Hemodiafiltration May Be Associated with Senescence-Related Phenotypic Alterations of Lymphocytes, Which May Predict Mortality in Patients Undergoing Dialysis

Senescence-resembling alterations on the lymphocytes of patients undergoing dialysis have been widely described. However, the pathophysiology behind these phenomena has not been clarified. In this study, we examined the impact of dialysis prescription on T and B lymphocytes, in patients undergoing dialysis.: T and B cell subsets were determined with flow cytometry in 36 patients undergoing hemodialysis and 26 patients undergoing hemodiafiltration, according to the expression of CD45RA, CCR7, CD31, CD28, CD57, and PD1 for T cells, and IgD and CD27 for B cells. The immune phenotype was associated with dialysis modality, hemofiltration volume, and mortality. Compared with hemodialysis, patients undergoing hemodiafiltration had a significantly decreased percentage of CD4+CD28-CD57- T cells [3.8 (2.4-5.3) vs. 2.1 (1.3-3.3)%, respectively, <i>p</i> = 0.002] and exhausted CD4+ T cells [14.1 (8.9-19.4) vs. 8.5 (6.8-11.7)%, respectively, <i>p</i> = 0.005]. Additionally, the hemofiltration volume was negatively correlated with CD8+ EMRA T cells (r = -0.46, <i>p</i> = 0.03). Finally, the increased exhausted CD4+ T cell percentage was associated with increased all-cause mortality in patients undergoing dialysis, independent of age. Hemodiafiltration, especially with high hemofiltration volume, may have beneficial effects on senescence-related immune phenotypes. Immune phenotypes may also be a predicting factor for mortality in patients undergoing dialysis.