What are FVIII inhibitors, and how can I measure them?
FVIII inhibitors appear in about 25% of severe hemophilia A patients. They are most common in patients with inversions, large deletions and nonsense mutations. Inhibitor titer varies 1000-fold; high titer seriously impairs treatment efficacy. Inhibitors can be transient or persistent. and appear irrespective of which FVIII concentrate is selected. High titer patients are treated with high doses of human or porcine concentrate. Though Chromogenix does not have an assay kit for FVIII inhibitor measurement, evaluation of a chromogenic FVIII inhibitor method using Coamatic Factor VIII and, if possible, including a candidate inhibitor standard, is planned. See Blombck M et al. XVIIth Hemophilia Congress Milan, Abstract 290 (1986) for and adaptation of Coatest Factor VIII.
