Lymphocyte subsets in the course of continuous ambulatory peritoneal dialysis

The present study evaluated whether estimation of lymphocyte subset counts can be more helpful than total lymphocyte count (TLC) in earlier diagnosis of immune and nutritional changes in the course of continuous ambulatory peritoneal dialysis (CAPD). For the study, 50 CAPD patients were divided into four groups depending on dialysis duration. Group I consisted of patients treated for 6-12 months (n = 15); group II, for 13-24 months (n = 16); group III, for 25-36 months (n = 12); and group IV, for more than 36 months (n = 7). Thirteen patients, being 8 +/- 7 days before CAPD initiation, were included in group 0. Flow cytometry was used for estimation of lymphocyte subsets (determination of CD3, CD4, CD8, CD19, and CD16 + 56 antigens). Our uremic patients started CAPD therapy with decreased TLC and lymphocyte subset (excluding CD16 + 56) counts. After 6-12 months of CAPD therapy, a significant increase in TLC, CD4:CD8 ratio, and all examined lymphocyte subset counts was observed. In the next years of CAPD therapy, TLC, CD3, CD4, CD8, and CD19 cell counts decreased. In patients on CAPD for more than 36 months, CD3, CD4, CD8, and CD19 cell counts were below the normal range, but mean TLC was maintained in the normal range, and CD16 + 56 exceeded the upper limit of normal. A significant negative correlation between CD19 cell count and dialysis duration was seen (r = -0.298, p = 0.035, n = 50). In conclusion, the first months of CAPD therapy see an improvement in immune and nutritional status as expressed by an increase in TLC, lymphocyte subset counts, and CD4:CD8 ratio. Repeat determinations of CD3, CD4, CD8, and CD19 cell counts indicate that these counts decrease earlier than an evaluation of TLC indicates. We recommend lymphocyte subset determinations for detection of immune and nutritional abnormalities in the course of CAPD treatment. An increase in natural killer cells above the normal range may reflect chronic sterile or infectious inflammatory response, which deteriorates nutritional status.