Quantitative human papillomavirus 16 and 18 levels in incident infections and cervical lesion development

First Report of Phodopus sungorus Papillomavirus Type 1 Infection in Roborovski Hamsters (Phodopus roborovskii)

Papillomaviruses (PVs) are considered highly species-specific with cospeciation as the main driving force in their evolution. However, a recent increase in the available PV genome sequences has revealed inconsistencies in virus–host phylogenies, which could be explained by adaptive radiation, recombination, host-switching events and a broad PV host range. Unfortunately, with a relatively low number of animal PVs characterized, understanding these incongruities remains elusive. To improve knowledge of biology and the spread of animal PV, we collected 60 swabs of the anogenital and head and neck regions from a healthy colony of 30 Roborovski hamsters (Phodopus roborovskii) and detected PVs in 44/60 (73.3%) hamster samples. This is the first report of PV infection in Roborovski hamsters. Moreover, Phodopus sungorus papillomavirus type 1 (PsuPV1), previously characterized in Siberian hamsters (Phodopus sungorus), was the only PV detected in Roborovski hamsters. In addition, after a detailed literature search, review and summary of published evidence and construction of a tanglegram linking the cladograms of PVs and their hosts, our findings were discussed in the context of available knowledge on PVs described in at least two different host species.

ADAR1 function affects HPV replication and is associated to recurrent human papillomavirus-induced dysplasia in HIV coinfected individuals

Infection by human papillomavirus (HPV) alters the microenvironment of keratinocytes as a mechanism to evade the immune system. A-to-I editing by ADAR1 has been reported to regulate innate immunity in response to viral infections. Here, we evaluated the role of ADAR1 in HPV infection in vitro and in vivo. Innate immune activation was characterized in human keratinocyte cell lines constitutively infected or not with HPV. ADAR1 knockdown induced an innate immune response through enhanced expression of RIG-I-like receptors (RLR) signaling cascade, over-production of type-I IFNs and pro-inflammatory cytokines. ADAR1 knockdown enhanced expression of HPV proteins, a process dependent on innate immune function as no A-to-I editing could be identified in HPV transcripts. A genetic association study was performed in a cohort of HPV/HIV infected individuals followed for a median of 6 years (range 0.1-24). We identified the low frequency haplotype AACCAT significantly associated with recurrent HPV dysplasia, suggesting a role of ADAR1 in the outcome of HPV infection in HIV+ individuals. In summary, our results suggest that ADAR1-mediated innate immune activation may influence HPV disease outcome, therefore indicating that modification of innate immune effectors regulated by ADAR1 could be a therapeutic strategy against HPV infection.

Viral load and integration status of HPV58 associated with cervical lesion severity in women of Northeast China

Objective

We aimed to evaluate the viral load and integration status of human papillomavirus 58 in women with different grades of cervical lesions to determine whether viral load and integration status are related to malignant transformation in HPV58-infected women.

Methods

A total of 212 cervical specimens were collected from women in Northeast China who had undergone human papillomavirus genotyping and were HPV58-positive. The HPV58 viral load was determined using real-time polymerase chain reaction, and the integration status was discriminated using the ratio of HPV58 E2 gene copy number to E6 gene copy number.

Results

The median HPV58 viral load in women with normal cervix or cervicitis, low-grade squamous cell intraepithelial lesion, high-grade squamous cell intraepithelial lesion and cervical cancer was 352.12, 864.21, 1199.75 and 693.04 copies/genome, respectively. High significance was obtained when comparing the viral load of infected women presenting normal/cervicitis with that of the women either with precancerous cervical lesions or cervical cancer (P < 0.05). The HPV58 genome was in the episomal form in 35 samples (16.5%), mixed episomal and integrated forms in 165 (77.8%) samples, and completely integrated into the host genome in 12 (5.7%) samples. The HPV58 E2/E6 copy number ratio in the cervical cancer group was significantly lower than that in the other groups (P < 0.01).

Conclusions

The HPV58 viral load in patients with precancerous cervical lesions or cervical cancer increases significantly with disease progression. The HPV58 E2/E6 copy number ratio in patients with cervical cancer is lower than that for less severe cervical lesions, suggesting a high degree of viral integration may be a considerable risk factor for cervical cancer.

