Concordance of HPV load and HPV mRNA for 16 carcinogenic/possibly carcinogenic HPV types in paired smear/tissue cervical cancer specimens.

HPV types with high viral load are associated with cervical abnormalities. However, viral load measurements and concordance of HPV loads and viral mRNA have not been demonstrated for all high-risk/possibly high-risk (HR-/pHR-)HPV types in cervical cancer (CxCa). Especially, the biological role of co-infecting HR-/pHR-HPV types with low viral load has not been thoroughly investigated. Using BSGP5+/6+-PCR/MPG genotyping, we analyzed viral loads for all currently defined 51 mucosal HPV types in 74 cervical smears from patients with CxCa and compared this data with HPV DNA and mRNA status in these patients' corresponding CxCa tissues. All cervical smear/tissue pairs were HPV DNA+. Overall HPV type agreement within pairs was 99% (complete agreement in 50%, partial agreement in 49%, and complete disagreement in 1% of cases). The proportion of multiple HPV types was significantly higher in smears compared to tissues (p<0.0001). High load HPV infections (>1 copy/cell) were found in 88% of HPV DNA+ smears, and were significantly associated with the presence of respective HPV DNA (kappa=0.685, CI: 0.567-0.803), and HPV mRNA (kappa=0.693, CI: 0.566-0.820) in CxCa tissues. In total, 93% (67/72) of high load HR-/pHR-HPV infections identified in smears were also present in corresponding CxCa tissues, and 93% (62/67) of these were HPV mRNA+. On the other hand, 78% (42/54) of low load HR-/pHR-HPV infections identified in smears were not detectable in tissues, including 11 out of 15 low load HPV16 infections. This data demonstrates that the presence of high HPV loads in CxCa smears predicts biologically active HR-/pHR-HPV types in tumor tissues.

Hepatitis C virus seroprevalence in the general female population of 9 countries in Europe, Asia and Africa.

BACKGROUND: New oral treatments with very high cure rates have the potential to revolutionize global management of hepatitis C virus (HCV), but population-based data on HCV infection are missing in many low and middle-income countries (LMIC). METHODS: Between 2004 and 2009, dried blood spots were collected from age-stratified female population samples of 9 countries: China, Mongolia, Poland, Guinea, Nepal, Pakistan, Algeria, Georgia and Iran. HCV antibodies were detected by a multiplex serology assay using bead-based technology. RESULTS: Crude HCV prevalence ranged from 17.4% in Mongolia to 0.0% in Iran. In a pooled model adjusted by age and country, in which associations with risk factors were not statistically heterogeneous across countries, the only significant determinants of HCV positivity were age (prevalence ratio for ≥45 versus <35 years = 2.84, 95%CI 2.18-3.71) and parity (parous versus nulliparous = 1.73, 95%CI 1.02-2.93). Statistically significant increases in HCV positivity by age, but not parity, were seen in each of the three countries with the highest number of HCV infections: Mongolia, Pakistan, China. There were no associations with sexual partners nor HPV infection. HCV prevalence in women aged ≥45 years correlated well with recent estimates of female HCV-related liver cancer incidence, with the slight exception of Pakistan, which showed a higher HCV prevalence (5.2%) than expected. CONCLUSIONS: HCV prevalence varies enormously in women worldwide. Medical interventions/hospitalizations linked to childbirth may have represented a route of HCV transmission, but not sexual intercourse. Combining dried blood spot collection with high-throughput HCV assays can facilitate seroepidemiological studies in LMIC where data is otherwise scarce.

Comparison of Two Widely Used Human Papillomavirus Detection and Genotyping Methods, GP5+/6+-Based PCR Followed by Reverse Line Blot Hybridization and Multiplex Type-Specific E7-Based PCR.

GP5+/6+-based PCR followed by reverse line blot hybridization (GP5+/6+RLB) and multiplex type-specific PCR (E7-MPG) are two human papillomavirus (HPV) genotyping methodologies widely applied in epidemiological research. We investigated their relative analytical performance in 4,662 samples derived from five studies in Bhutan, Rwanda, and Mongolia coordinated by the International Agency for Research on Cancer (IARC). A total of 630 samples were positive by E7-MPG only (13.5%), 24 were positive by GP5+/6+RLB only (0.5%), and 1,014 were positive (21.8%) by both methods. Ratios of HPV type-specific positivity of the two tests (E7-MPG:GP5+/6+RLB ratio) were calculated among 1,668 samples that were HPV positive by one or both tests. E7-MPG:GP5+/6+RLB ratios were >1 for all types and highly reproducible across populations and sample types. E7-MPG:GP5+/6+RLB ratios were highest for HPV53 (7.5) and HPV68 (7.1). HPV16 (1.6) and HPV18 (1.7) had lower than average E7-MPG:GP5+/6+RLB ratios. Among E7-MPG positive infections, median mean fluorescence intensity (MFI; a semiquantitative measure of viral load) tended to be higher among samples positive for the same virus type by GP5+/6+RLB than for those negative for the same type by GP5+/6+RLB. Exceptions, however, included HPV53, -59, and -82, for which the chances of being undetected by GP5+/6+RLB appeared to be MFI independent. Furthermore, the probability of detecting an additional type by E7-MPG was higher when another type was already detected by GP5+/6+RLB, suggesting the existence of masking effects due to competition for GP5+/6+ PCR primers. In conclusion, this analysis is not an evaluation of clinical performance but may inform choices for HPV genotyping methods in epidemiological studies, when the relative merits and dangers of sensitivity versus specificity for individual types should be considered, as well as the potential to unmask nonvaccine types following HPV vaccination.

