[Development of overt hemolytic anemia after splenectomy for thrombocytopenia in Evans syndrome with negative Coombs test].

A 69-year-old man was diagnosed as having idiopathic thrombocytopenic purpura (ITP) in April 2000, and treated with prednisolone (PSL) without effect. Splenectomy performed in June 2000 had only a transient and marginal influence on his platelet count. Two months later, he developed autoimmune hemolytic anemia (AIHA) without Coombs test positivity, and his diagnosis was changed to Coombs-negative Evans syndrome. Treatment with PSL led to recovery of his hemoglobin level, but not his platelet count. Although the mechanism responsible for development of AIHA after splenectomy in this patient with ITP remains unknown, close observation is required for any association with other autoimmune diseases such as SLE.