Abstract 13939: Anti-1-Adrenergic Receptor Autoantibody is an Independent Predictor of All Cause Mortality in Dialysis Patients

Abstract

Background: Recently, it was reported that haemodialysis patients have autoantibodies specific for β1-adrenergic receptor (β1-AR). We examined clinical significance of anti-β1-AR autoantibodies in dialysis patients.

METHODS: We prospectively enrolled 301 patients (males 59.5% and mean age 66.5 years), who started dialysis therapy at our department between February 2005 and December 2011. Mean estimated glomerular filtration rate (eGFR) was 5.4 mL/min/1.73m². Circulating anti-β1-AR autoantibodies were detected in 119 patients (39.5%) by ELISA. Relationships between autoantibodies and end point (all-cause death) were measured using Kaplan-Meier analysis and Cox models for case-mix and laboratory variables.

RESULTS: Among 296 patients (5 patients selecting kidney transplantation were excluded), a median follow-up period was 2.5 years (IQR 1.1-4.0), 37.0% had diabetes mellitus (DM), mean left ventricular ejection fraction (EF) was 62.0% and 130 patients (43.2%) were administered β-blockers. During a follow-up period, 69 patients (23.2%) died. The most major cause of death (33.3%) was cardiovascular disease (CVD). The value of anti-β1-AR autoantibodies was not correlated with EF (r<0.001, P=0.996). Kaplan-Meier analysis revealed that autoantibody-positive patients more frequently reached the end point than autoantibody-negative patients (Log-rank P=0.011) and all-cause mortality was significantly decreased in patients treated with β-blockers compared to those without (Log-rank P=0.034). However, response to β-blocker therapy differed significantly in the presence or absence of autoantibodies (P=0.032 or P=0.353, respectively). After adjustment for age, gender, DM, systolic/diastolic blood pressure, EF, eGFR, Hb, Alb, history of CVD and use of β-blockers, multivariable Cox regression analysis identified the value of anti-β1-AR antibodies as an independent predictor of all-cause mortality in dialysis patients (adjusted hazard ratio 1.241 [95%CI, 1.001-1.539], P=0.049).

CONCLUSIONS: These results suggest that anti-β1-AR autoantibodies is an independent predictor of mortality in dialysis patients. Our data suggest that β-blocker therapy might be more effective in dialysis patients with anti-β1-AR autoantibodies.