HPV16 RNA patterns defined by novel high-throughput RT-qPCR as triage marker in HPV-based cervical cancer precursor screening.

OBJECTIVE: Cervical cancer precursor screening by HPV testing has a low positive predictive value for advanced lesion. HPV16 RNA patterns characteristic for HPV16-transformed cells but based on laborious, cost-intensive singleplex NASBA reactions promised high value in triaging HPV16 DNA-positive women. METHODS: We developed two high-throughput reverse transcriptase quantitative (RT-q) PCR assays for the HPV16 transcripts E6*I, E1^E4 and E1C and the cellular transcript ubiquitin C and analysed RNA of 158 singly HPV16 DNA-positive cervical cell samples archived in PreservCyt buffer for the presence of transformation-associated HPV16 RNA patterns, i.e., upregulation of E6*I relative to E1^E4 and/or presence of E1C. RESULTS: HPV16 RNA pattern analyses classified 85% of 58 samples diagnosed ≤CIN1 (no cytologically and histologically detectable cervical lesion or CIN grade 1) as negative and 90% of 59 samples diagnosed as ≥CIN3 (CIN grade 3 or invasive cancer) as positive. Among 41 CIN grade 2 samples representing an intermediate lesion group, 49% were HPV16 RNA patterns-positive. Interestingly, 3 of 4 HPV16 RNA patterns-positive lesions initially diagnosed as ≤CIN1 at follow-up 5-24 months later had progressed to ≥CIN2. CONCLUSIONS: We successfully developed and validated a second generation of HPV16 RNA patterns assay by rapid RT-qPCR as triage marker for HPV16 DNA-positive women offering clinical utility to distinguish between the need for immediate colposcopy and continued observation. Limited follow-up data suggests that HPV16 RNA patterns-positivity in ≤CIN1 lesions can predict disease progression.

Hepatitis C Virus Seroprevalence in Mongolian Women Assessed by a Novel Multiplex Antibody Detection Assay.

BACKGROUND: Hepatitis C virus (HCV) infection causes hepatocellular carcinoma and is an important cause of mortality in both industrialized and developing countries. We developed a single-step high-throughput multiplex serology assay for HCV antibody detection and determined HCV prevalence in a highly endemic country. METHODS: Five proteins (Core, NS3, NS4A, NS5A, NS5B) each from the three most common subtypes of HCV (1a, 1b, 2a) were recombinantly expressed and used as antigens in a multiplexed antibody detection assay. Multiplex HCV serology was validated with 432 reference sera whose HCV status was established by commercial ELISA, Western blot, and RNA assays. HCV antibodies were determined in 1,023 sera representative for the adult female population of Mongolia. RESULTS: In reference sera, detection of HCV (mostly Core and NS3) antibodies by multiplex serology showed 100% sensitivity and 99.6% specificity, and was in very good agreement with the commercial diagnostic assays (kappa, 0.96; 95% confidence interval, 0.92-0.99). The role of antibodies to NS4 and NS5 remains to be evaluated. In Mongolia, overall HCV antibody prevalence was 18.9% (17.8% when age-standardized to the world population). HCV seroprevalence increased with age from 10% in women <30 years to 32% in women ≥50 years, but was not related to sexual risk factors. CONCLUSIONS: The single-step high-throughput multiplex HCV serology assay performs similarly to conventional HCV antibody screening followed by secondary confirmation assays. A very high HCV seroprevalence was confirmed across all socio-economic groups in the female population of Mongolia. IMPACT: Multiplex HCV serology facilitates large seroepidemiologic studies of HCV infection.

Biological activity of probable/possible high-risk human papillomavirus types in cervical cancer.

