ATELLICA IM ACTIVE-B12 (HOLOTRANSCOBALAMIN) (AB12)

Additional Manufacturer Narrative

A CUSTOMER FROM OUTSIDE THE UNITED STATES REPORTED OBSERVATION OF AN ELEVATED ACTIVE-B12 (HOLOTRANSCOBALAMIN) (AB12) RESULT WHICH WAS DISCORDANT RELATIVE TO REPEAT TESTING AND CLINICAL EXPECTATION. SIEMENS IS INVESTIGATING.

Description of Event or Problem

THE CUSTOMER REPORTS OBSERVATION OF AN ELEVATED ACTIVE-B12 (HOLOTRANSCOBALAMIN) (AB12) RESULT WHICH WAS DISCORDANT RELATIVE TO REPEAT TESTING WHEN USING AB12 LOT 104. AN INITIAL AB12 RESULT WITHIN NORMAL RANGE WAS OBTAINED FOR THE PATIENT IN QUESTION, BUT WAS CONSIDERED INCONSISTENT WITH PATIENT MEDICAL HISTORY. THE SAME SAMPLE WAS RE-TESTED THE NEXT DAY, PRODUCING A MUCH LOWER RESULT (BELOW REFERENCE RANGE). THE PATIENT RESULT WAS CORRECTED AND THE INITIAL RESULT WAS IDENTIFIED AS FALSELY ELEVATED. THE SAMPLE WAS ALSO RE-TESTED ON ANOTHER ATELLICA IM ANALYZER, AND IT PRODUCED A SIMILAR LOW RESULT. THERE ARE NO ALLEGATIONS OF ANY ADVERSE PATIENT CONSEQUENCES IN ASSOCIATION WITH THE OBSERVED DISCORDANCE. NO ISSUES WERE IDENTIFIED WITH ASSAY QUALITY CONTROL (QC) RESULTS.

Additional Manufacturer Narrative

A CUSTOMER FROM OUTSIDE THE UNITED STATES REPORTS OBSERVATION OF AN ELEVATED ATELLICA IM ACTIVE-B12 (HOLOTRANSCOBALAMIN) (AB12) RESULT WHICH WAS DISCORDANT RELATIVE TO REPEAT TESTING. UPDATE, 04-FEB-2026: SIEMENS HAS CONCLUDED THE INVESTIGATION. SIEMENS REVIEW OF AVAILABLE DATA SHOWED NO REAGENT PERFORMANCE ISSUES, AS QUALITY CONTROL (QC) AND CALIBRATION DATA WERE WITHIN EXPECTED RANGES, AND NO ANOMALIES WERE REPORTED FOR ANY OTHER PATIENT SAMPLES. NO SAMPLING ERRORS WERE IDENTIFIED AT THE TIME OF THE EVENT. THE CUSTOMER CONFIRMED THAT THE PATIENT SAMPLE HAD BEEN HANDLED CORRECTLY PRIOR TO BOTH INITIAL AND REPEAT TESTING. THE CUSTOMER DID NOT PROVIDE A DETAILED MEDICAL HISTORY FOR THE PATIENT. RETURN OF THE PATIENT SAMPLE FOR ADDITIONAL INVESTIGATION WAS DEEMED UNNECESSARY, AS THE DISCORDANT RESULT WAS NOT REPRODUCIBLE. BASED ON THE AVAILABLE INFORMATION, THE SPECIFIC CAUSE OF THE DISCORDANT RESULT CANNOT BE DETERMINED. OTHER PATIENT RESULTS WERE CONSIDERED ACCEPTABLE AND WERE PRODUCED WITH THE SAME REAGENT PACKS AT THE SAME TIME. THE CUSTOMER REMAINS OPERATIONAL WITH THE AB12 ASSAY. NO SYSTEMIC REAGENT OR INSTRUMENT ISSUES WERE IDENTIFIED. NOTE: IN SECTION H6, THE CODES FOR INVESTIGATION FINDINGS AND INVESTIGATION CONCLUSIONS HAVE BEEN UPDATED.