Serum Amyloid-A Rather Than C-Reactive Protein Is a Better Predictor of Mortality in Hemodialysis Patients

Abstract

The most frequent cause of death in hemodialysis patients is cardiovascular disease with chronic inflammation being an epidemiologically proved risk factor. Many studies have shown C-reactive protein (CRP) as the strongest predictor of long-term mortality of hemodialysis patients, while other reports have indicated acute phase proteins as potential predictors of the mortality. The present study therefore aimed to evaluate the prevalence of chronic inflammation in hemodialysis patients and the role of acute phase proteins together with lipids and divalent ions for predicting mortality in hemodialysis patients. Chronic inflammation was defined, based on the serum level of high sensitive CRIP > 8.4 mg/L and/or serum amyloid-A (SAA) > 8.9 mg/L. Acute phase proteins are defined as one whose plasma concentration increase (positive) or decreases (negative) by at least 25% during inflammation. High sensitive CRIP and SAA were positive acute phase proteins measured, while albumin and fetuin-A, a calcification inhibitor, were selected as negative acute phase proteins. This prospective 36-month follow-up study included 130 patients (60 males and 70 females, aged 55.1 +/- 12.9 years) maintained by hemodialysis for 107.2 +/- 54.72 months at a Nephrology Clinic in Belgrade. The prevalence of chronic inflammation was 35.4% (46 patients). During the follow-up period, 24 patients (18.5%) died and 2 patients received transplants. In multivariate analysis, potential independent predictors of mortality in hemodialysis patients are hyperphosphatemia, hypoalbuminemia, and high SAA. Considering that assays for SAA are widely used, we propose that SAA is the best predictor for outcomes of end-stage renal disease.