Short-term natural history of high-risk human papillomavirus infection in mid-adult women sampled monthly

Characterizing short-term HPV detection patterns and viral load may inform HPV natural history in mid-adult women. From 2011-2012, we recruited women aged 30-50 years. Women submitted monthly self-collected vaginal samples for high-risk HPV DNA testing for 6 months. Positive samples were tested for type-specific HPV DNA load by real-time PCR. HPV type-adjusted linear and Poisson regression assessed factors associated with (i) viral load at initial HPV detection and (ii) repeat type-specific HPV detection. One-hundred thirty-nine women (36% of 387 women with ≥4 samples) contributed 243 type-specific HR HPV infections during the study; 54% of infections were prevalent and 46% were incident. Incident (vs. prevalent) detection and past pregnancy were associated with lower viral load, whereas current smoking was associated with higher viral load. In multivariate analysis, current smoking was associated with a 40% (95% CI: 5-87%) increase in the proportion of samples that were repeatedly positive for the same HPV type, whereas incident (vs. prevalent) detection status and past pregnancy were each associated with a reduction in the proportion of samples repeatedly positive (55%, 95% CI: 38-67% and 26%, 95% CI: 10-39%, respectively). In a separate multivariate model, each log10 increase in viral load was associated with a 10% (95% CI: 4-16%) increase in the proportion of samples repeatedly positive. Factors associated with repeat HPV detection were similar to those observed in longer-term studies, suggesting that short-term repeat detection may relate to long-term persistence. The negative associations between incident HPV detection and both viral load and repeat detection suggest that reactivation or intermittent persistence was more common than new acquisition.

Interest of human papillomavirus DNA quantification and genotyping in paired cervical and urine samples to detect cervical lesions

BACKGROUND

Cervical cancer is caused by persistent infection with high-risk human papillomavirus (HR-HPV). Conventional human papillomavirus (HPV) testing requires cervical sampling. However, vaginal and urine self-sampling methods are more acceptable for patients and result in increased participation when they are available in screening programs. In this context, we have developed a non-invasive screening method via the detection of HPV DNA in urine samples.

PURPOSE

To compare HPV viral loads and genotypes in paired cervical and urine samples, and to assess correlation between virological and cytological results in women seeking gynecological consultation.

METHODS

Paired urine and cervical specimens were collected and analyzed from 230 of 245 women participating in the previously described prospective PapU study. HPV DNA detection and quantification were performed using a real-time PCR method with short fragment PCR primers. Genotyping was carried out using the INNO-LiPA HPV genotyping assay.

RESULTS

The prevalence of HPV in the 230 paired urine and cervical smear samples was 42 and 49 %, respectively. Overall agreement for HPV positivity and negativity between the paired samples was 90 % (κ = 0.80). High HPV viral load in both cervical and urine samples was associated with cytological abnormalities. HPV-positive women were mostly infected with HR-HPV types. The agreement between high- and low-risk HPV (LR-HPV) detection in both samples was 97 % (κ = 0.95 for HR-HPV and κ = 0.97 for LR-HPV).

CONCLUSIONS

High concordance rates for HPV-DNA quantification and high/low-risk HPV genotyping in paired urine/cervical samples suggest that urinary HPV DNA testing could be useful for cervical lesion screening.

Viral load and short-term natural history of type-specific oncogenic human papillomavirus infections in a high-risk cohort of midadult women

Oncogenic human papillomavirus (HPV) viral load may inform the origin of newly detected infections and characterize oncogenic HPV natural history in midadult women. From 2007 to 2011, we enrolled 521 25-65-year-old-female online daters and followed them triannually with mailed health and sexual behavior questionnaires and kits for self-sampling for PCR-based HPV DNA testing. Samples from oncogenic HPV positive women were selected for type-specific DNA load testing by real-time PCR with adjustment for cellularity. Linear or logistic regression models were used to evaluate relationships between viral levels, health and sexual behavior, and longitudinal oncogenic HPV detection. Type-specific viral levels were borderline significantly higher in oncogenic HPV infections that were prevalent versus newly detected (p = 0.092), but levels in newly detected infections were higher than in infections redetected after intercurrent negativity (p < 0.001). Recent sex partners were not significantly associated with viral levels. Compared with prevalent infections detected intermittently, the likelihood of persistent (OR = 4.31, 95% CI: 2.20-8.45) or single-time (OR = 1.32, 95% CI: 1.03-1.71) detection increased per 1-unit increase in baseline log10 viral load. Viral load differences between redetected and newly detected infections suggest a portion of new detections were due to new acquisition, although report of recent new sex partners (a potential marker of new infection) was not predictive of viral load; oncogenic HPV infections in midadult women with new partners likely represent a mix of new acquisition and reactivation or intermittent detection of previous infection. Intermittent detection was characterized by low viral levels, suggesting that intermittent detection of persisting oncogenic HPV infection may be of limited clinical significance.

