Time-course of the recovery of cellular immune function after high-dose chemotherapy and peripheral blood progenitor cell transplantation for high-grade non-Hodgkin's lymphoma.

Chemotherapy induces high remission rates in high-grade lymphoma. However relapse remains a major problem. One approach to this is myeloablative chemotherapy with transplantation of autologous bone marrow or peripheral blood progenitor cells (PBPC). Immunological mechanisms have been suggested to play a role in the prevention of relapse after transplantation. We investigated the recovery of cellular immune functions after high-dose chemotherapy and PBPC transplantation in 5 patients with high grade non-Hodgkin's lymphoma. All patients showed rapid reconstitution of natural killer (NK) and inducible lymphokine-activated killer (LAK)-activity 10-14 days after transplantation. Four of 5 patients showed higher levels of LAK-generation in the post-transplant period compared with levels prior to myeloablative treatment. Absolute lymphocyte counts in peripheral blood reached 1.0 x 10(9)/l between days 10 and 13 with a predominance of CD8+ cells and an inversion of the CD4/CD8 ratio. Four of 5 patients had a transient increase in CD56+ and CD16+ cell counts post-transplant. No change in the proportion of CD25+ cells was noted. These results show that PBPC transplantation leads to a rapid recovery of cellular immune functions after myeloablative chemotherapy and provides evidence for an increased presence of LAK precursor cells early in the post-transplant period which can be activated by IL-2 to exert high levels of cytotoxicity.