Refractory autoimmune hemolytic anemia secondary to Babesia

Abstract

Introduction: Babesia is endemic in the northeast and upper midwestern United States. Two species that cause human infections are Babesia microti and Babesia divergens. The parasite is transmitted by the bite of the tick Ixodes scapularis. Another mode of transmission is blood transfusion producing either an asymptomatic to mild flu-like illness or hemolytic anemia in immunocompromised and asplenic individuals. Hemolysis is usually non-immune and attributed to lysis of infected erythrocytes. Rarely the infection may cause immune dysregulation and lead to the formation of autoantibodies that cause immune mediated hemolytic anemia. Case Report: A previously healthy young adult male with a recent history of multiple blood transfusions, presented with refractory autoimmune hemolytic anemia within two months of transfusion. The anemia was unresponsive to various immunosuppressive medications and blood transfusions. On follow-up, his peripheral smears showed heavy parasitemia consistent with Babesia species. The organism was speciated to Babesia microti by polymerase chain reaction at the Center for Disease Control. The patient was treated with intravenous quinidine and oral clindamycin. Immune hemolytic anemia resolved following the treatment of Babesiosis. Conclusion: In conclusion, Babesiosis should be in the differential diagnosis of autoimmune hemolytic anemia in a patient with a history of blood transfusion and poor response to steroids or immunosuppressive drugs.