Previous studies have shown that, unlike in patients submitted to allogeneic BMT, administration of recombinant erythropoietin (Epo) after autologous BMT (ABMT) had no significant effect on erythroid recovery and transfusional requirements. On the other hand, it has also been shown that combining Epo with recombinant granulocyte colony-stimulating factor (G-CSF) in patients with the acquired immunodeficiency syndrome (AIDS) and with myelodysplastic syndromes resulted in additive effects on erythropoiesis. To test the effects of combined G-CSF + Epo therapy on erythroid recovery after autologous bone marrow transplantation a pilot randomized, three-arm trial was designed. Thirty patients suffering from lymphoid malignancies submitted to ABMT were randomly assigned to receive G-CSF alone (5 micrograms/kg, from day + 1 up to reaching an ANC > or = 10(9)/1), G-CSF + Epo (150 U/kg, from day +1 to +21), or neither of these (controls). Patients receiving G-CSF + Epo had significantly more reticulocytes on day +21 and reached 30 x 10(9)/1 reticulocytes earlier when compared to both G-CSF and control patients; however, the number of red blood cell (RBC) transfusions was not modified by the addition of Epo to G-CSF, although both groups had significantly fewer units transfused than controls. No effect on platelet recovery or platelet transfusional requirements was observed. Myeloid recovery was comparable in the G-CSF and G-CSF+Epo groups, and significantly accelerated as compared to controls. We conclude that the addition of Epo to G-CSF causes a slight acceleration of erythroid recovery after ABMT, but is not associated with transfusional benefits. Therefore, the present data do not support the use of Epo in association with G-CSF to hasten erythroid recovery after ABMT.