FIBRINOGEN DEGRADATION PRODUCTS IN PATIENTS WITH THE QUEBEC PLATELET DISORDER

The Quebec platelet disorder is a serious bleeding disorder associated with proteolysis of alpha-granular proteins, including fibrinogen. We evaluated fibrinogen degradation product (FDP) assays as screening te sts for this disorder. Patients with the Quebec platelet disorder (13/ 13) had elevated serum FDPs (P < 0.01) due to secreted degraded platel et fibrinogen, but normal plasma FDPs and D-dimers. Unrelated controls with bleeding disorders (32/34) had undetectable FDPs, and controls w ith FDPs due to disseminated intravascular coagulation (DIG) and other illnesses (11/11) had elevated FDPs in all assays (P < 0.01). Immunob lot analyses indicated plasma fibrinogen was normal in the Quebec pati ents and platelet FDPs were found in their platelet lysates, releasate s and serum samples. Their platelet FDPs were not altered by treatment with fibrinolytic inhibitors and were different from the FDPs in DIC and in plasmin-digested fibrinogen. Tests for serum FDPs may provide a simple rapid way to screen for the Quebec platelet disorder.