Background. Despite the well known association between interleukin-6 (IL-6) and cardiovascular mortality, no study has so far verified whether IL-6 adds prognostic information to that provided by C-reactive protein (CRP). Methods. A cohort of 218 haemodialysis patients from four different dialytic centres was followed-up retrospectively. Plasma IL-6 and CRP concentrations were determined. Full information on co-morbidities was available in 162 patients. Results. With respect to the lowest quartile (< 3.6 pg/ml for IL-6, and < 2.2 mg/l for CRP), the crude relative risk (RR) of death from all causes of the upper quartile (> 13.9 pg/ml for IL-6, and > 12.8 mg/l for CRP) was 5.20 (95% confidence interval 2.06–13.011) for IL-6 and 3.16 (1.41–7.12) for CRP. When both variables were included, the estimates were 4.10 (1.30–12.96) for IL-6 and 1.29 (0.47–3.57) for CRP. As to continuous variables, the relationship between both variables and mortality tended to level off for the highest values, but became fairly linear after log transformation of the variables. For one unit SD of the log (variable), the RR was 2.09 (1.52–2.88) for IL-6 and 1.66 (1.23–2.24) for CRP. When they were included in the same model, the estimates were 1.90 (1.18–2.82) for IL-6 and 1.16 (0.81–1.66) for CRP. Conclusions. IL-6 has a stronger predictive value than CRP for cardiovascular mortality and provides independent prognostic information, while conveying most of that provided by CRP.

Background. Resistance to erythropoiesis-stimulating agents (ESAs) is often associated with chronic inflammation. Here, we investigated how anaemia, ESA resistance and the plasma levels of biological markers of inflammation could influence all-cause and cardiovascular disease morbidity and mortality. Methods. Seven hundred and fifty-three haemodialysis (HD) patients (mean age 66 ± 14.2 years, mean dialytic age 70 ± 77 months and diabetes 18.8%) were enrolled and followed-up for 36 months. Demographic, clinical and laboratory data, co-morbidity conditions, administered drugs, all-cause mortality and fatal/non-fatal cardiovascular (CV) events were recorded. We measured ESA resistance index, C-reactive protein (CRP) and interleukin-6 (IL-6). Results. Six hundred and fifty-one patients (86.4%) received ESAs. Patients with haemoglobin level 11 g/dL. ESA resistance values categorized into quartiles (Quartile I 15.4) correlated with all-cause mortality and fatal/non-fatal CV events (RR 1.97, 95% CI 1.392–2.786; RR 1.619, 95% CI 1.123–2.332, respectively). Furthermore, albumin was significantly reduced versus reference patients and correlated with all-cause mortality and CV events; CRP levels were higher in hyporesponders (Quartile IV) (P < 0.001) and predicted all-cause mortality and CV events. IL-6 but not CRP was a strong predictor of ESA resistance. Conclusions. ESA responsiveness can be considered a strong prognostic factor in HD patients and seems to be tightly related to protein-energy wasting and inflammation.

Base-line serum levels of plasma C-reactive protein (CRP) are predictive of future myocardial infarction and sudden cardiac death in apparently healthy subjects, suggesting the hypothesis that chro...

Reactive oxygen species have been implicated in the pathophysiology of renal ischemia reperfusion injury. Antioxidants including polyphenolics have been found to protect renal cells from the cellular injury induced by ischemia and reperfusion. Resveratrol, a stilbene polyphenol found in grapes and red wine, has recently been found to protect isolated rat heart from ischemia reperfusion injury. This study was sought to determine if resveratrol could also protect renal cells from ischemic injury. Male Wistar rats were treated with control, resveratrol (0.23 μg/kg), vehicle used to solubilize resveratrol, and resveratrol plus L-NAME (15 mg/kg body wt), a nitric oxide blocker. Our results demonstrated that resveratrol administration reduced the mortality of ischemic rats from 50% to 10% and renal damage was reduced as indicated by histologic examination and serum creatinine level. The short-term administration of resveratrol also inhibited renal lipid peroxidation induced by ischemia and reperfusion both in cortex and in medulla. Electron paramagnetic resonance detected an increased formation of nitric oxide in the resveratrol-treated kidney that was reduced to the baseline value after treating the rats with L-NAME in addition to resveratrol. The results suggest that resveratrol reduced the renal ischemia reperfusion injury through a nitric oxide-dependent mechanism.

Background: Several studies have provided convincing evidence that in apparently healthy subjects elevated serum levels of plasma C-reactive protein (CRP) are associated with an increased risk of experiencing myocardial infarction and sudden cardiac death. It has been claimed that, in dialytic patients, the hepatic synthesis of this ‘acute phase response’ plasma protein is primarily induced by the macrophage-derived interleukin 6 (IL-6). Little information is available, however, regarding CRP and IL-6 plasma levels in pre-dialytic renal failure. Methods: Plasma CRP by a modification of the laser nephelometry technique, IL-6 and serum albumin were determined in 103 chronic pre-dialytic patients (mean age 50 ± 6.3 years; creatinine clearance (Cr.cl.) 36.3 ± 23.1 ml/min). Results: CRP was >5 mg/l (normal upper range) in 42% of the global population. CRP and IL-6 were significantly related (r = 0.35, p < 0.0004). CRP and IL-6 were related to renal function (CRP vs. Cr.cl., r = –0.56, p < 0.0001; IL-6 vs. Cr.cl., r = –0.55, p < 0.0001, Spearman correlation coefficient). When patients were divided in tertiles according to renal function, CRP median value resulted 7.9 mg/l (interquartile interval: 5–12) in the first tertile (Cr.cl. 45 ml/min) (p < 0.0001). A negative correlation between CRP and S-albumin was also found (r = –0.52, p < 0.0001, Spearman correlation coefficient). Conclusions: IL-6 and CRP were increased and were inversely related to creatinine clearance in our population of 103 chronic predialytic patients. The possibility of a decreased renal clearance of CRP and/or cytokines as a cause of an activated acute-phase response is discussed. A negative correlation between CRP and S-albumin was found confirming the link between chronic inflammation and malnutrition in chronic renal patients.