ULTRAVIOLET-B INDUCED SUPPRESSION OF INDUCTION OF CONTACT SENSITIVITYIN HUMAN SKIN IS NOT ASSOCIATED WITH TUMOR NECROSIS FACTOR-ALPHA-308 OR INTERLEUKIN-10 GENETIC POLYMORPHISMS

Low doses of ultraviolet B (UVB) can induce localized immunosuppressio n in skin. This effect may be important in the induction of skin cance rs and is thought to be mediated by tumour necrosis factor (TNF) (alph a and interleukin (IL) 10 iii conjunction with other factors. In human s a transition polymorphism in the TNF-alpha gene may affect TNF-alpha secretion and the promoter region of the IL-10 gene contains a CA rep eat polymorphism which may affect gene function. We have therefore inv estigated the association of these polymorphisms with WE-induced immun osuppression in humans. Volunteers (n=42) were irradiated with UVB the n sensitized on irradiated skin with diphenylcyclopropanone (DPCP) and subsequently antigen challenged with DPCP, DNA was extracted from blo od samples and volunteers genotyped for the TNF-alpha polymorphism by polymerase chain reaction (PCR) and restriction digestion, The CA repe at polymorphism was amplified by PCR and sized by gel electrophoresis. Twenty-four volunteers were susceptible to UVB-induced immunosuppress ion and 18 were resistant, The association of allele frequencies and p henotype was statistically tested using a chi(2)-test, For both the TN F-alpha and IL-10 polymorphisms, there was no statistically significan t association between allele types and response to UVB. These results indicate that variation in the immune response to UVB in humans is not associated with the TNF-alpha-308 transition or IL-10 CA repeat polym orphisms, although other as yet undetected DNA sequence variants of th ese genes may be involved.