ASPARTATE AMINOTRANSFERASE ACC. TO IFCC WITH PYRIDOXAL PHOSPHATE ACTIVATION

Additional Manufacturer Narrative

THE INVESTIGATION FOUND IN THIS CASE, TWO DIFFERENT ASSAY TYPES WERE USED TO DETERMINE THE ALT AND AST, ONE ASSAY WITH ACTIVATION AND ONE WITHOUT ACTIVATION. THE PATIENT WAS SUSPECTED TO HAVE A LIVER TUMOR/LIVER DISEASE. LIVER DISEASES CAN BE ASSOCIATED WITH PLP DEFICIENCY AND INCREASED TRANSAMINASE RESULTS, WHICH ARE NOT PROPERLY DETECTED WITH NON-ACTIVATING TESTS. A LACK OF PLP (PYRIDOXALPHOSPHA) CAN LEAD TO FALSE LOW ALT AND AST RESULTS WITH THE NONACTIVATED ASSAYS. THE CALIBRATION AND QC FOR EACH ASSAY WERE ACCEPTABLE. A HARDWARE CHECK TEST WAS PERFORMED ON THE ANALYZER AND WAS ACCEPTABLE. THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM.

Description of Event or Problem

THERE WAS AN ALLEGATION OF QUESTIONABLE ASPARTATE AMINOTRANSFERASE (AST) AND ALANINE AMINOTRANSFERASE (ALT) RESULTS FOR ONE PATIENT FROM THE COBAS PURE C 303 ANALYTICAL UNIT. THE CUSTOMER ALLEGED SOMETHING WITH THE PATIENT SAMPLE CAUSED DIFFERENT RESULTS FOR THE ASSAYS WITH PYRIDOXAL PHOSPHATE ACTIVATION COMPARED TO THE ASSAYS WITHOUT AS WERE USED ON THE COBAS C311. THIS MEDWATCH WILL COVER AST. REFER TO THE MEDWATCH WITH A1 PATIENT IDENTIFIER (B)(6) FOR THE ALT ASSAY. FOR AST: THE INITIAL RESULT WAS 243 U/L. THE REPEAT RESULTS USING THE SAME ANALYZER WERE 247 U/L AND 249 U/L. THE REPEAT RESULTS USING TWO COBAS C311 ANALYZERS WERE 66.9 U/L, 70 U/L, AND 70 U/L. ON (B)(6) 2024, A NEW SAMPLE FROM THE PATIENT HAD RESULTS OF 195 U/L AND 200 U/L. THE RESULT FROM THE COBAS C311 ANALYZER WERE 64 U/L AND 65.4 U/L. THE RESULTS FROM THE COBAS C311 WERE BELIEVED CORRECT AND REPORTED OUTSIDE OF THE LABORATORY.

Additional Manufacturer Narrative

THE COBAS PURE C 303 ANALYTICAL UNIT SERIAL NUMBER WAS (B)(6). THE INVESTIGATION IS ONGOING.