Different expression of immune checkpoint markers on bronchoalveolar lavage CD4+ cells: a comparison between hypersensitivity pneumonitis and sarcoidosis

Abstract

biotherapy -induced sarcoidosis) in the lungs. 8 However, to our knowledge, the actual expression of both types of checkpoints in patients with lung granulomatous disease has not been fully established.A particularly useful method for the examination of interstitial lung diseases in situ is bronchoalveolar lavage (BAL). This technique facilitates diagnosis and helps to assess the local cellular reaction as well as the release of inflammatory mediators. 9 We aimed to determine the expression of ICPs on bronchoalveolar lavage lymphocytes in HP and sarcoidosis, in association with immunological and clinical data. Patients and methodsWe enrolled patients suspected to have interstitial lung diseases. In the diagnostic procedure we followed the European Respiratory Society guidelines; details were described previously. 4 The exclusion criteria comprised: 1) treatment with systemic corticosteroids, methotrexate, azathioprine, biological drugs (eg, infliximab for sarcoidosis), or any other medication known to potentially cause interstitial lung pathology or influence the cytoimmunological BAL profile 8 2) respiratory failure, heart failure (New York Heart Association class IV), or acute coronary syndromes; 3) poor technical quality of the BAL material (eg, BAL fluid recovery <30% of instilled volume, percentage of contaminating epithelial cells >3% of BAL cells). 9 Hypersensitivity pneumonitis (n = 14) was diagnosed on the basis of clinical data, including typical symptomatology following allergen