Successful Treatment of Warm Autoimmune Hemolytic Anemia with a Positive Donath-Landsteiner Test Using Rituximab.

Paroxysmal cold hemoglobinuria (PCH) is a rare disease in adults, and its concurrent presentation with warm-type autoimmune hemolytic anemia (AIHA) has not yet been reported. We encountered a 19-year-old woman with AIHA and a positive Donath-Landsteiner test result identified by a hemolytic attack during blood transfusion. She also showed positive results for the direct Coombs and Donath-Landsteiner antibody tests. After treatment with prednisolone followed by rituximab, the AIHA improved, and the Donath-Landsteiner antibody test result turned negative. Clinicians should be aware that patients may present with concurrent warm-type AIHA and PCH and consider rituximab for its treatment.