A Favorable Clinical Trend Is Associated With CD8 T-Cell Immune Responses to the Human Papillomavirus Type 16 E6 Antigens in Women Being Studied for Abnormal Pap Smear Results

Objective. The goal of this study was to examine the role of CD8 T-cell responses to human papillomavirus type 16 (HPV-16) in a favorable clinical trend in women being studied for abnormal Pap smear results. Materials and Methods. Human papillomavirus-deoxyribonucleic acid testing and enzyme-linked immunospot assay using the HPV-16 E6 and E7 antigens were performed. The subjects with subsequent normal histologic diagnoses were considered to be regressors'' (n = 28), whereas those with histologic diagnoses of cervical intraepithelial neoplasia 1, 2, or 3 were considered to have short-term persistence of cervical abnormality and were designated to be persistors'' (n = 37). Results. There was a higher percentage of CD8 T-cell responses to the E6 antigen in the regressors (15/28 or 53.6%) when compared with the persistors (10/37 or 27.0%; p=.04), but there was no recorded response difference for the E7 antigen. Results were the same when the analyses for E6 included only subjects who were high-risk HPV-positive (p=.01). Conclusions. The CD8 T-cell immune responses to the HPV-16 E6 antigens but not to E7 antigens are associated with a favorable clinical trend regardless of HPV types currently detected.