A 9-month-old boy with life-threatening multiresistant pure red cell anemia/autoimmune hemolytic anemia within the frame of a possible, undiagnosed immune-mediated disease was initially treated with prednisone. Further-line therapies of the following 7 relapses included immunoglobulins, rituximab, cyclophosphamide, and alentuzumab followed by other maintenance treatments as cyclosporine, methotrexate, and mycophenolate. After all the administered therapies failed, the patient was successfully treated by splenectomy followed by fludarabine and then sirolimus as maintenance treatment. Relapses might have been caused by the lack of a complete debulking of triggering cells and/or ineffective maintenance therapy. Splenectomy and sirolimus may have played a complementary role in the management of both situations.