PURPOSE: Immunoglobulin G4 (IgG4) - related lung disease shows various lesions in respiratory system including bilateral hilar lymphadenopathy (BHL), bronchial wall thickening, interstitial pneumonia, nodule and consolidation in the lung, and pleural effusion. In the study, we studied clinical features of airway involvement of IgG4 related lung disease by analysis of 6 cases.
METHODS: We examined chest computed tomography (CT) findings, pulmonary function tests (PFTs), bronchoscopic inspection and histopathological examination of bronchial and lung tissues, in addition to serological examination for IgG4 and routine laboratory tests.
RESULTS: Five patients had documented autoimmune pancreatitis (AIP) and the other was diagnosed with AIP later. All six patients showed cough, bronchial wall thickening and BHL on chest CT findings and irregular airway stenosis by bronchoscopic observation. Histological findings of bronchus showed dense IgG4-positive plasma cell and lymphocyte infiltrates without granulomas. In addition to elevated serum IgG4 levels, PFTs showed airflow limitation as indicated by a median FEV1/FVC of 69.7%. The bronchoalveolar lavage fluids (BALF) of all six patients revealed an increased percentage of lymphocytes with predominance of CD4-positive T lymphocytes. Four of the six patients showed an increased eosinophil fraction in the BALF. Corticosteroid therapy dramatically reduced serum IgG4 and improved the BHL, airway stenosis and airflow limitation.
CONCLUSIONS: Airway involvement and air flow limitation are characteristic and steroid-sensitive as one of disorders of IgG4-related lung disease.
CLINICAL IMPLICATIONS: Recently much attention has focused on IgG4-related disorders as complication of AIP or distinct disease. IgG4-realted lung disease shows a unique airway manifestation such as bronchial asthma.
DISCLOSURE: The following authors have nothing to disclose: Keishi Kubo, Hiroshi Yamamoto, Michiko Ito, Masayuki Hanaoka, Masanori Yasuo, Tomonobu Koizumi, Takayuki Honda, Satoshi Kawakami, Shigeyuki Kawa
I have a request for my presentation. I have to be back to Japan on 25th October, Tuesday. Therefore I would like to wish the arrangement of my presentation at Sunday.