ABSENCE OF MERKEL CELLS IN LESIONAL SKIN

Background. In vitiligo, other than loss of melanocytes and melanin pigment in the lesional skin, keratinocytes are also involved. Human fetal Merkel cells are now generally considered to be derived from the epidermis.1 To date, no observations on Merkel cells in lesional skin of active vitiligo have been reported. Methods. Merkel cells were identified by indirect immunofluorescence microscopy using the monoclonal antibody TROMA 1. Results. No TROMA 1-positive cells were observed in the vitiliginous skin lesions in any of the specimens examined, whereas normal numbers of these cells were seen in the adjacent pigmented skin. Conclusions. This finding suggests that the processes that lead to damage of keratinocytes in vitiligo also involve other keratin-expressing cells such as the Merkel cells.