Association of HPV types 6, 11, 16, and 18 DNA detection and serological response in unvaccinated adolescent women

Antibodies directed against the human papillomavirus (HPV) L1 protein are detected in approximately 70% of individuals with HPV infections. The factors associated with a serological response are not characterized. It is hypothesized that the HPV viral load, duration of detection, or both would be associated with seropositivity in adolescent women. Adolescent women (n = 117), ages 15-17 at enrolment were followed for a mean of 6.2 years. Quarterly vaginal swabs (mean 22 per participant) were used to identify HPV 6, 11, 16, or 18 DNA (Roche PCR/Linear Array). Type-specific HPV infection was defined as ≥2 positive assays. To approximate viral load, Roche PCR/Linear Array test strips were scored visually based on the strength of signal relative to beta-globin controls. Sera collected near the end of study were tested by cLIA. Regression models were fit to assess associations between strength of signal (as represented by mean and cumulative strength of signal), duration of HPV detection, seropositivity, and serotiter. Detection of HPV DNA was associated with seropositivity for four types combined and for types 6, 16, and 18. Overall, 70.1% of DNA positive episodes were associated with type-specific seropositivity. The cumulative HPV DNA signal strength during periods of HPV detection for types 6, 11, 16, and 18 combined was associated with seropositivity (OR = 1.21, 95% CI 1.02-1.44 P = 0.026). No other HPV DNA predictors were found to be associated with seropositivity or serotiter.

Retrieval of HPV oncogenes E6 and E7 mRNA from cervical specimens using a manual open technology protocol

Background

HPV oncogenes mRNA detection gains momentum as an adjuvant for HPV-related cervical abnormalities diagnosis, but is based on costly detection assays not allowing viral type targeting.

Objective

To assess detection rate of HPV oncogenes E6/E7 mRNA from cervical specimens using a manual, open technology, fully customizable protocol and determine whether HPV-related epidemiological features influence mRNA retrieval. We reviewed literature and compared our retrieval rate with automated technologies.

Methods

We used 60 samples positive for HPV DNA types 16, 18, 31 and/or 45. We extracted mRNA with a TRizol-based protocol, and tested mRNA purity and concentration using light absorbance. We reverse-transcribed mRNA into cDNA for E6/7 detection.

Results

HPV oncogenes E6/E7 mRNA was retrieved from 36 (60%) out of 60 specimens. No HPV load-related clinical or epidemiological feature was significantly associated with mRNA retrieval. Presence of HPV-DNA 16/18 was associated with mRNA retrieval (OR = 9.08; 95% CI 1.26 to 65.32 for HPV 16; and 18.2; IC95% 1.86 to 391.44 for HPV 18).

Conclusions

The open-technology protocol yielded an mRNA detection rate similar to that of automated technologies. Advantages are lower costs and target HPV type customization.

Human papillomavirus DNA is rarely detected in colorectal carcinomas and not associated with microsatellite instability: the Seattle colon cancer family registry

BACKGROUND

Persistent infection with oncogenic human papillomavirus (HPV) types-16 and -18 is an established cause of cervical and other cancers. Some studies report detection of oncogenic HPV DNA in colorectal carcinomas, with prevalence estimates as high as 84%. However, other studies report detecting no HPV DNA in colorectal tumors.

METHODS

To evaluate the prevalence of HPV in colorectal cancer subsets, we conducted a case-case comparison study. This study included 555 cases of incident colorectal cancer from the Seattle Colon Cancer Family Registry (CCFR), ages 20 to 74 years and diagnosed between 1998 and 2002. Standardized interviews were used to elicit demographics and risk factor data. Tumor DNA was assayed for HPV-16 and -18 DNA using real-time PCR. Microsatellite instability (MSI) status was assessed using a standard 10-marker panel and confirmed with immunohistochemical staining. Prevalence estimates were calculated for the overall sample, and stratified by patient and tumor characteristics. Fisher exact test was used to compare prevalence between strata.

RESULTS

HPV-16 DNA was detected in 2% of colorectal tumors, but no HPV-18 DNA was detected. HPV-16 prevalence did not vary between cases according to sex, age, race, smoking-status, or MSI-status (P > 0.05). HPV-16 prevalence in rectal carcinomas was 5% compared with 1% in colon carcinomas (P = 0.03).

