In vitro test for the quantitative determination of γ‑glutamyltransferase (GGT) in human serum and plasma on Roche/Hitachi cobas c systems.
Enzymatic colorimetric assay
γ‑glutamyltransferase transfers the γ‑glutamyl group of L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide to glycylglycine.
GGT | |
L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide + glycylglycine |
|
L‑γ‑glutamyl‑glycylglycine + 5‑amino‑2‑nitrobenzoate |
The amount of 5‑amino‑2‑nitrobenzoate liberated is proportional to the GGT activity in the sample. It is determined by measuring the increase in absorbance photometrically.
Measuring range
3‑1200 U/L (0.05‑20.0 µkat/L)
Determine samples having higher activities via the rerun function. Dilution of samples via the rerun function is a 1:11 dilution. Results from samples diluted using the rerun function are automatically multiplied by 11.
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.
Standardized against Szasz (Persijn, van der Slik) LREFAbicht K, El-Samalouti V, Junge W, et al. Multicenter evaluation of new GGT and ALP reagents with new reference standardization and determination of 37 °C reference intervals. Clin Chem Lab Med 2001;39:Special Supplement pp S 346. | ||
Men | 8‑61 U/L | 0.13‑1.02 µkat/L |
Women | 5‑36 U/L | 0.08‑0.60 µkat/L |
Standardized against IFCC | ||
Reference Interval Study at 37 °C (corrected in 2005) LREFAbicht K, El-Samalouti V, Junge W, et al. Multicenter evaluation of new GGT and ALP reagents with new reference standardization and determination of 37 °C reference intervals. Clin Chem Lab Med 2001;39:Special Supplement pp S 346. ,LREFKytzia H-J. Reference intervals for GGT according to the new IFCC 37°C reference procedure. Clin Chem Lab Med 2005;43:A69 [abstract]. | ||
Men (n = 216) | 10‑71 U/L | 0.17‑1.19 µkat/L |
Women (n = 228) | 6‑42 U/L | 0.10‑0.70 µkat/L |
Consensus values (IFCC) LREFThomas L, Müller M, Schumann G, et al. Consensus of DGKL and VDGH for interim reference intervals on enzymes in serum. J Lab Med 2005;29(5):301-308. | ||
Men | < 60 U/L | < 1.00 µkat/L |
Women | < 40 U/L | < 0.67 µkat/L |
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % of initial value at a γ‑glutamyltransferase activity of 40 U/L (0.67 µkat/L).
Icterus:
Hemolysis:
Lipemia (Intralipid):
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 Roche/Hitachi 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 | |
05168775 190* | γ‑Glutamyltransferase ver.2 (1200 tests) | System‑ID 03 6598 8 | Roche/Hitachi cobas c 701/702 |
05168775 214* | γ‑Glutamyltransferase ver.2 (1200 tests) | System‑ID 03 6598 8 | Roche/Hitachi cobas c 701/702 |
Materials required (but not provided):
10759350 190 | Calibrator f.a.s. (12 x 3 mL) | Code 401 | |
10759350 360 | Calibrator f.a.s. (12 x 3 mL, for USA) | Code 401 | |
12149435 122 | Precinorm U plus (10 x 3 mL) | Code 300 | |
12149435 160 | Precinorm U plus (10 x 3 mL, for USA) | Code 300 | |
12149443 122 | Precipath U plus (10 x 3 mL) | Code 301 | |
12149443 160 | Precipath U plus (10 x 3 mL, for USA) | Code 301 | |
05117003 190 | PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 391 | |
05947626 190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 391 | |
05947626 160 | PreciControl ClinChem Multi 1 (4 x 5 mL, for USA) | Code 391 | |
05117216 190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 392 | |
05947774 190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 392 | |
05947774 160 | PreciControl ClinChem Multi 2 (4 x 5 mL, for USA) | Code 392 | |
05172152 190 | Diluent NaCl 9 % (119 mL) | System‑ID 08 6869 3 |
* Some kits shown may not be available in all countries.
GGTI2: ACN 8220: assay standardized against IFCC
GGTS2: ACN 8480: assay standardized against Szasz
Ready for use
cobas c 701/702 test definition | |||
Assay type | Rate A | ||
Reaction time / Assay points | 10/25‑38 | ||
Wavelength (sub/main) | 700/415 nm | ||
Reaction direction | Increase | ||
Units | U/L (µkat/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 25 µL | 75 µL | |
R3 | 20 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 3 µL | – | – |
Decreased | 3 µL | 15 µL | 150 µL |
Increased | 6 µL | – | – |
GGT‑2 | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 2 weeks |
On‑board on the Reagent Manager: | 1 hour |
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. |
Calibration mode | Linear |
Calibration frequency | 2‑point calibration |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against the original IFCC formulation (2002)
Use the appropriate calibrator value for the corresponding application.
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 U | 39.2 (0.655) | 0.5 (0.008) | 1.4 |
Precipath U | 181 (3.02) | 1 (0.02) | 0.5 |
Human serum A | 18.0 (0.301) | 0.6 (0.010) | 3.3 |
Human serum B | 472 (7.88) | 2 (0.03) | 0.3 |
Human serum C | 867 (14.5) | 4 (0.1) | 0.5 |
Intermediate precision | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
Precinorm U | 44.1 (0.736) | 0.8 (0.013) | 1.8 |
Precipath U | 221 (3.69) | 4 (0.07) | 1.7 |
Human serum 3 | 46.8 (0.782) | 1.5 (0.025) | 3.2 |
Human serum 4 | 256 (4.28) | 9 (0.15) | 3.7 |
Results for intermediate precision were obtained on the master system cobas c 501 analyzer.
