Weight loss reduces anti-ADAMTS13 autoantibodies and improves inflammatory and coagulative parameters in obese patients.

Obese patients have been described at increased risk of thrombotic thrombocytopenic purpura, a disease caused by anti-ADAMTS13 autoantibodies. ADAMTS13 has a structure homology with the adipokine thrombospondin-1. We previously demonstrated an increased presence of anti-ADAMTS13 antibodies in obese patients. We aimed to study the changes induced by weight loss after bariatric surgery on some inflammatory and coagulative parameters and their link with anti-ADAMTS13 autoantibodies. We studied 100 obese patients before and after weight loss induced by bariatric surgery and 79 lean volunteers as controls. We measured anthropometric, metabolic and inflammatory parameters, thrombospondin-1, ADAMTS13 activity, anti-ADAMTS13 autoantibodies, Von Willebrand factor. At baseline, 13 % of patients was positive for anti-ADAMTS13 autoantibodies, while all controls were negative. Thrombospondin-1 levels were higher in obese subjects with than without antibodies, with a positive correlation between the two parameters. In multiple logistic regression analysis only thrombospondin-1 levels predicted positivity for anti-ADAMTS13 antibodies. After weight loss both anti-ADAMTS13 antibodies and thrombospondin-1 reduced significantly. Weight loss in obesity improves the inflammatory and coagulative profile, and in particular anti-ADAMTS13 autoantibodies, ADAMTS13 activity and thrombospondin-1.