Transfusion-induced hemolysis in warm autoimmune hemolytic anemia with autoantibodies that have anti-e specificity: a case report and systematic review of the literature.

Warm autoimmune hemolytic anemia (wAIHA) is characterized by autoantibodies against proteins that comprise the Rh antigen system along with hemolysis. The presence of specific autoantibodies, especially autoantibodies with anti-e specificity, is rare. The pathophysiology, management, and outcomes in this condition, including with transfusion of e-antigen positive packed red blood cells (pRBCs), remain poorly understood. A 63-year-old woman presented with fatigue, jaundice, tea-colored urine, and dyspnea. She was diagnosed with wAIHA with anti-e specificity and developed worsening hemolysis after receiving a unit of e-antigen positive pRBCs with a drop in hemoglobin from 85 to 71 g/L. She achieved a complete response with a tapering course of prednisone and folate. We conducted a systematic review of the literature by searching MEDLINE, EMBASE, and Cochrane for articles on management of wAIHA with anti-e specificity published between 1946 and 2025. We identified eighteen cases of wAIHA mediated through autoantibodies with anti-e specificity, only one of which demonstrated hemolysis after transfusion with e-antigen positive pRBCs. Treatment with corticosteroids and rituximab was effective in many of these cases. This is the one of the few cases to demonstrate increased hemolysis after transfusion with e-antigen positive pRBCs in a patient with wAIHA and autoantibodies with anti-e specificity. In these patients, transfusion of e-antigen positive pRBCs should be avoided and if transfusion is necessary, it will be important to closely monitor for worsening hemolysis. Additionally, our case and those reported in the literature highlight the effectiveness of standard corticosteroid treatment for this rare type of wAIHA.