Tim Waterboer

Bead-Based Multiplex Genotyping of Human Papillomaviruses

ABSTRACT Typing of human papillomaviruses (HPV) by DNA hybridization procedures, such as reverse line blot (RLB) assay, is sensitive and well validated. However, the application of these assays to high-throughput analyses is limited. Here, we describe the development of multiplex human papillomavirus genotyping (MPG), a quantitative and sensitive high-throughput procedure for the identification of multiple high- and low-risk genital HPV genotypes in a single reaction. MPG is based on the amplification of HPV DNA by a general primer PCR (GP5+/6+) and the subsequent detection of the products with type-specific oligonucleotide probes coupled to fluorescence-labeled polystyrene beads (Luminex suspension array technology). Up to 100 different HPV types can be detected simultaneously with MPG, and the method is fast and labor saving. We detected all 22 HPV types examined with high specificity and reproducibility (the median interplate coefficient of variation was below 10%). Detection limits for the different HPV types varied between 100 and 800 pg of PCR products. We compared the performance of MPG to an established RLB assay on GP5+/6+-PCR products derived from 94 clinical samples. The evaluation showed an excellent agreement (kappa = 0.922) but also indicated a higher sensitivity of MPG. In conclusion, MPG appears to be highly suitable for large-scale epidemiological studies and vaccination trials as well as for routine diagnostic purposes.

Evaluation of Human Papillomavirus Antibodies and Risk of Subsequent Head and Neck Cancer

PURPOSE Human papillomavirus type 16 (HPV16) infection is causing an increasing number of oropharyngeal cancers in the United States and Europe. The aim of our study was to investigate whether HPV antibodies are associated with head and neck cancer risk when measured in prediagnostic sera. METHODS We identified 638 participants with incident head and neck cancers (patients; 180 oral cancers, 135 oropharynx cancers, and 247 hypopharynx/larynx cancers) and 300 patients with esophageal cancers as well as 1,599 comparable controls from within the European Prospective Investigation Into Cancer and Nutrition cohort. Prediagnostic plasma samples from patients (collected, on average, 6 years before diagnosis) and control participants were analyzed for antibodies against multiple proteins of HPV16 as well as HPV6, HPV11, HPV18, HPV31, HPV33, HPV45, and HPV52. Odds ratios (ORs) of cancer and 95% CIs were calculated, adjusting for potential confounders. All-cause mortality was evaluated among patients using Cox proportional hazards regression. RESULTS HPV16 E6 seropositivity was present in prediagnostic samples for 34.8% of patients with oropharyngeal cancer and 0.6% of controls (OR, 274; 95% CI, 110 to 681) but was not associated with other cancer sites. The increased risk of oropharyngeal cancer among HPV16 E6 seropositive participants was independent of time between blood collection and diagnosis and was observed more than 10 years before diagnosis. The all-cause mortality ratio among patients with oropharyngeal cancer was 0.30 (95% CI, 0.13 to 0.67), for patients who were HPV16 E6 seropositive compared with seronegative. CONCLUSION HPV16 E6 seropositivity was present more than 10 years before diagnosis of oropharyngeal cancers.

Human Papillomavirus-16 Is the Predominant Type Etiologically Involved in Penile Squamous Cell Carcinoma

