Poor lymphocyte recovery following CD34-selected autologous peripheral blood stem cell transplantation for non-Hodgkin's lymphoma.

Summary. Positive selection of CD34[sup +] cells in autologous grafts, designed to deplete tumour cells, also results in T-cell depletion. To assess the reconstitution of the different lymphocyte subsets and of the T-cell repertoire diversity following autologous transplantation of selected CD34[sup +] peripheral blood stem cells (PBSC), we analysed sequential blood samples in eight patients autografted for advanced B-cell non-Hodgkin's lymphoma in a phase I-II pilot study. Although natural killer cell recovery was rapid, T- and B-cell recovery was delayed with a median of 110/micro l CD4[sup +], 175/ml CD8[sup +] T cells and 45/micro l B cells at 12 months post-transplant. The naive CD45RA[sup +] T-cell compartment was profoundly deficient up to 12 months for both CD4[sup +] and CD8[sup +] subsets. A transient expansion of memory CD8[sup +]CD45RO[sup +] T cells consisting of an increased percentage of CD57[sup +]CD28[sup -] cells occurred within the first 3 months post-transplant, but the memory CD4[sup +]CD45RO[sup +] T cells remained far below the normal value. The CD8[sup +]CD28[sup +] T-cell subset did not recover. Using multiplex PCR analysis of the T-cell receptor g locus, we found that the repertoire diversity improved at 12 months after being poor and oligoclonal during the first 3 months post-transplant. As shown by monoplex PCRg analysis of every VJ combination, despite T-cell depletion of the graft, mature T-cells were carried over with the selected CD34[sup +] PBSC and contributed to the T-cell recovery after transplantation. [ABSTRACT FROM AUTHOR]