Longitudinal study of cervical squamous intraepithelial lesions in human immunodeficiency virus (HIV)-seropositive and at-risk HIV-seronegative women.

We examined incidence and correlates of progression and regression of abnormal cervical cytologic test results, defined as at least low-grade squamous intraepithelial lesions (SILs), in 774 human immunodeficiency virus (HIV)-seropositive and 391 HIV-seronegative women monitored semiannually for up to 5.5 years. During follow-up, 224 (35%) HIV-seropositive women and 34 (9%) HIV-seronegative women had incident SILs detected by Pap test; 47 (7%) HIV-seropositive women developed high-grade lesions. The incidence of SILs was 11.5 cases among HIV-seropositive and 2.6 cases among HIV-seronegative women per 100 person-years of observation (rate ratio, 4.5; 95% confidence interval, 3.1-6.4; P<.001). Risk of incident SILs and likelihood of Pap test progression were increased among HIV-seropositive women with CD4(+) lymphocyte counts <500 cells/mm(3) and among women with human papillomavirus (HPV) infection, with risk-ordering from low- to high-risk HPV type. SIL regression was less likely among HIV-seropositive women with higher HIV loads. No beneficial effect of highly active antiretroviral therapy was demonstrated.