الفهرس 
Biology of MelanocytesOnly 14 pages are availabe for public view
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Abstract
Vitiligo is an acquired, idiopathic leukoderma that is manifested by depigmented macules and patches of variable shape and size, due to melanocytes loss. Vitiligo can appear at any time, and it highly impairs the quality of life of patients The exact cause of vitiligo is still obscure. Many factors have been implicated in its development as stress, infection, neural abnormalities, autoimmunity, genetic susceptibility, melatonin receptor dysfunction, self-destruction and impaired melanocyte migration. Interleukin 33 is one of the most important discovered IL-1 family members. IL33 was initially discovered as a nuclear factor, and then described as an extracellular ligand for ST2 receptor. IL-33 can bind to the cell-surface receptor ST2, leading to the activation of intracellular signaling pathways. In contrast with other conventional cytokines, IL-33 can be secreted by unconventional pathways, and can be released by epithelial and endothelial cells after tissue trauma or necrosis. The aim of the work was to evaluate serum level of interleukin-33 in non-segmental vitiligo patients and to correlate its relationship with disease activity and extent. The study included 50 patients with non-segmental vitiligo and 50 age and sex matched healthy individuals served as a control group. Patients and controls were subjected to: • Complete history taking • General and dermatological examination • Wood’s light examination. • Laboratory investigation including serum level of interleukin 33 The results of this study revealed the followings: Clinical results • The mean age of patients in patients’ group was 31.74±17.19 years with a range of 10–60 years, whereas in control group the mean age was 30.32±15.52 years with a range 10-60 years. • The patients’ group included 60% females and 40% males while control group included 58% Females and 42% males. • There was positive family history in 20% of patients. • The duration of vitiligo ranged from 1 to 30 years, with a mean of 3.84±4.69. • Koebner phenomena were positive in 26 patients (52%). • 38% of the studied patients had vitiligo vulgaris, 32% had the acral type, 16% had the acro-facial type and 14% had the focal type. • As regards Vitiligo Disease Activity Score (VIDA score), there were 10 patients (20%) of grade (+ 4), 13 patients (26%) of grade (+3) , 8 patients (16%) of grade (+2), 11 patients (22%) of grade (+1) and 8 patients (16%) of grade (0). • Vitiligo Area Score Index ranges from 5- 95 % with mean 45.20 ± 23.52 Laboratory results The serum level of IL-33 is statistically significantly increased in patients’ group compared to controls (P. value < 0.001*). Its mean ± SD is 11.86±8.21 in patients’ group while 6.28±0.73 in control group. Clinico-serological correlations • There is significant increase in serum IL-33 level in patients with active disease as compared to patients with stable course (P. value < 0.001*). • There is significant positive correlation between serum IL-33 level and koebner phenomena (P. value < 0.001*). • There is significant positive correlation between the serum IL-33 level and VIDA score (P. value < 0.001*). • There is no significant correlation between serum IL-33 level and different types of vitiligo. • There is no significant correlation between serum IL-33 level and age, sex, family history, duration of disease, different types of vitiligo and VASI score.