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Serum 5‐ S ‐cysteinyldopa levels in patients with psoriasis undergoing narrowband ultraviolet B phototherapy
Author(s) -
Kikuchi K.,
Wakamatsu K.,
Tada Y.,
Komine M.,
Ito S.,
Tamaki K.
Publication year - 2008
Publication title -
clinical and experimental dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 78
eISSN - 1365-2230
pISSN - 0307-6938
DOI - 10.1111/j.1365-2230.2008.02792.x
Subject(s) - psoriasis , ultraviolet b , medicine , dermatology , narrowband , ultraviolet therapy , ultraviolet , optics , physics
Summary Background. Ultraviolet (UV) B radiation from sunlight can result in tanning or burning of the skin. Narrowband UVB (NB‐UVB), a relatively new light source that is not yet widely available, is effective for treating generalized psoriasis without the use of psoralens. Aims. The melanin‐related metabolite 5‐ S ‐cysteinyldopa (5‐ S ‐CD), which reflects pheomelanin production, has been used as a biological marker of melanoma progression, but there are no studies available on therapeutic UVB effects on serum 5‐ S ‐CD of human subjects. In the present study, we measured the time course of changes in serum levels of 5‐ S ‐CD in patients with psoriasis undergoing NB‐UVB phototherapy. Methods. In total, 11 Japanese patients with generalized psoriasis vulgaris received NB‐UVB treatment five times per week, at an initial dose of 0.1 J/cm 2 . The dose was increased by 10–20% per treatment for > 20 treatments. Serum samples were taken before and 3, 7, 10, 14 and 28 days after phototherapy. Results. After 4 weeks of NB‐UVB treatment, 9 of 11 patients were in remission, confirming the effectiveness of NB‐UVB for treating Japanese patients with psoriasis. Two patients withdrew before day 28 because of other complications. Mean level of 5‐ S ‐CD in serum was significantly increased on day 7, 10 14 and 28 compared with the level before phototherapy and it peaked on day 10. Conclusions. Serum 5‐ S ‐CD levels were significantly increased by therapeutic UVB exposure. Sustained levels of 5‐ S ‐CD in serum appear to reflect the degree of skin injury during NB‐UVB phototherapy.