Background:  HIV⁺ men who have sex with men (MSM) have high rates of anal human papilloma virus (HPV) infection, as well as anal dsyplasia. Smoking is associated with abnormal anal cytology and with an increased risk of anal cancer.

Methods:  In this prospective study, 269 intraanal and 281 perianal swabs from 281 HIV⁺ MSM participating in a screening program for anal dysplasia were included. HPV typing was performed by group α-specific polymerase chain reaction (PCR) and hybridization with type-specific probes. HPV16 DNA load was determined by real-time PCR and expressed as HPV16 DNA copies per β-globin gene copy.

Results:  Normal cytology, low-grade squamous intraepithelial lesions (LSIL), and high-grade squamous intraepithelial lesions (HSIL) were found in 60, 13, and 7% of perianal and in 49, 16, and 9% of intraanal swabs. HPV DNA, high-risk HPV DNA, and HPV16 DNA were found in 87, 74, and 46% of perianal and 87, 77, and 55% of intraanal swabs. Anogenital HPV, high-risk HPV, and HPV16 were found in 82, 69, and 48% of swabs from non-smokers and in 90, 82, and 53% of swabs from current smokers, respectively. Interestingly, anal HPV16 loads were significantly higher in smokers than in non-smokers. Moreover, anal HPV16 loads correlated with serum cotinine levels. Mean and median perianal HPV16 loads were 42 and 0.5 HPV16-copies per β-globin gene copy in non-smokers (n = 51) and 1154 and 13 in smokers (n = 51) (p = 0.021). Intraanal values were similar (62 and 0.5 in non-smokers [n = 59] vs 395 and 4 in smokers [n = 71]). HPV16 load differences between non-smokers and smokers were most pronounced in patients with normal cytology (mean load 48 in non-smokers vs 1460 in smokers), less distinct in LSIL swabs (mean 60 in non-smokers vs 328 in smokers), and only slight in HSIL swabs (mean 88 in non-smokers vs 179 in smokers).

Conclusions:  Smoking is associated with elevated anal HPV16 DNA loads in HIV⁺ MSM, especially in those with normal cytology. Since high HPV16 loads were previously shown to be associated with an increased risk for anogenital cancers, HIV⁺/HPV⁺ MSM should be encouraged to refrain from smoking.