Purpose: To describe the immunohematological response after multiple red blood cells transfusions in 112 patients with myelodysplastic syndromes (MDS).
Patients and methods: From 1982 to 1992 every patient with MDS entered the study. Immunohematological studies consisted of an antibody screening test (AST) and a direct antiglobulin test (DAT) at diagnosis and after every four transfused units of red blood cell concentrates.
Results: Twenty-three out of 112 patients (20.5%) presented a positive AST and/or DAT during the study period. Eleven out of the 23 patients (9.8%) developed a positive DAT, six of them with red cell alloantibodies associated. In the remaining 12 patients (10.7%) the immune response observed was the development of red cell alloantibodies without a positive DAT. No patient presented with positive AST or DAT at diagnosis and no differences were observed in the pattern of immunohematological response and the FAB subtype.
Conclusion: Patients with MDS have disordered immune systems with a high prevalence of autoantibodies against red cells. However, the incidence of red cell alloimmunization is similar to that observed in other multitransfused populations. Finally, despite the high immunization rate, the absence of any hemolytical reaction make the AST and DAT a safe and effective method of pretransfusion testing in this heavily transfused population.