Clinical features and outcomes of anti-neutrophil cytoplasmic autoantibody-associated vasculitis in Chinese elderly and very elderly patients.

PURPOSE Anti-neutrophil cytoplasmic autoantibody-associated vasculitis (AAV) is predominantly a disease of the elderly, and the incidence increases with age. However, there are few data focusing on the clinical features in elderly onset AAV, especially in very elderly onset AAV in China. The aim of this study was to explore whether elderly onset AAV shows any specific clinical features and outcomes in Chinese patients. METHODS We performed a retrospective study in Xiangya Hospital, a mixed tertiary medical center in south China. A total of 177 patients presenting with AAV were included between January 1, 2010 and December 31, 2017. Patients were divided into younger group (age < 65 years) and older group (age ≥ 65 years) which was sub-divided into elderly group (age 65-74 years) and very elderly group (age ≥ 75 years). And their medical records were analyzed by retrospective review. RESULTS We found patients in the very elderly group had more chest and cardiovascular involvement (P = 0.033 and P = 0.017). Older AAV patients had less renal involvement and lower serum C4 level (P = 0.013 and P = 0.003). Very elderly AAV patients had lower platelet counts. Patients in the younger group had a higher level of BVAS among three groups (P < 0.05 younger group vs. very elderly group; P < 0.05 younger group vs. elderly group). There were no significant difference in the proportion of ESRD patients among the three groups (P = 0.473). Patients in the very elderly group had the poorest patient survival (P = 0.002). CONCLUSION Older AAV patients had less renal involvement, lower serum C4 level and BVAS. The very elderly group got the most chest and cardiovascular involvement and had lower platelet counts. Older age is associated with higher mortality in AAV patients.