Alcoholic Liver Disease/Nonalcoholic Fatty Liver Disease Index at Diagnosis Is Associated with All-Cause Mortality during Follow-Up in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

Background and Objectives: The purpose of this study was to investigate whether a new index related to chronic liver disease, the alcoholic liver disease/nonalcoholic fatty liver disease index (ANI) at diagnosis, is associated with all-cause mortality during follow-up in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Materials and Methods: In this study, we included 270 patients with AAV. ANI was calculated using the following equation: ANI = −58.5 + 0.637 (adjusted mean corpuscular volume) + 3.91 (adjusted aspartate transaminase/alanine transaminase) − 0.406 (body mass index) + 6.35 (if male sex). All-cause mortality was defined as death from any cause during follow-up. Results: The median age of the 270 patients with AAV was 61.0 years (34.4% male and 66.6% female). The median ANI was significantly higher in deceased patients than in surviving patients. In the receiver operating characteristic curve analysis, ANI at diagnosis exhibited a statistically significant area under the curve for all-cause mortality during follow-up, and its cut-off was determined to be −0.59. Patients with ANI at diagnosis ≥ −0.59 exhibited a significantly higher risk for all-cause mortality and a significantly lower cumulative patient survival rate than those without. In the multivariable Cox analysis, ANI at diagnosis ≥ −0.59, together with age at diagnosis, was independently associated with all-cause mortality. Conclusions: This study is the first to demonstrate the predictive potential of ANI at diagnosis for all-cause mortality during follow-up in AAV patients without significant chronic liver diseases.