocardial infarction that serial determinations of CK isoenzymes find their most frequent application in the clinical laboratory.
After immunoinhibition with antibodies to the CK‑M subunit,
R1 | Imidazole buffer: 123 mmol/L, pH 6.5 (37 °C); EDTA: 2.46 mmol/L; Mg2+: 12.3 mmol/L; ADP: 2.46 mmol/L; AMP: 6.14 mmol/L; diadenosine pentaphosphate: 19 µmol/L; NADP (yeast): 2.46 mmol/L; N‑acetylcysteine: 24.6 mmol/L; HK (yeast): ≥ 36.7 µkat/L; G6P‑DH (E. coli): ≥ 23.4 µkat/L; preservative; stabilizers; additives. |
R2 | CAPSO* buffer: 20 mmol/L, pH 8.8 (37 °C); glucose: 120 mmol/L; EDTA: 2.46 mmol/L; creatine phosphate: 184 mmol/L; 4 monoclonal anti‑CK‑M antibodies (mouse), inhibiting capacity: > 99.6 % up to 66.8 µkat/L (4000 U/L) (37 °C) CK‑M subunit; preservative; stabilizers; additive. |
*CAPSO: 3-(cyclohexylamino)-2-hydroxy-1-propanesulfonic acid |
R1 is in position B and R2 is in position C.
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
H360D | May damage the unborn child. |
Prevention:
P201 | Obtain special instructions before use. |
P202 | Do not handle until all safety precautions have been read and understood. |
P280 | Wear protective gloves/ protective clothing/ eye protection/ face protection/ hearing protection. |
Response:
P308 + P313 | IF exposed or concerned: Get medical advice/attention. |
Storage:
P405 | Store locked up. |
Disposal:
P501 | Dispose of contents/container to an approved waste disposal plant. |
Product safety labeling follows EU GHS guidance.
Contact phone: all countries: +49-621-7590
For quality control, use control materials as listed in the “Order information” section. In addition, other suitable control material can be used.
The control intervals and limits should be adapted to each laboratory’s individual requirements. It is recommended to perform quality control always after lot calibration and subsequently at least every 8 weeks. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum: Nonhemolyzed serum is the specimen of choice and also recommended by IFCC.
Plasma: Li‑heparin, K2‑, K3‑EDTA plasma.
Li‑heparin in the usual concentration does not interfere with the test, but IFCC warns against its use.
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Stability in serum: LREFBraun S, Röschenthaler F, Jarausch J, et al. Analyte Stability of CK-MB Activity and cTnT in ICU Patient Serum and Heparin Plasma. Poster presented at Medica 2004, Düsseldorf. (Roche Diagnostics GmbH No. 04587979990). | 8 hours at 20‑24 °C 8 days at 2‑8 °C 4 weeks at −20 °C |
Stability in heparin plasma: LREFBraun S, Röschenthaler F, Jarausch J, et al. Analyte Stability of CK-MB Activity and cTnT in ICU Patient Serum and Heparin Plasma. Poster presented at Medica 2004, Düsseldorf. (Roche Diagnostics GmbH No. 04587979990). | 8 hours at 20‑24 °C 5 days at 2‑8 °C 8 days at −20 °C |
Stability in EDTA plasma: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 2 days at 20‑25 °C 7 days at 4‑8 °C 1 year at −20 °C |
In vitro test for the quantitative determination of the catalytic activity of creatine kinase MB subunit (CK‑MB) in human serum and plasma on the cobas c 111 system.
Immunological UV assay
Sample and addition of R1 (buffer/enzymes/coenzyme)
Addition of R2 (buffer/substrate/antibody) and start of reaction
Human CK‑MB is composed of two subunits, CK‑M and CK‑B which both have an active site. With the aid of specific antibodies to CK‑M, the catalytic activity of CK‑M subunits in the sample is inhibited to 99.6 % without affecting the CK‑B subunits. The remaining CK‑B activity, corresponding to half the CK‑MB activity, is determined by the total CK method. As the CK‑BB isoenzyme only rarely appears in serum and the catalytic activity of the CK‑M and CK‑B subunits hardly differ, the catalytic activity of the CK‑MB isoenzyme can be calculated from the measured CK‑B activity by multiplying the result by 2.
Measuring range
3‑2000 U/L (0.05‑33.4 µkat/L)
Determine samples having higher activities via the rerun function. Dilution of samples via the rerun function is a 1:3 dilution. Results from samples diluted by the rerun function are automatically multiplied by a factor of 3.
Lower limits of measurement
Limit of Blank, Limit of Detection and Limit of Quantitation | |
Limit of Blank | = 3 U/L (0.05 µkat/L) |
Limit of Detection | = 3 U/L (0.05 µkat/L) |
Limit of Quantitation | = 5 U/L (0.08 µkat/L) |
The Limit of Blank, Limit of Detection and Limit of Quantitation were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A2 requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte-free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the limit of blank and the standard deviation of low concentration samples. The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the limit of blank with a probability of 95 %).
The Limit of Quantitation is the lowest analyte concentration that can be reproducibly measured with a precision of 20 % CV. It has been determined using low concentration creatine kinase‑MB samples.
Reference intervals strongly depend on the patient group regarded and the specific clinical situation.
For healthy people: Reference range (37 °C) according to Klein et al.
< 25 U/L (< 0.418 µkat/L) |
For myocardial infarction diagnosis using the combination CK and CK‑MB (activity), and representing a CK consensus value based on long‑term experience:
1. | CKmen | > 190 U/L (3.17 µkat/L) |
CKwomen | > 167 U/L (2.79 µkat/L) | |
2. | CK‑MB | > 24 U/L (0.40 µkat/L) |
3. | The CK‑MB activity accounts for 6‑25 % of the total CK activity. |
When myocardial infarction is suspected the diagnostic strategy proposals in the consensus document of European and American cardiologists should in general be followed.
If despite the suspicion of myocardial infarction the values found remain below the stated limits, a fresh infarction may be involved. In such cases the determinations should be repeated after 4 hours.
