Objectives: To compare the expression of Bcl-xl (antiapoptotic) and Bax (proapoptotic) factors in psoriatic patients treated with calcipotriol alone with those treated with combination of calcipotriol and mometasone furoate, also to compare the expression of these factors in keratinocytes of lesional with non lesional skin of psoriatic patients and of controls, and lastly to correlate the level of these parameters with the disease severity.
Methods: Forty patients with psoriasis vulgaris were divided into two groups: group 1 (n=20) treated with topical calcipotriol for 6 weeks and group 2 (n=20) treated with combination of calcipotriol and mometasone furoate for 6 weeks. Before treatment, two punch biopsies were taken from the patients, one from psoriatic plaque and the other from non lesional skin , a third biopsy was taken from the psoriatic plaques of the patients after treatment , also another biopsy was taken from ten healthy subjects served as controls. All specimens were fixed in 10% formalin and sent to be paraffin embedded. Three slides were made from each biopsy; one was stained with Hx & E for microscopic examination, while the other two were prepared for immunohistochemical study one for Bcl-xl and the other for Bax. The serum level of calcium was measured in all patients before and after treatment and in controls.
Results: BCL-xl expression in group 1 after treatment nearly reached that of non lesional skin and controls while in group 2 it showed significant increase than non lesional skin and controls (P <0.01 and P<0.04 respectively). BCL-xl in both groups after treatment were significantly lower than those before treatment (P<0.0001 for each). Before treatment, there was significant increase in the level of BCL-xl expression with increasing the PASI score (P<0.02), whereas after treatment there was no significant difference. The mean values of Bax expression in both groups after treatment were significantly higher than those in controls and non lesional skin (P < 0.0001 in group 1 versus controls, P <0.02 in group 2 versus controls and P < 0.0001 in both groups versus non lesional skin). There was no statistically significant difference between the level of Bax before and after treatment either in group 1 or 2; also there was no statistically significant difference in Bax with increasing the PASI score before or after treatment. As regard to the serum calcium level, no statistically significant difference was noticed between both groups before or after treatment and controls.
Conclusions: Our study provided that the treatment of psoriasis vulgaris with calcipotriol reduces the proliferation of epidermal keratinocytes through normalization of Bcl-xl expression. As regard to the combination of calcipotriol and mometasone furoate, Bcl-xl expression was also reduced but to a lesser degree than calcipotriol alone.