Narrowband UVB Phototherapy for Clinically Isolated Syndrome: A Trial to Deliver the Benefits of Vitamin D and Other UVB-Induced Molecules

Abstract

Low vitamin D and insufficient sun exposure are additive independent risk factors for the development of multiple sclerosis (MS). The usual measure of vitamin D status, serum 25-hydroxy vitamin D [25(OH)D], is also a marker of recent exposure to the UVB rays of sunshine. The main evidence for a protective effect for MS development of higher 25(OH)D comes from observational studies, but this study design cannot separate out whether 25(OH)D is acting as a marker of vitamin D status, sun exposure, or both. In light of a lack of definitive outcomes in MS patients after trials of vitamin D supplementation and the ability of narrowband UVB to induce vitamin D, as well as other immune-regulatory molecules in skin, the Phototherapy for Clinically Isolated Syndrome (PhoCIS) trial was established to investigate the benefits of narrowband UVB, in addition to supplemented vitamin D, on MS development in individuals with Clinically Isolated Syndrome. We propose that the PhoCIS trial provides a fresh approach to re-defining the reported associations of 25(OH)D levels with MS development and progression.

Keywords: UV-induced immunosuppression; clinically isolated syndrome; multiple sclerosis; narrowband UVB phototherapy; trial; vitamin D; vitamin D supplementation.

Figure 1

Flow chart of the study design for Phototherapy for Clinically Isolated Syndrome. Participants are in the study for 12 months with half given narrowband UVB phototherapy. Blood is collected at the time of enrollment and after 7 days and 1, 2, 3, 6, and 12 months. Narrow band phototherapy is delivered three times per week for the first 8 weeks of their participation in the trial. Progression is monitored by MRIs after 3, 6, and 12 months.