RELATION BETWEEN HLA ANTIGENS AND SKIN-CANCER IN RENAL-TRANSPLANT RECIPIENTS IN QUEENSLAND, AUSTRALIA

On the basis of previous studies that showed a negative association be tween HLA-A11 and skin cancer in renal transplant recipients and a pos itive association with HLA-B27 and HLA-DR7, we performed a study in Qu eensland with 1098 recipients to address the question of whether the s ame associations could be found, The influence of HLA mismatching and HLA homozygosity on the risk of skin cancer was also studied, In contr ast to earlier studies, HLA-A11 was associated with an increased risk of skin cancer, On the other hand, we confirmed that the HLA-B27 antig en was associated with the development of skin cancer, but only when t he development of basal cell carcinomas alone was considered, and we c onfirmed that there is a weak but not statistically significant associ ation with HLA-DR7, No association between HLA mismatching or HLA homo zygosity and the development of skin cancer was observed, Environmenta l factors such as different levels of exposure to sunlight and infecti on with human papillomaviruses are factors that are most likely to be involved, We hypothesize that human papillomavirus-induced antigens pr evail in the skin cancers in the recipients living in the Netherlands, whereas antigens induced by solar radiation, the so-called ''photo-an tigens,'' may be more common in the skin cancers of the recipients liv ing in Queensland. Exposure to sunlight can also induce immunologic un responsiveness, and excessive exposure to sunlight in Australia may, t herefore, simply override the risk factors that are important in count ries with a more temperate climate.