P0312ALTERATIONS IN THE PROGRESS OF LYMPHOCYTE APOPTOSIS IN PRE- AND POST- DIALYSIS END STAGE RENAL DISEASE PATIENTS

Abstract Background and Aims Lymphocyte apoptosis, as a programmed mechanism of lymphocyte death, is essential in maintaining homeostasis and balance between inflammatory and immune reactions. Disturbances in the apoptotic progress, leading to fragmented lymphocytes, “late apoptotic” cells, may result in immunodeficiency, oncogenesis, atheromatosis, etc. Aim of the present study was to investigate the lymphocyte apoptotic progress in End Stage Renal Disease (ESRD) and the effect of dialysis. Method The study included patients on ESRD; measurements were performed at the first day of dialysis (T0) and repeated 6 months later (T6), while being on dialysis. Total lymphocytes and B lymphocytes (CD19+) were gated and stained with Annexin V to detect apoptotic cells; early and late apoptotic cells were quantified. The results were compared to age-matched healthy control group. Results ESRD patients had reduced lymphocyte and B cell count, 1550±592μ/L vs. 2692±690μ/L, p<0.001 and 120.4±80μ/L vs. 321.7±184.7μ/L, p=0.002, respectively, compared to controls. There was an increase in total lymphocytes and B cells, being on later apoptotic stages (LAS) in ESRD-T0 compared to controls, 0.3±0.8% vs. 0.06±0.1%, and 0.04±0.08% vs. 0.01±0.03%, respectively, although differences did not reach statistical significance. After 6 months on dialysis, a reduction was noticed in the population of lymphocytes on LAS, 0.18±0.2% from 0.34±0.8%, while there was an increase of B cells on LAS, 0.1±0.2% from 0.02±0.07, with subsequent alterations in total numbers of apoptotic cells were also evident Conclusion Late apoptotic changes affecting total and particularly B lymphocytes happen in ESRD, and initiation of dialysis seem to cause further alterations, which may be implicated in the increased morbidity and mortality of disease