Persistence of human papillomavirus type 16 infection is associated with lack of cytotoxic T lymphocyte response to the E6 antigens

Our cross-sectional study suggested that cytotoxic T lymphocyte (CTL) respo nses have a protective effect in squamous intraepithelial lesion (SIL) deve lopment. More CTL responses in women with human papillomavirus type 16 (HPV 16) infection without SILs than with SILs were detected. In the current lo ngitudinal study, the role of CTL in clearing HPV 16 infection in women wit hout SILs was investigated, Women with HPV 16 infection (n = 51) were enrol led, along with HPV 16-negative control women (n = 3), Twenty-two (55%) of 40 women who cleared HPV 16 infection had an E6 CTL response at least once, compared with none of 9 women who had HPV 16 persistence (P = .003), Such a difference was not demonstrated for E7; 25 (63%) of 40 women who cleared HPV 16 infection responded, versus 5 (56%) of 9 women with persistence (P = .720), It appears that lack of response to E6 is important in the persiste nce of HPV 16 infection.