Immune reconstitution after autologous progenitor hemopoietic cell transplantation. A study comparing autologous bone marrow and autologous peripheral blood transplantation

BACKGROUND: In order to find out the effect of peripheral blood (PB) hematopoietic progenitor cells on immune reconstitution the present study compares, through a randomized trial, some lymphoid subsets after peripheral blood (PBT) or bone marrow (BMT) autologous transplantation. MATERIAL AND METHODS: Twelve patients suffering from malignant hematological disorders were included (6 BMT and 6 PBT). From these patients 14 lymphoid and natural killer (NK) subsets were sequentially analyzed using appropriate dual staining. NK activity was analyzed by measuring Cr51 release from the K562 cell line. Studies were done in days and -6, +10, +17, +24, +31, +38, +52, +66, +90, +120, +180 and +360 after transplantation. RESULTS: The CD8+ cell regeneration was produced mainly by activated cells (CD38+), and no differences were observed between BMT and PBT, but CD8+ HLADR+ cells were higher in the PBT group. During the first year after transplantation CD4+ lymphoid cells were never within normal range, and its recovery was due to the memory subset (CD4+/CD45RO+). The CD19+ lymphocytes began their regeneration after the first month and it was produced mainly by by the CD19+/CD5+ subset. NK cells recovered faster in patients who underwent PBT, but NK activity was similar in both subgroups of patients and it was within normal range from day +17 until the end of the study. CONCLUSION: T, B and NK lymphoid reconstitution do not differ significantly between patients that receive BM or PB as hemathopoietic rescue, but PB seems influence a faster reconstitution of cytotoxic subsets (CD8+/HLADR+ and NK lymphoid cells).