Assessment of immune reconstitution status in recipients of a successful hematopoietic stem cell transplant from peripheral blood after reduced intensity conditioning

ObjectiveTo document immune reconstitution status after hematopoietic stem cell transplantation (HSCT) for malignant hematologic diseases.MethodsHematology patients who received a reduced intensity conditioning (RIC) were followed after successful allogeneic or autologous HSCT. Patients had at least 100 days post-transplant. T, B and NK cells in peripheral blood (PB), and CD34 +, CD133 + progenitor cells in bone marrow (BM) and peripheral blood (PB) were determined by flow cytometry.ResultsTwenty-seven HSCT recipients, 19 allogeneic and 8 autologous, were studied at a median 155 (100–721) days post-transplant. In the whole group the median value of CD34 + cells was 1.03% in the bone marrow and 0.04% in PB, whereas values for CD133 + cells were 0.39% and 0.13%, respectively, without statistical differences between autologous and allogeneic recipients. Significantly more B cells (CD3 −/CD56 −/CD19 +) were found in the autologous compared to the allogeneic group, 12.6 vs. 5.01, p = 0.04. An increased number of CD8 + lymphocytes with a 0.63 CD4:CD8 relationship was documented in PB.ConclusionIn clinically recovered autologous and allogeneic HSCT recipients BM and PB CD34 +/CD133 + hematoprogenitor homeostasis is maintained within normal ranges, with better B-cell reconstitution in the autologous group.