Association of the Charlson Comorbidity Index with Renal Outcome and All-Cause Mortality in Antineutrophil Cytoplasmatic Antibody-Associated Vasculitis

The aim of this study is to determine the effect of comorbidity assessed by the Charlson comorbidity index (CCI) at the time of diagnosis on the outcome of antineutrophil cytoplasmatic antibody (ANCA) associated vasculitis (AAV). This is a longitudinal observational study of 30 consecutive patients with AAV who were diagnosed and followed from January 1996 to December 2011. The degree of comorbidity at diagnosis and last visit was scored according to the age-adjusted Charlson comorbidity index (CCI (a)). The post hoc analysis of increment in CCI during the study period and its predictive value for patient and renal survival were analyzed. Thirty patients with AAV were included in this study. A higher CCI (a) at diagnosis was positively correlated with higher activity score of AAV (P = 0.016), a CCI (a) >5, and with an increased risk for mortality (odds ratio 12; confidence interval 1.8–79.68, P = 0.014). The mean increment (Δ) of CCI (a) during the study period was 1.26 ± 2.03 (6–5). Correlation was found between lower Δ CCI (a) and chronic kidney disease (P = 0.036) and mortality (P = 0.002). Comorbidity at the time of diagnosis of AAV is associated with reduced patient and renal survival. We suggest including the CCI score in the assessment of patients with AAV at diagnosis and at disease relapse.