Presence of anti-kinectin and anti-PMS1 antibodies in Japanese aplastic anaemia patients.

While anti-kinectin antibodies are frequently found in aplastic anaemia (AA) patients from the US (39%), we detected antibodies in only three of 30 (10%) of Japanese AA cases. Additionally, population differences in anti-postmeiotic segregation increased 1 (PMS1) responses were seen, with detectable antibody in 10% Japanese and 0% US AA patients. In one of the Japanese AA patients with detectible anti-kinectin antibodies, the autoantibody disappeared coincidentally with the partial resolution of pancytopenia. These results support the hypothesis that the epidemiology of AA is heterogeneous and suggest that anti-kinectin autoantibody titre may serve as a surrogate maker for the disease activity of AA.