THE SENSITIVITY OF CERVICAL CYTOLOGY IN HIV-INFECTED WOMEN

Abstract

BACKGROUND: Studies demonstrating a high prevalence of abnormal Pap smears and cervical intraepithelial neoplasia (CIN) in HIV-infected women have led to concerns about appropriate surveillance measures. The objective of this evaluation was to determine the specificity and sensitivity of cervical cytology in a large group of HIV-infected women. METHODS: From 1991 to 1994, 285 HIV-infected women were enrolled in a prospective cohort study of the natural history of HIV disease and associated gynecologic manifestations. The baseline examination included cervical cytology, colposcopy and colposcopically directed biopsy. If no lesion was visualized colposcopically, a biopsy was taken of the transformation zone. All cytology slides were reviewed by a senior cytologist after initial evaluation. All histopathology slides were reviewed by an experienced pathologist blinded to the woman's HIV status. RESULTS: Among 249 HIV-infected women who had cervical cytology, colposcopy and cervical biopsy, 32.4% had abnormal cytology, including 8.8% with atypical squamous cells of undetermined significance (ASCUS), 15.6% with low grade squamous intraepithelial lesions (SIL) and 8.0% with high grade SIL. On colposcopic visualization, 75% had lesions consistent with CIN or condylomatous lesions. Histology showed CIN1 in 19.3%, CIN2 in 7.6%, and CIN3 in 4.0%. The sensitivity and specificity of cytology for CIN of all grades were 0.60 and 0.80 respectively. For high grade CIN, the sensitivity and specificity were 0.83 and 0.74. The false negative rate of normal smears was 18% with 5 cases of CIN 2-3 and 26 of CIN 1. All women with CIN 2-3 had either an abnormal smear or a lesion on colposcopy. However, 15% of women with normal smears and no colposcopic evidence of CIN had CIN 1 on biopsy. CONCLUSION: Cervical cytology in HIV-infected women has sensitivity and specificity within the range reported in normal populations. However, the high prevalence of CIN in the immunodeficient suggest that colposcopy or other tests should supplement cytology because of its inherent limited sensitivity. Studies of the potential for progression of CIN in HIV-infected women are needed to resolve questions on appropriate screening protocols.