Neutrophilic airway inflammation in horses with heaves is characterized by a Th2-type cytokine profile

Am J Respir Crit Care Med. 2001 Oct 15;164(8 Pt 1):1410-3. doi: 10.1164/ajrccm.164.8.2012091.


Heaves in horses shares many similarities with human asthma, including lower airway inflammation, reversible airway obstruction, and bronchial hyperresponsiveness. Extrinsic asthma is an allergic response to environmental allergens and a similar immunologic mechanism may be implicated in heaves. It is now recognized that a Th2 subset of CD4+ lymphocytes is associated with allergic diseases such as atopic asthma. The purpose of this study was to determine whether airway inflammation in heaves is associated with a pattern of expression of cytokine suggestive of a Th2 type response. The expression of mRNA, encoding interleukin (IL)-4, IL-5, and interferon gamma (IFN-gamma) was measured in bronchoalveolar cells from seven horses with heaves and five control horses, using in situ hybridization and radiolabeled equine-specific cRNA probes coding for these cytokines. Bronchoalveolar cells of horses with heaves had an increased expression of IL-4 (p = 0.01) and IL-5 (p = 0.02) mRNA and a decreased expression of INF-gamma (p = 0.01) compared with control horses. Here we show that inflammatory cells in lungs from horses with heaves display a Th2-type cytokine profile that is consistent with the hypothesis that heaves is an allergic condition with similarity to human asthma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Asthma / immunology
  • Asthma / veterinary*
  • Bronchoalveolar Lavage Fluid / cytology
  • Cytokines / biosynthesis
  • Cytokines / genetics
  • Horse Diseases / immunology*
  • Horses
  • Inflammation / immunology
  • Inflammation / veterinary*
  • Neutrophils / immunology*
  • RNA, Messenger / biosynthesis
  • Th2 Cells / immunology*


  • Cytokines
  • RNA, Messenger