HIGH-DOSES OF RECOMBINANT-HUMAN-ERYTHROPOIETIN FAIL TO ACCELERATE PLATELET RECONSTITUTION IN ALLOGENEIC BONE-MARROW TRANSPLANTATION - RESULTS OF A PILOT-STUDY

Background and Objective. The effectiveness of recombinant human eryth ropoietin (rhEpo) in accelerating erythroid engraftment in patients un dergoing allogeneic bone marrow transplantation (BMT) has been demonst rated in previous studies. On the other hand, there are experimental d ata suggesting that high doses of rhEpo might also exert a stimulatory effect on thrombopoiesis. Methods. We carried out a pilot study on th e use of high doses of rhEpo (500 U/kg/day for 30 days after transplan t) iri ten patients (HD-Epo group) receiving BMT to evaluate the effec ts on both erythroid and platelet (Pit) engrafment. This group was com pared to ten BMT patients who had not received the hormone (Placebo gr oup). Results. The HD-Epo group patients showed signs of accelerated e rythropoietic recovery; In fact, the time required to reach a reticulo cyte count higher than 30x10(9)/L was significantly shorter than in th e Placebo group, while the number of high RNA content reticulocytes (H FR) was about three times greater. Circulating transferrin receptor (T fR) levels 30 clays after BMT were also significantly higher in the HD -Epo group than in the other. Finally, the number of red blood cell (R BC) transfusions in the first 30 days following BMT was about twofold lower in the HD-Epo group; moreover, 4/10 patients who were treated wi th HD-Epo did not require any RBC units. No significant effects on the engraftment of platelets or on the number of Pit transfusions were ob served in the HD-Epo as compared to the Placebo group. No adverse effe ct was noted on granulocytopoiesis, nor were any adverse clinical expe riences found in patients who had been treated with erythropoietin at high dosages. Interpretation and Conclusions. These data confirm that rhEpo may stimulate erythroid reconstitution after BMT, while its effe cts on Pit engraftment and on Pit transfusion requirements are minimal . (C) 1997, Ferrata Storti Foundation.