γ‑glutamyltransferase values for human serum and plasma samples obtained on a Roche/Hitachi cobas c 701 analyzer (y) were compared with those determined using the corresponding reagent on a Roche/Hitachi cobas c 501 analyzer (x).
Sample size (n) = 103
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 - 0.39 U/L | y = 1.017x - 0.474 U/L |
τ = 0.992 | r = 1.000 |
The sample activities were between 14.0 and 1168 U/L (0.234 and 19.5 µkat/L). |
γ‑glutamyltransferase is used in the diagnosis and monitoring of hepatobiliary diseases. Enzymatic activity of GGT is often the only parameter with increased values when testing for such diseases, and is one of the most sensitive indicators known. γ‑glutamyltransferase is also a sensitive screening test for occult alcoholism. Elevated GGT activities are found in the serum of patients requiring long‑term medication with phenobarbital and phenytoin.
In 1969, Szasz published the first kinetic procedure for GGT in serum using γ‑glutamyl‑p‑nitroanilide as substrate and glycylglycine as acceptor. In order to circumvent the poor solubility of γ‑glutamyl‑p‑nitroanilide, Persijn and van der Slik investigated various derivatives and found the water‑soluble substrate L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide to be superior in terms of stability and solubility. The results correlate with those derived using the original substrate.
In 2002, the International Federation of Clinical Chemistry (IFCC) recommended the standardized method for determining GGT including optimization of substrate concentrations, employment of NaOH, glycylglycine buffer and sample start. The GGT liquid reagent follows the formulation recommendation according to Szasz, but was optimized for performance and stability. The assay is optionally standardized against the original IFCC and Szasz methods. The performance claims and data presented here are independent from the standardization.
R1 | TRIS: 492 mmol/L, pH 8.25; glycylglycine: 492 mmol/L; preservative; additive |
R3 | L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide: 22.5 mmol/L; acetate: 10 mmol/L, pH 4.5; stabilizer; preservative |
R1 is in position B and R3 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.
For USA: Caution: Federal law restricts this device to sale by or on the order of a physician.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
|
Warning
H317 | May cause an allergic skin reaction. |
Prevention:
P261 | Avoid breathing dust/fume/gas/mist/vapours/spray. |
P272 | Contaminated work clothing should not be allowed out of the workplace. |
P280 | Wear protective gloves. |
Response:
P333 + P313 | If skin irritation or rash occurs: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
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, USA: 1-800-428-2336
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: Collect serum using standard sampling tubes.
Plasma: Li‑heparin and K2‑EDTA plasma
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.
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
Stability: LREFSzasz G. Methods of Enzymatic Analysis. 2nd English ed. New York. Academic Press, Inc 1974;717. ,LREFTietz NW, ed. Clinical Guide to Laboratory Tests, 3rd ed. Philadelphia PA: WB Saunders Company 1995;286. | 7 days at 15‑25 °C |
7 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
In vitro test for the quantitative determination of γ‑glutamyltransferase (GGT) in human serum and plasma on Roche/Hitachi cobas c systems.
Enzymatic colorimetric assay
γ‑glutamyltransferase transfers the γ‑glutamyl group of L‑γ‑glutamyl-3‑carboxy-4‑nitroanilide to glycylglycine.
L‑γ‑glutamyl-3-carboxy-4-nitroanilide + glycylglycine | GGT | |
L-γ-glutamyl-glycylglycine + 5-amino-2-nitrobenzoate |
The amount of 5‑amino‑2‑nitrobenzoate liberated is proportional to the GGT activity in the sample. It is determined by measuring the increase in absorbance photometrically.
3‑1200 U/L (0.05‑20.0 µkat/L)
Determine samples having higher activities via the rerun function. Dilution of samples via the rerun function is a 1:11 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 11.
Limit of Blank | = 3 U/L (0.05 µkat/L) |
Limit of Detection | = 3 U/L (0.05 µkat/L) |
Limit of Quantitation | = 3 U/L (0.05 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 γ‑glutamyltransferase samples.
Men | 8-61 U/L |
Women | 5-36 U/L |
Men (n = 216) | 10-71 U/L |
Women (n = 228) | 6-42 U/L |
Men | < 60 U/L |
Women | < 40 U/L |
Men | 0.13-1.02 µkat/L |
Women | 0.08-0.60 µkat/L |
Men (n = 216) | 0.17-1.19 µkat/L |
Women (n = 228) | 0.10-0.70 µkat/L |
Men | < 1.00 µkat/L |
Women | < 0.67 µkat/L* |
*calculated by unit conversion factor |
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % of initial value at a γ‑glutamyltransferase activity of 40 U/L.
