Features of clinical and laboratory diagnosis of rare coagulopathy – acquired hemophilia

Introduction. The formation of circulating autoantibodies capable of inhibiting factors of the blood coagulation system is accompanied by the occurrence of spontaneous and/or post-traumatic bleeding in patients without a history of previous disorders of the hemostasis system. One of the reasons for the development of such conditions is acquired hemophilia.Aim – to present algorithms for laboratory diagnosis of acquired hemophilia.Main findings. Primary diagnosis and control of therapy of the disease are carried out based on the results of coagulation studies, the decoding and interpretation of which often causes difficulties due to the low awareness of doctors about the algorithms for laboratory diagnosis and tactics for managing patients. In acquired hemophilia there is no direct relationship between the results of laboratory tests and the clinical manifestations of the disease, which is determined by the kinetics of the interaction of autoantibodies with blood coagulation factor (F) VIII. There is a «false» in vitro decrease in the activity of factors of the internal pathway (FIX, FXI and FXII), associated with the effect of a rapid inhibitor in high titers. An important laboratory task is the determination of lupus anticoagulant, which makes it difficult to timely diagnose and verify the diagnosis.