[Immunological studies of thrombotic thrombocytopenic purpura]

We studied the immunological changes in eight cases of thrombotic thrombocytopenic purpura (TTP). At autopsy, one case showed IgM deposition in the walls of the capillaries of heart and spleen. Coombs' test was negative in all cases and rheumatic factor was positive in four of eight cases. Anti-nuclear factor was positive in three cases including one case showed positive only during remission. One case, who was diagnosed as TTP complicated with systemic lupus erythematosus (SLE) showed some serological abnormalities for LE test, anti-streptkinase, anti-DNA antibodies, platelet bound IgG, and serum level of IgG by renal biopsy. There were little changes in complements levels. Platelet associated IgG (PAIgG) was positive in four of six cases, and this seemed to be the only abnormality associated with remission and relapses of TTP.