Immunoglobulins and cellular constituents of the BAL fluid of patients with sulfur mustard gas-induced pulmonary fibrosis

Abstract

Study objective: The acute heavy exposure to sulfur mustard gas can lead to pulmonary fibrosis (PF). This study was performed to determine the cellular and protein content of BAL fluid in 24 patients with sulfur mustard gas-induced PF.

Patients: Twenty-four veterans with sulfur mustard gas-induced PF and 18 nonexposed veterans serving as control subjects were enrolled into the study.

Measurements: Chest roentgenograms, pulmonary function tests (PFTs), tests for carbon monoxide diffusing capacity of the lung (DLCO), high-resolution CT scans of the chest, BAL via fiberoptic bronchoscopy, analyses of BAL fluids for cellular and protein constituents, and determinations of serum albumin and Ig levels were performed in all cases. A transbronchial lung biopsy was done in all patients following BAL.

Results: Neutrophilic alveolitis was the predominant feature. Neutrophils (p = 0.0001) and eosinophils (p = 0.0001) were the predominant cell types in the BAL fluid of patients with PF. There was a strong correlation between the BAL fluid neutrophil count (p = 0.76; p = 0.0003) or its percentage (p = 0.77; p = 0.0003) and the degree of fibrosis. Of the BAL fluid Ig levels, only the IgG level in the study group was significantly higher than the IgG level of the control group (p = 0.0001). Of the PFT physiologic parameters, only the percentage of DLCO showed a significant correlation with the degree of fibrosis (p = -0.76; p < 0.001).

Conclusion: The cellular constituents of BAL fluid in patients with sulfur mustard gas-induced PF are very similar to the cellular constituents seen in patients with idiopathic PF, and this finding indicates the presence of an ongoing active alveolitis in PF.