AUTOLOGOUS STEM-CELL TRANSPLANTATION - EVALUATION OF ERYTHROPOIETIC RECONSTITUTION BY HIGHLY FLUORESCENT RETICULOCYTE COUNTS, ERYTHROPOIETIN, SOLUBLE TRANSFERRIN RECEPTORS, FERRITIN, TIBC AND IRON DOSAGES

The plasma concentrations of erythropoietin (Ep), soluble transferrin receptors (sTfRs), iron, total iron binding capacity (TIBC) and ferrit in were monitored in five leukaemia patients undergoing autologous bon e marrow stem cell transplantation (BMSCT) and in 10 lymphoma and 21 o varian cancer patients undergoing autologous peripheral blood SCT (PBS CT); 9/21 ovarian cancer patients received recombinant human G-CSF and Ep and six recombinant human GM-CSF and Ep following SCT. All paramet ers were evaluated in relation to the kinetics of erythroid reconstitu tion as evaluated by haemoglobin (Hb) and reticulocyte levels [includi ng the fraction of immature reticulocytes, also called highly fluoresc ent reticulocytes (HFR)]. Leukaemia patients undergoing BMSCT showed o nly a delayed (occurring at days 35-50 after SCT) and partial RBC, neu trophil and platelet recovery, whereas all patients undergoing PBSCT e xhibited a rapid (occurring at days 10-15 after SCT) and sustained hae mopoietic recovery. The various levels of erythroid rescue observed am ong these patients markedly influenced the kinetics of the different p arameters investigated: (i) in leukaemia BMSCT patients sTfRs declined following SCT and remained at low levels thereafter, whereas Ep, iron , TIBC and ferritin showed a progressive and significant increase; (ii ) in the different groups of patients undergoing PBSCT: (a) sTfR level s first declined following SCT and then returned to pre-therapy values at days 12-16, this response preceded erythropoietic recovery; (b) Ep , total iron, TIBC and ferritin showed an initial increase in the firs t days following SCT and then returned to pre-therapy values. Altogeth er, these observations indicate that: (i) both sTfR levels and reticul ocyte counts are predictive parameters of erythropoietic recovery; (ii ) coordinated changes of biochemical parameters underlying iron metabo lism (iron, TIBC and ferritin) accompany erythroid rescue following SC T.