Bcl-2, active caspase-9 and inactive caspase-9 levels as markers of apoptosis in the serum and tissue of vitiligo patients

Abstract

Background Vitiligo is the most common depigmentation disorder of the skin. It is considered a multifactorial disorder. However, its exact etiology is unknown. As the acute inflammatory response is not a general finding in vitiligo, it was hypothesized that melanocytes may die in a controlled manner via apoptosis. Aim This study was done to evaluate Bcl-2, active caspase-9, and inactive caspase-9 levels in vitiligo in order to establish the role of apoptosis in the etiopathogenesis of vitiligo. Patients and methods We examined Bcl-2 (serum and tissue), active caspase-9 (serum) and inactive caspase-9 (tissue) levels of 48 vitiligo patients and 30 healthy volunteers by ELISA using commercial kits and immunohistochemically using the avidin–biotin immunoperoxidase complex technique. The collected data were analyzed by SPSS version 16. Results The mean age of vitiligo patients was 32.6±12.4 years. Of these, 65% of patients were women and 33% of patients have a positive family history. The mean vitiligo area scoring index was 5.84±6.57. Bcl-2 levels in the serum and tissues of patients were significantly lower than in controls. Bcl-2 expression in lesional skin was significantly lower than in the perilesional and unaffected skin. On the other hand, active caspase-9 level in patients’ serum was significantly higher than in controls. Inactive caspase-9 expression in lesional skin was significantly lower than in controls. Inactive caspase-9 expression in lesional skin was insignificantly lower than in the perilesional and unaffected skin. Conclusion Our data strongly support apoptosis rather than necrosis as a mechanism for melanocytes’ destruction in vitiligo.

Keywords

• active caspase-9
• apoptosis
• bcl-2
• inactive caspase-9
• vitiligo