Neonatal isoerythrolysis involving the Qc and Db antigens in a foal.

This research discusses a case where a mare gave birth to a foal which developed neonatal isoerythrolysis (NI), a potentially life-threatening condition that occurs when a mare’s antibodies attack her foal’s red blood cells. The study hints that whilst the majority of NI cases are attributed to the Aa or Qa antigen, other factors might be involved.

Case Overview

• The study focused on a Thoroughbred mare and her four offsprings born over a period spanning from 1987 to 1994.
• The first reported instance of suspected NI happened with her third foal in 1992 but recovered without any transfusion.
• In 1994, the mare delivered a filly that developed severe NI, requiring three blood transfusions.

Blood Analysis

• Blood typing analysis was carried out on the mare and her four foals.
• All four foals were found positive for the Qc, Db, and Dq antigens, and the last three were also positive for the Ua antigen.
• The mare, on the other hand, was negative for these antigens (Qc, Db, Dq, Ua).

Immune Reaction in the Mare

• The mare didn’t show any alloantibodies against the Ua antigen and showed no reaction to the Dq antigen.
• Yet, during 1994, the mare had strong reactions against the Db antigen characterized by strong agglutination at the time of parturition and a subsequent decrease.
• Her reactions towards the Qc antigen were characterized by weak lysis and an increase in titer during parturition, followed by a decrease.

Implications of the Study

• Findings from this study suggest that in addition to the Aa and Qa antigens, which are known to be involved in around 90% of all NI cases, other antigens such as Db and Qc may contribute to NI.

The research provides valuable insights into the possible involvement of other factors (antigens) in neonatal isoerythrolysis, thereby expanding the understanding of this condition in equines.