COBAS® FACTOR II AND FACTOR V TEST

Additional Manufacturer Narrative

THE SERIAL NUMBER OF THE ANALYZER IS (B)(6). THE INVESTIGATION IS ONGOING.

Description of Event or Problem

THERE WAS AN ALLEGATION OF A QUESTIONABLE RESULT WITH THE COBAS® FACTOR II AND FACTOR V TEST FOR A PATIENT SAMPLE TESTED ON A COBAS Z 480 ANALYZER. ON (B)(6) 2025, THE INITIAL RESULT WAS HET F2 (HETEROZYGOUS). ON (B)(6) 2025, A SECOND DRAW WAS TESTED AND THE RESULT WAS WT F2 (WILD TYPE). ON (B)(6) 2025, THE REPEAT RESULT OF THE ORIGINAL SAMPLE WAS HET F2. ON (B)(6) 2025, THE ORIGINAL SAMPLE, THE SECOND DRAW, AND ANOTHER DRAW SAMPLE WERE TESTED ON ANOTHER INSTRUMENT AND THE RESULTS WERE HET F2, ALL THREE TIMES.

Additional Manufacturer Narrative

A REVIEW OF THE DATA CONFIRMED THAT THE FACTOR II AND FACTOR V POSITIVE CONTROL AND NEGATIVE CONTROLS WERE VALID IN ALL RUNS, INDICATING THE ASSAY IS WORKING AS INTENDED. NO INSTRUMENT-RELATED ISSUE WAS IDENTIFIED. THE INVESTIGATION DETERMINED THAT THE DISCREPANT RESULTS BETWEEN HETEROZYGOUS AND WILD-TYPE F2 ARE LIKELY RELATED TO A SAMPLE/PATIENT-SPECIFIC ISSUE. BASED ON MULTIPLE TESTS, THE RESULT FOR WILD-TYPE F2 APPEARS TO BE AN OUTLIER. NO PRODUCT PROBLEM WAS IDENTIFIED.