Autoimmune Aspects of Vitiligo

Abstract

Vitiligo is a depigmenting disorder characterised by the loss of melanocytes from the cutaneous epidermis. Although the exact cause of the condition remains to be established, an autoimmune aetiology has been suggested and several observations support this theory. These will be the topic of discussion in this review. In brief, the disease is frequently associated with other disorders which have an autoimmune origin such as autoimmune thyroiditis and insulin-dependent diabetes mellitus. Furthermore, circulating antibodies and T lymphocytes which react against melanocyte antigens are present in the sera of a significant proportion of vitiligo patients compared with healthy individuals. Immunosuppressive therapies which are reasonably effective in treating the condition, well-studied animal models of the disease as well as the association of vitiligo with MHC antigens, all add credence to the hypothesis that immune mechanisms play a role in the development of vitiligo.

Vitiligo e emoções

“…O exame histopatológico padrão demonstra que o vitiligo compromete toda unidade melânica da pele, com anormalidades de melanócitos, de ceratinócitos e da célula de Langerhans, confirmadas por microscopia eletrônica. 1,2,3 A idade de surgimento das lesões é muito variável, sendo muito raro o aparecimento ao nascimento. Da mesma forma, a afecção pode surgir insidiosamente ou assumir uma evolução explosiva, tomando grandes áreas da superfície corporal em prazos menores de seis meses.…”

“…Os tipos básicos de distribuição são o segmentar e o não segmentar, sendo este o mais conhecido e paradigmáti-co da doença. 1,2,3 Existem diferentes teorias para explicar a origem do vitiligo, mas nenhuma delas consegue fazê-lo separadamente. Há a teoria autoimune, a teoria neurogênica, a teoria autotóxica e a teoria do estresse oxidativo, sem que se consiga determinar definitivamente a causa.…”

A single-nucleotide polymorphism in the gene encoding lymphoid protein tyrosine phosphatase (PTPN22) confers susceptibility to generalised vitiligo

“…Although the aetiology of vitiligo remains obscure, autoimmunity has been suggested to play a role in the pathogenesis of the disease. 1 Support for this theory arises from the frequent association of vitiligo with autoimmune disorders and the demonstration of autoantibodies to melanosomal proteins in the serum of patients with the disease. [2][3][4][5][6] More recently, autoreactive cytotoxic T lymphocytes (CTLs), which specifically recognise melanocyte differentiation antigens, have been detected in both the peripheral blood and perilesional skin of individuals with vitiligo.…”

Vitiligo and other hypopigmentation disorders in children and adolescents

“…As a possible theory for the etiology of vitiligo the following are cited: the autoimmune, oxidative stress theory (theory of self-destruction of melanocytes) and the neurogenic theory (1,2,3,4). Th e autoimmune theory is supported by experimental evidence and clinical association with other autoimmune diseases: pernicious anemia, Addison's disease, type 1 diabetes mellitus (T1DM), juvenile rheumatoid arthritis, alopecia areata and especially Hashimoto's thyroiditis (1,3,18,19,20,21). Vitiligo is relatively common in of autoimmune polyglandular insuffi ciency syndrome (APS), especially in type I (APS-I), where 25% of patients have vitiligo (22).…”