In vitro test for the quantitative determination of alanine aminotransferase (ALT) or aspartate aminotransferase (AST) with pyridoxal phosphate activation in human serum and plasma on
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05531462190R1: | 780 tests |
PYP: | 780 tests |
R3: | 780 tests |
05531446190R1: | 740 tests |
PYP: | 740 tests |
R3: | 740 tests |
ALTPM: ACN 8681, System‑ID 05 7462 6
ASTPM: ACN 8680, System‑ID 05 7461 8
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.
In vitro test for the quantitative determination of aspartate aminotransferase (AST) with pyridoxal phosphate activation in human serum and plasma on
This assay follows the recommendations of the IFCC, but was optimized for performance and stability.
AST in the sample catalyzes the transfer of an amino group between L‑aspartate and 2‑oxoglutarate to form oxaloacetate and L‑glutamate. The oxaloacetate then reacts with NADH, in the presence of malate dehydrogenase (MDH), to form NAD+. Pyridoxal phosphate serves as a coenzyme in the amino transfer reaction. It ensures full enzyme activation.
AST | ||
L‑Aspartate + 2‑oxoglutarate |
| oxaloacetate + L‑glutamate |
MDH | ||
Oxaloacetate + NADH + H+ |
| L‑malate + NAD+ |
The rate of the NADH oxidation is directly proportional to the catalytic AST activity. It is determined by measuring the decrease in absorbance.
Measuring range
5‑700 U/L (0.08‑11.7 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 limits of measurement
Lower detection limit of the test
5 U/L (0.08 µkat/L)
The lower detection limit represents the lowest measurable analyte level that can be distinguished from 0. 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 (< 5 U/L) will not be flagged by the instrument.
Acc. to IFCC/Standard Method 94 with pyridoxal phosphate activation measured at 37 °C:
Males: | 10‑50 U/L | (0.17‑0.85 µkat/L) |
Females: | 10‑35 U/L | (0.17‑0.60 µkat/L) |
Consensus values with pyridoxal phosphate activation:
Males: | up to 50 U/L | (up to 0.85 µkat/L) |
Females: | up to 35 U/L | (up to 0.60 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 an AST activity of 35 U/L (0.58 µkat/L).
Icterus:
Hemolysis:
Contamination with erythrocytes will elevate results, because the analyte level in erythrocytes is higher than in normal sera. The level of interference may be variable depending on the content of analyte in the lysed erythrocytes.
Lipemia (Intralipid):
Lipemic specimens may cause > Abs
Drugs: No interference was found at therapeutic concentrations using common drug panels.
Physiological plasma concentrations of Sulfasalazine or Sulfapyridine may lead to false results.
Cyanokit (Hydroxocobalamin) may cause interference with results.
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.
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| Analyzer(s) on which cobas c pack(s) can be used | |
05531446190 | Aspartate Aminotransferase acc. to IFCC (740 tests) | System‑ID 05 7461 8 | cobas c 701/702 |
Materials required (but not provided):
10759350190 | Calibrator f.a.s. (12 x 3 mL) | Code 401 | |
10759350360 | Calibrator f.a.s. (12 x 3 mL, for USA) | Code 401 | |
12149435122 | Precinorm U plus (10 x 3 mL) | Code 300 | |
12149435160 | Precinorm U plus (10 x 3 mL, for USA) | Code 300 | |
12149443122 | Precipath U plus (10 x 3 mL) | Code 301 | |
12149443160 | Precipath U plus (10 x 3 mL, for USA) | Code 301 | |
05117003190 | PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 391 | |
05947626190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 391 | |
05947626160 | PreciControl ClinChem Multi 1 (4 x 5 mL, for USA) | Code 391 | |
05117216190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 392 | |
05947774190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 392 | |
05947774160 | PreciControl ClinChem Multi 2 (4 x 5 mL, for USA) | Code 392 | |
05172152190 | Diluent NaCl 9 % (119 mL) | System‑ID 08 6869 3 |
ASTPM: ACN 8680
Connect bottle containing pyridoxal phosphate to bottle R1 using the enclosed adapter and mix gently. Transfer the content to bottle R1. Pour the mixture into cassette position B.
