• Once genes profiling in keratinocytes between lesional and nonlesional skin is accomplished, we would like to characterize these keratinocyte populations after therapy.
  

• Keratinocytes have not been studied by gene expression analysis in this setting. The results from microarray analysis will be useful to see if the difference between lesional and nonlesional gene expression is reversed by therapy.
  

Vitiligo is a disease caused by the disappearance of melanocytes in the epidermis. The pathogenesis of vitiligo is multifactorial. Theories include autoimmunity, neural, apoptosis and cytotoxicity. The medical treatments for vitiligo are marginal with a 40-60% response rate which does not guarantee full repigmentation. Understanding the pathogenesis of vitiligo will allow better targets for treatment.

Previous analysis of skin biopsies have found several of the changes in gene expression occurred in immune regulation, DNA replication and repair, oncogenes, signal transducers and transcription factors. These results give us insight as to what happens in lesional vs nonlesional skin which contains the epidermis, dermis, fat, blood vessels and immune cells.

We have the technology today to study specific cell populations from tissue by the use of laser capture microdissection. We propose to use this technique to study the keratinocyte population in vitiligo skin because past evidence suggests that they may play a role. In addition, the role keratinocytes in vitiligo may be important for treatment as this would be the ideal target for therapy. Keratinocytes have been studied in vitiligo.

The aim of the study is to isolate keratinocytes from normal skin, perilesional and lesional skin in vitiligo patients by laser capture microdissection and characterize their gene expression profile by gene microarray analysis and to compare keratinocyte gene expression in normal, perilesional and lesional vitiligo skin before and after narrow band UVB treatment.