Association between age at disease onset of anti-neutrophil cytoplasmic antibody-associated vasculitis and clinical presentation and short-term outcomes

OBJECTIVES: ANCA-associated vasculitis (AAV) can affect all age groups. We aimed to show that differences in disease presentation and 6month outcome between younger- and older-onset patients are still incompletely understood.METHODS: We included patients enrolled in the Diagnostic and Classification Criteria for Primary Systemic Vasculitis (DCVAS) study between October 2010 and January 2017 with a diagnosis of AAV. We divided the population according to age at diagnosis: <65years or ≥65years. We adjusted associations for the type of AAV and the type of ANCA (anti-MPO, anti-PR3 or negative).RESULTS: A total of 1338 patients with AAV were included: 66% had disease onset at <65years of age [female 50%; mean age 48.4years (s.d. 12.6)] and 34% had disease onset at ≥65years [female 54%; mean age 73.6years (s.d. 6)]. ANCA (MPO) positivity was more frequent in the older group (48% vs 27%; P=0.001). Younger patients had higher rates of musculoskeletal, cutaneous and ENT manifestations compared with older patients. Systemic, neurologic,cardiovascular involvement and worsening renal function were more frequent in the older-onset group. Damage accrual, measured with the Vasculitis Damage Index (VDI), was significantly higher in older patients, 12% of whom had a 6month VDI ≥5, compared with 7% of younger patients (P=0.01). Older age was an independent risk factor for early death within 6months from diagnosis [hazard ratio 2.06 (95% CI 1.07, 3.97); P=0.03].CONCLUSION: Within 6months of diagnosis of AAV, patients >65years of age display a different pattern of organ involvement and an increased risk of significant damage and mortality compared with younger patients.