inforMED
MalfunctionGGP

HEMOSIL VON WILLEBRAND FACTOR ACTIVITY

Received Mar 20, 2012 · Event occurred Nov 14, 2011

Report 1217183-2012-00002 · MDR key 2513261

Device

Generic name

Factor Deficiency Test

Model number

NA

Catalog number

0020004700

Lot number

B11655

Product problems

  • Incorrect Or Inadequate Test Results

Patient

Not reported

  • No Information

Narrative

Description of Event or Problem

CUSTOMER COMPLAINT RECEIVED INDICATING A NORMAL VWF ACTIVITY AND VWF ANTIGEN RESULTS (HIGH RATIO) COULD HAVE MISSED A TYPE 2 VWD. SPECIFICALLY, PT SAMPLE HAD A VWF ACTIVITY, VWF ANTIGEN AND MULTIMER ANALYSIS RUN. THE VWF ACTIVITY GAVE A RESULT OF 99% AND THE VWF ANTIGEN GAVE A RESULT OF 71%. THE RATIO WAS 1.39, WHICH WAS REPORTED OUT. THE MULTIMER ANALYSIS INDICATED A TYPE 2 PATTERN AND A RISTOCETIN WAS ORDERED. THE RISTOCETIN TEST RECOVERED 45%.

Additional Manufacturer Narrative

ATTACH IS A SYNOPSIS OF THE TESTING TO DATE AND THE INVESTIGATION THAT IS ON-GOING AT THE CONTRACT MFR, BIOKIT. A FOLLOW-UP REPORT WILL BE FILED AS SOON AS THE CONCLUSION AND RISK ASSESSMENT ARE FINALIZED. CONCLUSION: A REVIEW OF THE DIFFERENCE BETWEEN COLUMNS B AND C AS WELL AS THE RATIOS IN COLUMNS D AND E INDICATES THAT THERE ARE SOME SAMPLES FOR WHICH INCUBATION WITH BOVINE IGG CAUSED THE VWF ACTIVITY RESULT AND THUS THE RATIO TO DECREASE, WHICH SUGGESTS THE PRESENCE OF HABIA IN THESE PT SAMPLES. STATUS: BIOKIT IS CURRENTLY PERFORMING FURTHER INVESTIGATION OF THE REAGENT.