Propylthiouracil-induced hemolytic anemia

Propylthiouracil (PTU)-induced hemolytic anemia is extremely rare. We reported a case of Graves' disease with these unusual clinical manifestations. A 41-year-old female presented with recurrent attacks of severe hemolytic anemia after PTU therapy. Sugar water test and erythrocytes osmotic fragility test revealed no cellular membrane defect of red blood cells. Antinuclear antibody, direct and indirect Coombs' tests were all negative and glucose-6-phosphate dehydrogenase activity was also within normal limits. PTU was not discontinued promptly due to unrecognizableness of such a rare case until two months later with recurrent attacks of severe hemolytic anemia. 1-131 therapy was performed on suspicion of related hemolytic anemia. Unfortunately, challenge of PTU occurred incidentally after discontinuation of PTU followed by severe hemolytic anemia. The diagnosis of PTU-induced hemolytic anemia was established thereafter. A MEDLINE search revealed only one such case reported in English literature. This is the first case report in Taiwan. It should be kept in mind that hemolytic anemia may be a rare complication of PTU therapy.