PERIPHERAL-BLOOD LYMPHOID SUBSETS AND LONG-TERM CLINICAL COURSE OF KIDNEY RECIPIENTS - A LONGITUDINAL-STUDY

A longitudinal study of peripheral blood lymphocyte subsets was perfor med in 23 renal allograft recipients treated with prophylactic antilym phocyte antibodies, CsA, and steroids. At day 0 samples were obtained before transplantation (Tx), and afterwards at months +1, +3, +6, +9, +12, +24, +36, and +48. In all patients, after the depletion of lympho id subsets during antilymphocyte antibody treatment, CD8+ lymphocytes recovered and reached higher values than those observed prior to Tx. T his was mainly due to an increase in CD8+CD45RA+ lymphocytes; in contr ast, the levels of ''memory'' CD4+ T cells and the CD4+CD62L+ subset r emained low during all the follow-up period. In patients with preserve d graft function (n = 14) (with creatinine levels below 200 mu mol/mL) , the initial, relative decrease in CD4+ T cells was never reversed an d the recovery of CD8+ lymphocytes started early. They also presented a peak of HLA-DR antigen expression at 1 month, not observed in those patients displaying a suboptimal graft function. At 1 month, the patie nts with suboptimal graft function (n = 9) (with creatinine levels abo ve 200 mu mol/mL) showed higher number of CD4+ T cells, delayed recove ry of CD8+ lymphocytes, and higher percentage of activated lymphocytes from month +3 on than well-functioning kidney recipients. Both CD8+ l ymphocytes and HLA-DR+ T cells, found at month +1 post-Tx, were negati vely correlated with the concentration of creatinine along the follow- up. Interestingly, the mean percentage of CD4+CD25+ T cells found 36 a nd 48 months after Tx were positively correlated with creatinine conce ntration at these times. These findings indicate that variations in th e distribution of lymphocyte subsets are related with a long-term graf t outcome. Within the first month after Tx, a rapid recovery of CD8+ l ymphocytes, but not of CD4+ T cells, and a peak of HLA-DR expression, are associated with a good graft function. In contrast, long-term expr ession of activation markers is related with renal dysfunction. (C) 19 98 Wiley-Liss, Inc.