PURPOSE Human papillomavirus (HPV) infections are suggested to be involved in the development of penile squamous cell carcinoma (SCC), but comprehensive studies to define the association are limited. Therefore, we performed molecular and serologic analyses for a broad spectrum of HPV types on a large series of 83 penile SCCs, and we compared serological findings to those of age-matched male controls (N = 83). METHODS Penile SCCs were subjected to detection and typing assays for mucosal and cutaneous HPVs and to subsequent, type-specific viral load and viral gene expression assays. Sera of patients and of controls were analyzed for type-specific mucosal and cutaneous HPV L1, E6, and/or E7 antibodies using bead-based, multiplex serology. RESULTS HPV DNA of mucosal and/or cutaneous types was found in 46 of 83 (55%) penile SCCs. HPV16 was the predominant type, appearing in 24 (52%) of 46 of penile SCCs. The majority of HPV16 DNA-positive SCCs (18 of 24; 75%) demonstrated E6 transcriptional activity and a high viral load. Additionally, HPV16 molecular findings were strongly associated with HPV16 L1-, E6-, and E7-antibody seropositivity. Furthermore, serologic case-control analyses demonstrated that, in addition to the association of HPV16 with penile SCC, seropositivity against any HPV type was significantly more common in patients compared with in controls. HPV18 and HPV6 seropositivity were associated with HPV16-negative SCCs but were not correlated to molecular findings. CONCLUSION HPV16 is the main HPV type etiologically involved in the development of penile SCC. Although individuals who develop penile SCC show a greater prior exposure to a broad spectrum of HPV types, insufficient evidence was found to claim a role for HPV types other than HPV16 in penile carcinogenesis.

Homogeneous Amplification of Genital Human Alpha Papillomaviruses by PCR Using Novel Broad-Spectrum GP5+ and GP6+ Primers

ABSTRACT Human papillomavirus (HPV) DNA detection and typing are important for diagnosis and management of HPV-associated diseases. One of the most commonly used PCR methods, GP5+/6+, shows weaknesses in amplifying certain types. To circumvent this limitation, we developed and validated broad-spectrum primers targeting the GP5+/6+ region. The addition of eight upstream and two downstream BSGP5+/6+ (BS) primers improved amplification of plasmids of 14 genital HPV types 10- to 1,000-fold versus GP5+/6+ PCR without altering sensitivity for the 10 others. For these 24 types, an analytic sensitivity of ≤1,000 plasmid copies in the presence of 100 ng cellular DNA was obtained. Additionally, we integrated an internal β-globin PCR into both HPV PCR systems, allowing simultaneous DNA quality control without affecting the sensitivity of HPV detection. Furthermore, we describe five additional low-risk HPV probes used in multiplex HPV genotyping (MPG) for simultaneous identification of all 15 high-risk, 3 putative high-risk, and 9 low-risk HPV genotypes. The performance of BSGP5+/6+ multiplexed with β-globin primers was compared to that of standard GP5+/6+ with DNA from 1,112 cervical scrapings. There was 79% overall agreement (kappa = 0.816). BSGP5+/6+ was significantly more sensitive than GP5+/6+ for detection of HPV 30, 39, 42, 44, 51, 52, 53, 68, 73, and 82, detecting 212 additional HPV infections and increasing the proportion of multiple infections from 17.2 to 26.9% in cancer patients. In conclusion, BSGP5+/6+ multiplexed with β-globin PCR provides an improvement in type-specific amplification sensitivity and homogeneity compared to GP5+/6+ and offers simultaneous internal control of DNA quality. BSGP5+/6+-MPG, therefore, is suitable for epidemiologic and also diagnostic applications.

Low human papillomavirus prevalence in head and neck cancer: results from two large case–control studies in high-incidence regions

BACKGROUND Recent studies support an important role for human papillomavirus (HPV) in a subgroup of head and neck squamous cell carcinomas (HNSCC). We have evaluated the HPV deoxyribonucleic acid (DNA) prevalence as well as the association between serological response to HPV infection and HNSCC in two distinct populations from Central Europe (CE) and Latin America (LA). METHODS Cases (n = 2214) and controls (n = 3319) were recruited from 1998 to 2003, using a similar protocol including questionnaire and blood sample collection. Tumour DNA from 196 fresh tissue biopsies was analysed for multiple HPV types followed by an HPV type-specific polymerase chain reaction (PCR) protocol towards the E7 gene from HPV 16. Using multiplex serology, serum samples were analysed for antibodies to 17 HPV types. Statistical analysis included the estimation of adjusted odds ratios (ORs) and the respective 95% confidence intervals (CIs). RESULTS HPV16 E7 DNA prevalence among cases was 3.1% (6/196), including 4.4% in the oropharynx (3/68), 3.8% in the hypopharynx/larynx (3/78) and 0% among 50 cases of oral cavity carcinomas. Positivity for both HPV16 E6 and E7 antibodies was associated with a very high risk of oropharyngeal cancer (OR = 179, 95% CI 35.8-899) and hypopharyngeal/laryngeal cancer (OR = 14.9, 95% CI 2.92-76.1). CONCLUSIONS A very low prevalence of HPV DNA and serum antibodies was observed among cases in both CE and LA. The proportion of head and neck cancer caused by HPV may vary substantially between different geographical regions and studies that are designed to evaluate the impact of HPV vaccination on HNSCC need to consider this heterogeneity.

