Ultraviolet radiation intensity predicts the relative distribution of dermatomyositis and anti–Mi-2 autoantibodies in women
Version of Record online: 30 JUL 2009
Copyright © 2009 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 60, Issue 8, pages 2499–2504, August 2009
How to Cite
Love, L. A., Weinberg, C. R., McConnaughey, D. R., Oddis, C. V., Medsger, T. A., Reveille, J. D., Arnett, F. C., Targoff, I. N. and Miller, F. W. (2009), Ultraviolet radiation intensity predicts the relative distribution of dermatomyositis and anti–Mi-2 autoantibodies in women. Arthritis & Rheumatism, 60: 2499–2504. doi: 10.1002/art.24702
- Issue online: 30 JUL 2009
- Version of Record online: 30 JUL 2009
- Manuscript Accepted: 1 MAY 2009
- Manuscript Received: 23 JAN 2009
- Intramural Research programs of the National Institute of Environmental Health Sciences, NIH
Because studies suggest that ultraviolet (UV) radiation modulates the myositis phenotype and Mi-2 autoantigen expression, we conducted a retrospective investigation to determine whether UV radiation may influence the relative prevalence of dermatomyositis and anti–Mi-2 autoantibodies in the US.
We assessed the relationship between surface UV radiation intensity in the state of residence at the time of onset with the relative prevalence of dermatomyositis and myositis autoantibodies in 380 patients with myositis from referral centers in the US. Myositis autoantibodies were detected by validated immunoprecipitation assays. Surface UV radiation intensity was estimated from UV Index data collected by the US National Weather Service.
UV radiation intensity was associated with the relative proportion of patients with dermatomyositis (odds ratio [OR] 2.3, 95% confidence interval [95% CI] 0.9–5.8) and with the proportion of patients expressing anti–Mi-2 autoantibodies (OR 6.0, 95% CI 1.1–34.1). Modeling of these data showed that these associations were confined to women (OR 3.8, 95% CI 1.3–11.0 and OR 17.3, 95% CI 1.8–162.4, respectively) and suggests that sex influences the effects of UV radiation on autoimmune disorders. Significant associations were not observed in men, nor were UV radiation levels related to the presence of antisynthetase or anti–signal recognition particle autoantibodies.
This first study of the distribution of myositis phenotypes and UV radiation exposure in the US showed that UV radiation may modulate the clinical and immunologic expression of autoimmune disease in women. Further investigation of the mechanisms by which these effects are produced may provide insights into pathogenesis and suggest therapeutic or preventative strategies.