BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    COAGULATION FACTOR VIII DEFICIENT PLASMA

    MDR report key: 23377292 · Received October 24, 2025

    Report

    Report Number
    9610806-2025-00050
    Event Type
    Malfunction
    Date Received
    October 24, 2025
    Date of Event
    September 29, 2025
    Report Date
    October 24, 2025
    Manufacturer
    SIEMENS HEALTHCARE DIAGNOSTICS PRODUCTS GMBH
    Product Code
    GJT
    UDI-DI
    00842768004032
    PMA / PMN Number
    K924396
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    NZ
    Reporter Occupation
    OTHER HEALTH CARE PROFESSIONAL
    Health Professional
    Yes

    Narratives

    Additional Manufacturer Narrative · 0

    AN OUTSIDE OF THE UNITED STATES (OUS) CUSTOMER CONTACTED THE SIEMENS CUSTOMER CARE CENTER TO REPORT DISCORDANT ELEVATED COAGULATION FACTOR VIII / DADE ACTIN FS ACTIVATED PTT REAGENT RESULTS THAT WERE OBTAINED ON ONE PATIENT SAMPLE ON THE CS-2500 INSTRUMENT. THE FOLLOWING CONCLUSION IS MADE BY SIEMENS HEALTHINEERS: THE ISSUE IS CAUSED BY A KNOWN INTERFERENT FROM THE MEDICATION (EMICIZUMAB) AS THIS LEADS TO ELEVATED RESULTS WITH ONE-STAGE CLOTTING ASSAYS (APTT AND APTT BASED FVIII DETERMINATION). THIS IS A WELL-KNOWN AND GENERIC INTERFERENCE BASED ON ASSAY PRINCIPLES. THE DRAMATIC SHORTENING OF APTT CAUSED BY EMICIZUMAB LEADS TO SIGNIFICANT INTERFERENCE WITH THE ONE-STAGE FVIII ACTIVITY ASSAY. THIS PHENOMENON HAS BEEN THOROUGHLY DESCRIBED IN STUDIES SUCH AS 'LABORATORY MONITORING IN EMICIZUMAB-TREATED PERSONS WITH HEMOPHILIA A' AND 'EFFECTS AND INTERFERENCES OF EMICIZUMAB, A HUMANISED BISPECIFIC ANTIBODY MIMICKING ACTIVATED FACTOR VIII COFACTOR FUNCTION, ON COAGULATION ASSAYS', BOTH AVAILABLE ON PUBMED." EMICIZUMAB DOES NOT INTERFERE WITH THE SIEMENS COAGULATION FACTOR VIII / FACTOR VIII CHROMOGENIC ASSAY . NO FVIII ACTIVITY IS EXHIBITED BY EMICIZUMAB USING THE SIEMENS CHROMOGENIC ASSAY. THIS FITS TO CUSTOMER OBSERVATION. OBTAINED RESULT FOR SAMPLE OF A PATIENT WITH SEVERE HEMOPHILIA A TREATED WITH EMICIZUMAB. ACCORDING TO COMPLAINT DESCRIPTION REMAINING FVIII ACTIVITY IS ~1%. THE APTT BASED FVIII DETERMINATION SHOWED A HIGHLY OVERESTIMATED RESULT DUE TO INTERFERENCE OF EMICIZUMAB.

    Description of Event or Problem · 0

    THE CUSTOMER REPORTED THE OBSERVATION OF DISCORDANT INCREASED RESULTS OF COAGULATION FACTOR VIII / DADE ACTIN FS ACTIVATED PTT REAGENT ASSAY FOR ONE PATIENT WITH KNOWN HEMOPHILIA A ON THE CS-2500 SYSTEM USING APTT WITH FACTOR VIII. THE SAMPLE WAS REPEATED WITH AN ALTERNATE METHOD SIEMENS COAGULATION FACTOR VIII / FACTOR VIII CHROMOGENIC ASSAY AND RECOVERED LOWER. THERE ARE NO KNOWN REPORTS OF PATIENT INTERVENTION OR ADVERSE HEALTH CONSEQUENCES DUE TO THE DISCORDANT RESULT.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    242584 COAGULATION FACTOR VIII DEFICIENT PLASMA PLASMA, COAGULATION FACTOR DEFICIENT GJT SIEMENS HEALTHCARE DIAGNOSTICS PRODUCTS GMBH NOT PROVIDED 00842768004032

    Patients

    Seq Age Sex Outcome Treatment
    1 9 YR Male