Regression of melanoma, but not keratoacanthoma, is associated with increased HLA-B22 and decreased HLA-B27 and HLA-DR1

Sixty three Caucasian patients with either melanoma, keratoacanthoma or squ amous cell carcinoma were human leucocyte antigen (HLA) typed. The regressi ng tumour groups were compared with their non-regressing counterparts, and the patient groups were compared with a control Caucasian population. Melan oma patients showing histological regression were more likely to be HLA-B22 positive, and HLA-B27 and -DR1 negative, than those without features of re gression. When compared with a control population, the group of melanoma pa tients were more likely to be HLA-B22 positive. Comparison of the group of keratoacanthomas, a self-regressing tumour, and the group of squamous cell carcinomas, a non-regressing tumour, did not show any significant differenc es in HLA typing. (C) 1999 Lippincott Williams & Wilkins.