Icterus:
Hemolysis:
Lipemia (Intralipid):
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
|
| Analyzer(s) on which cobas c packs can be used | |
08057796190 | γ‑Glutamyltransferase ver.2 (400 tests) | System‑ID 2060 001 | cobas c 303, cobas c 503 |
Materials required (but not provided):
10759350190 | Calibrator f.a.s. (12 x 3 mL) | Code 20401 | |
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 |
GGT2-I: ACN 20600: assay standardized against IFCC
GGT2-S: ACN 20601: assay standardized against Szasz
Ready for use
Reporting time | 10 min | ||
Wavelength (sub/main) | 700/415 nm | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 19 µL | 57 µL | |
R3 | 15 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 2.3 µL | – | – |
Decreased | 2.3 µL | 10 µL | 100 µL |
Increased | 2.3 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: | 12 weeks |
Calibrators | S1: H2O S2: C.f.a.s. |
Calibration mode | Linear |
Calibration frequency | Full calibration |
Use the appropriate calibrator value for the corresponding application.
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against the original IFCC formulation (2002)
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).
Repeatability | Mean | SD | CV |
PCCC1a) | 45.8 | 0.382 | 0.8 |
PCCC2b) | 207 | 0.772 | 0.4 |
Human serum 1 | 8.57 | 0.449 | 5.2 |
Human serum 2 | 30.9 | 0.646 | 2.1 |
Human serum 3 | 62.7 | 0.679 | 1.1 |
Human serum 4 | 598 | 3.55 | 0.6 |
Human serum 5 | 1155 | 6.04 | 0.5 |
Intermediate precision | Mean | SD | CV |
PCCC1 FREFPreciControl ClinChem Multi 1 | 45.6 | 0.463 | 1.0 |
PCCC2 FREFPreciControl ClinChem Multi 2 | 207 | 1.67 | 0.8 |
Human serum 1 | 7.97 | 0.420 | 5.3 |
Human serum 2 | 30.6 | 0.703 | 2.3 |
Human serum 3 | 62.7 | 0.708 | 1.1 |
Human serum 4 | 598 | 3.69 | 0.6 |
Human serum 5 | 1161 | 10.6 | 0.9 |
γ‑glutamyltransferase values for human serum and plasma samples obtained on
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 − 1.98 U/L | y = 1.023x − 1.96 U/L |
τ = 0.981 | r = 0.999 |
The sample activities were between 4.81 and 941 U/L.
γ‑glutamyltransferase 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 = 1.010x + 1.44 U/L | y = 1.019x + 0.534 U/L |
τ = 0.982 | r = 1.000 |
The sample activities were between 3.10 and 1001 U/L.
γ‑glutamyltransferase is used in the diagnosis and monitoring of hepatobiliary diseases. Enzymatic activity of GGT is often the only parameter with increased values when testing for such diseases, and is one of the most sensitive indicators known. γ‑glutamyltransferase is also a sensitive screening test for occult alcoholism. Elevated GGT activities are found in the serum of patients requiring long-term medication with phenobarbital and phenytoin.
In 1969, Szasz published the first kinetic procedure for GGT in serum using γ‑glutamyl‑p‑nitroanilide as substrate and glycylglycine as acceptor. In order to circumvent the poor solubility of γ‑glutamyl‑p‑nitroanilide, Persijn and van der Slik investigated various derivatives and found the water‑soluble substrate L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide to be superior in terms of stability and solubility. The results correlate with those derived using the original substrate.
In 2002, the International Federation of Clinical Chemistry (IFCC) recommended the standardized method for determining GGT including optimization of substrate concentrations, employment of NaOH, glycylglycine buffer and sample start. The GGT liquid reagent follows the formulation recommendation according to Szasz, but was optimized for performance and stability. The assay is optionally standardized against the original IFCC and Szasz methods. The performance claims and data presented here are independent from the standardization.
R1 | TRIS: 492 mmol/L, pH 8.25; glycylglycine: 492 mmol/L; preservative; additive |
R3 | L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide: 22.5 mmol/L; acetate: 10 mmol/L, pH 4.5; stabilizer; preservative |
R1 is in position B and R3 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:
|
Warning
H317 | May cause an allergic skin reaction. |
Prevention:
P261 | Avoid breathing dust/fume/gas/mist/vapours/spray. |
P272 | Contaminated work clothing should not be allowed out of the workplace. |
P280 | Wear protective gloves. |
Response:
P333 + P313 | If skin irritation or rash occurs: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
Disposal:
P501 | Dispose of contents/container to an approved waste disposal plant. |
Product safety labeling follows EU GHS guidance.
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 12 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: Collect serum using standard sampling tubes.
Plasma: Li‑heparin and K2‑EDTA plasma
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: LREFSzasz G. Methods of Enzymatic Analysis. 2nd English ed. New York. Academic Press, Inc 1974;717. ,LREFTietz NW, ed. Clinical Guide to Laboratory Tests, 3rd ed. Philadelphia PA: WB Saunders Company 1995;286. | 7 days at 15‑25 °C 7 days at 2‑8 °C 1 year at (-15)‑(-25) °C |
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
In vitro test for the quantitative determination of γ‑glutamyltransferase (GGT) in human serum and plasma on Roche/Hitachi cobas c systems.
Enzymatic colorimetric assay
γ‑glutamyltransferase transfers the γ‑glutamyl group of L‑γ‑glutamyl-3‑carboxy-4‑nitroanilide to glycylglycine.
L‑γ‑glutamyl-3-carboxy-4-nitroanilide + glycylglycine | GGT | |
L-γ-glutamyl-glycylglycine + 5-amino-2-nitrobenzoate |
The amount of 5‑amino‑2‑nitrobenzoate liberated is proportional to the GGT activity in the sample. It is determined by measuring the increase in absorbance photometrically.
