Eosinophilic granulomatosis with polyangiitis: diagnosis and treatment-related issues

Abstract

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic necrotizing vasculitis of small to medium-sized vessels associated with antineutrophil cytoplasmic antibodies (ANCA). EGPA is usually diagnosed in patients with bronchial asthma (BA) and is characterized by a predominant lesion of the lungs, skin, and peripheral nervous system. ANCAs to myeloperoxidase are detected in 1/3 of patients with EGPA. Presence or absence of ANCAs differentiates 2 disease phenotypes with different clinical characteristics and prognosis. New opportunities for the treatment of EGPA appeared after identification of the key role of eosinophils in EGPA and development of targeted drugs for the treatment of eosinophilic BA that are being studied now. Aim of the review is to highlight modern approaches to the diagnosis and treatment of patients with EGPA, primarily through the use of targeted biological therapy. Conclusion. EGPA is a multisystem disease with ambivalent manifestations associated with eosinophilic or ANCA-mediated small vessel injuries. Currently, there is no “gold standard” for the diagnosis of EGPA, although the efficacy of pharmacological therapy is directly related to early detection and timely initiation of treatment. Monoclonal antibodies targeting interleukin-5 (IL-5) are an effective alternative to conventional systemic corticosteroids used alone or in combination with immunosuppressants (cyclophosphamide for induction and azathioprine for maintenance therapy) in patients with severe/refractory disease and unfavorable prognosis. The clinical benefits of the targeted anti-IL-5 drug mepolizumab were confirmed in a randomized controlled trial, and this drug was approved for the treatment of patients with EGPA. Currently, new drugs, including targeted ones, are being tested for induction and maintenance therapy. Pulmonologists and rheumatologists should coordinate patient management to improve the results of treatment and the prognosis of the disease.