Clinical significance of detecting asbestos bodies in bronchoalveolar lavage fluid in diffuse lung disease

Asbestos bodies (ABs) in bronchoalveolar lavage fluid (BALF) are valuable markers for assessing past asbestos exposure. However, the clinical significance of detecting ABs at ≥1 AB/mL in patients with diffuse lung disease remains unclear. Herein, we investigated the clinical utility of detecting ABs at this threshold, focusing on its association with asbestos exposure history, bronchoalveolar lavage (BAL) cellular analysis, imaging findings, and the rate of respiratory function decline in patients with diffuse lung disease.

This retrospective single-center study included patients who underwent BAL and asbestos body (AB) quantification for respiratory disease evaluation. The relationship between the AB number (cutoff: 1 AB/mL) and clinical parameters was analyzed. Pulmonary function decline was assessed in patients with ≥1 year of follow-up.

This study involved 304 patients. An AB number of ≥1 AB/mL was significantly associated with asbestos exposure history (p < 0.001) and the presence of pleural plaques on computerized tomography (CT) imaging (p < 0.001). However, no significant differences were found in BAL cellular patterns or respiratory function decline between patients with an AB number of ≥1 AB/mL and those with <1 AB/mL.

The presence of ≥1 AB/mL in the BALF reflects substantial asbestos exposure and is associated with pleural plaques on CT imaging but not with BAL cellular patterns or the rate of decline in respiratory function. These findings suggest that AB detection in BALF has limited predictive value for respiratory function decline but could be valuable for identifying unrecognized asbestos exposure in patients with diffuse lung disease.