A RANDOMIZED STUDY COMPARING THE EFFECT OF GM-CSF AND G-CSF ON IMMUNERECONSTITUTION AFTER AUTOLOGOUS BONE-MARROW TRANSPLANTATION

Haemopoietic growth factors (HGFs) have been shown to accelerate recov ery from severe neutropenia after autologous bone marrow transplantati on (ABMT) but their effect on immune reconstitution is not well define d, The present study compares, through randomized trial, the in viva e ffect of GM-CSF and G-CSF administration on the immune recovery of pat ients who underwent ABMT. For that purpose, we have sequentially analy sed 14 different T, B and NK lymphoid cell subsets using appropriate d ual staining during the first year following transplant (days +6, +17, +31, +66, +90, +120, +180, +360). 24 patients with lymphoproliferativ e disorders (20 lymphomas and four multiple myelomas) and who had unde rgone ABMT were included in the study, The median age was 43 years (ra nge 22-62 years). All lymphoma patients were homogenously conditioned with BEAM, Our results shaw that both GM-CSF and G-CSF aid T-cell (CD3 (+)/alpha beta) recovery though their contribution varies depending on the T-cell subset analysed. G-CSF contributed to a significantly fast er recovery of CD8(+) cells (P = 0 . 03). The CD8(+) cell regeneration was produced mainly by activated cells (CD38(+)/HLA-DR(+)) which lack ed the CD11b antigen. In contrast, GM-CSF favoured the regeneration of CD4(+) cells (through both the CD45R0(+) and CD45RA(+) subset), leadi ng to a higher CD4(+):CD8(+) ratio (P = 0 . 007). No statistically sig nificant differences were detected in the three groups of patients as regards both the recovery of NK cells and NK activity. Furthermore, th e use of HGF did not seem to exert a significant influence on the reco very of B lymphocytes. This recovery was based on the CD5(+) subpopula tion that showed a rapid rise after the first month, We suggest that G -CSF and GM-CSF not only influence myeloid recovery, but also regenera tion of the immune system after ABMT.