Judging the carcinogenicity of human papillomavirus (HPV) types rarely found in cervical cancer (CxCa) is hindered by lack of studies of their biological activity in cancer tissues. To asses transcriptional activity of HPV types, we have developed ultra-short amplimer, splice-site specific, E6*I mRNA RT-PCR assays for 12 high-risk (HR)-HPV (IARC Group 1) and eight probable/possible high-risk (pHR)-HPV types (IARC Group 2A/B carcinogens). Previously unreported E6*I splice sites of the six pHR-HPV types 26, 53, 67, 70, 73 and 82 were identified by cloning and sequencing. We analyzed 97 formalin-fixed paraffin-embedded (FFPE) Mongolian CxCa biopsies for presence of HPV DNA by two sensitive genotyping assays, for E6*I transcripts of all HR-/pHR-HPV types identified and for expression of HPV surrogate markers p16(INK4a), pRb and p53. E6*I of at least one HR-/pHR-HPV was expressed in 94 (98%) of cancer tissues including seven with pHR-HPV types 26, 66, 70 or 82 as single transcribed types. Fifty-eight of E6*I mRNA transcribing cases were analyzable by immunohistochemistry and displayed p16(INK4a) overexpression in 57 (98%), pRb downregulation in 56 (97%) and p53 downregulation in 36 (62%) tissues. The newly developed E6*I mRNA RT-PCR assays appeared to be highly sensitive method to analyze HPV transcription in FFPE materials. Our finding of viral oncogene transcription of pHR-HPV types 26, 66, 70 and 82 in cervical tumors, in the absence of any other transcriptionally active HR-type and with p16(INK4a) overexpression and pRb downregulation, may support a reassessment of the carcinogenicity classification of these pHR-HPV types.

Dried blood spot samples for seroepidemiology of infections with human papillomaviruses, Helicobacter pylori, Hepatitis C Virus, and JC Virus.

BACKGROUND: To establish antibody analysis from dried blood spots (DBS) on filter paper for seroepidemiologic infection and cancer association studies, we analyzed data from a population-based study in Mongolia. METHODS: Using multiplex serology, we analyzed 985 paired DBS and serum samples from the same donors for antibodies to 12 different proteins from four groups of infectious agents: human papillomaviruses (HPV), Helicobacter pylori (H. pylori), hepatitis C virus (HCV), and JC polyomavirus (JCV). RESULTS: Quantitative antibody reactivities in serum and DBS showed good correlation, with median correlation coefficients (Pearson R(2)) of 0.88 (range, 0.80-0.90) for high-titer (i.e., H. pylori, HCV, JCV) and 0.79 (range, 0.72-0.85) for low-titer antibodies (i.e., HPV). For high-titer antibodies, serum and DBS data were comparable (median slope of linear trend line, 1.14; range, 1.09-1.21), whereas for low-titer antibodies, DBS reactivities were lower than in serum (median slope, 0.54; range, 0.50-0.80). By extrapolating seropositivity cutoff points previously defined for serum to DBS, we found high agreement (>89% for all antigens) of dichotomized DBS and serum results and median kappa values for high- and low-titer antibodies of 0.86 and 0.78 (range, 0.78-0.92 and 0.55-0.86), respectively. Epidemiologic associations with known risk factors for HPV antibodies were as strong for DBS as for serum. CONCLUSIONS: DBS provide a reliable alternative to serum or plasma for detection of antibodies against various pathogens by multiplex serology. IMPACT: DBS do not require blood centrifugation and allow storage and shipment at ambient temperature, thus facilitating field work for seroepidemiologic studies especially in environments with limited technical infrastructure.

Hepatitis B and C virus infections in hepatocellular carcinoma and cirrhosis in Mongolia.

The incidence of hepatocellular carcinoma (HCC) in Mongolia is far higher than that of any other cancer in the country, and among the highest worldwide. The relative importance of infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) is unclear. We reviewed (i) medical records for 963 patients with HCC and 941 patients with cirrhosis admitted for the first time to the National Cancer Center of Mongolia and the National Center for Communicable Diseases, respectively, from 2000 to 2009,and (ii) articles published from 1990 to 2010 on the seroprevalence of hepatitis B surface antigen (HBsAg) and antibodies against hepatitis C virus (anti-HCV) among individuals with and without liver disease. Among those with HCC, the seroprevalence of HBsAg, anti-HCV and dual infections was 50, 27 and 21%, respectively. Corresponding percentages among the patients with cirrhosis were 40, 39, and 20%. In both diseases, HCV infection was relatively more prevalent in women than in men and, in cirrhosis, inpatients older than 45 years of age. In healthy individuals,from published articles, anti-HCV seroprevalence steadily increased with age (from 3% at age 0-5 years to 34% at age ≥ 50 years), whereas HBsAg seroprevalence stayed constant at about 8%. The future benefit of childhood vaccination against HBV in Mongolia will be undermined by the consequences of a severe HCV epidemic and a uniquely high burden of dual infections.

