Objectives The purpose of this single center study was to describe the epidemiologic, serological and clinical features and long term outcomes of patients who have been diagnosed with eosinophilic granulomatosis with polyangitis (EGPA) based on the history or presence of asthma plus eosinophilia plus pulmonary infiltrates plus sinus abnormality (i.e. “eosinophilic phenotype”) in comparison with patients who met the additional 1990 ACR classification criteria of neuropathy and/or presented histopathological evidence of eosinophilic vasculitis (i.e. “vasculitic phenotype”).
Methods Patients with a diagnosis of EGPA made according to the 1990 ACR classification criteria for the disease were enrolled in this retrospective study. Data collected included: 1) gender 2) age at diagnosis 3) age at inclusion 4) ACR classification criteria fulfilled 5) cumulative clinical features retrospectively assessed according to the Birmingham Vasculitis Activity Score (BVAS) glossary 6) blood and sputum eosinophil count at the diagnosis 7) ANCA status 8) long term outcomes (i.e. relapses, and damage recorded by the VDI). Statistical analysis was performed using SPSS 13 (SPSS Inc., Chicago IL, USA). A 2-tailed value of p < 0.05 was taken to indicate statistical significance
Results We enrolled 47 EGPA patients (23F:24M; mean age at the onset 47±15yrs; mean follow-up 7±5yrs). According to the ACR criteria fulfilled: 13/47 had an “eosinophilic phenotype” and 34/47 a “vasculitic phenotype”. ANCA-MPO were detected in 21/47 (44%) patients. Patients with “vasculitic” manifestations were older at the diagnosis (49±14 vs 39±13 yrs, p=0.28) and showed a higher prevalence of cutaneous manifestations (p=0.04) and a higher positivity for ANCA-MPO (p=0.02). The “eosinophilic” subset presented higher sputum eosinophil count (p=0.04) and a higher prevalence of bronchiectasis (p=0.003). Patients with ANCA-MPO positivity had less frequent cardiac manifestations (p=0.04) and a higher prevalence of relapses (p=0.006). No significant differences were observed regarding other systemic manifestations, asthma control, therapeutic approaches, BVAS, VDI, FFS and quality of life between the two disease subsets.
Conclusions This study confirmed the presence of different pathogenetic and clinical subsets in EGPA, however, their respective global outcomes do not clearly differ. Asthma was poorly controlled in both the “vasculitic” and the “eosinophilic” subsets. In the latter, the evidence that a higher eosinophilic-mediated bronchial inflammation may contribute to the asthma severity sheds a new light for targeted therapies in EGPA.
Disclosure of Interest: None Declared