Effect of parathyroid hormone on cellular immunity in uremic patients undergoing peritoneal dialysis

Abstract

Objective The clinical relevance of altered lymphocyte function and its possible relation with uremic toxins such as parathyroid hormone (PTH) is not well understood. We studied the changes in cellular immunity in patients on continuous ambulatory peritoneal dialysis therapy and examined the relationship between T-lymphocyte function and plasma levels of PTH. Patients and Methods Thirty-seven patients (16 male, 21 female) were enrolled in the study. The patients were divided into 2 groups: 22 patients with increased levels of PTH and 15 patients with normal levels of PTH. Lymphocyte subsets (CD2+, CD3+, CD3+/4+, CD3+/8+, CD19+, CD3−/16+56+, CD4/CD8 ratio) were quantitated in both groups using monoclonal antibodies and flow cytometric analysis. Analysis of variance testing was performed to analyze differences between the groups. Results A significant increase in CD3 was observed in patients with increased levels of PTH (71.6±7.9 vs. 57.5±28.1, p<.05). CD3/8 population was also increased in patients with elevated PTH (26.96±8.01 vs. 20.8±13.78, p=NS). CD4/CD8 ratios were lower in patients with elevated PTH than in those who had normal PTH (1.67±0.78 vs. 3.03±2.54, p<.05). No specific differences were observed between these 2 patient groups in CD19 and natural killer cells. Conclusions Elevated PTH seems to affect lymphocyte function and is associated with changes in cellular immunity in a peritoneal dialysis population. Our study is continuing in order to enlarge the study population and collect more data, which will lead to more solid conclusions.