Low Incidence of Anti-CD36 Antibodies in Acquired Thrombotic Thrombocytopenic Purpura

Abstract

Acquired idiopathic thrombotic thrombocytopenic purpura (TTP) is characterized by severe ADAMTS13 deficiency due to the presence of autoantibodies against ADAMTS13. Previous studies using Western blot and immunoprecipitation techniques detected autoantibodies against the membrane antigen CD36 in over 50% of acquired TTP patients. The pathological or clinical significance of this apparent correlation however remains elusive. We reevaluated this potential link by analyzing a cohort of 76 patients with acute acquired TTP for the presence of anti-CD36 autoantibodies using a newly developed enzyme-linked immunosorbent assay (ELISA). Circulating anti-CD36 antibodies were detected in only 4/76TTP patients and 2/63 healthy donors, with no statistically significant difference (p=0.096) in antibody levels between the two populations. The gross discrepancy in the frequency of anti-CD36 antibodies detected in previous studies and the current one is likely due to the difference in methods used for antibody detection and in sample size. Our data indicate that patients with acquired TTP do not exhibit an increased incidence of anti-CD36 antibodies.