Analysis of cellular and protein content of broncho-alveolar lavage fluid from patients with idiopathic pulmonary fibrosis and chronic hypersensitivity pneumonitis.

TLDR

The study aimed to evaluate cellular and protein components in the lower respiratory tract of patients with idiopathic pulmonary fibrosis and chronic hypersensitivity pneumonitis. Broncho‑alveolar lavage was performed on 58 patients (19 IPF, 7 CHP, and 32 controls). In IPF patients, lavage revealed an inflammatory and eosinophilic response with markedly elevated IgG that decreased with corticosteroid therapy yet eosinophils persisted, whereas CHP patients showed eosinophils and IgG, increased IgM, fewer inflammatory cells, and a strikingly higher lymphocyte proportion (38–74%) with elevated T cells and reduced B cells, indicating that the lung may act as an independent immune organ and that lavage analysis has diagnostic and therapeutic value in fibrotic lung disease.

Abstract

To evaluate cellular and protein components in the lower respiratory tract of patients with idiopathic pulmonary fibrosis (IPF) and chronic hypersensitivity pneumonitis (CHP), limited broncho-alveolar lavage was done in 58 patients (19 IPF, 7 CHP, and 32 controls). Analysis of the cells and protein in the lavage fluids from patients with IPF revealed an inflammatory and eosinophilic response and a significant elevation of IgG in the lungs. With corticosteroid therapy, inflammation diminished but eosinophils remained. Lavage fluid from patients with CHP also had eosinophils and elevated levels of IgG. However, in contrast to IPF, lavage fluid from CHP patients contained IgM, fewer inflammatory cells, and a strikingly increased number (38-74%) of lymphocytes. Identification of lavage lymphocytes in CHP showed that T lymphocytes were significantly elevated and B lymphocytes were decreased compared to peripheral blood. These studies suggest nthat the lung in IPF and CHP may function as a relatively independent immune organ, and that analysis of cells and proteins in broncho-alveolar lavage fluid may be of diagnostic, therapeutic, and investigative value in evaluating patients with fibrotic lung disease.