3‑1200 U/L (0.05‑20.0 µkat/L)
Determine samples having higher activities via the rerun function. Dilution of samples via the rerun function is a 1:11 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 11.
Limit of Blank | = 3 U/L (0.05 µkat/L) |
Limit of Detection | = 3 U/L (0.05 µkat/L) |
Limit of Quantitation | = 3 U/L (0.05 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 γ‑glutamyltransferase samples.
Men | 8-61 U/L |
Women | 5-36 U/L |
Men (n = 216) | 10-71 U/L |
Women (n = 228) | 6-42 U/L |
Men | < 60 U/L |
Women | < 40 U/L |
Men | 0.13-1.02 µkat/L |
Women | 0.08-0.60 µkat/L |
Men (n = 216) | 0.17-1.19 µkat/L |
Women (n = 228) | 0.10-0.70 µkat/L |
Men | < 1.00 µkat/L |
Women | < 0.67 µkat/L* |
*calculated by unit conversion factor |
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % at a γ-glutamyltransferase activity of 40 U/L.
Icterus:
Hemolysis:
Lipemia (Intralipid):
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
|
| Analyzer(s) on which cobas c packs can be used | |
08057796190 | γ‑Glutamyltransferase ver.2 (400 tests) | System‑ID 2060 001 | |
10759350360 | Calibrator f.a.s. (12 x 3 mL) | Code 20401 | |
05947626160 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 20391 | |
05947774160 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 20392 | |
08063494190 | Diluent NaCl 9 % (123 mL) | System‑ID 2906 001 |
GGT2-I: ACN 20600: assay standardized against IFCC
GGT2-S: ACN 20601: assay standardized against Szasz
Ready for use
Reporting time | 10 min | ||
Wavelength (sub/main) | 700/415 nm | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 19 µL | 57 µL | |
R3 | 15 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 2.3 µL | – | – |
Decreased | 2.3 µL | 10 µL | 100 µL |
Increased | 2.3 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: | 12 weeks |
Calibrators | S1: H2O S2: C.f.a.s. |
Calibration mode | Linear |
Calibration frequency | Full calibration |
Use the appropriate calibrator value for the corresponding application.
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against the original IFCC formulation (2002)
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).
Repeatability | Mean | SD | CV |
PCCC1a) | 45.8 | 0.382 | 0.8 |
PCCC2b) | 207 | 0.772 | 0.4 |
Human serum 1 | 8.57 | 0.449 | 5.2 |
Human serum 2 | 30.9 | 0.646 | 2.1 |
Human serum 3 | 62.7 | 0.679 | 1.1 |
Human serum 4 | 598 | 3.55 | 0.6 |
Human serum 5 | 1155 | 6.04 | 0.5 |
Intermediate precision | Mean | SD | CV |
PCCC1 FREFPreciControl ClinChem Multi 1 | 45.6 | 0.463 | 1.0 |
PCCC2 FREFPreciControl ClinChem Multi 2 | 207 | 1.67 | 0.8 |
Human serum 1 | 7.97 | 0.420 | 5.3 |
Human serum 2 | 30.6 | 0.703 | 2.3 |
Human serum 3 | 62.7 | 0.708 | 1.1 |
Human serum 4 | 598 | 3.69 | 0.6 |
Human serum 5 | 1161 | 10.6 | 0.9 |
γ‑glutamyltransferase values for human serum and plasma samples obtained on a
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 − 1.98 U/L | y = 1.023x − 1.96 U/L |
τ = 0.981 | r = 0.999 |
The sample activities were between 4.81 and 941 U/L.
γ‑glutamyltransferase 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 = 1.010x + 1.44 U/L | y = 1.019x + 0.534 U/L |
τ = 0.982 | r = 1.000 |
The sample activities were between 3.10 and 1001 U/L.
γ‑glutamyltransferase is used in the diagnosis and monitoring of hepatobiliary diseases. Enzymatic activity of GGT is often the only parameter with increased values when testing for such diseases, and is one of the most sensitive indicators known. γ‑glutamyltransferase is also a sensitive screening test for occult alcoholism. Elevated GGT activities are found in the serum of patients requiring long-term medication with phenobarbital and phenytoin.
In 1969, Szasz published the first kinetic procedure for GGT in serum using γ‑glutamyl‑p‑nitroanilide as substrate and glycylglycine as acceptor. In order to circumvent the poor solubility of γ‑glutamyl‑p‑nitroanilide, Persijn and van der Slik investigated various derivatives and found the water‑soluble substrate L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide to be superior in terms of stability and solubility. The results correlate with those derived using the original substrate.
In 2002, the International Federation of Clinical Chemistry (IFCC) recommended the standardized method for determining GGT including optimization of substrate concentrations, employment of NaOH, glycylglycine buffer and sample start. The GGT liquid reagent follows the formulation recommendation according to Szasz, but was optimized for performance and stability. The assay is optionally standardized against the original IFCC and Szasz methods. The performance claims and data presented here are independent from the standardization.
R1 | TRIS: 492 mmol/L, pH 8.25; glycylglycine: 492 mmol/L; preservative; additive |
R3 | L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide: 22.5 mmol/L; acetate: 10 mmol/L, pH 4.5; stabilizer; preservative |
R1 is in position B and R3 is in position C.
For in vitro diagnostic use.
