Human papillomavirus (HPV) types differ profoundly in cervical carcinogenicity. For the most carcinogenic type HPV16, variant lineages representing further evolutionary divergence also differ in cancer risk. Variants of the remaining 10 to 15 carcinogenic HPV types have not been well studied. In the first prospective, populationbased study of HPV variants, we explored whether, on average, the oldest evolutionary branches within each carcinogenic type predicted different risks of >2-year viral persistence and/or precancer and cancer [cervical intraepithelial neoplasia grade 3+ (CIN3+)]. We examined the natural history of HPV variants in the 7-year, 10,049-woman Guanacaste Cohort Study, using a nested case-control design. Infections were assigned to a variant lineage determined by phylogenetic parsimony methods based on URR/E6 sequences. We used the Fisher's combination test to evaluate significance of the risk associations, cumulating evidence across types. Globally, for HPV types including HPV16, the P value was 0.01 for persistence and 0.07 for CIN3+. Excluding HPV16, the P values were 0.04 and 0.37, respectively. For HPV16, non-European viral variants were significantly more likely than European variants to cause persistence [odds ratio (OR), 2.6; P = 0.01] and CIN3+ (OR, 2.4; P = 0.004). HPV35 and HPV51 variant lineages also predicted CIN3+. HPV variants generally differ in risk of persistence. For some HPV types, especially HPV16, variant lineages differ in risk of CIN3+. The findings indicate that continued evolution of HPV types has led to even finer genetic discrimination linked to HPV natural history and cervical cancer risk. Larger viral genomic studies are warranted, especially to identify the genetic basis for HPV16's unique carcinogenicity. Cancer Res; 70(8); 3159-69. ©2010 AACR.
Human immunodeficiency virus (HIV) infection and related immunosuppression are associated with excess risk for cervical neoplasia and human papillomavirus (HPV) persistence. Type-specific HPV infection was assessed at 6-month intervals for HIV-positive and HIV-negative women (median follow-up, 2.5 and 2.9 years, respectively). The type-specific incidence of HPV infection was determined, and risk factors for HPV persistence were investigated by statistical methods that accounted for repeated measurements. HIV-positive women were 1.8, 2.1, and 2.7 times more likely to have high-, intermediate-, and low-risk HPV infections, respectively, compared with HIV-negative women. In multivariate analysis, high viral signal, but not viral risk category, was independently associated with persistence among HIV-positive subjects (odds ratio [OR], 2.5; 95% confidence interval [CI], 2.1-2.9). Furthermore, persistence was 1.9 (95% CI, 1.5-2.3) times greater if the subject had a CD4 cell count <200 cells/microL (vs. >500 cells/microL). Thus, HIV infection and immunosuppression play an important role in modulating the natural history of HPV infection.
The Costa Rica HPV16/18 Vaccine Trial (CVT) showed that four-year vaccine efficacy against 12-month HPV16/18 persistent infection was similarly high among women who received one, two, or the recommended three doses of the bivalent HPV16/18 L1 virus-like particle (VLP) vaccine. Live-attenuated viral vaccines, but not simple-subunit vaccines, usually induce durable lifelong antibody responses after a single dose. It is unclear whether noninfectious VLP vaccines behave more like live-virus or simple-subunit vaccines in this regard. To explore the likelihood that efficacy will persist longer term, we investigated the magnitude and durability of antibodies to this vaccine by measuring HPV16-and HPV18-specific antibodies by VLP-ELISA using serum from enrollment, vaccination, and annual visits through four years in four vaccinated groups; one-dose (n ¼ 78), two-doses separated by one month (n ¼ 140), two doses separated by six months (n ¼ 52), and three scheduled doses (n ¼ 120, randomly selected). We also tested enrollment sera from n ¼ 113 HPV16-or HPV18 L1-seropositive women prevaccination, presumably from natural infection. At four years, 100% of women in all groups remained HPV16/18 seropositive; both HPV16/18 geometric mean titers (GMT) among the extended two-dose group were non-inferior to the three-dose group, and ELISA titers were highly correlated with neutralization titers in all groups. Compared with the natural infection group, HPV16/18 GMTs were, respectively, at least 24 and 14 times higher among the two-dose and 9 and 5 times higher among one-dose vaccinees. Antibody levels following one-dose remained stable from month 6 through month 48. Results raise the possibility that even a single dose of HPV VLPs will induce long-term protection. Cancer Prev Res; 6(11); 1242-50. Ó2013 AACR.
