Study of the relation between two common cyclooxygenase 2 gene polymorphisms with risk of developing and subtypes of vitiligo in Egyptian patients

Background/Purpose: Genetic factors play an important role in the pathogenesis of vitiligo. Cyclooxygenase 2 (COX2) gene induced by ultraviolet radiation controls the synthesis of prostaglandins, which are are found to be beneficial in treating vitiligo. COX2 gene polymorphism has been previously evaluated in Chinese population. We aimed to study the relation between two common COX2 gene polymorphisms with vitiligo and its subtypes amongEgyptian patients. Patients and Methods: This study included 200 participants (100 vitiligo patients and 100 healthy controls). COX2-765G/C and -1195A/G gene polymorphism was studied by restriction fragment length polymorphism polymerase chain reaction analysis and the results were compared between the two groups and among different subtypes of vitiligo. Results: Frequency of COX2-1195 AA, AG, GG genotypes showed no significant association among patients with vitiligo (P = 0.626, 0.321, 0.08, respectively); those with generalized vitiligo (P = 0.739, 0.291, 0.101, respectively) and those with segmental vitiligo (P = 0.410, 1.00, 0.676, respectively) compared to the control group. Regarding COX2-765G/C genotypes, GG genotype was more frequent among patients with vitiligo [84 (84%)] compared to controls [63 (63%)] (P = 0.001). GC genotype was significantly less frequent [15 (15%)] among patients compared to controls [32 (32%)] (P = 0.005). Generalized and segmental types of vitiligo also showed no significant difference in the frequency of COX2-765G/C genotypes compared with controls. Limitations: Being a pilot study, a relatively small number of participants were included. Conclusion: COX2-1195A/G gene polymorphism is not associated with the risk of developing vitiligo or with vitiligo subtypes. COX2-765 GG genotype is associated with vitiligo, especially of the generalized type.

Study of serum levels and skin expression of S100B protein in psoriasis

Abstract Background: S100B protein was reported to be elevated in psoriatic patients' serum, with no previous evaluation of its skin expression, in contrast to the extensively studied S100 protein. Objective: To evaluate the serum level and skin expression of S100B in psoriasis to assess its possible involvement in its pathogenesis. Methods: Serum level of S100B protein was estimated in 40 psoriatic patients of different clinical varieties and 10 healthy controls. S100B protein expression was assessed immunohistochemically in lesional and non-lesional skin of patients and in normal skin of controls. Relation to disease severity was also evaluated. Results: Serum level of S100B protein was significantly higher in psoriatic patients (0.15±0.03 µg/l) than in controls (0.03±0.007 µg/l) (P-value <0.001) with no significant correlation with PASI score. On comparing grades of S100B protein skin expression in lesional and non-lesional skin biopsies, a statistically significant difference was found (P=0.046) with higher percentage of strong S100B skin expression (60%) in non-lesional than in lesional (42%) skin. All the control biopsies showed negative expression. Study limitations: Relatively small sample size with a limited range of low PASI scores. Conclusion: This study points to a potential link between psoriasis and S100B protein with higher serum and skin expression in patients than in controls.