Comprehensive genotype and phenotype characterization in non-­severe Hemophilia A patients on assay discrepancies

SUELDO R; ROSSETTI LILIANA C.; ZIEGLER BETIANA M.; MARCHIONE VANINA D.; RADIC CLAUDIA PAMELA; ABELLEYRO MIGUEL MARTIN; DE BRASI CARLOS D; BAQUES A.; ARIAS M.

Londres

Congreso; XXX Congress of the International Society on Thrombosis and Haemostasis (ISTH; 2022

Background: One-­third of patients with non-­severe Hemophilia A (nsHA) presents a discrepancy between the results of FVIII activity (FVIII:C) measured by one-­stage-­assay (OSA) and chromogenic-­ substrate-­assays (CSA). It is observed that this situation can lead to misunderstanding the diagnostic in Hemophilia A (HA) or even worst to get a wrong classification regarding the severity of the disease. Aims: Consider the impact of the discrepancies between OSA and CSA, to face the diagnostic and classification of Patients with Hemophilia and also evaluate the F8-­genotype and phenotype. Methods: 111 patients having bleeding disorders with a diagnostic of HA between 2012 and 2021 were evaluated. We performed laboratory hemostasis studies in all samples (Prothrombin time, Activated Partial thromboplastin time (aPTT), Thrombin Time (TT), aPTT 1:1 mix, OSA, CSA, vWF:Ag, vWF:CoR, Siemens Healthineers; Sysmex CS-­2500). The Initial classification of the disease was performed with OSA (Severe Hemophilia A: sHA