Insights from a trial of narrowband UVB for early multiple sclerosis.

There is a greater prevalence of multiple sclerosis (MS), a neurological autoimmune condition, in populations living further from the equator, hypothesised to be due to reduced sunlight exposure. There exists a proven sunlight surrogate therapy for dermatological inflammatory conditions, in the form of narrowband (NB; 311-312 nm)-UVB phototherapy. Yet, there is a paucity of randomized trials of the therapeutic delivery of NB-UVB beyond dermatology for conditions with a systemic inflammatory component. To investigate the potential for use in MS, the PhoCIS trial (narrowband UVB phototherapy for Clinically Isolated Syndrome)(ACTRN 12614000185662), was established. Participants with Clinically Isolated Syndrome, the earliest symptomatic form of MS, were given NB-UVB (24 sessions over 8 weeks) and followed for 12 months. The published clinical, immunological, and quality of life results from the PhoCIS trial have uncovered new evidence of systemic immune stabilisation by NB-UVB. This perspective provides the first unified overview of these results to inspire future randomised trials of NB-UVB across other autoimmune diseases which share both prevalence that follows UVB exposure, and systemic immune dysregulation.