BackgroundHuman papillomavirus (HPV) infection is one of the most common sexually transmitted infections. However, only a small percentage of high-risk (HR) HPV infections progress to cervical precancer and cancer. In this study, we investigated the role of the cervicovaginal microbiome (CVM) in the natural history of HR-HPV. MethodsThis study was nested within the placebo arm of the Costa Rica HPV Vaccine Trial that included women aged 18-25 years of age. Cervical samples from two visits of women with an incident HR-HPV infection (n = 273 women) were used to evaluate the prospective role of the CVM on the natural history of HR-HPV. We focus specifically on infection clearance, persistence, and progression to cervical intraepithelial neoplasia grade 2 and 3 (CIN2+). The CVM was characterized by amplification and sequencing the bacterial 16S V4 rRNA gene region and the fungal ITS1 region using an Illumina MiSeq platform. OTU clustering was performed using QIIME2. Functional groups were imputed using PICRUSt and statistical analyses were performed using R. ResultsAt Visit 1 (V1) abundance of Lactobacillus iners was associated with clearance of incident HR-HPV infections (Linear Discriminant Analysis (LDA)>4.0), whereas V1 Gardnerella was PLOS PATHOGENS PLOS Pathogens | https://doi.
The objective of this study was to characterize longitudinal patterns of drug injection behavior for individuals and to identify their early determinants. Participants were 1,339 injection drug users recruited into the AIDS Link to Intravenous Experience (ALIVE) Study in Baltimore, Maryland, through community outreach efforts. The study was initiated in 1988, and follow-up continued through 2000, with semiannual visits. Patterns of self-reported drug injection (yes/no) were defined for each participant, based on the number of drug-use transitions. The effect of baseline factors was assessed using multinomial logistic regression models. Over the 12-year study period, four patterns were noted: 29% of participants remained persistent drug injectors, 20% ceased injection, 14% relapsed once, and 37% had multiple transitions. Persistent injectors had the shortest follow-up and the highest mortality. For persons who changed their behavior, 3.4 years elapsed before their first cessation attempt, on average. Factors differentiating the groups included history of incarceration, young age, participation in drug treatment programs, recent overdose, and commercial sex. The observed long-term injection patterns are consistent with the view of drug addiction as a chronic disease. This view emphasizes the need for prolonged efforts to sustain cessation and to prevent adverse health and social outcomes among injection drug users.
In this study population, having high antibody levels against HPV16 and HPV18 following natural infection was associated with reduced risk of subsequent HPV16 and HPV18 infections.
A small percentage of women with cervical HPV infection progress to cervical neoplasia, and the risk factors determining progression are incompletely understood. We sought to define the genetic loci involved in cervical neoplasia and to assess its heritability using unbiased unrelated case/control statistical approaches. We demonstrated strong association of cervical neoplasia with risk and protective HLA haplotypes that are determined by the amino-acids carried at positions 13 and 71 in pocket 4 of HLA-DRB1 and position 156 in HLA-B. Furthermore, 36% (standard error 2.4%) of liability of HPV-associated cervical pre-cancer and cancer is determined by common genetic variants. Women in the highest 10% of genetic risk scores have approximately >7.1% risk, and those in the highest 5% have approximately >21.6% risk, of developing cervical neoplasia. Future studies should examine genetic risk prediction in assessing the risk of cervical neoplasia further, in combination with other screening methods.
Human papillomavirus (HPV) L1 VLP-based vaccines are protective against HPV vaccine-related types; however, the correlates of protection have not been defined. We observed that vaccination with Cervarix™ induced cross-neutralizing antibodies for HPV types for which evidence of vaccine efficacy has been demonstrated (HPV31/45) but not for other types (HPV52/58). In addition, HPV31/45 cross-neutralizing titers showed a significant increase with number of doses (HPV31, p<0.001; HPV45, p<0.001) and correlated with HPV16/18 neutralizing titers, respectively. These findings raise the possibility that cross-neutralizing antibodies are effectors of cross-protection observed for the HPV16/18 vaccine.
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