Influence of environmental and genetic factors on allergen-specific immunoglobulin-E levels in sera from Lipizzan horses.

The research tried to understand how environmental factors and genetic backgrounds influence the production of specific allergy-related antibodies in Lipizzan horses. It emphasized a significant influence of environmental factors such as specific studfarm conditions as well as genetic heritability. Also, specific horse immune system-related genes were associated with different levels of these antibodies.

Study Design and Methods

• The study included 448 Lipizzan horses from 6 different studfarms.
• The researchers tested the horses’ blood samples for levels of IgE, a type of antibody produced during allergic reactions, against two mould extracts (Alternaria alternata and Aspergillus fumigatus) and three recombinant allergens from these moulds.
• All these measurements were performed using ELISA, a common laboratory technique used to measure antibody levels.

Findings

• The study found that both the horses’ environment (specifically, the conditions at each studfarm) and their genetic makeup influenced their production of allergen-specific IgE levels.
• Heritability, or the proportion of observed differences that can be attributed to inherited genetic factors, was found to be 0.33 for IgE levels against the two mould extracts and 0.21 for one of the recombinant allergens.
• However, heritability was negligible for the other two recombinant allergens.

Role of Major Histocompatibility Complex (MHC)

• The researchers also explored the association between MHC class I antigens and the specific IgE levels. MHC class I antigens are molecules that present antigens to the immune cells and play a crucial role in immune response.
• The most significant association was between the equine leucocyte antigen (ELA) A8 and undetectable IgE levels against two of the recombinant allergens.
• Other significant associations observed included ELA A1 and higher IgE levels, ELA A14 and lower IgE levels against the mould extracts, and in one studfarm, ELA Be27 was associated with lower Aspergillus-specific IgE levels.

Significance of the Study

• The findings underscore the role of both environmental and genetic factors in allergic response in horses.
• The observed associations between specific MHC class I antigens and different IgE levels could echo the genetic influence on an allergic reaction.
• This study can help in the understanding of the allergic reaction in horses and may guide the development of better diagnostic tools or treatments for horse allergies.