Joint report of the First International Workshop on Lymphocyte Alloantigens of the Horse held 24-29 October 1981.

This research article discusses a 1981 international workshop that focused on defining six equine lymphocyte alloantigen (ELA) specificities. Antisera were examined from different laboratories and tested against horse lymphocytes in order to identify ELA antigens.

Participants and Methodology

• The workshop consisted of participants from 12 laboratories across four different countries.
• A total of 195 antisera were submitted by these laboratories for the workshop’s analysis.
• The submitted antisera were exchanged among the participating laboratories for robust testing procedures.
• The tests employed were part of a standard lymphocyte microcytoxicity assay program and were conducted on the isolated lymphocytes from 1009 horses of several different breeds.

Data Analysis and Results

• Once collected, all data was analysed by a single computerised operation.
• During analysis, the ‘chi-square’ values of all antisera with all horses’ cells were calculated to ensure thorough comparisons between different antisera.
• Based on this analysis, 15 antisera clusters were discovered.
• However, only six of these clusters met the stringent criteria established by the workshop for the successful identification of ELA antigens.

Findings and Interpretation

• In the course of the analysis, it was found that no horse positively reacted with more than two of these six specificities.
• This suggests that the ELA antigens are probably contained within a specific genetic region called the ELA region.
• Though not conclusively proven during the workshop, the consensus was these six clusters of antisera likely represent alleles of this single genetic region.
• Finally, it’s postulated that this important genetic region may be the major histocompatibility complex of the horse, highlighting potential avenues for further study and investigation.