CONCLUSIONS

Among a large sample of colorectal carcinomas, prevalence of HPV-16 and -18 was very low. Prior studies detecting high HPV prevalence in colorectal carcinomas are likely the result of contamination from the anal canal or clinical processing.

IMPACT

HPV is unlikely to play a large role in colorectal carcinogenesis.

Human papillomavirus genotype detection and viral load in paired genital and urine samples from both females and males

The ability to detect type-specific high risk HPV (HR-HPV) infections in samples from females and males is important for monitoring the epidemiology of HPV and the impact of vaccination. Type-specific detection concordance between paired urine and genital samples from females (n = 264) undergoing routine colposcopy and males (n = 88) attending a genito-urinary medicine clinic was evaluated using an in-house genotyping assay. The overall inter-rater agreement (κ) was 0.781 for female pairs and 0.346 for male pairs. Female urine had sensitivity for detection of HPV16/18 and HR-HPV of 75% and 84%, respectively, while male urine had sensitivities of 13% and 28%, respectively. Genital samples had a higher HPV DNA copy number than urine although a small proportion (10%) of urine samples had a higher copy number than the corresponding genital sample. The proportion of females with normal cytology positive for HPV16/18 was 19%, increasing to 57% in moderate or severely dyskaryotic samples. The same trend was seen in the corresponding urine (19-43%) compounded by the reduced sensitivity of this sample type. The HPV16 viral load in female genital samples, but not in urine, was weakly associated with cervical disease stage. Despite reduced sensitivity, urine appears to be an appropriate surrogate sample for type-specific HPV detection in females for epidemiological objectives. The lower sensitivity and lack of association between viral load and disease stage in urine suggest that urine may not be useful for clinical management of HPV infection. The utility of urine for type-specific detection in males is less certain.

Serum antibody response following genital {alpha}9 human papillomavirus infection in young men

Background. Although the prevalence of human papillomavirus (HPV) genital infection is similarly high in males and females, seroprevalence is lower in males. This study assessed rates and determinants of seroconversion after detection of genital HPV infection in young men. Methods. We investigated HPV type-specific seroconversion in a cohort of heterosexual male university students who had an α9 HPV type (HPV-16, -31, -33, -35, -52, -58, or -67) detected in the genital tract (n = 156). HPV DNA and antibodies were detected and typed using liquid bead-based multiplex assays. We calculated seroconversion using Kaplan-Meier survival analysis. Cox proportional hazards models with generalized estimating equations were used to examine associations with seroconversion. Results. Within 24 months of detecting genital HPV infection, type-specific seroconversion ranged from 4% for HPV-52 to 36% for HPV-31. HPV-16 seroconversion at 24 months was 13% (95% confidence interval [CI], 7%-25%). Among incident HPV infections, ever cigarette smoking and infection site(s) (shaft/scrotum and glans/urine vs shaft/scrotum or glans/urine only) were positively associated with type-specific seroconversion. Conclusions. For each of the α9 HPV types, type-specific seroconversion within 24 months was observed in 36% or less of infected men. Seroconversion might be related to cigarette smoking and genital site(s) infected.

Early natural history of incident, type-specific human papillomavirus infections in newly sexually active young women

BACKGROUND

Characterizing short-term detection patterns of young women's incident α-genus human papillomavirus (HPV) infections may further our understanding of HPV transmission.

METHODS

Between 2000 and 2007, we followed 18- to 22-year-old female university students with triannual HPV DNA and Papanicolaou testing. Using Kaplan-Meier methods, we estimated duration of detectable, type-specific incident infections; time to redetection (among infections that became undetectable); and time to cervical lesion development after incident infection. We evaluated risk factors for short-term persistent versus transient infection with logistic regression.

RESULTS

Three hundred three incident, type-specific infections were detected in 85 sexually active women. Median time to first negative test after incident infection was 9.4 (95% CI: 7.8-11.2) months; 90.6% of infections became undetectable within 2 years. About 19.4% of infections that became undetectable were redetected within 1 year. Cervical lesions were common and 60% were positive for multiple HPV types in concurrent cervical swabs. Incident HPV detection in the cervix only (vs. the vulva/vagina only or both sites) was associated with short-term transience.

CONCLUSIONS

Although most incident infections became undetectable within 2 years, redetection was common. Cervical lesions were a common early manifestation of HPV infection.

IMPACT

It remains unclear whether potentially modifiable risk factors can be identified to reduce infection duration (and transmission likelihood).

