Indications for Screening a Patient with Hemophilia A for a Factor VIII Inhibitor

Indications for screening for Factor VIII inhibitor:

(1) periodic monitoring in a patient with severe hemophilia requiring Factor VIII replacement therapy (many patients who develop an inhibitor will do so 8-12 days after the initial exposure)

(2) before surgery or other invasive procedure that may precipitate bleeding

(3) less than expected clinical response to Factor VIII replacement

(4) less than expected rise in Factor VIII activity following Factor VIII replacement

(5) increasing dosage requirements of Factor VIII