The clinical features and treatment of eosinophilic granulomatosis with polyangiitis (EGPA) in Turkey: one or two distinct diseases?

Eosinophilic granulomatosis with polyangiitis (EGPA) is defined the disease as having two subgroups, ANCA (+) and ANCA (-). We aimed to compare EGPA subgroups in terms of clinical features, outcomes, and treatments. A multidisciplinary team was established under our vasculitis centre since October 2014. Totally 50 EGPA patients were enrolled. Clinical features, treatments, and outcomes (FFS, VDI, relapse) were reviewed. For relapse-free survival analysis, time to first relapse was compared according to ANCA phenotype by Kaplan-Meier survival analysis and log-rank test. 17 (34%) patients were in ANCA (+), 33 (66%) patients were in ANCA (-) group. ANCA (-) patients were significantly younger at the diagnosis time (37.9 ± 14.3 vs 53.8 ± 16.3; p = 0.001) and had more nasal polyposis (45.5% vs 11.8%; p = 0.017). ANCA (+) patients had higher BVAS (17[13] vs 9[4]; p = 0.002), renal involvement and peripheral neuropathy were more common in this group, while cardiac involvement was seen only in ANCA (-) group (n = 3). Biological agents (mepolizumab or rituximab) were prescribed to nine patients in ANCA (-) and two patients in ANCA (+) group. The median duration of follow-up was 47 (IQR 69.9) months. ~ 40% of patients had at least one relapse, but relapse-free survival rate was similar between the groups. However, the predictor of first relapse was elevated Ig E level [OR (95% CI): 6.5 (1.09-38.63) p = 0.04]. Consequently, both clinical features, disease activity, and treatments appear to be significantly different between EGPA subgroups. The relapse risk was similar although clinical features and treatment strategies were different. Also, elevated Ig E levels may be a precursor for the relapse.