Unresolved questions concerning human papillomavirus infection and transmission: a modelling perspective

Mathematical transmission models are widely used to forecast the potential impact of interventions such as vaccination and to inform the development of health policy. Effective vaccines are now available for the prevention of cervical cancer and other diseases attributable to human papillomavirus (HPV). Considerable uncertainties remain regarding the characterisation of HPV infection and its sequelae, infectivity, and both vaccine-conferred and naturally-acquired immunity. In this review, we discuss the key knowledge gaps that impact on our ability to develop accurate models of HPV transmission and vaccination.

Factors affecting transmission of mucosal human papillomavirus

Human papillomavirus (HPV) is the most common sexually transmitted infection. The effect of HPV on public health is especially related to the burden of anogenital cancers, most notably cervical cancer. Determinants of exposure to HPV are similar to those for most sexually transmitted infections, but determinants of susceptibility and infectivity are much less well established. Gaps exist in understanding of interactions between HPV, HIV, and other sexually transmitted infections. The roles of mucosal immunology, human microbiota at mucosal surfaces, host genetic factors and hormonal concentrations on HPV susceptibility and infectivity are poorly understood, as are the level of effectiveness of some primary or secondary preventive measures other than HPV vaccination (such as condoms, male circumcision, and combination antiretroviral therapy for HIV). Prospective couples studies, studies focusing on mucosal immunology, and in-vitro raft culture studies mimicking HPV infection might increase understanding of the dynamics of HPV transmission.

Is human papillomavirus viral load a clinically useful predictive marker? A longitudinal study

BACKGROUND

It has been suggested that in women who test positive for high-risk human papillomavirus (HPV) types, viral load can distinguish women who are at increased risk of cervical neoplasia from those who are not.

METHODS

Quantitative PCR (qPCR) was used to measure HPV copy number in serial samples taken from 60 and 58 young women previously found to have incident cervical HPV16 or HPV18 infections, respectively, using GP5+/GP6+ primers; women provided at least three samples for qPCR testing, at least one of which was positive.

RESULTS

A 10-fold increase in HPV16 or HPV18 copy number was associated with a modestly increased risk of acquiring a cytologic abnormality [HPV16: hazards ratio, 1.76 (95% confidence interval, 1.38-2.25); HPV18: hazards ratio, 1.59 (95% confidence interval, 1.25-2.03)]. However, in most women, copy number increased during follow-up, before decreasing again. In women with a HPV16 infection, the median copy number per 1,000 cells was 7.7 in their first qPCR HPV-positive sample, 1,237 in the sample yielding the maximum copy number, and 7.8 in their last qPCR HPV-positive sample; corresponding copy numbers for women with HPV18 infection were 2.3, 87, and 2.4. Maximum HPV16 and HPV18 copy number did not differ significantly between women who acquired an incident cervical cytologic abnormality and those who did not.

CONCLUSION

Whereas large relative increases in copy number are associated with an increased risk of abnormality, a single measurement of viral load made at an indeterminate point during the natural history of HPV infection does not reliably predict the risk of acquiring cervical neoplasia. Therefore, a single measure of HPV viral load cannot be considered a clinically useful biomarker.

Koilocytes indicate a role for human papilloma virus in breast cancer

BACKGROUND

High-risk human papilloma viruses (HPVs) are candidates as causal viruses in breast cancer. The scientific challenge is to determine whether HPVs are causal and not merely passengers or parasites. Studies of HPV-related koilocytes in breast cancer offer an opportunity to address this crucial issue. Koilocytes are epithelial cells characterised by perinuclear haloes surrounding condensed nuclei and are commonly present in cervical intraepithelial neoplasia. Koilocytosis is accepted as pathognomonic (characteristic of a particular disease) of HPV infection. The aim of this investigation is to determine whether putative koilocytes in normal and malignant breast tissues are because of HPV infection.

METHODS

Archival formalin-fixed normal and malignant breast specimens were investigated by histology, in situ PCR with confirmation of the findings by standard PCR and sequencing of the products, plus immunohistochemistry to identify HPV E6 oncoproteins.

RESULTS

human papilloma virus-associated koilocytes were present in normal breast skin and lobules and in the breast skin and cancer tissue of patients with ductal carcinoma in situ (DCIS) and invasive ductal carcinomas (IDCs).

INTERPRETATION

As koilocytes are known to be the precursors of some HPV-associated cervical cancer, it follows that HPVs may be causally associated with breast cancer.