Travel to sunny countries is associated with changes in immunological parameters

Abstract

Under laboratory conditions, various studies have shown that changes in immunological parameters must be expected after exposure to ultraviolet (UV) light. The objective of the present study was to evaluate, whether such changes can also be revealed after a vacation to a sunny country without prior adaptation to ultraviolet radiation. In 32 volunteers white blood cells, lymphocyte subpopulations, sIL2-R, sCD14, immunoglobulins and complement factor C3 were determined before and after a vacation in a country with abundant sunshine during winter. The subjects received relevant doses of UVB as confirmed by questionnaires, UVB-dosimetry and the significant increase of 25-hydroxyvitamin D. After vacation, there was a significant decrease of the CD4/8 ratio and the serum concentration of IgG. The serum concentration of sIL2-R, sCD14, IgA and C3 was increased after the journey. Sunshine exposure without prior adaptation may be responsible for significant alterations in the immune system in association with a vacation during winter.

The Essential Role of Epstein-Barr Virus in the Pathogenesis of Multiple Sclerosis

“…Exposure to natural sunlight or treatment in a solarium increases the proportion of CD8+ T cells and decreases the CD4/CD8 T cell ratio in peripheral blood (Hersey and others 1983a; Hersey and others 1983b; Falkenbach and Sedlmeyer 1997). Exactly how sunlight increases the number of CD8+ T cells is unclear, but the effect is probably mediated at least in part by vitamin D because (1) among cells of the immune system, activated CD8+ T cells express the highest concentrations of the vitamin D receptor (Veldman and others 2000); (2) vitamin D increases the mitogen-induced proliferation of CD8+ T cells and decreases the CD4/CD8 ratio in bovine PBMC in vitro (Nonnecke and others 1993); (3) vitamin D administration increases the CD8+ T cell count (Žofková and Kancheva 1997); and (4) vitamin D deficiency is associated with a decreased proportion of CD8+ T cells and increased CD4/CD8 ratio (Çakmak and others 1999).…”

Hypothesis—Ultraviolet‐B Irradiance and Vitamin D Reduce the Risk of Viral Infections and thus Their Sequelae, Including Autoimmune Diseases and some Cancers†

“…Once MS develops, UVB and vitamin D can reduce the severity of the disease. The mechanism seems to be vitamin D‐induced apoptosis of CD4 T lymphocytes (57).…”

Linkage analysis of variations in CD4:CD8 T cell subsets between C57BL/6 and DBA/2

“…[5][6][7][8] Autoimmunity, diet and even exposure to sunshine have been reported to affect the ratio. [9][10][11] Although environmental and other factors may affect the numbers of CD4 to CD8 T cells in an individual, it is clear that the ratio is also under genetic control. [12][13][14] Since the maturation of CD4 and CD8 T cells is controlled by interactions of their ␣␤ T cell receptors with class II and class I major histocompatibility complex proteins (MHC) and peptides in the thymus, one would predict that CD4 to CD8 ratios would be affected by TCR and MHC genes.…”