Volume 67, Issue 6, Pages 2477-2487 (June 2005) Genetic and clinical factors influence the baseline permeability of the peritoneal membrane  Gaalle Gillerot, Eric Goffin, Catherine Michel, Pieter Evenepoel, W.I.M.V.A.N. Biesen, Michel Tintillier, Peter Stenvinkel, Olof Heimbarger, Bengt Lindholm, Louise Nordfors, Annie Robert, Olivier Devuyst  Kidney International  Volume 67, Issue 6, Pages 2477-2487 (June 2005) DOI: 10.1111/j.1523-1755.2005.00357.x Copyright © 2005 International Society of Nephrology Terms and Conditions

Figure 1 Relationship between the comorbidity grade (A) and serum albumin concentration (B) and the mass transfer area coefficient for creatinine (MTACcreat) in the 152 PD patients. (A) The comorbidity grade exerts a significant influence the MTACcreat (high grade: 13.4 ± 0.6 mL/min/1.73m2; medium grade: 12.9 ± 0.6 mL/min/1.73m2; low grade: 10.7 ± 0.4 mL/min/1.73m2, ANOVA, P = 0.003). (B) Correlation between serum albumin level and MTACcreat. Kidney International 2005 67, 2477-2487DOI: (10.1111/j.1523-1755.2005.00357.x) Copyright © 2005 International Society of Nephrology Terms and Conditions

Figure 2 Effect of the -174G/C polymorphism of IL-6 on the expression of IL-6 mRNA in the peritoneum: quantitative real-time RT-PCR analysis. (A) Standard curves of amplification for IL-6 and GAPDH in peritoneum samples: the slopes (mean of 3 independent experiments) were obtained by linear regression, and they were similar for GAPDH (-3.46 ± 0.06) and IL-6 (-3.41 ± 0.06). The threshold cycle (Ct) is the number of cycles at which the fluorescence signal reached a fixed threshold above baseline. (B) Representative real-time RT-PCR tracings of IL-6 versus GAPDH in the peritoneum of PD patients harboring either the -174CC or the -174GG variant of IL-6. The duplicate curves are shown. The threshold levels in this tracing were 26.3 (GAPDH), 33.8 (-174CC IL-6), and 35.8 (-174GG IL-6). (C) Quantification of the mRNA expression of IL-6 in the peritoneum of four PD patients harboring either the -174CC (black bar) or the -174GG (gray bar) genotype (copies of IL-6 normalized to copies of GAPDH: 4.07 ± 1.9 × 10−3 vs. 0.6 ± 0.3 × 10−3, P = 0.03). Kidney International 2005 67, 2477-2487DOI: (10.1111/j.1523-1755.2005.00357.x) Copyright © 2005 International Society of Nephrology Terms and Conditions

Figure 3 Influence of the -174G/C polymorphism of IL-6 on the concentrations of IL-6 in the dialysate (A) and plasma (B). The ELISA was performed in duplicate in the 56 PD patients for whom frozen plasma and dialysate samples obtained at the time of the first PET were available. The plasma and dialysate IL-6 concentrations were significantly higher in patients harboring the CC and GC genotypes compared with the GG genotype [plasma IL-6 (geometric means 95% CI): 6.75 (4.07–10.96) and 5.5 (3.72–7.94) vs. 2.58 (1.82–3.55) respectively, ANOVA, P = 0.002][dialysate IL-6 (geometric means 95% CI): 86.81 (40.74–181.97) and 97.95 (51.29–181.97) vs. 29.83 (20.89–40.74) respectively, P = 0.003]. Kidney International 2005 67, 2477-2487DOI: (10.1111/j.1523-1755.2005.00357.x) Copyright © 2005 International Society of Nephrology Terms and Conditions

Figure 4 Influence of the -174G/C polymorphism of IL-6 on the mass transfer area coefficient for creatinine (MTACcreat) in the 152 PD patients. The MTACcreat was significantly lower among patients harboring the CC and GC genotypes than in patients with the GG genotype (12.9 ± 0.8 and 12.8 ± 0.5 vs. 10.7 ± 0.4 mL/min/1.73m2, ANOVA, P = 0.006). Kidney International 2005 67, 2477-2487DOI: (10.1111/j.1523-1755.2005.00357.x) Copyright © 2005 International Society of Nephrology Terms and Conditions

Figure 5 Hypothetical framework for the effect of the -174G/C polymorphism of the promoter of IL-6 on the transport of small solutes across the peritoneal membrane in patients on peritoneal dialysis. For details see text. Kidney International 2005 67, 2477-2487DOI: (10.1111/j.1523-1755.2005.00357.x) Copyright © 2005 International Society of Nephrology Terms and Conditions