THE PHENOTYPE AND RECONSTITUTION OF IMMUNOREGULATORY T-CELL SUBSETS AFTER T-CELL-DEPLETED ALLOGENEIC AND AUTOLOGOUS BONE-MARROW TRANSPLANTATION

In the present study, we examined changes in the expression of CD45RA, CD31, and CD29 on total CD4 and CD8 lymphocytes in patients who had received CD6 T cell-depleted allogeneic marrow and received no immune suppressive drugs after engraftment in order to identify defects in reconstitution of immunoregulatory T cells after allogeneic BMT. Results following allo-BMT were compared with normal controls and patients following autologous BMT. We showed that CD4(+)CD45RA(+), CD4(+)CD29(+) (CD29(high)), and CD4(+)CD31(+) cells were markedly decreased during the first 24 months after allo- and auto-BMT. CD8(+)CD45RA(+) cells recovered to normal levels within the first month after auto-BMT, while after allo-BMT, the CD8(+)CD45RA(+) cells were at slightly low levels during the first month, but gradually increased to normal levels by 12 months post-BMT. CD8(+)CD29(+) cells were increased during the first 12 months both after allo- and auto-BMT although during the first month, a decreased percentage of CD8(+)CD29(+) cells was observed in allo-BMT patients. More important, CD4(+)CD29(+), CD8(+)CD29(+), and CD8(+)S6F1(+) cells were significantly increased in patients with moderate-to-severe acute GVHD (grades II-IV) compared with those with or without mild acute GVHD (grade I), suggesting that CD4 helper-inducer (CD4(+)CD29(high)) and CD8 killer-effector (CD8(+)CD29(high)SGF1(+)) cells play an important role in the pathophysiology of acute GVHD.