Maximum diagnostic efficiency of the CK‑MB determination will be obtained when a sequential sampling protocol is used and consideration is given to the time pattern of activity over a 6 to 48 hour period. When only CK‑MB activity is used, the diagnostic efficiency will be lower and will vary with the sampling time.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
The total CK activity of the specimen should be determined prior to performing the CK‑MB assay. The amount of anti‑human CK‑M subunit antibody in the CK‑MB reagent is sufficient for the complete inhibition of up to 4000 U/L CK‑M activity. If the total CK activity exceeds 4000 U/L, the specimen requires dilution because complete inhibition of the CK‑M subunit is no longer assured. In patients with a disposition to macro‑CK formation, implausibly high CK‑MB values may be measured in relation to the total CK, since the macroforms mainly consist of CK‑B subunits. As these patients have generally not suffered a myocardial infarction, additional diagnostic measures are necessary.
Criterion: Recovery within ± 10 % of initial value at a creatine kinase‑MB activity of ≥ 25 U/L (≥ 0.42 µkat/L).
Icterus:
Hemolysis:
Lipemia (Intralipid):
Adenylate kinase: Adenylate kinase (AK) may cause positive interference. Sources of AK in the blood are erythrocytes, muscle, and liver. In order to reduce AK interference to a minimum, AMP and Ap5A are included in the reagent. The AMP/Ap5A mixture causes 97 % inhibition of the AK from erythrocytes and muscle, and 95 % inhibition of the AK from liver.
Drugs: No interference was found at therapeutic concentrations using common drug panels.
Exceptions: Cyanokit (hydroxocobalamin), Cefoxitin, Sulfasalazine and Sulfapyridine at therapeutic concentrations interfere with the test.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on the cobas c 111 analyzer. For information about test combinations requiring special wash steps, please refer to the latest version of the carry-over evasion list found with the CLEAN Method Sheet and the operator’s manual for further instructions.
Where required, special wash/carry-over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which kit(s) can be used | |
07442050190 | Creatine Kinase‑MB (2 x 50 tests) | cobasc 111 |
Materials required (but not provided):
11447394216 | Calibrator f.a.s. CK‑MB (3 x 1 mL) | Code 402 | |
PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 391 | ||
05947626190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 391 | |
05117216190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 392 | |
05947774190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 392 | |
04774230190 | NaCl Diluent 9 % (4 x 12 mL) | Code 951 |
CKMB2: ACN 546
Ready for use
Measuring mode | Absorbance |
Abs. calculation mode | Kinetic |
Reaction direction | Increase |
Wavelength A/B | 340/552 nm |
Calc. first/last | 27-38 |
Unit | U/L (µkat/L) |
Reaction mode | R1-S-SR |
Diluent (H2O) | ||
R1 | 100 µL | - |
Sample | 5 µL | - |
SR | 20 µL | - |
Total volume | 125 µL |
Shelf life at 2‑8 °C: | See expiration date on reagent |
On-board in use and refrigerated on the analyzer: | 4 weeks |
Shelf life at 2‑8 °C: | See expiration date on reagent |
On-board in use and refrigerated on the analyzer: | 4 weeks |
Calibrator | C.f.a.s. CK-MB Deionized water is used automatically by the instrument as the zero calibrator. |
Calibration mode | Linear regression |
Calibration interval | Each lot and as required following quality control procedures |
Traceability: This method has been standardized against the IFCC Method for Creatine Kinase
Representative performance data on the cobas c 111 analyzer are given below. Results obtained in individual laboratories may differ.
Repeatability and intermediate precision were determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP5 requirements (2 aliquots per run, 2 runs per day, 21 days). The following results were obtained:
Repeatability | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
|---|---|---|---|
Human serum 1 | 23.1 (0.39) | 0.5 (0.01) | 2.2 |
Human serum 2 | 107 (1.79) | 1.3 (0.02) | 1.2 |
Human serum 3 | 274 (4.58) | 2.3 (0.04) | 0.9 |
Human serum 4 | 926 (15.5) | 8.9 (0.15) | 1.0 |
Human serum 5 | 1734 (29.0) | 14 (0.23) | 0.8 |
PCCC Multi 1* | 40.9 (0.68) | 0.8 (0.01) | 1.9 |
PCCC Multi 2 | 92.3 (1.54) | 1.1 (0.02) | 1.2 |
Intermediate precision | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
|---|---|---|---|
Human serum 1 | 23.1 (0.39) | 0.6 (0.01) | 2.5 |
Human serum 2 | 107 (1.79) | 2.3 (0.04) | 2.1 |
Human serum 3 | 274 (4.58) | 5.4 (0.09) | 2.0 |
Human serum 4 | 926 (15.5) | 20 (0.33) | 2.2 |
Human serum 5 | 1734 (29.0) | 35 (0.58) | 2.0 |
PCCC Multi 1 | 40.9 (0.68) | 0.9 (0.02) | 2.2 |
PCCC Multi 2 | 92.3 (1.54) | 1.1 (0.02) | 1.2 |
*PCCC = PreciControl ClinChem
Creatine kinase‑MB values for human serum and plasma samples obtained on a
Sample size (n) = 52
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 0.988x - 1.54 U/L | y = 0.989x - 1.33 U/L |
τ = 0.962 | r = 1.000 |
The sample activities were between 8.3 and 1988 U/L (0.14 and 33.2 µkat/L). |
Creatine kinase (CK) appears as three isoenzymes which are dimers composed of two types of monomer subunits. The isoenzymes comprise all three combinations of monomers, M (for skeletal muscle derived) and B (for brain derived), as represented by the notations MM, MB, and BB.
Many organs contain CK, but the distribution of isoenzymes is different in each one. Skeletal muscle is very rich in the MM isoenzyme, while brain, stomach, intestine, bladder, and lung contain primarily the BB isoenzyme. The MB isoenzyme has been found in appreciable amounts (15 to 20 percent) only in myocardial tissue. Therefore, total serum CK activity is elevated in a number of diseases. This lack of specificity limits its diagnostic value. However, the striking difference in the CK isoenzyme patterns from different organs has made CK one of the most useful enzymes for diagnostic purposes in acute myocardial infarction. CK‑MB appears in serum reflecting its unique presence in myocardial tissue. It is in supporting the diagnosis of suspected myocardial infarction that serial determinations of CK isoenzymes find their most frequent application in the clinical laboratory.
