title: Alterations of epidermal proliferation and cytokeratin expression in skin biopsies from heavy draught horses with chronic pastern dermatitis.
abstract: We report the historical, clinical and histopathological characteristics of skin lesions in biopsies from 37 heavy draught horses with chronic pastern dermatitis. The skin lesions were divided into four macroscopic groups: scaling (group I, n=5), hyperkeratotic and hyperplastic plaque-like lesions (group II, n=14), nodular skin masses (group III, n=16) and verrucous skin lesions (group IV, n=2). The principal histological findings were hyperkeratosis and epidermal hyperplasia. There was a gradual increase in epidermal hyperplasia from groups I to IV, suggesting that the lesions represent different stages of disease. In all cases, there was perivascular dermatitis dominated by T lymphocytes with an increase in MHC class II-positive dendritic-like cells. Immunohistochemical labelling for cytokeratins CK5/6(4), CK10 and CK14 indicated a change in their expression pattern. This correlated with the degree of epidermal hyperplasia, indicating abnormal differentiation of keratinocytes. There was a statistically significant correlation between the severity of skin lesions and several other factors including increasing age, increasing cannon circumference, prominence of anatomical structures such as fetlock tufts of hairs, ergots and chestnuts, and bulges in the fetlock region.
authors.affiliation: Klinik für Pferde, Tierärztliche Hochschule Hannover, Bischofsholer Damm 15, D-30173 Hannover, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Geburek
authors.forename: Bernhard
authors.initials: B
authors.lastname: Ohnesorge
authors.forename: Eckehard
authors.initials: E
authors.lastname: Deegen
authors.forename: Renate
authors.initials: R
authors.lastname: Doeleke
authors.forename: Marion
authors.initials: M
authors.lastname: Hewicker-Trautwein
mesh_terms: D000367:Age Factors; D000818:Animals; D001706:Biopsy / Q000662:veterinary; D001947:Breeding; D002455:Cell Division; D004817:Epidermis / Q000473:pathology*; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D005533:Foot Dermatoses / Q000145:classification / Q000473:pathology / Q000662:veterinary*; D006734:Horse Diseases / Q000145:classification / Q000473:pathology*; D006736:Horses; D006965:Hyperplasia / Q000662:veterinary; D007150:Immunohistochemistry / Q000662:veterinary; D007633:Keratins / Q000378:metabolism*; D019394:Ki-67 Antigen / Q000276:immunology; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D012867:Skin / Q000166:cytology / Q000378:metabolism / Q000473:pathology
chemical_list: D019394:Ki-67 Antigen; D007633:Keratins