Exercise the normal precautions required for handling all laboratory reagents.
Disposal of all waste material should be in accordance with local guidelines.
Safety data sheet available for professional user on request.
For USA: Caution: Federal law restricts this device to sale by or on the order of a physician.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
|
Warning |
H317 | May cause an allergic skin reaction. |
Prevention:
P261 | Avoid breathing dust/fume/gas/mist/vapours/spray. |
P272 | Contaminated work clothing should not be allowed out of the workplace. |
P280 | Wear protective gloves. |
Response:
P333 + P313 | If skin irritation or rash occurs: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
P501 | Dispose of contents/container to an approved waste disposal plant. |
Product safety labeling follows EU GHS guidance.
Contact phone: 1-800-428-2336
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 12 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: Collect serum using standard sampling tubes.
Plasma: Li‑heparin and K2‑EDTA plasma
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: LREFSzasz G. Methods of Enzymatic Analysis. 2nd English ed. New York. Academic Press, Inc 1974;717. ,LREFTietz NW, ed. Clinical Guide to Laboratory Tests, 3rd ed. Philadelphia PA: WB Saunders Company 1995;286. | 7 days at 15‑25 °C 7 days at 2‑8 °C 1 year at (-15)‑(-25) °C |
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
In vitro test for the quantitative determination of γ‑glutamyltransferase in human serum and plasma on the cobas c 111 system.
Enzymatic colorimetric assay
γ‑glutamyltransferase transfers the γ‑glutamyl group of L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide to glycylglycine.
L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide + glycylglycine | GGT |
L‑γ‑glutamyl‑glycylglycine + 5‑amino‑2‑nitrobenzoate |
The amount of 5‑amino‑2‑nitrobenzoate liberated is proportional to the GGT activity in the sample. It is determined by measuring the increase in absorbance photometrically.
3‑1200 U/L (0.05‑20.0 µkat/L)
Determine samples having higher activities via the rerun function. Dilution of samples via the rerun function is a 1:10 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 10.
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).
Men | 8‑61 U/L | (0.13‑1.02 µkat/L) |
Women | 5‑36 U/L | (0.08‑0.60 µkat/L) |
Men (n = 216) | 10‑71 U/L | (0.17‑1.19 µkat/L) |
Women (n = 228) | 6‑42 U/L | (0.10‑0.70 µkat/L) |
Men | < 60 U/L | (< 1.00 µkat/L) |
Women | < 40 U/L | (< 0.67 µkat/L) |
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % of initial value at a γ‑glutamyltransferase activity of 40 U/L (0.668 µkat/L).
Icterus:
Hemolysis:
Lipemia (Intralipid):
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 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 | |||
05401461 190 | γ-Glutamyltransferase ver.2 (2 × 100 tests) | cobasc 111 |
Materials required (but not provided):
10759350 190 | Calibrator f.a.s. (12 × 3 mL) | Code 401 | |
10759350 360 | Calibrator f.a.s. (12 × 3 mL, for USA) | Code 401 | |
12149435 122 | Precinorm U plus (10 × 3 mL) | Code 300 | |
12149435 160 | Precinorm U plus (10 × 3 mL, for USA) | Code 300 | |
12149443 122 | Precipath U plus (10 × 3 mL) | Code 301 | |
12149443 160 | Precipath U plus (10 × 3 mL, for USA) | Code 301 | |
05117003 190 | PreciControl ClinChem Multi 1 (20 × 5 mL) | Code 391 | |
05947626 190 | PreciControl ClinChem Multi 1 (4 × 5 mL) | Code 391 | |
05947626 160 | PreciControl ClinChem Multi 1 (4 × 5 mL, for USA) | Code 391 | |
05117216 190 | PreciControl ClinChem Multi 2 (20 × 5 mL) | Code 392 | |
05947774 190 | PreciControl ClinChem Multi 2 (4 × 5 mL) | Code 392 | |
05947774 160 | PreciControl ClinChem Multi 2 (4 × 5 mL, for USA) | Code 392 |
GGTS2: | ACN 480 | Szasz standardization |
GGTI2: | ACN 220 | IFCC standardization - Not for use in the US |
Ready for use
Measuring mode | Absorbance |
Abs. calculation mode | Kinetic |
Reaction direction | Increase |
Wavelength A/B | 409/659 nm |
Calc. first/last | 26/38 |
Unit | U/L |
Reaction mode | R1‑S‑SR |
Diluent (H2O) | ||
R1 | 25 µL | 35 µL |
Sample | 3 µL | 20 µL |
SR | 20 µL | 20 µL |
Total volume | 123 µL |
Shelf life at 2‑8 °C: | See expiration date on reagent |
On-board in use and refrigerated on the analyzer: | 3 weeks |
Calibrators | Calibrator f.a.s. Standard 2 is defined by a fixed value. |
Calibration mode | Linear regression |
Calibration interval | Each lot and as required following quality control procedures. |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against the original IFCC formulation (2002)
Representative performance data on the cobas c 111 analyzer 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, 10 days). The following results were obtained:
Repeatability | Mean | SD | CV |
|---|---|---|---|
Precinorm U | 44.2 (0.74) | 0.6 (0.01) | 1.4 |
Precipath U | 221 (3.69) | 1 (0.02) | 0.4 |
Human serum 1 | 29.1 (0.49) | 0.6 (0.01) | 1.9 |
Human serum 2 | 481 (8.03) | 2 (0.03) | 0.4 |
Intermediate precision | Mean | SD | CV |
|---|---|---|---|
Precinorm U | 38.3 (0.64) | 0.7 (0.01) | 1.9 |
Precipath U | 194 (3.24) | 1 (0.02) | 0.7 |
Human serum 3 | 18.1 (0.30) | 0.6 (0.01) | 3.5 |
Human serum 4 | 322 (5.38) | 2 (0.03) | 0.6 |
γ‑glutamyltransferase values for human serum and plasma samples obtained on a cobas c 111 analyzer (y) using the γ‑Glutamyltransferase ver.2 reagent (GGT‑2) and the application GGTS2 were compared with those determined using the corresponding reagent on a COBAS INTEGRA 400 analyzer (x).
