Leukotriene B4 in equine asthma syndrome: what do we know so far?

Abstract

ABSTRACT: The term “equine asthma syndrome” (EAS) was recently proposed due to the resemblance of the equine disease to human asthma. Leukotrienes cause constriction of the bronchi, especially in the lower airways and increase mucus secretion in the respiratory system. Leukotriene B4 (LTB4) has been discovered as a strong chemotactic factor, which plays a role in neutrophil migration. The immunologic background of EAS remains not fully elucidated despite many studies on the pathogenesis. This study aimed to evaluate the LTB4 concentration in the bronchoalveolar lavage fluid (BALF) of horses with and without pulmonary inflammatory disease. Thirty-five mixed breed horses were studied and LTB4 was determined by using specific ELISA Kit. The horses were grouped by 2 different criteria for statistical analysis of data: 1) according to the values for BALF citology and 2) according to the detection of LTB4 in BALF. There was significant difference of effect of age on the LTB4 detection in equine BALF. Younger animals were the majority where it was possible to detect LTB4 values in LBA. In conclusion, there was an effect of age on the detection of LTB4 in equine BALF, where LTB4 levels were more easily detected in younger animals than older animals and the results of this study raise the possibility of considering future studies with the objective of establishing the real role and the best moment to detect LTB4 in BALF of the equine asthma syndrome.