TINA-QUANT HEMOGLOBIN A1CDX GEN.3

Description of Event or Problem

THERE WAS AN ALLEGATION OF DISCREPANT RESULTS FOR 1 PATIENT SAMPLE TESTED FOR TINA-QUANT HEMOGLOBIN A1CDX GEN.3 (A1CX3) ON A COBAS C 503 ANALYTICAL UNIT.THE INITIAL RESULT WAS 4.0%. THE CUSTOMER REPEATED THE SAMPLE USING A SEBIA CAPILLARYS ELECTROPHORESIS INSTRUMENT, AND THE RESULT WAS 6.1%.ON (b)(6) 2026, THE SAMPLE WAS REPEATED 5 TIMES, AND NO NUMERIC RESULTS WERE PROVIDED, ONLY CLCT.E ALARMS.THE CUSTOMER "LEFT THE SAMPLE TO SETTLE OVERNIGHT."ON (b)(6) 2026, THE SAMPLE WAS REPEATED, YIELDING A RESULT OF 4.05%. THE CUSTOMER QUESTIONED WHY THE RESULTS BELOW THE MEASURING RANGE OF 4.2% - 20.1% WERE NOT ACCOMPANIED BY DATA FLAGS. THE CUSTOMER ALSO QUESTIONED WHY FLAGS DON¿T APPEAR BASED ON THE PATIENT¿S CLINICAL CONDITION (SC GENOTYPE).

Additional Manufacturer Narrative

THE C503 ANALYZER SERIAL NUMBER WAS 24S0-07. PRODUCT LABELING STATES: "AS A MATTER OF PRINCIPLE, CARE MUST BE TAKEN WHEN INTERPRETING ANY HBA1C RESULT FROM PATIENTS WITH HB VARIANTS. ABNORMAL HEMOGLOBINS MIGHT AFFECT THE HALF LIFE OF THE RED CELLS OR THE IN VIVO GLYCATION RATES. IN THESE CASES, EVEN ANALYTICALLY CORRECT RESULTS DO NOT REFLECT THE SAME LEVEL OF GLYCEMIC CONTROL THAT WOULD BE EXPECTED IN PATIENTS WITH NORMAL HEMOGLOBIN. WHENEVER IT IS SUSPECTED THAT THE PRESENCE OF AN HB VARIANT (E.G. HBSS, HBCC OR HBSC) AFFECTS THE CORRELATION BETWEEN THE HBA1C VALUE AND GLYCEMIC CONTROL, HBA1C MUST NOT BE USED FOR THE DIAGNOSIS OF DIABETES MELLITUS."THE INVESTIGATION IS ONGOING.