Hyaluronate concentration in tracheal lavage fluid from clinically normal horses and horses with chronic obstructive pulmonary disease.

The conducted research measured hyaluronate (HA) concentration in the tracheal lavage fluid from both healthy horses and horses suffering from chronic obstructive pulmonary disease (COPD). The findings revealed that HA concentration was significantly higher in horses affected with COPD which could potentially be used as an indicator of chronic inflammatory changes in COPD-afflicted lungs.

Study Participants and Methodology

• The research involved tracheal lavage fluid samples from 18 horses, including 11 with COPD, and 7 healthy horses serving as controls.
• A clinical examination of the respiratory tract, tracheal lavage, and blood samples were collected from both groups and the analysis was focused on horses with no clinical signs of respiratory tract disease and horses with signs of COPD.
• Some horses underwent repeated examinations at one-week intervals, resulting in 42 samples.
• The collected tracheal lavage fluid samples were analyzed for cell numbers and urea concentration. Meanwhile, HA concentration was determined by a radiometric assay.

Key Findings

• Results showed a significant difference (P = 0.005) in the HA concentrations between the two groups. The mean HA concentration in horses with COPD was 1,880 (+/-309) micrograms per litre, compared to the control horses, which had a mean HA concentration of 256 (+/-72) micrograms per litre.
• The increase in HA concentration was consistent in repeated sample collections and analysis for the horses suffering from COPD.

Conclusions

• The study suggests that horses suffering from chronic respiratory tract inflammation like COPD have an HA concentration about seven times higher than the reference values. One possible explanation offered is that high HA concentration may reflect pathophysiological changes in the connective tissue around the bronchi and bronchioli, causing a continuous overproduction of HA in horses affected by severe forms of COPD.
• The study concludes that the determination of tracheal lavage fluid HA concentration can be used as a marker for chronic inflammatory changes in the lungs affected by COPD, presenting a possible new indicator for COPD detection and management.