Sample size (n) = 79
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 = 1.017× - 0.829 U/L т = 0.982 | y = 1.022× - 1.03 U/L r = 1.00 |
The sample activities were between 8.00 and 1142 U/L (0.134 and 19.1 µkat/L).
γ‑glutamyltransferase is used in the diagnosis and monitoring of hepatobiliary diseases. Enzymatic activity of GGT is often the only parameter with increased values when testing for such diseases, and is one of the most sensitive indicators known. γ‑glutamyltransferase is also a sensitive screening test for occult alcoholism. Elevated GGT activities are found in the serum of patients requiring long-term medication with phenobarbital and phenytoin.
In 1969, Szasz published the first kinetic procedure for GGT in serum using γ‑glutamyl‑p‑nitroanilide as substrate and glycylglycine as acceptor. In order to circumvent the poor solubility of γ‑glutamyl‑p‑nitroanilide, Persijn and van der Slik investigated various derivatives and found the water-soluble substrate L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide to be superior in terms of stability and solubility. The results correlate with those derived using the original substrate.
In 2002, the International Federation of Clinical Chemistry (IFCC) recommended the standardized method for determining GGT including optimization of substrate concentrations, employment of NaOH, glycylglycine buffer and sample start. The GGT liquid reagent follows the formulation recommendation according to Szasz, but was optimized for performance and stability. The assay is optionally standardized against the original IFCC and Szasz methods. The performance claims and data presented here are independent from the standardization.
R1 | TRIS: 492 mmol/L, pH 8.25; glycylglycine: 492 mmol/L; preservative; additive |
SR | L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide: 22.5 mmol/L; acetate: 10 mmol/L, pH 4.5; stabilizer; preservative |
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.
For USA: Caution: Federal law restricts this device to sale by or on the order of a physician.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
Warning
H317 | May cause an allergic skin reaction. |
Prevention:
P261 | Avoid breathing dust/fume/gas/mist/vapours/spray. |
P272 | Contaminated work clothing should not be allowed out of the workplace. |
P280 | Wear protective gloves. |
Response:
P333 + P313 | If skin irritation or rash occurs: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
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, USA: 1-800-428-2336
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: Collect serum using standard sampling tubes.
Plasma: Li‑heparin, K3‑EDTA plasma.
Note: K3‑EDTA plasma values are approximately 6 % lower than serum values.
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: LREFSzasz G. Methods of Enzymatic Analysis. 2nd English ed. New York. Academic Press, Inc 1974;717. ,LREFTietz NW, ed. Clinical Guide to Laboratory Tests, 3rd ed. Philadelphia PA: WB Saunders Company 1995;286. | 7 days at 20‑25 °C 7 days at 4‑8 °C 1 year at ‑20 °C |
See the limitations and interferences section for details about possible sample interferences.
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
In vitro test for the quantitative determination of γ‑glutamyltransferase (GGT) in human serum and plasma on Roche/Hitachi cobas c systems.
Enzymatic colorimetric assay
γ‑glutamyltransferase transfers the γ‑glutamyl group of L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide to glycylglycine.
GGT | |
L-γ-glutamyl-3-carboxy-4-nitroanilide + glycylglycine | |
L-γ-glutamyl-glycylglycine + 5-amino-2-nitrobenzoate |
The amount of 5‑amino‑2‑nitrobenzoate liberated is proportional to the GGT activity in the sample. It is determined by measuring the increase in absorbance photometrically.
Measuring range
3‑1200 U/L (0.05‑20.0 µkat/L)
Determine samples having higher activities via the rerun function. Dilution of samples via the rerun function is a 1:11 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 11.
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).
Standardized against Szasz (Persijn, van der Slik) LREFAbicht K, El-Samalouti V, Junge W, et al. Multicenter evaluation of new GGT and ALP reagents with new reference standardization and determination of 37 °C reference intervals. Clin Chem Lab Med 2001;39:Special Supplement pp S 346. | ||
Men | 8-61 U/L | 0.13-1.02 µkat/L |
Women | 5-36 U/L | 0.08-0.60 µkat/L |
Standardized against IFCC | ||
Reference Interval Study at 37 °C (corrected in 2005) LREFAbicht K, El-Samalouti V, Junge W, et al. Multicenter evaluation of new GGT and ALP reagents with new reference standardization and determination of 37 °C reference intervals. Clin Chem Lab Med 2001;39:Special Supplement pp S 346. ,LREFKytzia H-J. Reference intervals for GGT according to the new IFCC 37°C reference procedure. Clin Chem Lab Med 2005;43:A69 [abstract]. | ||
Men (n = 216) | 10-71 U/L | 0.17-1.19 µkat/L |
Women (n = 228) | 6-42 U/L | 0.10-0.70 µkat/L |
Consensus values (IFCC) LREFThomas L, Müller M, Schumann G, et al. Consensus of DGKL and VDGH for interim reference intervals on enzymes in serum. J Lab Med 2005; 29(5):301-308. | ||
Men | < 60 U/L | < 1.00 µkat/L |
Women | < 40 U/L | < 0.67 µkat/L |
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % of initial value at a γ‑glutamyltransferase activity of 40 U/L (0.67 µkat/L).