After immunoinhibition with antibodies to the CK‑M subunit,
R1 | Imidazole buffer: 123 mmol/L, pH 6.5 (37 °C); EDTA: 2.46 mmol/L; Mg2+: 12.3 mmol/L; ADP: 2.46 mmol/L; AMP: 6.14 mmol/L; diadenosine pentaphosphate: 19 µmol/L; NADP (yeast): 2.46 mmol/L; N‑acetylcysteine: 24.6 mmol/L; HK (yeast): ≥ 36.7 µkat/L; G6P‑DH (E. coli): ≥ 23.4 µkat/L; preservative; stabilizers; additives. |
SR | CAPSO* buffer: 20 mmol/L, pH 8.8 (37 °C); glucose: 120 mmol/L; EDTA: 2.46 mmol/L; creatine phosphate: 184 mmol/L; 4 monoclonal anti‑CK‑M antibodies (mouse), inhibiting capacity: > 99.6 % up to 66.8 µkat/L (4000 U/L) (37 °C) CK‑M subunit; preservative; stabilizers; additive. |
*CAPSO: 3-(cyclohexylamino)-2-hydroxy-1-propanesulfonic acid |
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
![](\"http://pim-media.roche.com/Images/GHS_silhouete_9007200177046539_All.jpg\"/)
H360D | May damage the unborn child. |
Prevention:
P201 | Obtain special instructions before use. |
P202 | Do not handle until all safety precautions have been read and understood. |
P280 | Wear protective gloves/ protective clothing/ eye protection/ face protection/ hearing protection. |
Response:
P308 + P313 | IF exposed or concerned: Get medical advice/attention. |
Storage:
P405 | Store locked up. |
Disposal:
P501 | Dispose of contents/container to an approved waste disposal plant. |
Product safety labeling follows EU GHS guidance.
Contact phone: all countries: +49-621-7590
For quality control, use control materials as listed in the “Order information” section. In addition, other suitable control material can be used.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum: Nonhemolyzed serum is the specimen of choice and also recommended by IFCC.
Plasma: Li‑heparin, K2‑, K3‑EDTA plasma.
Li‑heparin in the usual concentration does not interfere with the test, but IFCC warns against its use.
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
Stability in serum: LREFBraun S, Röschenthaler F, Jarausch J, et al. Analyte Stability of CK-MB Activity and cTnT in ICU Patient Serum and Heparin Plasma. Poster presented at Medica 2004, Düsseldorf. (Roche Diagnostics GmbH No. 04587979990). | 8 hours at 20‑24 °C |
8 days at 2‑8 °C | |
4 weeks at -20 °C | |
Stability in heparin plasma: LREFBraun S, Röschenthaler F, Jarausch J, et al. Analyte Stability of CK-MB Activity and cTnT in ICU Patient Serum and Heparin Plasma. Poster presented at Medica 2004, Düsseldorf. (Roche Diagnostics GmbH No. 04587979990). | 8 hours at 20‑24 °C |
5 days at 2‑8 °C | |
8 days at -20 °C | |
Stability in EDTA plasma: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 2 days at 20‑25 °C |
7 days at 4‑8 °C | |
1 year at -20 °C |
In vitro test for the quantitative determination of the catalytic activity of creatine kinase MB subunit (CK‑MB) in human serum and plasma on
Immunological UV assay
Sample and addition of R1 (buffer/enzymes/coenzyme)
Addition of R2 (buffer/substrate/antibody) and start of reaction.
Human CK‑MB is composed of two subunits, CK‑M and CK‑B which both have an active site. With the aid of specific antibodies to CK‑M, the catalytic activity of CK‑M subunits in the sample is inhibited to 99.6 % without affecting the CK‑B subunits. The remaining CK‑B activity, corresponding to half the CK‑MB activity, is determined by the total CK method. As the CK‑BB isoenzyme only rarely appears in serum and the catalytic activity of the CK‑M and CK‑B subunits hardly differ, the catalytic activity of the CK‑MB isoenzyme can be calculated from the measured CK‑B activity by multiplying the result by 2.
Measuring range
3‑2000 U/L (0.05‑33.4 µkat/L)
Determine samples having higher activities via the rerun function. Dilution of samples via the rerun function is a 1:3 dilution. Results from samples diluted by the rerun function are automatically multiplied by a factor of 3.
Lower limits of measurement
Limit of Blank, Limit of Detection and Limit of Quantitation | |
Limit of Blank | = 3 U/L (0.05 µkat/L) |
Limit of Detection | = 3 U/L (0.05 µkat/L) |
Limit of Quantitation | = 5 U/L (0.08 µkat/L) |
The Limit of Blank, Limit of Detection and Limit of Quantitation were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A2 requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples. The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the limit of blank with a probability of 95 %).
The Limit of Quantitation is the lowest analyte concentration that can be reproducibly measured with a precision of 20 % CV. It has been determined using low concentration creatine kinase‑MB samples.
Reference intervals strongly depend on the patient group regarded and the specific clinical situation.
For healthy people: Reference range (37 °C) according to Klein et al.
< 25 U/L (< 0.418 µkat/L) |
For myocardial infarction diagnosis using the combination CK and CK‑MB (activity), and representing a CK consensus value based on long‑term experience:
1. | CKmen | > 190 U/L (3.17 µkat/L) |
CKwomen | > 167 U/L (2.79 µkat/L) | |
2. | CK‑MB | > 24 U/L (0.40 µkat/L) |
3. | The CK‑MB activity accounts for 6‑25 % of the total CK activity. |
When myocardial infarction is suspected the diagnostic strategy proposals in the consensus document of European and American cardiologists should in general be followed.
If despite the suspicion of myocardial infarction the values found remain below the stated limits, a fresh infarction may be involved. In such cases the determinations should be repeated after 4 hours.
Maximum diagnostic efficiency of the CK‑MB determination will be obtained when a sequential sampling protocol is used and consideration is given to the time pattern of activity over a 6 to 48 hour period. When only CK‑MB activity is used, the diagnostic efficiency will be lower and will vary with the sampling time.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
The total CK activity of the specimen should be determined prior to performing the CK‑MB assay. The amount of anti‑human CK‑M subunit antibody in the CK‑MB reagent is sufficient for the complete inhibition of up to 4000 U/L CK‑M activity. If the total CK activity exceeds 4000 U/L, the specimen requires dilution because complete inhibition of the CK‑M subunit is no longer assured. In patients with a disposition to macro‑CK formation, implausibly high CK‑MB values may be measured in relation to the total CK, since the macroforms mainly consist of CK‑B subunits. As these patients have generally not suffered a myocardial infarction, additional diagnostic measures are necessary.
