DIABETIC NEPHROPATHY AS AN ADDITIONAL FACTOR CAUSES DISTURBANCES IN T CELL IMMUNITY IN CHRONIC KIDNEY DISEASE PATIENTS

Abstract Background and Aims Chronic kidney disease (CKD) and Diabetes Mellitus (DM), are chronic inflammatory conditions, and may both affect T-cell immunity. However, our knowledge about alterations of specific T cell subpopulations, as well as the further modifications occurring after dialysis initiation, is limited. The present study aimed to investigate the changes of T lymphocyte subtypes in CKD patients due to Diabetic Nephropathy (DN-CKD) and compare to nonDN-CKD patients. Furthermore, the effect of dialysis, was also estimated in both groups. Method In 30 DN-CKD, 30 nonDN-CKD patients and 25 healthy individuals, cytometric analysis of T cell subpopulations was performed, including CD4+, CD8+, CD4+CD28null, CD8+CD28null, Natural Killer cells and Tregs. Measurements were performed at the day started (T0) on either hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD) and repeated six months later (T6). Results At time T0, CD4+, NK cells and Tregs were significantly reduced (p=0.001, p=0.01, p<0.0001, respectively), while CD28null cells were increased (p=0.005) in CKD patients compared to controls. CD4CD28null and CD8CD28null (%) cells were increased in DN-CKD compared to nonDN-CKD (p=0.03, p=0.02, respectively). At time T6, a significant increase in total CD28null cells were noticed in DN patients (p=0.05) but not in nonDN patients. More interestingly, DN-CKD patients who started on HD showed a significant increase in CD4CD28null cells [from 30(14-100) to 52.7(15-203), p=0.02], CD8CD28null cells [from 130(47-400) to 212(25-1192), p=0.02] and NK cells [from 137(56-275) to 266(103-456), p=0.01], while those DN-CKD started on CAPD showed a significant reduction in the percentage of CD4CD28null cells [from 9.8(2.9-19.8) to 6.9(1.3-+18), p=0.05]. Conclusion Patients with CKD due to DN are more likely to have impaired T cell immunity, mainly regarding CD28null cells, which further deteriorates after initiation of HD. Instead, CAPD method seems to ameliorate those changes.