Seroprevalence of 34 Human Papillomavirus Types in the German General Population

The natural history of infections with many human papillomavirus (HPV) types is poorly understood. Here, we describe for the first time the age- and sex-dependent antibody prevalence for 29 cutaneous and five mucosal HPV types from 15 species within five phylogenetic genera (alpha, beta, gamma, mu, nu) in a general population. Sera from 1,797 German adults and children (758 males and 1,039 females) between 1 and 82 years (median 37 years) were analysed for antibodies to the major capsid protein L1 by Luminex-based multiplex serology. The first substantial HPV antibody reactions observed already in children and young adults are those to cutaneous types of the genera nu (HPV 41) and mu (HPV 1, 63). The antibody prevalence to mucosal high-risk types, most prominently HPV 16, was elevated after puberty in women but not in men and peaked between 25 and 34 years. Antibodies to beta and gamma papillomaviruses (PV) were rare in children and increased homogeneously with age, with prevalence peaks at 40 and 60 years in women and 50 and 70 years in men. Antibodies to cutaneous alpha PV showed a heterogeneous age distribution. In summary, these data suggest three major seroprevalence patterns for HPV of phylogenetically distinct genera: antibodies to mu and nu skin PV appear early in life, those to mucosal alpha PV in women after puberty, and antibodies to beta as well as to gamma skin PV accumulate later in life.

Abundance of Multiple High-Risk Human Papillomavirus (HPV) Infections Found in Cervical Cells Analyzed by Use of an Ultrasensitive HPV Genotyping Assay

ABSTRACT PCR methods enable the detection of a large variety of human papillomavirus (HPV) genotypes that infect the anogenital tract. However, PCR with consensus primers, general primers, and, to a lesser extent, broad-spectrum primers may underrepresent the true prevalence of HPV, especially the true prevalence of multiple infections. We compared the rate of HPV positivity determined by a broad-spectrum PCR with primers BSGP5+ and BSGP6+ (BS-PCR) coupled to an established bead-based multiplex HPV genotyping (MPG) assay with the rate of HPV positivity determined by a multiplex PCR with type-specific primers (TS-PCR) coupled to a newly developed MPG assay for 735 selected cervical scraping samples. While the primers used for the BS-PCR are located within the L1 region of the HPV genome, the primers used for the TS-PCR target the E7 gene. The overall rates of positivity for the 19 HPV types included in both assays were 60.9% and 72.2% by the BS-PCR and the TS-PCR, respectively, and the two assays found multiple infections in 34.8% and 58.0% of the specimens, respectively. Both HPV detection assays allowed the semiquantitative detection of HPV types and identified the same dominant HPV type in 66.6% of the multiple infections. In conclusion, the TS-PCR-MPG assay significantly increased the rate of detection of HPV DNA and the number of infections with multiple HPV types detected and demonstrated that the prevalence of low-copy-number HPV infections in the anogenital tract may be strongly underestimated by conventional HPV amplification methods, especially in cases of multiple infections. As a consequence, PCR-TS-MPG appears to be highly suited for analysis of the significance of multiple infections in the development of cervical cancer and for the study the natural history and the latency of HPV.