Criterion: Recovery within ± 10 % of initial value at a creatine kinase‑MB activity of ≥ 25 U/L (≥ 0.42 µkat/L).
Icterus:
Hemolysis:
Lipemia (Intralipid):
Adenylate kinase: Adenylate kinase (AK) may cause positive interference. Sources of AK in the blood are erythrocytes, muscle, and liver. In order to reduce AK interference to a minimum, AMP and Ap5A are included in the reagent. The AMP/Ap5A mixture causes 97 % inhibition of the AK from erythrocytes and muscle, and 95 % inhibition of the AK from liver.
Drugs: No interference was found at therapeutic concentrations using common drug panels.
Exceptions: Cyanokit (hydroxocobalamin) and Cefoxitin at therapeutic concentrations interfere with the test.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on cobas c systems. The latest version of the carry‑over evasion list can be found with the NaOHD-SMS-SmpCln1+2-SCCS Method Sheets. For further instructions refer to the operator’s manual. cobas c 502 analyzer: All special wash programming necessary for avoiding carry‑over is available via the cobas link, manual input is required in certain cases.
Where required, special wash/carry‑over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
07190808190 | Creatine Kinase‑MB (100 tests) | System‑ID 07 7484 7 | cobas c 311, cobas c 501/502 |
Materials required (but not provided):
11447394216 | Calibrator f.a.s. CK‑MB (3 x 1 mL) | Code 402 | |
05117003190 | PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 391 | |
05947626190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 391 | |
05117216190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 392 | |
05947774190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 392 | |
04489357190 | Diluent NaCl 9 % (50 mL) | System-ID 07 6869 3 |
For cobas c 311/501 analyzers:
CKMB2: ACN 546
For cobas c 502 analyzer:
CKMB2: ACN 8546
Ready for use
cobas c 311 test definition | |||
Assay type | Rate A | ||
Reaction time / Assay points | 10 / 21‑57 | ||
Wavelength (sub/main) | 546/340 nm | ||
Reaction direction | Increase | ||
Units | U/L (µkat/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 100 µL | – | |
R2 | 20 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 5 µL | – | – |
Decreased | 15 µL | 15 µL | 120 µL |
Increased | 5 µL | – | – |
cobas c 501 test definition | |||
Assay type | Rate A | ||
Reaction time / Assay points | 10 / 30‑70 | ||
Wavelength (sub/main) | 546/340 nm | ||
Reaction direction | Increase | ||
Units | U/L (µkat/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 100 µL | – | |
R2 | 20 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 5 µL | – | – |
Decreased | 15 µL | 15 µL | 120 µL |
Increased | 5 µL | – | – |
cobas c 502 test definition | |||
Assay type | Rate A | ||
Reaction time / Assay points | 10 / 30‑70 | ||
Wavelength (sub/main) | 546/340 nm | ||
Reaction direction | Increase | ||
Units | U/L (µkat/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 100 µL | – | |
R2 | 20 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 5 µL | – | – |
Decreased | 15 µL | 15 µL | 120 µL |
Increased | 10 µL | – | – |
CKMB | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 8 weeks |
Diluent NaCl 9 % | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 12 weeks |
Calibrators | S1: H2O S2: C.f.a.s. CK‑MB |
Calibration mode | Linear |
Calibration frequency | 2‑point calibration |
Traceability: This method has been standardized against the IFCC Method for Creatine Kinase
Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.
Repeatability and intermediate precision were determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP5 requirements (2 aliquots per run, 2 runs per day, 21 days). The following results were obtained:
Repeatability | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
|---|---|---|---|
Human serum 1 | 17.9 (0.30) | 0.4 (0.01) | 2.2 |
Human serum 2 | 29.1 (0.49) | 0.4 (0.01) | 1.2 |
Human serum 3 | 524 (8.76) | 2.5 (0.04) | 0.5 |
Human serum 4 | 1040 (17.4) | 4.9 (0.08) | 0.5 |
Human serum 5 | 1844 (30.8) | 25 (0.42) | 1.4 |
PCCC Multi 1* | 41.0 (0.68) | 0.3 (0.01) | 0.8 |
PCCC Multi 2 | 99.2 (1.66) | 0.5 (0.01) | 0.5 |
Intermediate precision | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
|---|---|---|---|
Human serum 1 | 17.8 (0.30) | 0.5 (0.01) | 2.8 |
Human serum 2 | 29 (0.48) | 0.6 (0.01) | 1.9 |
Human serum 3 | 531 (8.87) | 4.4 (0.07) | 0.8 |
Human serum 4 | 1040 (17.4) | 8.4 (0.14) | 0.8 |
Human serum 5 | 1843 (30.8) | 38 (0.63) | 2.1 |
PCCC Multi 1 | 40.2 (0.67) | 0.7 (0.01) | 1.7 |
PCCC Multi 2 | 98.7 (1.65) | 1.5 (0.03) | 1.5 |
*PCCC = PreciControl ClinChem
The data obtained on cobas c 501 analyzer(s) are representative for cobas c 311 analyzer(s).
Creatine kinase‑MB values for human serum and plasma samples obtained on a cobas c 501 analyzer (y) were compared with those determined using the corresponding reagent on a Roche/Hitachi MODULAR P analyzer (x).
Sample size (n) = 113
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.007x + 2.36 U/L | y = 0.999x + 2.68 U/L |
τ = 0.915 | r = 1.000 |
The sample activities were between 5.8 and 1967 U/L (0.10 and 32.8 µkat/L). |
The data obtained on cobas c 501 analyzer(s) are representative for cobas c 311 analyzer(s).
Creatine kinase (CK) appears as three isoenzymes which are dimers composed of two types of monomer subunits. The isoenzymes comprise all three combinations of monomers, M (for skeletal muscle derived) and B (for brain derived), as represented by the notations MM, MB, and BB.
