Dendritic cells: ultrastructural and immunophenotypical changes upon nb-UVB in vitiligo skin

Abstract

The role of dendritic cells in vitiligo is still unclear. Few studies have provided contradictory results about their quantitative variation and no data exist concerning their immunophenotypical distribution in diseased skin. The purpose of our study was to analyze the presence, the distribution, the immunophenotypical markers and the effects of nb-UVB therapy on dendritic cells in nonlesional, perilesional, and lesional vitiligo skin. Punchbiopsies of 6 mm were taken from lesional, perilesional, and non-lesional skin of 12 patients affected by nonsegmental vitiligo, treated with nb-UVB. An immunohistochemical and an ultrastructural analysis were performed. Immunohistochemical and ultrastructural analysis showed both quantitative and qualitative modifications of Langerhans cells. Nb-UVB therapy, one of the most effective treatments for the disease, was able to reduce the Langerhans cells number and to redistribute main dendritic subsets. This study underlines the importance of dendritic cells, Langerhans cells in particular, in non-segmental vitiligo, in its pathogenesis and in its better therapeutical approach.

Treatment of Non-Segmental Vitiligo with Narrowband UVB Phototherapy (311 Nm): Clinical Efficacy and Mechanisms of Action

“…al. [22] and also confirms data obtained by K. Taguchi et al [32] regarding an important role of these cells in immunosupressive effects of narrowband UVB phototherapy.…”

“…Moreover, we found a significant increase in the quantity of CD83+ dendritic cells in all three zones of vitiligo lesions. There are very few publications indicating involvement of CD83+ cells in vitiligo disease process [22]. CD83 molecule is a marker of the mature and activated dendritic cells [23].…”

Mechanisms of melanocyte death in vitiligo

“…But the efficacy of vitamin D in vitiligo treatment still warrants clarification. And the phototherapy, NB‐UVB might also be associated with decreased Langerhans cell distribution in vitiligo epidermis after treatment 153 …”

Vitiligo road map

“…Phosphorylated focal adhesion kinase (p125 FAK ) and MMP‐2, both of which are critical for melanocyte migration, are significantly elevated in NB UVB‐irradiated melanocytes . Langerhans cells, suspected of having an essential role in the pathogenesis of vitiligo, are reduced in number following NB UVB therapy . A study examining the efficacy of different combination therapies with NB UVB (tacrolimus, pimecrolimus, betamethasone, calcipotriol, phenylalanine) has revealed the highest repigmentation rate is achieved with 0.05% betamethasone dipropionate cream plus 311‐nm NB UVB microfocused phototherapy .…”