Evaluation of the Langerhans cells role in vitiligo and its relationship to NB-UVB

Background: Langerhans cells (LCs) are antigen-presenting cells that are characterized by CD1a and CD207/langerin expression. The disturbance in the communication network among keratinocytes, melanocytes, and antigen-presenting cells may be involved in vitiligo pathogenesis.

Aims: The current work aims to detect and quantify LCs in involved skin of patients affected by vitiligo before and after treatment with NB-UVB using CD1a immunohistochemistry, in addition to correlate percentage of LCs with the clinicopathological parameters.

Methods: Twenty vitiligo patients and 10 age and sex matched controls were investigated. Patients were received NB-UVB thrice weekly for 12 weeks.

Results: There was a significant reduction in LCs percentage in skin affected by vitiligo before treatment in comparison with normal skin. About 65% (13/20) of vitiligo patients responded to NB-UVB, and the liability to respond was correlated with LCs percentage in specimens before treatment. However, there was no statistical difference between specimens before and after treatment regarding LCs percentage.

Conclusions: Reduction in LCs in vitiligo may be a sign of active disease and melanocytes destruction. The percentage of LCs affects response to NB-UVB since higher percentage is associated with greater response to therapy. Therefore, modulation of LCs as a type of immunotherapy could be beneficial in improvement of vitiligo.