Cellular Immunity in Chronic Kidney Disease and Changes After Kidney Transplantation

This study evaluates changes in cellular immunity components, from chronic kidney disease stage V (CKD-V) to long-term transplantation (lKTx). We applied flow cytometry to determine total, CD4⁺, CD8⁺, CD28^- T-lymphocytes, Natural killer cells (NK) and regulatory T-lymphocytes (Tregs), in peripheral blood of 56 patients with CKD-V, 207 patients on hemodialysis (HD), 149 recently transplanted (rKTx), 26 lKTx patients and 49 healthy volunteers as a control group (CG). Lymphocyte proportion decreased in CKD vs. CG [20.2 (14.4-25.8) vs. 29.7 (24.4-38.1)%, p < 0.001] without further deterioration in HD [19.9 (15.3-23.7)%, p = 0.83 vs. CKD-V] and increased in rKTx [24.7 (20-32.6)%, p < 0.001 vs. HD], and lKTx [25.5 (21.9-35)%, p = 0.16 vs. CG]. Similar kinetics were observed in CD4⁺ subpopulations, however CD8⁺ T-cells gradually increased from CG to lKTx. NK remained stable in CKD-V and HD, reduced in rKTx, and marginally increased in lKTx. Tregs gradually declined until HD and suboptimally improved with transplantation. CD28^- subpopulations largely increased in lKTx, compared with HD [CD4⁺CD28^-: 12.6 (4.7-27.6) vs. 6 (2.1-13.2)%, p = 0.006, CD8⁺CD28^-: 68.4 (54.4-90.3) vs. 45.5 (28.4-58.9)%, p < 0.001], independently of age for CD8⁺CD28^- (p = 0.33). Cellular immunity subpopulations show significant changes in the spectrum of CKD, with transplantation restoring total lymphocytes and CD4⁺ T-cells, but not Tregs and NK. LKTx was associated with a large increase in CD28^- subpopulations.