Hyaluronan (hyaluronic acid) in lung lavage of asbestos-exposed humans and sheep

Abstract

The concentration of hyaluronan was measured in the bronchoalveolar lavage fluid (BALF) of 18 control subjects and 27 workers from the asbestos mills and mines of Québec, 9 without asbestosis and 18 with asbestosis. Hyaluronan was also measured in the BALF of 9 control sheep exposed to 100 ml phosphate-buffered saline (PBS) at 10 day intervals for 39 months, and 13 sheep exposed at the same intervals to 100 mg chrysotile in 100 ml PBS for 24 months. At month 24, the asbestos-exposed sheep were classified into 3 groups: (A) 4 sheep exposed to PBS alone, (B) 4 sheep exposed to 10 mg chrysotile asbestos every 10 days, and (C) 5 sheep exposed to 100 mg chrysotile asbestos every 10 days for 15 months. The BALF hyaluronan averaged 53.9 +/- 7.4 ng/ml in human controls, 67.5 +/- 10.3 ng/ml in asbestos-exposed workers without asbestosis, and 206 +/- 83 ng/ml in workers with asbestosis (p less than 0.05 vs. normal). In the control sheep, BALF hyaluronan was 34.7 +/- 6.9 ng/ml, and it was 31.5 +/- 17.8 ng/ml in the low-dosage asbestos-exposed group (A), 83.0 +/- 27.7 ng/ml in the intermediate-dose group (B), and 248.0 +/- 134.7 ng/ml in the high-dosage group (C) (p less than 0.05 vs. controls). In contrast, the release of plasminogen activator, a protease that may play a role in limiting the fibrotic process, was increased in group A, but not in groups B and C. In conclusion, BALF hyaluronan constitutes an indicator of lung interstitial tissue changes that may reflect the activity of the fibrosing alveolitis associated with chronic asbestos exposure.

Increased Levels of Hyaluronic Acid in Bronchoalveolar Lavage from Patients with Interstitial Lung Diseases, Relationship with Lung Function and Inflammatory Cells Recruitment

“…We found that patients with ILD showed a significant increase in HA and IL-6 levels in BAL compared with control subjects. In accordance with our results, other reports have previously shown increased levels of HA in patients with farmer's lung-HP [27] [28], sarcoidosis [10], asbestos-exposed individuals [29] and patients with idiopathic pulmonary fibrosis [30]. Our results raise the question about a possible role for HA in the pathogenesis of ILD.…”

Extracellular Superoxide Dismutase in Pulmonary Fibrosis

“…Indeed, we have found that EC-SOD does bind to HA and can directly inhibit oxidative degradation of this matrix and cell surface component both in vitro and in vivo (unpublished observation). Hyaluronan accumulation has also been reported in bleomycin (95 -97 ) and asbestos-induced lung injury and fibrosis (16). In fact, BAL fluid from bleomycintreated animals shows increased concentrations of both the native high molecular weight HA, as well as lower molecular weight HA fragments (95).…”

Role of hyaluronan and hyaluronan-binding proteins in lung pathobiology

“…Increased HA and its degradation products are observed in animal models of chronic obstructive pulmonary disease (COPD) and bleomycin-induced lung injury (31,101,160). Furthermore, increased HA levels are observed in bronchoalveolar lavage (BAL) fluid and/or plasma from patients with lung disorders such as pulmonary fibrosis (7), COPD (31), allergic alveolitis (128), asthma (115,161), interstitial lung disease (14), sarcoidosis (89), and idiopathic pulmonary arterial hypertension (106). An increase in HA production has also been reported in airway epithelial cells in response to tunicamycin-induced endoplasmic reticulum stress (70).…”