Regeneration of functional and activated NK and T sub-subset cells in the marrow and blood after autologous bone marrow transplantation: a prospective phenotypic study with 2/3-color FACS analysis.

The phenotypic reconstitution of lymphoid cells in the bone marrow and peripheral blood was examined prospectively in 27 patients who underwent autologous bone marrow transplantation (ABMT) for leukemia/lymphoma. Patterns of activation within NK and T cell subsets as well as T sub-subsets were studied with monoclonal antibodies in two- and three-color FACS analysis. NK-like cells (CD16+) were found to be increased in the peripheral blood and bone marrow after ABMT. The expression of two activation markers, 4F2 and HLA-DR, was sustainedly increased within this subset. High numbers of CD4+ and CD8+ T cells carrying surface HLA-DR were found early after ABMT both in blood and marrow. The T suppressor inducer cell sub-subset (CD45R+ CD4+) was severely depressed in both the blood and marrow 6-9 months post-ABMT. Using three-color FACS analysis, half of this T sub-subset was shown to express HLA-DR+. The levels of T suppressor effector-like cells (CD11+ CD8+) remained within the normal range in both peripheral blood and bone marrow during follow-up. The HLA-DR expression was elevated and equally distributed between the CD11- CD8+ and CD11+ CD8+ sub-subset cells. There was no major impact of marrow T cell purging or CMV carrier status on the phenotypic NK/T cell reconstitution. The present results provide an immune phenotypic basis for the suggested generation of anti-leukemic NK-like and T suppressor-like activity after ABMT.