Many organs contain CK, but the distribution of isoenzymes is different in each one. Skeletal muscle is very rich in the MM isoenzyme, while brain, stomach, intestine, bladder, and lung contain primarily the BB isoenzyme. The MB isoenzyme has been found in appreciable amounts (15 to 20 percent) only in myocardial tissue. Therefore, total serum CK activity is elevated in a number of diseases. This lack of specificity limits its diagnostic value. However, the striking difference in the CK isoenzyme patterns from different organs has made CK one of the most useful enzymes for diagnostic purposes in acute myocardial infarction. CK‑MB appears in serum reflecting its unique presence in myocardial tissue. It is in supporting the diagnosis of suspected myocardial infarction that serial determinations of CK isoenzymes find their most frequent application in the clinical laboratory.
After immunoinhibition with antibodies to the CK‑M subunit,
R1 | Imidazole buffer: 123 mmol/L, pH 6.5 (37 °C); EDTA: 2.46 mmol/L; Mg2+: 12.3 mmol/L; ADP: 2.46 mmol/L; AMP: 6.14 mmol/L; diadenosine pentaphosphate: 19 µmol/L; NADP (yeast): 2.46 mmol/L; N‑acetylcysteine: 24.6 mmol/L; HK (yeast): ≥ 36.7 µkat/L; G6P‑DH (E. coli): ≥ 23.4 µkat/L; preservative; stabilizers; additives. |
R2 | CAPSO* buffer: 20 mmol/L, pH 8.8 (37 °C); glucose: 120 mmol/L; EDTA: 2.46 mmol/L; creatine phosphate: 184 mmol/L; 4 monoclonal anti‑CK‑M antibodies (mouse), inhibiting capacity: > 99.6 % up to 66.8 µkat/L (4000 U/L) (37 °C) CK‑M subunit; preservative; stabilizers; additive. |
*CAPSO: 3-(cyclohexylamino)-2-hydroxy-1-propanesulfonic acid |
R1 is in position B and R2 is in position C.
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
H360D | May damage the unborn child. |
Prevention:
P201 | Obtain special instructions before use. |
P202 | Do not handle until all safety precautions have been read and understood. |
P280 | Wear protective gloves/ protective clothing/ eye protection/ face protection/ hearing protection. |
Response:
P308 + P313 | IF exposed or concerned: Get medical advice/attention. |
Storage:
P405 | Store locked up. |
Disposal:
P501 | Dispose of contents/container to an approved waste disposal plant. |
Product safety labeling follows EU GHS guidance.
Contact phone: all countries: +49-621-7590
For quality control, use control materials as listed in the \"Order information\" section.
In addition, other suitable control material can be used.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum: Nonhemolyzed serum is the specimen of choice and also recommended by IFCC.
Plasma: Li‑heparin, K2‑, K3‑EDTA plasma.
Li‑heparin in the usual concentration does not interfere with the test, but IFCC warns against its use.
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
Stability in serum: LREFBraun S, Röschenthaler F, Jarausch J, et al. Analyte Stability of CK-MB Activity and cTnT in ICU Patient Serum and Heparin Plasma. Poster presented at Medica 2004, Düsseldorf. (Roche Diagnostics GmbH No. 04587979990). | 8 hours at 20‑24 °C |
8 days at 2‑8 °C | |
4 weeks at -20 °C | |
Stability in heparin plasma: LREFBraun S, Röschenthaler F, Jarausch J, et al. Analyte Stability of CK-MB Activity and cTnT in ICU Patient Serum and Heparin Plasma. Poster presented at Medica 2004, Düsseldorf. (Roche Diagnostics GmbH No. 04587979990). | 8 hours at 20‑24 °C |
5 days at 2‑8 °C | |
8 days at -20 °C | |
Stability in EDTA plasma: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 2 days at 20‑25 °C |
7 days at 4‑8 °C | |
1 year at -20 °C |
In vitro test for the quantitative determination of the catalytic activity of creatine kinase MB subunit (CK‑MB) in human serum and plasma on COBAS INTEGRA systems.
Immunological UV assay
Sample and addition of R1 (buffer/enzymes/coenzyme)
Addition of R2 (buffer/substrate/antibody) and start of reaction.
Human CK‑MB is composed of two subunits, CK‑M and CK‑B which both have an active site. With the aid of specific antibodies to CK‑M, the catalytic activity of CK‑M subunits in the sample is inhibited to 99.6 % without affecting the CK‑B subunits. The remaining CK‑B activity, corresponding to half the CK‑MB activity, is determined by the total CK method. As the CK‑BB isoenzyme only rarely appears in serum and the catalytic activity of the CK‑M and CK‑B subunits hardly differ, the catalytic activity of the CK‑MB isoenzyme can be calculated from the measured CK‑B activity by multiplying the result by 2.
Measuring range
3‑2000 U/L (0.05‑33.4 µkat/L)
Determine samples having higher activities via the rerun function. Dilution of samples via the rerun function is a 1:3 dilution. Results from samples diluted by the rerun function are automatically multiplied by a factor of 3.
Lower limits of measurement
Limit of Blank, Limit of Detection and Limit of Quantitation | |
Limit of Blank | = 3 U/L (0.05 µkat/L) |
Limit of Detection | = 3 U/L (0.05 µkat/L) |
Limit of Quantitation | = 5 U/L (0.08 µkat/L) |
The Limit of Blank, Limit of Detection and Limit of Quantitation were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A2 requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples. The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the limit of blank with a probability of 95 %).
The Limit of Quantitation is the lowest analyte concentration that can be reproducibly measured with a precision of 20 % CV. It has been determined using low concentration creatine kinase‑MB samples.
Reference intervals strongly depend on the patient group regarded and the specific clinical situation.
For healthy people: Reference range (37 °C) according to Klein et al.
< 25 U/L (< 0.418 µkat/L) |
For myocardial infarction diagnosis using the combination CK and CK‑MB (activity), and representing a CK consensus value based on long‑term experience:
1. | CKmen | > 190 U/L (3.17 µkat/L) |
CKwomen | > 167 U/L (2.79 µkat/L) | |
2. | CK‑MB | > 24 U/L (0.40 µkat/L) |
3. | The CK‑MB activity accounts for 6‑25 % of the total CK activity. |
When myocardial infarction is suspected the diagnostic strategy proposals in the consensus document of European and American cardiologists should in general be followed.
If despite the suspicion of myocardial infarction the values found remain below the stated limits, a fresh infarction may be involved. In such cases the determinations should be repeated after 4 hours.
