Discrepancies in Non-severe Hemophilia A. Experience in a Hemophilia Center in Argentina

SUELDO, E; PORSELLA, R; ROSSETTI CL; MARCHIONE VD; RADIC CP; DE BRASI C; BAQUES, A; ARIAS, M

Congreso; Virtual Meeting of the International Society on Thrombosis and Haemostasis (ISTH); 2021

Background: Diagnosis of hemophilia A is generally based on the measurement of plasma factor VIII activity using the one-stage assay (FVIII:OSA) or the two-stage chromogenic substrate assay (FVIII:CSA).The results of these methods show considerable discrepancy in about one-third of non-severe hemophilia A patients. This can lead to failure in diagnosing HA or incorrectly classifying the severity of the disease.Aims: To evaluate the frequency of discrepancies between FVIII:OSA and FVIII:CSA, in the diagnostic classification of Patients with Hemophilia.Methods: From 2012 to 2020, 107 patients with bleeding disorders were diagnosed as Hemophilia A (HA). Hemostasis laboratory studies were performed (Prothrombin time (PT), Activated Partial thromboplastin time (aPTT), Thrombin Time (TT), aPTT 1:1 mix, FVIII:OSA, FVIII:CSA, vW:Ag, vW:CoR). Patients were initially categorized into the different clinical categories by FVIII:OSA (Severe Hemophilia A: sHA