Investigation of bovine serum albumin‐specific IgE expression in horses

Abstract

SummaryBackgroundNeonatal foals are born essentially agammaglobulinaemic and therefore must ingest colostrum or receive immunoglobulins to maintain health. Failure of passive transfer treatment involves administration of equine colostrum, plasma or commercial powdered colostrum (CPC). Anecdotal reports suggest the risk of anaphylaxis associated with plasma transfusion in neonates receiving CPC prior to gut closure. Bovine serum albumin (BSA) in CPC may serve as a target for BSA‐specific immunoglobulin E (IgE) in donor equine plasma.ObjectivesTo determine the presence of BSA‐specific IgE in samples of commercial equine plasma, samples were collected following routine vaccination in healthy horses and horses experiencing adverse vaccine reactions.Study designProspective observational.MethodsSerum was collected from: 65 healthy horses at days 0, 14, 28, 90, 180, 270 and 365 post‐vaccination; 26 horses after vaccine reaction at days 1, 180 or 270 post‐vaccination; 4 horses not vaccinated; and 9 horses from a commercial plasma donor herd. BSA‐specific IgE was determined using enzyme‐linked immunosorbent assay.ResultsBovine serum albumin‐specific IgE was not detected in non‐vaccinated horses and was identified in all vaccinated horses. Younger horses demonstrated a trend for higher fold changes in post‐vaccination BSA‐specific IgE expression compared to older horses. No significant difference in BSA‐specific IgE levels between commercial plasma donors and healthy horses was identified. No significant difference in post‐vaccination BSA‐specific IgE levels between the reactor and healthy horses at days 180 and 270 post‐vaccination were identified.Main limitationsSmall number of reactor horses at day 180 and 270 post‐vaccination with most samples being collected 24 h. There were no healthy horse samples for 24 h post‐vaccination; therefore, it was not possible to compare the groups at this timepoint.ConclusionsHorses may express BSA‐specific IgE following vaccination. There may be a risk of hypersensitivity type reaction when veterinarians administer commercial plasma to neonatal foals consuming CPC prior to gut closure.