Analysis of peritoneal leukocyte population with different dialysis fluids

Uremic patients have leukocyte defects. In peritoneal dialysis patients some alterations could be induced by dialysis fluids. We analyzed the changes in immune cells (blood and peritoneal effluent), with the use of three solutions with different biocompatibility. We included 21 patients, 9 on 1 exchange/day icodextrin and 12 with lactate-buffered solutions. A cytometric study (cell subsets, activation markers and toll-like receptors) was performed. In 12 it was repeated after 3 months switch to a low-glucose degradation product (GDP) fluid. With lactate fluids, we observed B-lymphopenia, increase of T-cells and T-lymphocyte activation. In peritoneal effluent more monocytes and activation markers related to blood were found with conventional fluids. Icodextrin induced an increase of blood natural-killer cells, B-lymphocytes and CD8+CD38+ compared with lactate-buffered solution. In peritoneum more monocytes and less B-lymphocytes were found with icodextrin compared with biocompatible solution. Low-GDP fluid induced a decrease in lymphocyte activation markers (blood and effluent). The most biocompatible solution (low-GDP) induced the lowest expression of peritoneal monocytes and TLR4. Low-GDP solutions preserve peritoneum immune defences better, which could be important to avoid peritonitis and preserve peritoneal function. Although we found an association between TLR4 expression and biocompatibility, further investigations are needed in order to determine if such molecule could be a marker of peritoneum dysfunction.