Flow cytometric determination of RBC survival in autoimmune hemolytic anemia

BACKGROUND: In cases of warm autoimmune hemolytic anemia (WAIHA), crossmatc h incompatible RBCs are most often used for transfusion. The determination of the in vivo survival of transfused and autologous RBCs in WAIHA is helpf ul in the assessment of the efficacy of transfusion and other therapeutic i nterventions. CASE REPORT: A 38-year-old man presented with acute WAIHA, thrombocytopenia , and neutropenia. Steroids and IVIG therapy were ineffective, and the pati ent received RBCs. Because of increasing hemolysis and persisting thrombocy topenia, splenectomy was performed, resulting in partial remission. Further improvement was achieved by immunosuppressive therapy. MATERIALS AND METHODS AND RESULTS: Survival of transfused and autologous RB Cs was determined, using a flow cytometric method based on the determinatio n of different blood group antigens of patient and donor RBCs. The survival of autologous and transfused RBCs before splenectomy was determined on two consecutive days. The life span of autologous RBCs remained rather stable at 69 and 64 hours on Days 10 and II, respectively, whereas the life span o f transfused RBCs decreased from 186 hours to 25 hours. After splenectomy, the life span of transfused RBCs almost normalized: 43 days at postsplenect omy Day 3 and 87 days at postsplenectomy Day 69. CONCLUSION: Flow cytometry was successfully used to determine changing hemo lytic activity during the clinical course of WAIHA, Additionally, the survi val of transfused RBCs could be measured, which may be helpful to judge for the compatibility of allogeneic RBCs. Thus, we were able to show the thera peutic inefficacy of steroids and immunoglobulins, and quick improvement af ter splenectomy.