Icterus:
Hemolysis:
Lipemia (Intralipid):
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 Roche/Hitachi 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 not required.
Where required, special wash/carry‑over evasion programming must be implemented prior to reporting results with this test.
Analyzer(s) on which cobas c packs can be used | |||
03002721 122 | γ‑Glutamyltransferase ver.2 400 tests | System‑ID 07 6598 8 | Roche/Hitachi cobas c 311, cobas c 501/502 |
Materials required (but not provided):
10759350 190 | Calibrator f.a.s. (12 x 3 mL) | Code 401 | |
10759350 360 | Calibrator f.a.s. (12 x 3 mL, for USA) | Code 401 | |
12149435 122 | Precinorm U plus (10 x 3 mL) | Code 300 | |
12149435 160 | Precinorm U plus (10 x 3 mL, for USA) | Code 300 | |
12149443 122 | Precipath U plus (10 x 3 mL) | Code 301 | |
12149443 160 | Precipath U plus (10 x 3 mL, for USA) | Code 301 | |
10171743 122 | Precinorm U (20 x 5 mL) | Code 300 | |
10171735 122 | Precinorm U (4 x 5 mL) | Code 300 | |
10171778 122 | Precipath U (20 x 5 mL) | Code 301 | |
10171760 122 | Precipath U (4 x 5 mL) | Code 301 | |
05117003 190 | PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 391 | |
05947626 190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 391 | |
05947626 160 | PreciControl ClinChem Multi 1 (4 x 5 mL, for USA) | Code 391 | |
05117216 190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 392 | |
05947774 190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 392 | |
05947774 160 | PreciControl ClinChem Multi 2 (4 x 5 mL, for USA) | Code 392 | |
04489357 190 | Diluent NaCl 9 % (50 mL) | System‑ID 07 6869 3 |
For cobas c 311/501 analyzers:
GGTI2: ACN 220: assay standardized against IFCC
GGTS2: ACN 480: assay standardized against Szasz
For cobas c 502 analyzer:
GGTI2: ACN 8220: assay standardized against IFCC
GGTS2: ACN 8480: assay standardized against Szasz
Ready for use
cobas c 311 test definition | |||
Assay type | Rate A | ||
Reaction time / Assay points | 10 / 13‑42 | ||
Wavelength (sub/main) | 700/415 nm | ||
Reaction direction | Increase | ||
Units | U/L (µkat/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 25 µL | 75 µL | |
R2 | 20 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 3 µL | – | – |
Decreased | 3 µL | 15 µL | 150 µL |
Increased | 3 µL | – | – |
cobas c 501 test definition | |||
Assay type | Rate A | ||
Reaction time / Assay points | 10 / 19‑56 | ||
Wavelength (sub/main) | 700/415 nm | ||
Reaction direction | Increase | ||
Units | U/L (µkat/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 25 µL | 75 µL | |
R2 | 20 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 3 µL | – | – |
Decreased | 3 µL | 15 µL | 150 µL |
Increased | 3 µL | – | – |
cobas c 502 test definition | |||
Assay type | Rate A | ||
Reaction time / Assay points | 10 / 19‑56 | ||
Wavelength (sub/main) | 700/415 nm | ||
Reaction direction | Increase | ||
Units | U/L (µkat/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 25 µL | 75 µL | |
R2 | 20 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 3 µL | – | – |
Decreased | 3 µL | 15 µL | 150 µL |
Increased | 6 µL | – | – |
GGT‑2 | |
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 |
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. |
Calibration mode | Linear |
Calibration frequency | 2‑point calibration |
Traceability: This method has been standardized against the original IFCC formulation (2002)
Use the appropriate calibrator value for the corresponding application.
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 U | 45.3 (0.757) | 0.4 (0.007) | 0.9 |
Precipath U | 226 (3.77) | 2 (0.03) | 0.7 |
Human serum 1 | 34.0 (0.568) | 0.3 (0.005) | 0.9 |
Human serum 2 | 150 (2.51) | 1 (0.02) | 0.8 |
Intermediate precision | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
Precinorm U | 44.1 (0.736) | 0.8 (0.013) | 1.8 |
Precipath U | 221 (3.69) | 4 (0.07) | 1.7 |
Human serum 3 | 46.8 (0.782) | 1.5 (0.025) | 3.2 |
Human serum 4 | 256 (4.28) | 9 (0.15) | 3.7 |
γ‑glutamyltransferase values for human serum and plasma samples obtained on a Roche/Hitachi cobas c 501 analyzer (y) were compared with those determined using the corresponding reagent on a Roche/Hitachi 917 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 = 0.989x - 0.428 U/L | y = 0.980x + 0.219 U/L |
τ = 0.979 | r = 1.000 |
The sample activities were between 4.50 and 1100 U/L (0.075 and 18.4 µkat/L). |
γ‑glutamyltransferase is used in the diagnosis and monitoring of hepatobiliary diseases. Enzymatic activity of GGT is often the only parameter with increased values when testing for such diseases, and is one of the most sensitive indicators known. γ‑glutamyltransferase is also a sensitive screening test for occult alcoholism. Elevated GGT activities are found in the serum of patients requiring long-term medication with phenobarbital and phenytoin.
