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.