Maximum diagnostic efficiency of the CK‑MB determination will be obtained when a sequential sampling protocol is used and consideration is given to the time pattern of activity over a 6 to 48 hour period. When only CK‑MB activity is used, the diagnostic efficiency will be lower and will vary with the sampling time.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
The total CK activity of the specimen should be determined prior to performing the CK‑MB assay. The amount of anti‑human CK‑M subunit antibody in the CK‑MB reagent is sufficient for the complete inhibition of up to 4000 U/L CK‑M activity. If the total CK activity exceeds 4000 U/L, the specimen requires dilution because complete inhibition of the CK‑M subunit is no longer assured. In patients with a disposition to macro‑CK formation, implausibly high CK‑MB values may be measured in relation to the total CK, since the macroforms mainly consist of CK‑B subunits. As these patients have generally not suffered a myocardial infarction, additional diagnostic measures are necessary.
Criterion: Recovery within ± 10 % of initial value at a creatine kinase‑MB activity of ≥ 25 U/L (≥ 0.42 µkat/L).
Icterus:
Hemolysis:
Lipemia (Intralipid):
Adenylate kinase: Adenylate kinase (AK) may cause positive interference. Sources of AK in the blood are erythrocytes, muscle, and liver. In order to reduce AK interference to a minimum, AMP and Ap5A are included in the reagent. The AMP/Ap5A mixture causes 97 % inhibition of the AK from erythrocytes and muscle, and 95 % inhibition of the AK from liver.
Drugs: No interference was found at therapeutic concentrations using common drug panels.
Exceptions: Cyanokit (hydroxocobalamin), Cefoxitin, Sulfasalazine and Sulfapyridine at therapeutic concentrations interfere with the test.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on COBAS INTEGRA analyzers. Refer to the CLEAN Method Sheet for further instructions and for the latest version of the Extra wash cycle list.
Where required, special wash/carry-over evasion programming must be implemented prior to reporting results with this test.
Analyzer(s) on which cobas c pack(s) can be used | |||
07190808190 | Creatine Kinase‑MB (100 tests) | System‑ID 07 7484 7 | COBAS INTEGRA 400 plus |
Materials required (but not provided):
11447394216 | Calibrator f.a.s. CK‑MB (3 x 1 mL) | System-ID 07 7996 2 | |
05117003190 | PreciControl ClinChem Multi 1 (20 x 5 mL) | System-ID 07 7469 3 | |
05947626190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | System-ID 07 7469 3 | |
05117216190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | System-ID 07 7470 7 | |
05947774190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | System-ID 07 7470 7 | |
20756350322 | NaCl Diluent 9 % (6 x 22 mL) | System-ID 07 5635 0 |
Test CKMB2, test ID 0-057
Ready for use
Measuring mode | Absorbance |
Abs. calculation mode | Kinetic |
Reaction mode | R1‑S‑SR |
Reaction direction | Increase |
Wavelength A/B | 340/552 nm |
Calc. first/last | 10/50‑69 |
Unit | U/L |
Diluent (H2O) | ||
R1 | 100 µL | - |
Sample | 5 µL | - |
SR | 20 µL | - |
Total volume | 125 µL |
Shelf life at 2‑8 °C | See expiration date on cobas c pack label |
On‑board in use at 10‑15 °C | 8 weeks |
Calibrator | C.f.a.s. CK‑MB Use deionized water as zero calibrator. |
Calibration mode | Linear regression |
Calibration replicate | Duplicate recommended |
Calibration interval | Each lot and as required following quality control procedures |
Traceability: This method has been standardized against the IFCC Method for Creatine Kinase
Representative performance data on the COBAS INTEGRA analyzers are given below. Results obtained in individual laboratories may differ.
Repeatability and intermediate precision were determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP5 requirements (2 aliquots per run, 2 runs per day, 21 days). The following results were obtained:
Repeatability | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
|---|---|---|---|
Human serum 1 | 22.2 (0.37) | 0.7 (0.01) | 3.2 |
Human serum 2 | 31.6 (0.53) | 0.5 (0.01) | 1.7 |
Human serum 3 | 562 (9.39) | 3.0 (0.05) | 0.5 |
Human serum 4 | 1105 (18.5) | 7.0 (0.12) | 0.6 |
Human serum 5 | 1949 (32.6) | 27 (0.45) | 1.4 |
PCCC Multi 1* | 44.5 (0.74) | 0.6 (0.01) | 1.3 |
PCCC Multi 2 | 106 (1.77) | 0.8 (0.01) | 0.7 |
Intermediate precision | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
|---|---|---|---|
Human serum 1 | 22.2 (0.37) | 0.8 (0.01) | 3.8 |
Human serum 2 | 31.6 (0.53) | 0.7 (0.01) | 2.2 |
Human serum 3 | 562 (9.39) | 5.0 (0.08) | 0.9 |
Human serum 4 | 1085 (18.1) | 9.8 (0.16) | 0.9 |
Human serum 5 | 1949 (32.6) | 34 (0.57) | 1.7 |
PCCC Multi 1 | 43.5 (0.73) | 0.8 (0.01) | 1.8 |
PCCC Multi 2 | 104 (1.74) | 1.6 (0.03) | 1.5 |
*PCCC = PreciControl ClinChem
Creatine kinase‑MB values for human serum and plasma samples obtained on a COBAS INTEGRA 400 plus analyzer (y) were compared with those using the corresponding reagent on a Roche/Hitachi MODULAR P analyzer (x).
Sample size (n) = 117
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.016x + 3.75 U/L | y = 1.011x + 4.26 U/L |
τ = 0.897 | r = 1.000 |
The sample activities were between 5.0 and 1967 U/L (0.08 and 32.8 µkat/L). |
Creatine kinase (CK) appears as three isoenzymes which are dimers composed of two types of monomer subunits. The isoenzymes comprise all three combinations of monomers, M (for skeletal muscle derived) and B (for brain derived), as represented by the notations MM, MB, and BB.
Many organs contain CK, but the distribution of isoenzymes is different in each one. Skeletal muscle is very rich in the MM isoenzyme, while brain, stomach, intestine, bladder, and lung contain primarily the BB isoenzyme. The MB isoenzyme has been found in appreciable amounts (15 to 20 percent) only in myocardial tissue. Therefore, total serum CK activity is elevated in a number of diseases. This lack of specificity limits its diagnostic value. However, the striking difference in the CK isoenzyme patterns from different organs has made CK one of the most useful enzymes for diagnostic purposes in acute myocardial infarction. CK‑MB appears in serum reflecting its unique presence in myocardial tissue. It is in supporting the diagnosis of suspected myocardial infarction that serial determinations of CK isoenzymes find their most frequent application in the clinical laboratory.
