Effects of interleukin-6 T15A single nucleotide polymorphism on baseline peritoneal solute transport rate in incident peritoneal dialysis patients

Abstract

◆ Objective: To study the genetic effects of various inflammatory cytokines on peritoneal solute transport rate (PSTR) in incident Korean peritoneal dialysis (PD) patients. ◆ Design: Case-control association study. ◆ Methods: 132 patients with baseline peritoneal equilibration test within 1 - 3 months after starting PD were enrolled. We analyzed the influence of single nucleotide polymorphisms (SNPs) of interleukin-6 (IL-6; -572G/C, T15A), tumor necrosis factor-alpha (TNF-α; -1031C/ T, -863C/A, -308G/A), and IL-10 (-1082A/G, -592A/C) on baseline PSTR. Clinical parameters such as age, gender, presence of diabetes mellitus, comorbidity, C-reactive protein, and residual renal function were also included as covariates. ◆ Results: The T15A SNP of IL-6 (rs13306435) was associated with PSTR. Patients with TA genotype (n = 18) had significantly lower D4/P creatinine (0.65 ± 0.087 vs 0.73 ± 0.110, p = 0.0046) and higher D4/D0 glucose (0.39 ± 0.174 vs 0.31 ± 0.119, p = 0.027) than patients with TT genotype (n = 114). The Log value of the dialysate appearance rate of IL-6 had a strong positive correlation with D4/P creatinine (r2= 0.1294, p < 0.0001) and was significantly lower in the TA genotype than the TT genotype (201.7 ± 14.42 vs 116.8 ± 88.91 pg/minute, p = 0.0358). By multiple Logistic regression, TA genotype was negatively associated with a higher PSTR (high or high average; odds ratio 0.18; 95% confidence interval 0.048 - 0.666). Conclusions: In incident Korean PD patients, T15A polymorphism of IL-6 is associated with dialysate IL-6 concentration and baseline PSTR. Copyright © 2009 International Society for Peritoneal Dialysis.