Risk factors for squamous intraepithelial lesions on Pap smear in women at risk for human immunodeficiency virus infection.

To determine risk factors for squamous intraepithelial lesions (SIL) on Pap smear, 253 women at risk for human immunodeficiency virus (HIV) infection had Pap smear, HIV antibody testing, CD4+ cell measurements, and human papillomavirus (HPV) genome detection by Southern blot hybridization. Associated with SIL (P < .05) on univariate analysis were genital HPV (SIL prevalence in HPV-positive subjects, 36.3%; odds ratio [OR], 9.3; 95% confidence interval [CI], 4.2-20.3) and HIV infection (SIL prevalence in seropositive subjects, 21.9%; OR, 2.5; 95% CI, 1.2-5.1). No demographic or behavioral variables were associated with risk for SIL. Multivariate analyses identified genital HPV infection (OR, 6.78; 95% CI, 2.9-15.7), detection of known high-risk HPV types (OR, 11.8; 95% CI, 4.1-34.1), strong HPV Southern blot signal strength (OR, 10.8; 95% CI, 3.5-33.7), and severe HIV-related immunosuppression (OR, 3.1; 95% CI, 1.04-9.5) as independent risk factors associated with SIL. Thus, severe immunosuppression due to HIV infection increases the risk for SIL mediated by HPV infection.