After immunoinhibition with antibodies to the CK‑M subunit,
R1 | Imidazole buffer: 123 mmol/L, pH 6.5 (37 °C); EDTA: 2.46 mmol/L; Mg2+: 12.3 mmol/L; ADP: 2.46 mmol/L; AMP: 6.14 mmol/L; diadenosine pentaphosphate: 19 µmol/L; NADP (yeast): 2.46 mmol/L; N‑acetylcysteine: 24.6 mmol/L; HK (yeast): ≥ 36.7 µkat/L; G6P‑DH (E. coli): ≥ 23.4 µkat/L; preservative; stabilizers; additives. |
SR | CAPSO* buffer: 20 mmol/L, pH 8.8 (37 °C); glucose: 120 mmol/L; EDTA: 2.46 mmol/L; creatine phosphate: 184 mmol/L; 4 monoclonal anti‑CK‑M antibodies (mouse), inhibiting capacity: > 99.6 % up to 66.8 µkat/L (4000 U/L) (37 °C) CK‑M subunit; preservative; stabilizers; additive. |
*CAPSO: 3-(cyclohexylamino)-2-hydroxy-1-propanesulfonic acid |
R1 is in position B and SR is in position C.
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
H360D | May damage the unborn child. |
Prevention:
P201 | Obtain special instructions before use. |
P202 | Do not handle until all safety precautions have been read and understood. |
P280 | Wear protective gloves/ protective clothing/ eye protection/ face protection/ hearing protection. |
Response:
P308 + P313 | IF exposed or concerned: Get medical advice/attention. |
Storage:
P405 | Store locked up. |
Disposal:
P501 | Dispose of contents/container to an approved waste disposal plant. |
Product safety labeling follows EU GHS guidance.
Contact phone: all countries: +49-621-7590
Reference range | PreciControl ClinChem Multi 1 |
Pathological range | PreciControl ClinChem Multi 2 |
Control interval | 24 hours recommended |
Control sequence | User defined |
Control after calibration | Recommended |
For quality control, use control materials as listed in the “Order information” section. In addition, other suitable control material can be used.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum: Nonhemolyzed serum is the specimen of choice and also recommended by IFCC.
Plasma: Li‑heparin, K2‑, K3‑EDTA plasma.
Li‑heparin in the usual concentration does not interfere with the test, but IFCC warns against its use.
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
Stability in serum: LREFBraun S, Röschenthaler F, Jarausch J, et al. Analyte Stability of CK-MB Activity and cTnT in ICU Patient Serum and Heparin Plasma. Poster presented at Medica 2004, Düsseldorf. (Roche Diagnostics GmbH No. 04587979990). | 8 hours at 20‑24 °C |
8 days at 2‑8 °C | |
4 weeks at -20 °C | |
Stability in heparin plasma: LREFBraun S, Röschenthaler F, Jarausch J, et al. Analyte Stability of CK-MB Activity and cTnT in ICU Patient Serum and Heparin Plasma. Poster presented at Medica 2004, Düsseldorf. (Roche Diagnostics GmbH No. 04587979990). | 8 hours at 20‑24 °C |
5 days at 2‑8 °C | |
8 days at -20 °C | |
Stability in EDTA plasma: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 2 days at 20‑25 °C |
7 days at 4‑8 °C | |
1 year at -20 °C |
In vitro test for the quantitative determination of the catalytic activity of creatine kinase MB subunit (CK‑MB) in human serum and plasma on
Immunological UV assay
Sample and addition of R1 (buffer/enzymes/coenzyme)
Addition of R2 (buffer/substrate/antibody) and start of reaction.
Human CK‑MB is composed of two subunits, CK‑M and CK‑B which both have an active site. With the aid of specific antibodies to CK‑M, the catalytic activity of CK‑M subunits in the sample is inhibited to 99.6 % without affecting the CK‑B subunits. The remaining CK‑B activity, corresponding to half the CK‑MB activity, is determined by the total CK method. As the CK‑BB isoenzyme only rarely appears in serum and the catalytic activity of the CK‑M and CK‑B subunits hardly differ, the catalytic activity of the CK‑MB isoenzyme can be calculated from the measured CK‑B activity by multiplying the result by 2.
Measuring range
3‑2000 U/L (0.050‑33.4 µkat/L)
Determine samples having higher activities via the rerun function. Dilution of samples via the rerun function is a 1:3 dilution. Results from samples diluted by the rerun function are automatically multiplied by a factor of 3.
Lower limits of measurement
Lower detection limit of the test
3 U/L (0.05 µkat/L)
The lower detection limit represents the lowest measurable analyte level that can be distinguished from zero. It is calculated as the value lying 3 standard deviations above that of the lowest standard (standard 1 + 3 SD, repeatability, n = 21).
Values below the lower detection limit (< 3 U/L) will not be flagged by the instrument.
Reference intervals strongly depend on the patient group regarded and the specific clinical situation.
For healthy people: Reference range (37 °C) according to Klein et al.
< 25 U/L | (< 0.418 µkat/L) |
For myocardial infarction diagnosis using the combination CK and CK‑MB (activity), and representing a CK consensus value based on long‑term experience:
1. | CKmen | > 190 U/L (3.17 µkat/L) |
CKwomen | > 167 U/L (2.79 µkat/L) | |
2. | CK‑MB | > 24 U/L (0.40 µkat/L) |
3. | The CK‑MB activity accounts for 6‑25 % of the total CK activity. |
When myocardial infarction is suspected the diagnostic strategy proposals in the consensus document of European and American cardiologists should in general be followed.
If despite the suspicion of myocardial infarction the values found remain below the stated limits, a fresh infarction may be involved. In such cases the determinations should be repeated after 4 hours.
