Eosinophilic Granulomatosis with Polyangiitis: clinical predictors of long-term asthma severity.

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.Retrospective cohort study of patients who fulfilled standardized criteria for EGPA that were followed in a single referral center between 1990-2017. Baseline and 3 (±1) years of follow-up clinical, laboratory and pulmonary function data were analyzed.

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<0.01), elevated serum total IgE levels (p<0.05), increased use of high dose inhaled (ICS; p<0.05) and oral corticosteroids (OCS; p<0.001) for respiratory symptoms the year before the diagnosis of EGPA. 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 testing (p<0.05). Long-term PFTs did not improve during long-term follow-up regardless of ICS or OCS therapy. Using multivariate binary logistic regressions, severe rhinosinusitis (p=0.038), pulmonary infiltrates (p=0.011), overweight (BMI>25kg/m²; p=0.041) and severe/uncontrolled asthma at vasculitis diagnosis (p<0.001) independently predicted severe/uncontrolled asthma at the 3-year endpoint.

In asthmatic patients with EGPA, long-term severe/uncontrolled asthma is associated with baseline pulmonary and ENT manifestations, but not with clear-cut vasculitic features.