Changes of lymphocyte subsets in leukemia patients who received allogenic bone marrow transplantation.

Proportional changes of lymphocyte subsets in the peripheral blood were monitored by two-color flow-cytometry in seven leukemia patients who had received allogenic bone marrow transplantation (BMT). Lymphocyte counts, and proportions of T and B-cells returned to normal ranges between the 2nd and 12th months after BMT. Activated T-cells prominently increased after BMT, and the values gradually returned toward normal. As to lymphocyte subsets, the proportions of CD 4+ cells had remained low, while those of CD 8+ cells high for a whole observation period after BMT. The changes of CD 4+ cells were caused by the decrease of suppressor-inducer T-cells (CD 4+ Leu 8+). High proportion of CD 8+ cells was mainly associated with increased suppressor T-cells (CD 8+ CD 11+). Among natural killer (NK) cells, highly active NK cells (CD 16+ CD 57-) markedly increased shortly after BMT, and gradually returned to normal. CD 16 -CD 57+ NK cells increased beyond normal ranges after the 2nd month. The incidence or degree of acute and chronic graft-versus-host diseases (GVHD) did not correlate with the changes of any lymphocyte subsets. The present results suggest that the increase of activated T-cells shortly after BMT reflects lymphocyte reconstitution. The prolonged immune deficiency after BMT might be related to either deficient expression of homing receptor (Leu 8 antigen) on CD 4+ cells or increased suppressor T-cells (CD 8+ CD 11+). In addition, the early increase of NK cells after BMT may compensate for the immune deficiency in BMT patients.