Eosinophilic Granulomatosis With Polyangiitis: Clinical Predictors of Long-term Asthma Severity

Background: The long-term clinical course of asthma in patients with eosinophilic granulomatosis with polyangiitis (EGPA) remains unclear. We aimed to characterize long-term asthma in EGPA and to identify baseline predictors of long-term asthma severity. Methods: This retrospective cohort study included patients who fulfilled standardized criteria for EGPA who were followed up in a single referral center between 1990 and 2017. Baseline and 3 (± 1) years of follow-up clinical, laboratory, and pulmonary function data were analyzed. Results: Eighty-nine patients with EGPA and a documented asthma assessment at baseline and at 3 years from diagnosis were included. Severe/uncontrolled asthma was observed in 42.7% of patients at diagnosis and was associated with previous history of respiratory allergy (P < .01), elevated serum total IgE levels (P < .05), and increased use of high-dose inhaled corticosteroids (ICSs; P < .05) and oral corticosteroids (OCSs; P < .001) for respiratory symptoms the year before the EGPA diagnosis. During follow-up, an improvement or worsening in asthma severity was noted in 12.3% and 10.1% of patients, respectively. Severe/uncontrolled asthma was present in 40.5% of patients at 3 years and was associated with increased airway resistance on pulmonary function tests (PFTs; P < .05). Long-term PFTs did not improve during long-term follow-up regardless of ICS or OCS therapy. Multivariate binary logistic regression results indicated that severe rhinosinusitis (P = .038), pulmonary infiltrates (P = .011), overweight (BMI ≥ 25 kg/m²; P = .041), and severe/uncontrolled asthma at vasculitis diagnosis (P < .001) independently predicted severe/uncontrolled asthma at the 3-year end point. Conclusions: In patients with asthma with EGPA, long-term severe/uncontrolled asthma is associated with baseline pulmonary and ear, nose, and throat manifestations but not with clear-cut vasculitic features.