Regulatory T lymphocytes and selected cytokines in horses with mild to severe equine asthma and different inflammatory cytology profiles.

The paper studies the correlation between Tregs, or regulatory T lymphocytes, inflammatory cytokines, and asthma severity in horses. It establishes a connection and various correlations between age, grade of asthma, and levels of inflammation and specific regulatory T lymphocytes.

Objective and Methodology of the Research

• The aim of the study was to investigate the role of Tregs, or regulatory T lymphocytes, and inflammatory cytokines in Bronchoalveolar Lavage Fluid (BALF) and peripheral blood (PB) of adult horses suffering from mild to severe asthma.
• The research focused on horses of different breeds, ages ranging between 2 and 20 years, who had asthma. These horses were categorized based on their clinical scores and type of inflammation detected through cytological findings.
• The researchers measured the plasma levels of various cytokines – IFN-γ, IL-4, IL-10, IL-17, and Matrix Metalloproteinase-9 (MMP-9) in the BALF by using a method called Enzyme-linked Immunosorbent Assay (ELISA).
• Tregs in the BALF and PB were detected using flow cytometry, a technique that helps evaluate physical and chemical characteristics of particles in a fluid as they pass through a laser.

Principal Findings

• The findings showed horses with severe equine asthma (SEA) were older compared to horses with mild-moderate equine asthma (MEA) and had higher concentrations of MMP-9 in their BALF, a relevant measure of inflammation.
• Horses with neutrophilic inflammation were also of a higher age, grade of clinical score, and a higher percentage of Tregs and MMP-9 concentration in their BALF as compared to the horses from the mastocytic inflammation group.
• The study found positive correlations between age, neutrophils (type of white blood cell that forms an essential part of the immune system), grade of asthma severity, and Tregs in the BALF and PB.
• Importantly, the study also found that the percentage of Tregs in the BALF was positively correlated with those in the PB, providing a less invasive method of measurement.

Significance of the Study

• The study helps deepen the understanding of the inflammatory process in equine asthma and the role of Tregs and inflammatory cytokines.
• The positive correlation found between Tregs in the BALF and Tregs in the PB can potentially offer a less invasive measure for assessing inflammation in these horses.