DETERMINANTS OF SQUAMOUS INTRAEPITHELIAL LESIONS (SIL) ON PAP SMEAR -THE ROLE OF HPV INFECTION AND OF HIV-1-INDUCED IMMUNOSUPPRESSION

This study aimed to identify risk factors for squamous intraepithelial lesions (SIL) in women with known HIV status and to explore the assoc iation between SIL, HPV subtype, and HIV-induced immunosuppression, Th e study population consisted of women with known HIV serological statu s who were attending a network of 16 clinical centres in Italy. Detail ed behavioural data, clinical and laboratory parameters, and samples f or diagnosis of SIL by Papanicolau smear and HPV infection using a pol ymerase chain reaction (PCR) were obtained from each study participant , The strength of the association between SIL and possible risk factor s was assessed calculating crude and adjusted odds ratios derived from univariate analysis and multivariate models. We enrolled 236 women, o f whom 135 (57.2%) were HIV-infected, SIL was diagnosed in 57 women (2 4.1%); of these, 48 (35.6%) were HIV-infected and 9 (8.9%) were HIV-ne gative. HPV-DNA was detected in 41 (72%) women with SIL and in 45 (25% ) women without SIL, HPV-DNA was more often detected among HIV-infecte d women than among HIV-negative women (40% vs, 32%), but the differenc e was not statistically significant. Women infected with high-risk typ es or with low-risk-uncharacterised types of HPV both had a higher ris k of SIL compared with HPV-negative women (respectively, AOR: 17.53 an d AOR: 2.89). HIV-infected women with severe or moderate immunosuppres sion were more likely to have SIL than HIV-negative women (respectivel y, AOR: 7.29 and AOR: 3.09) also independently from HPV infection. Wom en reporting use of a contraceptive pill had a 2.5 times higher risk o f SIL compared with those who never used hormonal contraceptives, The results confirm that high-risk HPV types are strongly associated with SIL, and that HIV infection may strengthen the effect of HPV at cervic al level. The use of oral contraceptives may slightly increase the ris k of SIL in women with at-risk behaviour for HIV infection.