Increased prevalence of squamous intraepithelial lesions in systemic lupus erythematosus: association with human papillomavirus infection

Abstract

Objective: To compare the prevalence of abnormal Pap smears in patients with systemic lupus erythematosus (SLE) with that in a large group of healthy controls, and to determine whether SLE itself is an independent risk factor. The association of human papillomavirus (HPV) infection and the use of immunosuppressive agents with abnormal Pap smears in SLE was also assessed.

Methods: Eighty-five SLE patients participated in this cross-sectional study. A sample of cervical cells was collected from each patient for routine cytologic examination. HPV was typed by restriction and sequencing analysis. A structured questionnaire was administered to the subjects to ascertain the possible behavioral and biologic risk factors associated with cervical atypia. Data on 2,080 healthy female subjects were retrieved for comparison.

Results: The mean (+/-SD) age of SLE patients and controls was 42 +/- 9 years and 44 +/- 10 years, respectively. The prevalence of abnormal Pap smears was significantly increased in SLE patients compared with controls (16.5% versus 5.7%). The prevalence of squamous intraepithelial lesions was increased approximately 6-fold in SLE patients (11.8%) compared with controls (2.0%). SLE itself remained an independent risk factor for abnormal Pap smears (odds ratio 3.5, 95% confidence interval 1.8-6.9). The overall prevalence of HPV infection in SLE patients and controls was 11.8% and 7.3%, respectively. However, 10.6% of SLE patients were infected with at least 1 high-risk type of HPV, compared with 4.2% of controls. Multiple infections were also more common in SLE patients than in controls (4.7% versus 1.1%). There were no significant differences in the use of immunosuppressive agents between SLE patients with normal Pap smears and those with abnormal Pap smears.

Conclusion: Abnormal Pap smears were more common among SLE patients than controls, even after adjusting for HPV status. SLE-associated immunosuppression increases susceptibility to high-risk HPV infection and multiple HPV infections. The use of immunosuppressant agents was not associated with abnormal Pap smears.