Serologic Response to Oncogenic Human Papillomavirus Types in Male and Female University Students in Busan, South Korea

In the absence of genital samples, human papillomavirus (HPV) serology may be useful to assess HPV infection in young men and women. HPV seroprevalence and determinants of seropositivity were assessed in 817 female and 518 male university students in Busan, South Korea, of whom 74% and 44%, respectively, reported never having had penetrative sexual intercourse. Type-specific HPV DNA status, assessed by a short PCR fragment primer set, was available from genital samples. Seropositivity to L1 proteins of HPV types 16, 18, 31, 33, 45, 52, and 58 were assessed using multiplex HPV serology. Among women, HPV seroprevalence was significantly higher among sexually active (26.1%) than nonsexually active students [11.1%, odds ratio (OR) = 2.9; 95% confidence interval (95% CI), 1.8-4.7], although the association was weaker than that for HPV DNA prevalence (OR, 14; 95% CI, 4.7-42). Furthermore, HPV seroprevalence was higher among HPV DNA-positive (24%) than HPV DNA-negative women (13%), and there was a positive correlation of type-specific seroprevalence with the presence of HPV DNA of the same type. In contrast, HPV seropositivity among men was not associated with sexual behavior or the presence of HPV DNA. Seroprevalence correlates with genital HPV exposure in young women, but its meaning in young men is unclear. (Cancer Epidemiol Biomarkers Prev 2007;16(9):1874–9)

Multicenter Study of the Association between Betapapillomavirus Infection and Cutaneous Squamous Cell Carcinoma

Human papillomaviruses (betaPV) from the beta genus cannot be classified according to their oncogenicity due to a paucity of information. This study evaluates the association between betaPV infection and cutaneous squamous cell carcinoma in conjunction with measures of UV exposure and susceptibility. We performed case-control studies in the Netherlands, Italy, and Australia, countries with profoundly different UV exposures. The presence of 25 betaPV types in eyebrow hair follicles was determined using a highly sensitive HPV DNA genotyping assay, and antibodies for the 15 most prevalent betaPV types in a total of 689 squamous cell carcinoma cases and 845 controls were detected using multiplex serology. Multivariate logistic regression models were used for case-control comparisons and interaction analyses. BetaPV DNA was detected in eyebrow hairs of more than 90% of all participants. The presence of betaPV DNA was associated with an increased risk of squamous cell carcinoma in the Netherlands (OR = 2.8; 95% CI 1.3-5.8) and Italy (OR = 1.7; 95% CI 0.79-3.6), but not in Australia (OR = 0.91; 95% CI 0.53-1.6). Seropositivity for betaPV in controls ranged between 52% and 67%. A positive antibody response against 4 or more betaPV types was associated with squamous cell carcinoma in Australia (OR = 2.2; 95% CI 1.4-3.3), the Netherlands (OR = 2.0; 95% CI 1.2-3.4) and fair-skinned Italians (OR = 1.6, 95% CI 0.94- 2.7). The association between UV susceptibility and squamous cell carcinoma was stronger in betaPV-seropositive people. These combined data support the hypothesis that betaPV may play a role in the development of cutaneous squamous cell carcinoma.

A case-control study of betapapillomavirus infection and cutaneous squamous cell carcinoma in organ transplant recipients

We examined the association between betapapillomavirus (betaPV) infection and cutaneous squamous cell carcinoma (SCC) in organ transplant recipients. A total of 210 organ transplant recipients with previous SCC and 394 controls without skin cancer were included. The presence of 25 betaPV types in plucked eyebrow hairs was determined using a human papillomavirus (HPV) DNA genotyping assay, and antibodies for the 15 most prevalent betaPV types were detected using multiplex serology. We used multivariate logistic regression models to estimate associations between various measures of betaPV infection and SCC. BetaPV DNA was highly prevalent (>94%) with multiple types frequently detected in both groups. We found a significant association between SCC and the concordant detection of both antibodies and DNA for at least one betaPV type (adjusted OR 1.6; 95% CI 1.1;2.5). A borderline‐significant association with SCC was found for HPV36 (adjusted OR 2.4; CI 1.0;5.4), with similar associations for HPV5, HPV9 and HPV24. These data provide further evidence of an association between betaPV infection and SCC in organ transplant recipients. Confirmation of a betaPV profile predictive of risk for SCC may pave the way for clinically relevant pretransplant HPV screening and the development of preventive and therapeutic HPV vaccination.