Objective: The clinical relevance of altered lymphocyte function and the possible relation with uremic toxins, such as parathyroid hormone (PTH) is not well understood. We studied the changes in cellular immunity in patients in hemodialysis (HD) therapy and examined the relationship between T-lymphocyte function and plasma levels of PTH.
Patients and methods: Thirty-four patients (14 male) were enrolled in this study (mean age: 63.20 +/- 10.01 years, M +/- SD, 12 h/week HD). Our study population was divided into two groups: 18 patients with increased levels of PTH and 16 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 (Immunotech, Coulter) and flow cytometric analysis. Following analysis of variance (ANOVA) testing was performed to test differences between groups (SPSS version 10).
Results: A significant increase of CD2 was noticed in patients with increased levels of PTH (84.8 +/- 5.5 vs. 79.8 +/- 4, p<0.05). The CD3 population was also increased in patients with elevated PTH (72 +/- 8.6 vs. 68 +/- 9.2, p=NS). This group of patients had also significantly increased levels of CD3/8 (44.8 +/- 9.8 vs. 37.1 +/- 5.8, p<0.05). The CD4/CD8 ratio levels were higher in patients with elevated PTH compared with those who had normal PTH (2.2 +/- 1.5 vs. 1.5 +/- 0.8, p=NS).
Conclusions: The elevated level of PTH seems to affect the lymphocyte function and is associated with changes in cellular immunity in the hemodialysis population. Our study is in progress in order to enlarge our study population and collect more data, which will lead us to more solid conclusions.