DADE ACTIN FS ACTIVATED PTT REAGENT

Additional Manufacturer Narrative

AN OUTSIDE OF THE UNITED STATES (OUS) CUSTOMER CONTACTED A SIEMENS CUSTOMER CARE CENTER TO REPORT DISCORDANT INCREASED FACTOR VIII (F VIII) RESULTS OBTAINED ON ONE PATIENT MEASURED WITH ACTIN FS ON THE CS-5100 INSTRUMENT COMPARED TO ALTERNATE METHOD. TWO DIFFERENT SAMPLES FROM THE SAME PATIENT WERE TESTED ON TWO DATES ((B)(6) 2026). THIS MDR IS ABOUT THE RESULTS OBTAINED ON (B)(6) 2026, RESULTS OBTAINED ON (B)(6) 2026 ARE REFERENCED IN A SEPARATE MDR. THE AVAILABLE DATA CONFIRM THAT THE DISCREPANCY IS LIMITED TO FVIII RESULTS, WHILE OTHER TEST RESULTS FOR THE SAME PATIENT WERE NOT REPORTED AS DISCREPANT. MEASUREMENTS WITH FACTOR-DEFICIENT PLASMAS SHOW EXPECTED RECOVERIES, AND NO INDICATION OF AN INHIBITOR WAS REPORTED. ADDITIONALLY, THE PATIENT RESULTS SHOW DECREASED VON WILLEBRAND FACTOR ANTIGEN (VWF AG) AND ACTIVITY (VWF AC), INDICATING REDUCED VWF LEVELS. DIFFERENCES BETWEEN FVIII RESULTS OBTAINED WITH DIFFERENT ASSAY SYSTEMS MAY OCCUR DUE TO METHODOLOGICAL VARIABILITY BETWEEN APTT-BASED ASSAYS, PARTICULARLY IN SAMPLES WITH ALTERED VWF LEVELS. BASED ON THE PROVIDED INFORMATION, THERE IS NO INDICATION OF AN ANALYTICAL PROBLEM SPECIFIC TO THE SIEMENS SYSTEM. THE OBSERVED DISCREPANCY IN FVIII RESULTS IS MOST LIKELY ATTRIBUTABLE TO METHOD-DEPENDENT DIFFERENCES BETWEEN THE ASSAY SYSTEMS USED. NO EVIDENCE IS AVAILABLE SUGGESTING INTERFERENCE FROM TRANEXAMIC ACID (EXACYL). THE CUSTOMER IS OPERATIONAL. THE INSTRUMENT IS PERFORMING ACCORDING TO SPECIFICATIONS. NO FURTHER EVALUATION OF THIS DEVICE IS REQUIRED.

Description of Event or Problem

THE CUSTOMER REPORTED THE OBSERVATION OF DISCORDANT INCREASED FACTOR VIII (F VIII) RESULTS OBTAINED ON ONE PATIENT SAMPLE MEASURED WITH ACTIN FS ON THE CS-5100 INSTRUMENT COMPARED TO ALTERNATE METHOD. NO RESULT WAS REPORTED. IT IS UNCLEAR WHICH IS THE CORRECT RESULT. THERE ARE NO KNOWN REPORTS OF PATIENT INTERVENTION OR ADVERSE HEALTH CONSEQUENCES DUE TO THE DISCORDANT INCREASED F VIII RESULTS.