ANCA-positive and ANCA-negative phenotypes of eosinophilic granulomatosis with polyangiitis (EGPA): outcome and long-term follow-up of 50 patients from a single Polish centre

Objective. The aim of the study was to compare the course of the disease and treatment outcomes in ANCA-positive and ANCA-negative eosinophilic granulomatosis with polyangiitis (EGPA) patients from one Polish tertiary referral centre. Methods. Retrospective and prospective cohort study carried out on 50 patients treated in our department between 1998 and 2012. EGPA diagnosis was based on the American College of Rheumatology (ACR) criteria. Treatment protocol was based primarily on the predictive Five Factor Score (FFS) scale. Clinical characteristics of the patients, general symptoms, organ involvement, treatment regimen, and follow-up outcomes were evaluated according to ANCA status. Results. Fifteen ANCA-positive patients and 35 ANCA-negative patients were enrolled. At the time of diagnosis ANCA-positive patients had a higher incidence of renal involvement (53% vs. 7.7%; p<0.001), skin involvement (93.3% vs. 57.1%; p=0.03), and peripheral neuropathy in the form of mononeuritis multiplex (60% vs. 25.7%; p=0.021). ANCA-negative patients had significantly more frequent cardiac manifestations, but only with regard to the entire period of follow-up (68.6% vs. 33.3%; p=0.021). Patients in both groups were under the same treatment regimens, however steroid dose necessary to maintain remission of the disease was significantly higher in the group of ANCA-positive patients (9 +/- 2.5 vs. 7.4 +/- 1.9 mg/day of methylprednisolone; p=0.023). The presence of ANCA did not affect the frequency of relapses. Conclusion. Our results confirm the differences in clinical disease presentation based on ANCA status and indicate that ANCA-positive patients should be treated more aggressively.