Antiphospholipid antibodies in haemophilia patients with severe bleeding tendency: cause, consequence or a consequential cause?

Antibody profile in Indian severe haemophilia A patients with and without FVIII inhibitors

Diagnosis and management of haemophilia patients with inhibitors is often tricky due to the heterogeneous nature of the antibodies with regard to their kinetics, as well as the co-existence of other interfering antibodies. Plasma samples from severe haemophilia A patients from India with and without FVIII inhibitors were analysed for the presence of possible co-existing antibodies such as lupus anticoagulants (LA), anti-cardiolipin antibodies (ACLA), anti-β2-glycoprotein-I (anti-β2-GP-I) antibodies, viral transfusion transmitted disease (HIV, HBsAg, HCV) related antibodies, anti-cyclic citrullinated peptides (anti-CCP), and anti-nuclear antibodies. A high incidence of LA and anti-HCV antibodies was detected in Indian haemophilia A patients similar to earlier reports. More importantly, a relatively high incidence of autoantibodies to nuclear antigens (18.62%) and anti-CCP antibodies (1.38%) associated with autoimmune disorders was also seen in these congenital haemophilia A patients with and without inhibitors. Knowledge on the antibody profile in these haemophilia patients especially in those with FVIII inhibitors along with correlation with the clinical manifestations and other risk factors for inhibitor development could possibly shed more light on the complex immune response in these patients.

Challenges of multiple mutations in individual patients with haemophilia

Multiple mutations in the same gene within a haemophilia family are being increasingly reported and raise many issues with regard to the specificity of the mutations in causing the disease. In a proportion of families with multiple mutations, discordant phenotypic severity is often observed among the affected members. Understanding whether these mutations influence additively or non-additively the structure, stability and function of the protein will help in a better clinical evaluation of these patients. In case of haemophilia A, out of 2740 entries, ten are double mutants. Among the 2891 patient entries in the Haemophilia B mutation database, there are 34 double mutants and one triple mutant. The major challenge in patients with multiple mutations lies in genetic diagnosis and counselling especially in developing countries wherein the entire gene is not being sequenced and the screening is stopped as soon as the mutation is identified. As of now, the presence of multiple mutations stresses the importance of additional DNA testing in patients with known mutations who have unusual phenotypes or additional, unexplained clinical problems, until more cost-effective techniques for screening the entire gene are identified.