Retrospective investigation of automated hematology analyzer-determined indicators of neutrophil activation in blood samples from horses with asthma.

The research aims to explore the signs of neutrophil activation in the blood of healthy and asthmatic horses and examine any correlations with corticosteroid treatment. The study indicated that asthmatic horses have larger neutrophils that carry more myeloperoxidase (MPO) compared to healthy ones. However, the researchers found that these factors do not significantly help in diagnosing equine asthma due to overlapping data among groups.

Research Goals

• The study was designed to identify the indicators of neutrophil activation in the blood samples of healthy and asthmatic horses.
• Another goal was to assess potential associations between these indicators and corticosteroid treatment. Corticosteroids are commonly prescribed to reduce inflammation, which is a principal symptom of asthma.

Methodology

• The study comprised 48 horses: 14 with severe equine asthma (SEA), 21 with mild to moderate equine asthma (MEA), and 13 healthy controls.
• In a three-part retrospective study, previous hematology analyzer data for these horses were reviewed.
• The researchers studied neutrophil size, neutrophil light absorbance (NLA), and myeloperoxidase (MPO) index in the blood samples.
• Following a 2-week corticosteroid treatment, changes in these variables were evaluated in a subset of the horses: 5 with SEA and 6 controls.
• The same variables were examined in another subset of 8 SEA-affected horses after the same treatment and a post-treatment washout period of a week.

Findings

• The SEA-affected horses showed significantly greater values for all three variables compared to the MEA and control groups.
• After corticosteroid treatment, both the control and SEA-affected horses showed a noteworthy decrease in NLA and MPO index along with a decrease in neutrophil size in SEA horses.
• In the SEA-affected horses, the post-washout period showed a significant increase in neutrophil size and non-significant increases in NLA and MPO index.

Conclusions

• The study suggested that horses with exacerbated SEA have larger neutrophils containing more MPO, as compared to neutrophils of MEA-affected and healthy horses.
• Despite this, the study concluded that these variables might have limited diagnostic value for equine asthma, as data overlap was observed between the different groups.