Local Cervical Immunity in Women with Low-grade Squamous Intraepithelial Lesions and Immune Responses After Abrasion

Minor trauma to the uterine cervix is supposed to induce local immunity to prevent cervical lesions causedby human papillomavirus (HPV) infection. This study aimed to investigate the local cervical immunity in womenwith low grade squamous intraepithelial lesion (LSIL) and effects of abrasion after cryosurgery or Pap smear.One hundred women with LSIL and known results of HPV detection were recruited. HPV positive women wererandomly divided according to abrasion into cryotherapy and Pap smear observation groups. Cervical tissuesand cervico-vaginal lavage (CVL) were collected at 6 and 12 months after allocation. The levels of cytokines atfirst recruitment were compared with cytokine levels at 6 months after abrasions. The mRNA of IFN-γ , TNF-αand IL-10 in cervical tissues and these cytokines secreted in CVL were determined using real time PCR andELISA, respectively. Anti-HPV16 IgG and IgA antibodies in CVL were assessed by western blotting. At firstrecruitment of women with LSIL (100 cases), IL-10 mRNA and cytokine in HPV positive group (60 cases) wassignificantly higher than negative group (40 cases). IFN-γ and TNF-α mRNA level in both groups were comparablebut their secretions in CVL were significantly increased in HPV negative group. After abrasion for 6 months inHPV-positive women, all mRNA and secreted cytokines were changed, but no significant difference was observedbetween cryotherapy and observation groups. When individuals were compared between first recruitment andafter abrasion for 6 months, IFN-γ mRNA and anti-HPV16 L1 IgA antibodies were significantly increased in thecryotherapy group. The results suggest that modulation of local cervical immunities by abrasion might promotedifferent effects in clearance of HPV-related cytological abnormalities.