Clinical characteristics of eosinophilic granulomatosis with polyangiitis involving the lung in 13 patients.

OBJECTIVES: Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic vasculitis, which often starts with respiratory symptoms such as asthma, and it is difficult to make early clinical diagnosis.This study aims to improve the therapeutic level of EGPA with lung involvement via analyzing the clinical characteristics, diagnosis, and treatment . METHODS: We retrospectively analyzed the clinical data of 13 EGPA patients with lung involvement who were diagnosed from February 1, 2014 to July 31, 2021 in the Second Xiangya Hospital, Central South University. RESULTS: The ratio of male to female in 13 patients was 7꞉6. The patients were diagnosed at median age 52 (46-68) years old and 6 had been diagnosed as "bronchial asthma". Pulmonary clinical manifestations mainly included cough, expectoration, wheezing, and shortness of breath; while extra-pulmonary manifestations mainly included rash and subcutaneous mass, fever, limb numbness, muscle and joint pain, abdominal pain, etc. Peripheral blood tests of all patients showed that 11 patients had eosinophils ≥10%, 10 had elevated inflammatory indicators, and 3 were anti-neutrophil cytoplasmic antibody (ANCA) positive. The major lung imaging features were patches or strips of increased density, multiple nodules, bronchiectasis, bronchial wall thickening, exudation, mediastinal lymph nodes, and so on. Eight patients had sinusitis and 9 with abnormal electromyography. Extravascular eosinophil infiltration was found in 9 patients. Six patients with lung biopsy showed eosinophil, lymphocyte, and plasma cell infiltration, 3 patients were involved in small blood vessels, and 1 had granuloma. Pulmonary function tests were performed in 7 patients, 5 of them showed different degrees of pulmonary ventilation dysfunction, and 4 of them had diffusion dysfunction. Almost all patients respond well to glucocorticoid and immunosuppressant. CONCLUSIONS: EGPA is rare in clinical, often involving multiple systems with great harm and may combine with asthmatic manifestations. Pulmonary involvement is relatively common. However, due to insufficient recognition of this disease and huge heterogeneity of pulmonary imaging manifestations, misdiagnosis and missed diagnosis are easy to occur. Relevant laboratory, imaging, and biopsy examination should be performed as early as possible with comprehensive consideration of extrapulmonary involvement. Early identification has great significance to improve the diagnosis rate and prognosis of diseases.