INTERLEUKIN-6 PREDICTS HYPOALBUMINEMIA, HYPOCHOLESTEROLEMIA, AND MORTALITY IN HEMODIALYSIS-PATIENTS

Low serum albumin and low serum cholesterol levels are among the most consistent predictors of mortality in patients with end-stage renal di sease (ESRD) undergoing hemodialysis. Hypoalbuminemia is often interpr eted as a marker of poor nutrition, but serum albumin and cholesterol levels can also be low as part of a cytokine-mediated acute-phase reac tion to acute or chronic inflammation. Here we report the results from a 900-day prospective study designed to determine whether tumor necro sis factor-alfa (TNF-alpha) and interleukin-l (IL-6) predict serum alb umin and cholesterol levels and mortality in a group of 90 ambulatory, adult hemodialysis patients with no acute infection, hospitalization or surgery, and no known acquired immunodeficiency syndrome (AIDS), ma lignancy, or liver disease. Measurable levels of TNF-alpha and/or IL-6 were found in 89 of 90 patients. Significant relationships were found between TNF-alpha and IL-6 and the degree of hypoalbuminemia and dysl ipoproteinemia. IL-6 was the strongest predictor of mortality in univa riate and multivariate analysis, followed by age, albumin level, and b ody mass index (BMI). Although the cause of hypercytokinemia was not a ddressed in this study, the data support the view that hypoalbuminemia and hypocholesterolemia are negative acute-phase responses to inflamm atory stimuli. These results suggest that efforts to identify the natu re of the stimuli for cytokine production and to lower cytokine levels in hemodialysis patients might be effective in improving the survival of patients undergoing hemodialysis. (C) 1998 by the National Kidney Foundation, Inc.