A possible role for CD8+ T lymphocytes in the cell-mediated pathogenesis of pemphigus vulgaris.

Pemphigus vulgaris (PV) is an autoimmune blistering disease whose pathogenesis involves both humoral and cell-mediated immune response. Though the pathogenetic role of autoantibodies directed against desmoglein 3 is certain, a number of other factors have been suggested to determine acantholysis in PV. In this study we examined the possible role of CD8+ T cells in the development of acantholysis by a passive transfer of PV autoantibodies using CD8 deficient mice, and we also studied the inflammatory infiltrate of PV skin lesions by immunohistochemical staining. The results of the immunohistochemical staining to study the expression of CD3, CD4, and CD8 in PV skin lesions showed that CD4+ are more expressed than CD8+ in the inflammatory infiltrate of PV lesions, confirming the data of the previous literature. The passive transfer study showed a lower incidence of pemphigus in the group of CD8 deficient mice compared to the control one of wild-type mice. These results suggest that CD8+ T cells may play a role in the pathogenesis of PV, perhaps through the Fas/FasL pathway.

Polyglandular autoimmune diseases in a dermatological clinical setting: vitiligo-associated autoimmune diseases.

Vitiligo is an acquired hypomelanotic disorder characterized by depigmented macules resulting from the loss of functional melanocytes. Many different etiological hypotheses have been suggested for vitiligo, the most recent of which involves a combination of interacting environmental and genetic factors. Among the various pieces of evidence in support of an autoimmune origin of vitiligo, there is the epidemiological association with several autoimmune diseases. The most frequently reported association is with autoimmune thyroiditis; however, other diseases such as rheumatoid arthritis, diabetes mellitus, pernicious anemia and chronic urticaria have been described in variable percentages, depending upon the genetics of the population studied. Among the diseases described in association with vitiligo there are the so-called autoimmune polyglandular syndromes (APS). Here we report 31 cases of APS diagnosed in 113 vitiligo patients, according to the newest classification. Autoimmune association was more present in generalized non segmental vitiligo and was more frequent in females. The most frequent association was with thyroid autoimmune disease, followed by autoimmune gastritis and alopecia areata. ANA positivity was similar to that reported previously in the general population. We stress the importance of an assessment for autoimmune diseases in vitiligo patients.