Mapping Of Conformational Epitopes, And Analyze Of The Distribution Of Ig Isotypes And Subclasses Using A Semi-Quantitative Multiplex Assay In 6 Cases Of Postpartum Acquired Hemophilia

Background and objectives: Acquired hemophilia (AH) is a severe life-threatening autoimmune disease due to the development of polyclonal autoantibodies (autoAbs) which neutralize the procoagulant activity of coagulation factor VIII (FVIII). The most common epitopes for autoAbs to FVIII are located in the A2, A3 and C2 domains of FVIII. We have recently developed a multiplex assay based on the Luminex technology that allows simultaneously the detection and epitope mapping of anti-FVIII antibodies (Lavigne-Lissalde et al, Thromb; Haemost. 2008). This technology is fast and requires only 100 μl of plasma and we showed that most autoAbs to FVIII are monospecific and preferentially bind to the light chain (LC) of FVIII. The aim of the present study was to evaluate the epitope specificity and IgG isotype/subclasses of autoAbs to FVIII detected in the post partum period.