Equine Common Variable Immunodeficiency

This presentation will review our current knowledge about common variable immunodeficiency (CVID), a late-onset condition that affects horses and humans, and is characterized by B cell lymphopenia, antibody deficiency, and susceptibility to recurrent bacterial infections. This immunodeficiency manifests in non-familial male and female horses of different breeds, frequently in adult age. Clinical signs and available diagnostics will be described. The cause of CVID is unknown but involves epigenetic mechanisms of gene silence, including downregulation in the gene expression of B cell signature transcription factors. The clinical presentation, diagnostics and management of horses affected with CVID will be discussed. Recently obtained knowledge about the mechanisms of disease will be presented.