VWF AG

Additional Manufacturer Narrative

AN OUTSIDE OF THE UNITED STATES (OUS) CUSTOMER CONTACTED SIEMENS CUSTOMER CARE CENTER TO REPORT A DISCORDANT RESULT THAT WERE OBTAINED FOR ONE PATIENT SAMPLE ON THE CS-5100 INSTRUMENT FOR THE ASSAY VWF AG. SIEMENS IS INVESTIGATING THE ISSUE. IN ADDITION THE CUSTOMER REPORTED DISCORDANT RESULTS THAT WERE OBTAINED ON THE SAME PATIENT SAMPLE AND ON ONE ADDITIONAL PATIENT SAMPLES ON THE CS-5100 INSTRUMENT FOR THE ASSAY INNOVANCE VWF AC. A SEPARATE REPORT WAS FILED FOR INNOVANCE VWF AC RESULTS. VWF AG REAGENT IS MARKETED IN THE UNITED STATES UNDER SIEMENS MATERIAL NUMBER 10483455. THE 510(K) NUMBER DOCUMENTED IN SECTION G4 IS FOR THE US PRODUCT.

Description of Event or Problem

THE CUSTOMER REPORTED A FALSELY DEPRESSED VWF-AG (VON-WILLEBRAND FACTOR ANTIGEN) RESULT WAS OBTAINED ON A PATIENT SAMPLE ON A CS-5100 INSTRUMENT. THE ERRONEOUS RESULT WAS REPORTED TO THE PHYSICIAN(S). THE SAMPLE WAS REPEATED ON THE SAME INSTRUMENT. THE REPEAT RESULT WAS HIGHER THAN THE ERRONEOUS RESULT. THE REPEAT RESULT WAS REPORTED, AS THE CORRECT RESULT, TO THE PHYSICIAN(S). THERE ARE NO KNOWN REPORTS OF PATIENT INTERVENTION OR ADVERSE HEALTH CONSEQUENCES DUE TO THE DISCORDANT, DEPRESSED VWF-AG RESULT.