The Association Between Age at Diagnosis and Disease Characteristics and Damage in Patients With ANCA-Associated Vasculitis

Abstract

Objective: This study examined the relationship between age at diagnosis and disease characteristics and damage in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

Methods: Analysis of a prospective longitudinal cohort of patients with granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic GPA (EGPA) in the Vasculitis Clinical Research Consortium (2013-2021). Disease cohorts were divided by age at diagnosis (years): children (<18), young adults (18-40), middle-aged adults (41-65), and older adults (>65). Data included demographics, ANCA type, clinical characteristics, Vasculitis Damage Index (VDI) scores, ANCA Vasculitis Index of Damage (AVID) scores, and novel disease-specific and non-disease-specific damage scores built from VDI and AVID items.

Results: Analysis included data from 1020 patients with GPA/MPA and 357 with EGPA. Female predominance in GPA/MPA decreased with age at diagnosis. AAV in childhood was more often GPA and proteinase 3-ANCA positive. Children with GPA/MPA experienced more subglottic stenosis and alveolar hemorrhage; children and young adults with EGPA experienced more alveolar hemorrhage, need for intubation, and gastrointestinal involvement. Older adults (GPA/MPA) had more neurologic manifestations. After adjusting for disease duration, medications, tobacco, and ANCA, all damage scores increased with age at diagnosis for GPA/MPA (P < 0.001) except the disease-specific damage score, which did not differ (P = 0.44). For EGPA, VDI scores increased with age at diagnosis (P < 0.009), whereas all other scores were not significantly different.

Conclusion: Age at diagnosis is associated with clinical characteristics in AAV. Although VDI and AVID scores increase with age at diagnosis, this is driven by non-disease-specific damage items.

Figure 1.. ANCA-Associated Vasculitis Disease-Specific Damage Score (AAV-DSDS).

Scoring system for the ANCA-Associated Vasculitis Disease-Specific Damage Score (AAV-DSDS) for patients with granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Each group is worth 1 point regardless of the number of items met within each group. Group numbers 20 and 21 are only applicable to patients with EGPA. Maximum possible scores are 19 points for patients with GPA/MPA and 21 points for patients with EGPA.

Figure 2.. Medications ever received by patients with granulomatosis with polyangiitis and microscopic polyangiitis (GPA/MPA, A) and eosinophilic granulomatosis with polyangiitis (EGPA, B) stratified by age at diagnosis before and after 2012.

Patients diagnosed during the year 2012 are included in the “Diagnosed Before 2012” category.

Figure 3.. Differences in damage scores based on age at diagnosis among patients with granulomatosis with polyangiitis and microscopic polyangiitis.

Differences in damage scores between age at diagnosis groups were assessed among patients with granulomatosis with polyangiitis and microscopic polyangiitis after adjusting for disease duration, medication use, tobacco use, and ANCA type. Cohorts were divided by age at diagnosis (years): children (< 18), young adults (18-40), middle-aged adults (> 40-65), and older adults (> 65). Younger age at diagnosis groups were compared to older age at diagnosis groups. A negative estimated difference (i.e., to the left of zero) in damage scores between age at diagnosis groups represents a lower score, or less damage. If a horizontal line crosses zero, the difference in damage scores between those two age at diagnosis groups is not significant.

Figure 4.. Differences in damage scores based on age at diagnosis among patients with eosinophilic granulomatosis with polyangiitis.

Differences in damage scores between age at diagnosis groups were assessed among patients with eosinophilic granulomatosis with polyangiitis after adjusting for disease duration, medication use, tobacco use, and ANCA type. Cohorts were divided by age at diagnosis (years): children (< 18), young adults (18-40), middle-aged adults (> 40-65), and older adults (> 65). Younger age at diagnosis groups were compared to older age at diagnosis groups. A negative estimated difference (i.e., to the left of zero) in damage scores between age at diagnosis groups represents a lower score, or less damage. If a horizontal line crosses zero, the difference in damage scores between those two age at diagnosis groups is not significant.