Objectives: Recombinant human erythropoietin (rHuEpo) improves anemia in 25% of patients with myelodysplastic syndromes (MDS). The variable and sometimes low response rate to rHuEpo treatment raises the question whether the existence of autoantibodies against erythropoietin (epo) is partially responsible. In the present study we investigated the presence of anti-epo autoantibodies in MDS patients.
Methods: Forty-three patients with MDS were studied. Sixteen patients had refractory anemia (RA), 13 had RA with ringed sideroblasts, 3 had RA with excess of blasts (RAEB), 9 had RAEB in transformation and 2 patients had chronic myelomonocytic leukemia. They were divided in 3 groups according to rHuEpo treatment. Group A consisted of 10 patients who did not receive rHuEpo treatment. Group B included 13 patients who were on rHuEpo treatment (150 IU/kg subcutaneously, 3 times weekly) showing an increase of hemoglobin (Hb) values or reduction of transfusion requirements and Group C consisted of 20 patients who did not respond or stopped responding to rHuEpo treatment. Laboratory studies consisted of a complete blood cell count, measurement of serum epo and determination of anti-epo antibodies using ELISA.
Results: There were no significant differences with regard to age and sex among the three groups. No autoantibodies against epo were found in the examined sera, apart from a female patient from group A who showed a low positive titer.
Conclusion: We suggest that anti-epo autoantibodies do not contribute to the development of MDS-related anemia and are not responsible for the modest response to rHuEpo treatment. Further investigation is needed to identify possible reasons for the low response rate to rHuEpo treatment.