Selenium supplementation, soluble tumor necrosis factor-alpha receptor type 1, and C-reactive protein during psoriasis therapy with narrowband ultraviolet B

Abstract

Objective: We examined the influence of supplementation with selenomethionine on soluble tumor necrosis factor-alpha receptor type 1 (sTNF-R1) and C-reactive protein (CRP) concentrations in patients with psoriasis who were treated with narrowband ultraviolet B.

Methods: Thirty-seven patients had narrowband ultraviolet B therapy five times a week and received 200 mug of selenium daily as selenomethionine (group 1, n = 19) or placebo (group 2, n = 18) for 4 wk. Assessment, performed at baseline, after 2 and 4 wk, and 4 wk after the end of treatment included measurement of the Psoriasis Area and Severity Index (PASI) and serum concentrations of selenium (micrograms per liter), sTNF-R1 (nanograms per milliliter), and CRP (milligrams per liter). Control sera were obtained from 20 healthy volunteers.

Results: Baseline PASI was 12.70 +/- 5.48 (13.02 +/- 6.25 in group 1 and 12.37 +/- 4.71 in group 2), selenium concentration was 50.55 +/- 9.54 (49.05 +/- 10.38 and 52.13 +/- 8.61, respectively), sTNF-R1 concentration was 1.91 +/- 0.38 (1.96 +/- 0.37 and 1.87 +/- 0.40, respectively), and CRP concentration was 25.34 +/- 8.27 (26.12 +/- 8.42 and 24.57 +/- 7.72). In controls, selenium concentration was 48.71 +/- 9.39 (P > 0.05 versus patients), sTNF-R1 concentration was 1.48 +/- 0.30 (P < 0.05), CRP concentration was <6. The baseline sTNF-R1 level correlated to PASI value (r = 0.40, P < 0.05) and CRP concentration (r = 0.36, P > 0.05). The treatment resulted in an almost parallel decrease in PASI in both groups. At 4 wk after the end of treatment, selenium concentrations were 83.77 +/- 5.13 in group 1 and 52.12 +/- 7.54 in group 2 (P < 0.05), sTNF-R1 concentrations were 1.72 +/- 0.27 and 1.47 +/- 0.26 (P < 0.05), and CRP concentrations were 7.72 +/- 4.23 and 8.15 +/- 3.32, respectively (P > 0.05). Selenium concentration correlated inversely with CRP in group 1.

Conclusion: The results confirm that sTNF-R1 and CRP concentrations are increated in active psoriasis and that supplementation with selenomethionine for 4 wk in safe doses is ineffacious as adjuvant therapy in patients with psoriasis.