Immune mechanisms in vitiligo

V itiligo is a caused by cytes. As disfiguring disease of the skin that is the selective destruction of melanoa result, white patches of complete depigmentation appear on the skin. The disease is asymptomatic and does not adversely affect survival; however, it can cause severe disfigurement, lead to serious psychological stresses, and interfere with employment.’ The striking aspect of vitiligo is that the damage it causes is highly selective; it is almost entirely restricted to melanocytes. Vitiligo normally begins with small areas of complete depigmentation. There is usually no preceding inflammation, and the lesions themselves are asymptnmatic. The disease progresses with enlargement of existing lesions and appearance of new lesions. Spontaneous repigmentation, usually only partial, occurs in some patients. When repigmentation occurs, it often arises from hair follicles, suggesting that melanocytes in this location are relatively spared. Vitiligo occurs in several animals including Smyth (formerly called DAM) chickens; Belgian Tervuren dogs; Siamese cats; Arabian, Lipizzaner, and Camargue horses; and Sinclair miniswine.J---‘7 These provide experimental models in which the cause of the disease can be studied experimentally. Vitiligo is familial in some patients and can occur in twins,:suggesting that in some cases it results from an inherent genetic defect that expresses itself in melanocytes. Mt;m4 however, some favor a polygenie mode of inheritance. 1” Several HLA abnormalities ha been associated with vitiligo, including associations with Dr4, B13, BW35, and A30.“,“,“-‘”