title: An immunodeficiency in Fell ponies: a preliminary study into cellular responses.
abstract: A putative immunodeficiency, causing mortality in UK Fell pony foals (Fell pony syndrome), was studied in affected foals and compared with healthy, age-matched foals. Differential cell counts of peripheral blood indicated that the syndrome foals were lymphopenic (P<0.05). Flow cytometric analysis of circulating leucocytes showed a reduced MHC II expression (P<0.01) on lymphocytes but not on polymorphonuclear cells in affected foals. There were no changes in the percentages of CD4+ or CD8+ T cells. There was an increased (P<0.05) expression of CD11a/18 by the lymphocytes of the syndrome foals, compared to the control foals, which is probably a response to systemic bacterial infections. The syndrome foals' lymphocytes responded to mitogens (PHA, ConA, PWM) at normal levels. The data do not conform to any known immunodeficiencies identified in any other species. Further analyses will be required, particularly on bone marrow function.
authors.affiliation: Department of Veterinary Clinical Science and Animal Husbandry, The University Of Liverpool, UK.
authors.forename: S C
authors.initials: SC
authors.lastname: Bell
authors.forename: C
authors.initials: C
authors.lastname: Savidge
authors.forename: P
authors.initials: P
authors.lastname: Taylor
authors.forename: D C
authors.initials: DC
authors.lastname: Knottenbelt
authors.forename: S D
authors.initials: SD
authors.lastname: Carter
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001947:Breeding; D015496:CD4-Positive T-Lymphocytes; D018414:CD8-Positive T-Lymphocytes; D005434:Flow Cytometry / Q000662:veterinary; D005802:Genes, MHC Class II; D006734:Horse Diseases / Q000276:immunology*; D006736:Horses; D007111:Immunity, Cellular; D007153:Immunologic Deficiency Syndromes / Q000276:immunology / Q000662:veterinary*; D008213:Lymphocyte Activation; D008231:Lymphopenia / Q000276:immunology / Q000662:veterinary*; D006113:United Kingdom