Maximum diagnostic efficiency of the CK‑MB determination will be obtained when a sequential sampling protocol is used and consideration is given to the time pattern of activity over a 6 to 48 hour period. When only CK‑MB activity is used, the diagnostic efficiency will be lower and will vary with the sampling time.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
The total CK activity of the specimen should be determined prior to performing the CK‑MB assay. The amount of anti‑human CK‑M subunit antibody in the CK‑MB reagent is sufficient for the complete inhibition of up to 4000 U/L CK‑M activity. If the total CK activity exceeds 4000 U/L, the specimen requires dilution because complete inhibition of the CK‑M subunit is no longer assured. In patients with a disposition to macro‑CK formation, implausibly high CK‑MB values may be measured in relation to the total CK, since the macroforms mainly consist of CK‑B subunits. As these patients have generally not suffered a myocardial infarction, additional diagnostic measures are necessary.
Criterion: Recovery within ± 10 % of initial value at a creatine kinase‑MB activity of ≥ 25 U/L (≥ 0.42 µkat/L).
Icterus:
Hemolysis:
Lipemia (Intralipid):
Adenylate kinase: Adenylate kinase (AK) may cause positive interference. Sources of AK in the blood are erythrocytes, muscle, and liver. In order to reduce AK interference to a minimum, AMP and Ap5A are included in the reagent. The AMP/Ap5A mixture causes 97 % inhibition of the AK from erythrocytes and muscle, and 95 % inhibition of the AK from liver.
Drugs: No interference was found at therapeutic concentrations using common drug panels.
Cyanokit (hydroxocobalamin) and Cefoxitin at therapeutic concentrations interfere with the test.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on cobas c systems. All special wash programming necessary for avoiding carry‑over is available via the cobas link, manual input is required in certain cases. The latest version of the carry‑over evasion list can be found with the NaOHD/SMS/SmpCln1+2/SCCS Method Sheet and for further instructions refer to the operator’s manual.
Where required, special wash/carry‑over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
05168562190* | Creatine Kinase‑MB (600 tests) | System‑ID 03 5924 4 | cobas c 701/702 |
05168562214* | Creatine Kinase‑MB (600 tests) | System‑ID 03 5924 4 | cobas c 701/702 |
Materials required (but not provided):
11447394216 | Calibrator f.a.s. CK‑MB (3 x 1 mL) | Code 402 | |
PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 391 | ||
05947626190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 391 | |
05117216190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 392 | |
05947774190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 392 | |
05172152190 | Diluent NaCl 9 % (119 mL) | System‑ID 08 6869 3 |
* Some kits shown may not be available in all countries.
CKMB: ACN 8060
CKMB2: ACN 8546
Ready for use
cobas c 701/702 test definition | |||
Assay type | Rate A | ||
Reaction time / Assay points | 10 / 30‑38 | ||
Wavelength (sub/main) | 546/340 nm | ||
Reaction direction | Increase | ||
Units | U/L (µkat/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 100 µL | – | |
R3 | 20 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 5 µL | – | – |
Decreased | 15 µL | 15 µL | 120 µL |
Increased | 10 µL | – | – |
CKMB | |
Shelf life at 2-8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 4 weeks |
On‑board on the Reagent Manager: | 24 hours |
Diluent NaCl 9 % | |
Shelf life at 2-8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 4 weeks |
On‑board on the Reagent Manager: | 24 hours |
Calibrators | S1: H2O S2: C.f.a.s. CK‑MB |
Calibration mode | Linear |
Calibration frequency | 2‑point calibration |
Traceability: This method has been standardized against the IFCC Method for Creatine Kinase
Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.
Precision was determined using human samples and controls in an internal protocol with repeatability (n = 21) and intermediate precision (3 aliquots per run, 1 run per day, 21 days). The following results were obtained:
Repeatability | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
Precinorm CK‑MB | 35.0 (0.584) | 0.5 (0.008) | 1.5 |
Precipath CK‑MB | 207 (3.46) | 1 (0.01) | 0.3 |
Human serum A | 19.5 (0.326) | 0.5 (0.008) | 2.6 |
Human serum B | 660 (11.0) | 1 (0.0) | 0.2 |
Human serum C | 1811 (30.2) | 6 (0.1) | 0.3 |
Intermediate precision | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
Precinorm CK‑MB | 32.1 (0.536) | 1.1 (0.018) | 3.5 |
Precipath CK‑MB | 173 (2.89) | 1 (0.02) | 0.7 |
Human serum N | 20.4 (0.341) | 0.9 (0.015) | 4.5 |
Human serum H | 184 (3.07) | 2 (0.03) | 0.9 |
Results for intermediate precision were obtained on a Roche/Hitachi 917 analyzer.
Creatine kinase‑MB values for human serum and plasma samples obtained on a
Sample size (n) = 129
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 0.988x + 2.23 U/L | y = 0.993x + 2.56 U/L |
τ = 0.924 | r = 1.000 |
The sample activities were between 3.00 and 1861 U/L (0.050 and 31.1 µkat/L). |
Creatine kinase (CK) appears as three isoenzymes which are dimers composed of two types of monomer subunits. The isoenzymes comprise all three combinations of monomers, M (for skeletal muscle derived) and B (for brain derived), as represented by the notations MM, MB, and BB.
Many organs contain CK, but the distribution of isoenzymes is different in each one. Skeletal muscle is very rich in the MM isoenzyme, while brain, stomach, intestine, bladder, and lung contain primarily the BB isoenzyme. The MB isoenzyme has been found in appreciable amounts (15 to 20 percent) only in myocardial tissue. Therefore, total serum CK activity is elevated in a number of diseases. This lack of specificity limits its diagnostic value. However, the striking difference in the CK isoenzyme patterns from different organs has made CK one of the most useful enzymes for diagnostic purposes in acute myocardial infarction. CK‑MB appears in serum reflecting its unique presence in myocardial tissue. It is in supporting the diagnosis of suspected myocardial infarction that serial determinations of CK isoenzymes find their most frequent application in the clinical laboratory.
After immunoinhibition with antibodies to the CK‑M subunit,
R1 | Imidazole buffer: 123 mmol/L, pH 6.5 (37 °C); EDTA: 2.46 mmol/L; Mg2+: 12.3 mmol/L; ADP: 2.46 mmol/L; AMP: 6.14 mmol/L; diadenosine pentaphosphate: 19 µmol/L; NADP (yeast): 2.46 mmol/L; N‑acetylcysteine: 24.6 mmol/L; HK (yeast): ≥ 36.7 µkat/L; G6P‑DH (E. coli): ≥ 23.4 |
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