HLA EXPRESSION IN PREINVASIVE CERVICAL NEOPLASIA IN RELATION TO HUMANPAPILLOMA-VIRUS INFECTION

A significant proportion of cervical carcinomas show loss of major his tocompatibility complex human leucocyte antigen (HLA) class I expressi on while upregulating HLA class II expression. These changes may have direct consequences for immune surveillance of the human papilloma vir us (HPV) infection which is strongly associated with cervical malignan cy. A relationship between changes in HLA expression and HPV infection may be evident in the evolution of premalignant disease. This immunoh istological study of 104 colposcopic biopsies establishes that HLA cla ss II expression occurs in a significant proportion of squamous epithe lia showing histological evidence of war virus infection and cervical intraepithelial neoplasia (CIN) I to III. In comparison, alteration of HLA class I expression in cervical premalignant lesions is rare. Ther e is no correlation between the detection of high risk HPV DNA (types 16, 18, 31 and 33) by polymerase chain reaction (PCR) and the MHC clas s II phenotype of the lesion. This suggests that altered HLA class II expression is neither a consequence nor a prerequisite for HPV infecti on.