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Background: End-stage renal disease patients (ESRD) on maintenance hemodialysis (HD) are at increased risk of acquiring hepatitis C virus (HCV) infection. An early and accurate diagnosis of HCV infection is important for the prevention of viral transmission and the management of ESRD patients on HD but conventional ELISA and PCR have often failed to reveal active HCV infection. Objectives: This study evaluated the prevalence of HCV infection in ESRD patients from all HD units in central Greece using a sensitive HCV-RNA transcription mediated amplification (TMA) assay and compared its sensitivity with that of anti-HCV ELISA. Study design: Anti-HCV antibody (third generation ELISA), HCV-RNA (TMA) and HCV genotypes (HCV TMA-LiPA) were determined in 366 ESRD Greek patients. Results: In total, 132 (36%) ESRD patients were HCV positive by ELISA or TMA; 44 by TMA alone, 16 by ELISA alone and 72 positive by both assays. More than half of the viraemic patients had genotype 3a. Conclusions: HCV-RNA (TMA) assay appears to increase the accuracy in the diagnosis of HCV infection in HD patients compared to the anti-HCV ELISA and could serve as an additional screening tool in these patients.

Background/Aims: Insulin resistance is a well-known phenomenon in uremia. Resistin, a recently discovered insulin inhibitor secreted by adipocytes, is associated with obesity and insulin resistance in mice. Adiponectin, also secreted by adipocytes, is known to reduce insulin resistance in humans. The aim of the present study was to address the hypothesis that changes in resistin or adiponectin serum levels may relate to body composition and to insulin resistance in patients with end-stage renal disease. Methods: In a cross-sectional study, 33 non-diabetic patients (24 males and 9 females, mean age 61.5 ± 15.8 years) with end-stage renal disease on chronic hemodialysis (treatment duration 41 ± 31 months) that lacked signs of infection were enrolled. The control group consisted of 33, matched for age, sex and body mass index (BMI), healthy volunteers (22 males, 11 females, mean age 62.6 ± 12.1 years). BMI (kg/m2) was calculated from body weight and height. Body fat (%) was measured by means of bioelectrical impedance. Blood samples were taken always in the morning after a 12-hour fasting period before and after the hemodialysis session. Resistin and adiponectin serum concentrations were measured by enzyme immunoassays and insulin by an electrochemiluminescence immunoassay. The post-treatment values were corrected regarding the hemoconcentration. The homeostasis model assessment index (HOMA-R) was calculated as an estimate of insulin resistance from the fasting glucose and insulin serum levels. Results: Pre-treatment resistin serum levels were significantly increased in hemodialysis patients compared to healthy controls (19.2 ± 6.2 vs. 3.9 ± 1.8 ng/ml; p < 0.001). Hemodialysis did not alter resistin levels, as pre- and post-treatment levels were not different when corrected for hemoconcentration (19.2 ± 6.2 vs. 18.7 ± 5.0 ng/ml; p = 0.54). Adiponectin levels were also increased in hemodialysis patients compared to healthy controls (25.4 ± 21.5 vs. 10.5 ± 5.9 µg/ml; p < 0.001). A significant inverse correlation was observed between the serum adiponectin levels before the hemodialysis session on the one hand and the BMI (r = –0.527, p = 0.002), the HOMA-R (r = –0.378, p < 0.05) and the fasting insulin levels (r = –0.397, p < 0.05) on the other. However, no significant correlation was observed between serum resistin levels on the one hand versus HOMA-R index (3.2 ± 3.9 mmol·µIU/ml; r = –0.098, p = 0.59), insulin levels (13.3 ± 14.4 mU/l; r = –0.073, p = 0.69), glucose levels (89 ± 13 mg/dl; r = –0.049, p = 0.78), BMI (25.6 ± 3.7 kg/m2; r = –0.041, p = 0.82) and body fat content (26.4 ± 8.4%; r = –0.018, p = 0.94) on the other hand. Conclusion: Resistin serum levels are significantly elevated in non-diabetic patients with end-stage renal disease that are treated by hemodialysis. The hemodialysis procedure does not affect the resistin levels. Along with previous observations in patients with renal insufficiency in the pre-dialysis stage, our findings implicate an important role of the kidney in resistin elimination. However, increased resistin serum levels in hemodialysis patients are not related to reduced insulin sensitivity encountered in uremia.