New insights into leukotrichia in nonsegmental vitiligo: A cross-sectional study.

BACKGROUND: Leukotrichia has been considered a predictor of poor outcome in vitiligo. However, studies considering the different clinical aspects of leukotrichia in vitiligo patients are few. AIM: Our aim was to conduct a detailed clinical study to provide insights into the relevance and associations of leukotrichia in non-segmental vitiligo. METHODS: In this cross-sectional study, vitiligo patients attending the dermatology outpatient clinic and phototherapy unit at Cairo University Hospital over a period of 6 months (April-September 2016) were included. Family history, clinical details, the Vitiligo Global Issues Consensus Conference classification, the Dermatology Life Quality Index, Vitiligo Area and Severity Index, Vitiligo Extent Score, Vitiligo Disease Activity Score and Vellus Score were determined and these measurements were correlated to leukotrichia. RESULTS: Out of the 101 patients studied, leukotrichia was found in 47 (46.5%) patients, with vellus hair involved in 37 (78.7%), terminal hairs in 30 (63.8%) and both in 20 (42.5%) patients. Vellus hair involvement was significantly higher in generalized bilaterally symmetrical vitiligo than in acrofacial or unclassified vitiligo. The incidence of scalp leukotrichia also was higher in generalized symmetrical vitiligo than in acrofacial vitiligo. The Vellus Score showed significant associations with Vitiligo Area and Severity Index, Vitiligo Extent Score and the Dermatology Life Quality Index. LIMITATIONS: This was a short-term study with a small sample size. Prognostic and therapeutic correlations were not studied; prospective longitudinal studies are needed for further evaluation. CONCLUSION: Leukotrichia was found in almost half of the studied sample and its frequency varied among the different types of vitiligo.

Development of melanocye-keratinocyte co-culture model for controls and vitiligo to assess regulators of pigmentation and melanocytes.

BACKGROUND: There is a need to develop an in vitro skin models which can be used as alternative system for research and testing pharmacological products in place of laboratory animals. Therefore to study the biology and pathophysiology of pigmentation and vitiligo, reliable in vitro skin pigmentation models are required. AIM: In this study, we used primary cultured melanocytes and keratinocytes to prepare the skin co-culture model in control and vitiligo patients. METHODS: The skin grafts were taken from control and patients of vitiligo. In vitro co-culture was prepared after culturing primary melanocytes and keratinocytes. Co- cultures were treated with melanogenic stimulators and inhibitors and after that tyrosinase assay, MTT assay and melanin content assay were performed. RESULTS: Melanocytes and keratinocytes were successfully cultured from control and vitiligo patients and after that co-culture models were prepared. After treatment of co-culture model with melanogenic stimulator we found that tyrosinase activity, cell proliferation and melanin content increased whereas after treatment with melanogenic inhibitor, tyrosinase activity, cell proliferation and melanin content decreased. We also found some differences in the control co-culture model and vitiligo co-culture model. CONCLUSION: We successfully constructed in vitro co-culture pigmentation model for control and vitiligo patients using primary cultured melanocytes and keratinocytes. The use of primary melanocytes and keratinocytes is more appropriate over the use of transformed cells. The only limitation of these models is that these can be used for screening small numbers of compounds.