R3 is ready for use.
cobas c 701/702 test definition | |||
Assay type | Rate A | ||
Reaction time / Assay points | 10 / 29‑38 | ||
Wavelength (sub/main) | 700/340 nm | ||
Reaction direction | Decrease | ||
Units | U/L (µkat/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 60 µL | 51 µL | |
R3 | 20 µL | 20 µL | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 9 µL | – | – |
Decreased | 9 µL | 15 µL | 135 µL |
Increased | 18 µL | – | – |
ASTPM | |
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: | 0 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. |
Calibration mode | Linear |
Calibration frequency | 2‑point calibration - after reagent lot change - 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 using calibrated pipettes together with a manual photometer providing absolute values and the substrate‑specific absorptivity, ε.
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, 20 days). The following results were obtained:
Repeatability | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
Precinorm U | 46.2 (0.772) | 1.1 (0.018) | 2.4 |
Precipath U | 159 (2.66) | 1 (0.02) | 0.6 |
Human serum A | 18.0 (0.301) | 1.2 (0.020) | 6.8 |
Human serum B | 142 (2.37) | 1 (0.02) | 1.0 |
Human serum C | 607 (10.1) | 2 (0.0) | 0.4 |
Intermediate precision | Mean U/L (µkat/L) | SD U/L (µkat/L) | CV % |
Precinorm U | 49.0 (0.818) | 0.8 (0.013) | 1.6 |
Precipath U | 149 (2.49) | 1 (0.02) | 0.8 |
Human serum 3 | 40.7 (0.680) | 1.3 (0.022) | 3.1 |
Human serum 4 | 190 (3.17) | 3 (0.05) | 1.3 |
Results for intermediate precision were obtained on the master system cobas c 501 analyzer.
AST values for human serum and plasma samples obtained on a cobas c 701 analyzer (y) were compared with those determined using the corresponding reagent on a cobas c 501 analyzer (x).
Sample size (n) = 308
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 = 1.003x - 0.086 U/L | y = 0.993x + 0.468 U/L |
τ = 0.888 | r = 1.000 |
The sample activities were between 6.40 and 663 U/L (0.11 and 11.1 µkat/L). |
The enzyme aspartate aminotransferase (AST) is widely distributed in tissue, principally hepatic, cardiac, muscle, and kidney. Elevated serum levels are found in diseases involving these tissues. Hepatobiliary diseases, such as cirrhosis, metastatic carcinoma, and viral hepatitis also increase serum AST levels. Following myocardial infarction, serum AST is elevated and reaches a peak 2 days after onset.
2 isoenzymes of AST have been detected, cytoplasmic and mitochondrial. Only the cytoplasmic isoenzyme occurs in normal serum, while the mitochondrial, together with the cytoplasmic isoenzyme, has been detected in the serum of patients with coronary and hepatobiliary disease.
The addition of pyridoxal phosphate to the assay causes an increase in aminotransferase activity. The activation is higher for AST than for ALT. Pyridoxal phosphate activation prevents falsely low aminotransferase activity in patient samples with insufficient endogenous pyridoxal phosphate (vitamin B6 deficiency).
R1 | TRIS buffer: 264 mmol/L, pH 7.8 (37 °C); L‑aspartate: 792 mmol/L; MDH (microorganism): ≥ 24 µkat/L; LDH (microorganisms): ≥ 48 µkat/L; albumin (bovine): 0.25 %; preservative |
Bottle | Pyridoxal phosphate: 730 µmol/L |
R3 = cobas c pack position C | NADH: ≥ 1.7 mmol/L; 2‑oxoglutarate: 94 mmol/L; 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.
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.
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: LREFWHO Publication: Use of anticoagulants in diagnostic laboratory investigations, WHO/DIL/LAB/99.1 Rev.2:Jan 2002. | 4 days at 20‑25 °C |
7 days at 4‑8 °C | |
3 months at -20 °C |
Aspartate Aminotransferase acc. to IFCC with pyridoxal phosphate activation
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