title: Cutaneous infiltrates and peripheral blood immune responses in dogs with immunomodulatory-responsive lymphocytic-plasmacytic pododermatitis.
abstract: This study characterizes T- and B-lymphocyte responses in the peripheral blood and lesional skin of dogs with immunomodulatory-responsive lymphocytic-plasmacytic pododermatitis (ImR-LPP), a term previously proposed to denote a subpopulation of dogs with idiopathic pododermatitis. T-cell (CD3+, CD4+ and CD8+ ) and B-cell (CD21+) counts were significantly increased in both the epidermis and dermis of lesional ImR-LPP skin compared with that in pedal skin from healthy controls. CD3+ , CD4+, CD8+ and CD21+ cells were commonly observed in perivascular sites in the superficial dermis, periadnexally, beneath the dermal-epidermal (DE) junction and in the epidermis of lesional ImR-LPP skin. The CD8+ /CD3+ T-cell ratio in peripheral blood was significantly increased in the ImR-LPP group (0.42 versus 0.35 in controls). Serum IgA, IgG and IgM concentrations were all significantly elevated in affected dogs. Lymphocyte stimulation indices in ImR-LPP dogs were comparable with control levels except for a lower response to ionomycin (6.0 versus 11.1). Dogs with ImR-LPP had a higher incidence and mean (semi-quantitative) score for IgA, IgG and IgM deposits in the epidermis, and a significantly increased incidence of dermal IgA+, IgG+ and IgM+ mononuclear inflammatory cells. The results indicate that upregulated T- and B-lymphocyte responses may contribute to the pathogenesis of the skin lesions observed in dogs with ImR-LPP.
authors.affiliation: School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland. rory.breathnach@ucd.ie
authors.forename: Rory M
authors.initials: RM
authors.lastname: Breathnach
authors.forename: Shay
authors.initials: S
authors.lastname: Fanning
authors.forename: Grace
authors.initials: G
authors.lastname: Mulcahy
authors.forename: Hugh F
authors.initials: HF
authors.lastname: Bassett
authors.forename: Eric
authors.initials: E
authors.lastname: Strobl
authors.forename: Boyd R
authors.initials: BR
authors.lastname: Jones
mesh_terms: D000818:Animals; D003872:Dermatitis / Q000276:immunology / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000276:immunology* / Q000473:pathology; D004285:Dogs; D005260:Female; D005534:Foot Diseases / Q000276:immunology / Q000473:pathology / Q000662:veterinary*; D007136:Immunoglobulins / Q000097:blood*; D008214:Lymphocytes / Q000145:classification / Q000502:physiology; D008297:Male; D012867:Skin / Q000166:cytology
chemical_list: D007136:Immunoglobulins