In 1969, Szasz published the first kinetic procedure for GGT in serum using γ‑glutamyl‑p‑nitroanilide as substrate and glycylglycine as acceptor. In order to circumvent the poor solubility of γ‑glutamyl‑p‑nitroanilide, Persijn and van der Slik investigated various derivatives and found the water‑soluble substrate L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide to be superior in terms of stability and solubility. The results correlate with those derived using the original substrate.
In 2002, the International Federation of Clinical Chemistry (IFCC) recommended the standardized method for determining GGT including optimization of substrate concentrations, employment of NaOH, glycylglycine buffer and sample start. The GGT liquid reagent follows the formulation recommendation according to Szasz, but was optimized for performance and stability. The assay is optionally standardized against the original IFCC and Szasz methods. The performance claims and data presented here are independent from the standardization.
R1 | TRIS: 492 mmol/L, pH 8.25; glycylglycine: 492 mmol/L; preservative; additive |
R2 | L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide: 22.5 mmol/L; acetate: 10 mmol/L, pH 4.5; stabilizer; preservative |
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.
For USA: For prescription use only.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
Warning
H317 | May cause an allergic skin reaction. |
Prevention:
P261 | Avoid breathing dust/fume/gas/mist/vapours/spray. |
P272 | Contaminated work clothing should not be allowed out of the workplace. |
P280 | Wear protective gloves. |
Response:
P333 + P313 | If skin irritation or rash occurs: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
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, USA: 1-800-428-2336
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: Collect serum using standard sampling tubes.
Plasma: Li‑heparin and K2‑EDTA plasma
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: LREFSzasz G. Methods of Enzymatic Analysis. 2nd English ed. New York. Academic Press, Inc 1974;717. ,LREFTietz NW, ed. Clinical Guide to Laboratory Tests, 3rd ed. Philadelphia PA: WB Saunders Company 1995;286. | 7 days at 15‑25 °C |
7 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
In vitro test for the quantitative determination of the catalytic activity of GGT (EC 2.3.2.2; γ‑glutamyl peptide: amino acid γ‑glutamyltransferase) in human serum and plasma on COBAS INTEGRA systems.
Enzymatic colorimetric assay
Gamma‑glutamyltransferase transfers the γ‑glutamyl group of L-γ-glutamyl-3‑carboxy-4‑nitroanilide to glycylglycine.
L‑γ‑glutamyl‑3‑carboxy‑4‑nitroanilide + glycylglycine | GGT |
L‑γ‑glutamyl‑glycylglycine + 5‑amino‑2‑nitrobenzoate |
The amount of 5‑amino-2‑nitrobenzoate liberated is proportional to the GGT activity in the sample. It is determined by measuring the increase in absorbance at 409 nm.
3‑1200 U/L (0.05‑20 µkat/L)
Determine samples having higher activities via the rerun function. Dilution of samples via the rerun function is a 1:10 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 10.
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 a zero sample (zero sample + 3 SD, repeatability, n = 21).
Men (n = 216) | 10‑71 U/L | (0.17‑1.19 µkat/L) |
Women (n = 228) | 6‑42 U/L | (0.10‑0.70 µkat/L) |
Men | < 60 U/L | (< 1.00 µkat/L) |
Women | < 40 U/L | (< 0.67 µkat/L) |
Conversion factors to other temperatures have been published
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % of initial value.
Icterus:
Hemolysis:
Lipemia (Intralipid):
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 INTEGRA analyzers.
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 | |
03002721 122 | γ-Glutamyltransferase ver.2 (400 tests) | System-ID 07 6598 8 | COBAS INTEGRA 400 plus |
Materials required (but not provided):
10759350 190 | Calibrator f.a.s. (12 × 3 mL) | System-ID 07 3718 6 | |
12149435 122 | Precinorm U plus (10 × 3 mL) | System-ID 07 7999 7 | |
12149443 122 | Precipath U plus (10 × 3 mL) | System-ID 07 8000 6 | |
10171743 122 | Precinorm U (20 × 5 mL) | System-ID 07 7997 0 | |
10171735 122 | Precinorm U (4 × 5 mL) | System-ID 07 7997 0 | |
10171778 122 | Precipath U (20 × 5 mL) | System-ID 07 7998 9 | |
10171760 122 | Precipath U (4 × 5 mL) | System-ID 07 7998 9 | |
05117003 190 | PreciControl ClinChem Multi 1 (20 × 5 mL) | System-ID 07 7469 3 | |
05947626 190 | PreciControl ClinChem Multi 1 (4 × 5 mL) | System-ID 07 7469 3 | |
05117216 190 | PreciControl ClinChem Multi 2 (20 × 5 mL) | System-ID 07 7470 7 | |
05947774 190 | PreciControl ClinChem Multi 2 (4 × 5 mL) | System-ID 07 7470 7 |
Test GGTI2, test ID 0‑498, standardized against IFCC
Ready for use
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