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- Exposure to sunlight
There is little reported research on the role of sunlight on risk or progression of HIV.
However, one such study was found, conducted in Baltimore, Maryland, finding a reduced rate of progression, although not statistically significant, to AIDS for those purposely seeking sun exposure (odds ratio, 0.67; 95% CI, 0.39-1.11; P = 0.12)1.
A study in Amsterdam found a possible effect of solar UV on cellular immunity of patients with HIV:
We analysed the immunological data of the HIV-infected homosexual men who participated in the Amsterdam Cohort Study on HIV infection and AIDS (1984-1996; n = 556). The effect of season on the individual development of various immunological parameters in time was examined by means of a random effects model for repeated measurements. Lower levels in the mean number of CD4+ T cells and the mean CD4+/CD8+ ratio were found during summer and spring, respectively (P = 0.0001/0.0001). For the CD8+ T cells, high mean values were observed both in April and September (P = 0.0001). The highest T-cell reactivity values were found during the summer (P = 0.0001). No effect of season on the viral load was established. The seasonal effect on CD4+ T cells seemed to be more pronounced at a more advanced stage of the HIV infection. It is concluded that the lower CD4+ T-cell counts during summer support the notion that solar UVR may have a suppressive effect on the cellular immunity of HIV-infected persons. However, whether this observation can be attributed to the effect of ambient UVR solely is questionable, as the other immunological parameters follow different seasonal courses and other reports suggest that both internal and environmental factors influence immunological parameters2.
However, those with HIV have an increased risk of non-melanoma skin cancer3. Although exposure to UV radiation is an important initiating factor in skin cancer, the exact relationship between non-melanoma skin cancer risk and nature, extent and timing of exposure remains poorly understood.
An emerging important risk factor for this kind of cancer is immunosuppression, In fact, immunosuppressive treatments seem to act as a catalyst for skin carcinogenesis as they increase the frequency, number and aggressiveness of such tumors4. However, increased UV irradiance may not be advisable for those with HIV/AIDS.
Page last edited: 09 May 2011
- Saah, A. J. Horn, T. D. Hoover, D. R. Chen, C. Whitmore, S. E. Flynn, C. Wesch, J. Detels, R. Anderson, R. Solar ultraviolet radiation exposure does not appear to exacerbate HIV infection in homosexual men. The Multicenter AIDS Cohort Study. AIDS. 1997 Nov 15; 11 (14): 1773-8.
- Termorshuizen, F. Geskus, R. B. Roos, M. T. Coutinho, R. A. Van Loveren, H. Seasonal influences on immunological parameters in HIV-infected homosexual men: searching for the immunomodulating effects of sunlight. Int J Hyg Environ Health. 2002 Jul; 205 (5): 379-84.
- Aubin, F. Parriaux, N. Robert, C. Blanc, D. Drobacheff, C. Laurent, R. Humbert, P. Cutaneous reaction to ultraviolet irradiation in human-immunodeficiency-virus-infected patients. A case-control study. Dermatology. 1999; 198 (3): 256-60.
- Euvrard, S. Kanitakis, J. Claudy, A. Skin cancers after organ transplantation. N Engl J Med. 2003 Apr 24; 348 (17): 1681-91.