Abundance of multiple high-risk human papillomavirus (HPV) infections found in cervical cells analyzed by use of an ultrasensitive HPV genotyping assay.

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.

Epigenetic silencing of interferon-kappa in human papillomavirus type 16-positive cells.

We have investigated interferon-kappa (IFN-kappa) regulation in the context of human papillomavirus (HPV)-induced carcinogenesis using primary human foreskin keratinocytes (HFK), immortalized HFKs encoding individual oncoproteins of HPV16 (E6, E7, and E6/E7), and cervical carcinoma cells. Here, IFN-kappa was suppressed in the presence of E6, whereas its expression was not affected in HFKs or E7-immortalized HFKs. Transcription could be reactivated after DNA demethylation but was decreased again upon drug removal. Partial reactivation could also be accomplished when E6 was knocked down, suggesting a contribution of E6 in IFN-kappa de novo methylation. We identified a single CpG island near the transcriptional start site as being involved in selective IFN-kappa expression. To prove the functional relevance of IFN-kappa in building up an antiviral response, IFN-kappa was ectopically expressed in cervical carcinoma cells where protection against vesicular stomatitis virus-mediated cytolysis could be achieved. Reconstitution of IFN-kappa was accompanied by an increase of p53, MxA, and IFN-regulatory factors, which was reversed by knocking down either IFN-kappa or p53 by small interfering RNA. This suggests the existence of a positive feedback loop between IFN-kappa, p53, and components of IFN signaling pathway to maintain an antiviral state. Our in vitro findings were further corroborated in biopsy samples of cervical cancer patients, in which IFN-kappa was also downregulated when compared with normal donor tissue. This is the first report showing an epigenetic silencing of type I IFN after HPV16 oncogene expression and revealing a novel strategy on how high-risk HPVs can abolish the innate immune response in their genuine host cells.

Epidemiology and prevention of human papillomavirus and cervical cancer in China and Mongolia.

To develop a comprehensive intervention policy for future management of cervical cancer in China and Mongolia, it is essential to review the prevalence of human papillomavirus (HPV) infection, cervical cancer incidence and mortality, status of cervical screening and issues related to prophylactic HPV vaccines. Invasive cervical cancer (ICC) remains an important health problem among women in both China and Mongolia. However, a significant proportion of the burden is observed in rural settings. In areas of China and Mongolia where data are available, HPV prevalence is relatively high, with sexual activity being the most important risk factor. Nationwide programs for cervical cancer screening do not exist, and the majority of women have never been screened. However, government and non-governmental organizations have been collaborating to establish demonstration centers in both high- and low-resource settings to provide screening and obtain geographic specific data. To date, the prophylactic HPV vaccines are not licensed in China or Mongolia, although with wide coverage, the HPV vaccine could potentially prevent as much as three quarters of ICC cases among Chinese and Mongolian women. Ultimately, the introduction of HPV vaccination will present specific challenges, as well as opportunities, for developing advocacy, information and communication strategies that will involve policymakers and the general public.

Human papillomavirus infection in Ulaanbaatar, Mongolia: a population-based study.

Data on human papillomavirus (HPV) and cervical cancer burden in Central Asia are scarce. To investigate HPV infection in Ulaanbaatar, the capital of Mongolia, we obtained cervical cell specimens from a population of 969 women ages 15 to 59 years. DNA of 44 HPV types was detected using a GP5+/6+ PCR-based assay. Seropositivity for L1 proteins of HPV 16, 18, 31, 33, 45, 52, and 58 was assessed using multiplex HPV serology. Cytologic abnormalities were detected in 127 women (13.1%), among whom 6 cervical intraepithelial neoplasia grade 3 and 2 invasive cervical cancers were diagnosed. Overall HPV DNA prevalence was 35.0%, being highest (48.5%) in women ages <25 years. High-risk types were detected in 24.5% of women. HPV DNA prevalence declined with age but remained >25% in all age groups. HPV seroprevalence was also very high (38.0%) and increased steadily from 33.2% to 48.9% in women ages <25 and 50 to 59 years, respectively. However, the proportion of women positive for both HPV markers of any individual HPV type was low. HPV16 was the most frequently detected type by PCR (6.1%), serology (23.0%), or both (2.1%). Lifetime number of sexual partners and induced abortions were shown to be directly associated with HPV DNA and/or seroprevalence. HPV prevalence in Ulaanbaatar was higher than that detected by similar HPV testing protocols in other populations in Asia or elsewhere and would suggest an important, yet unquantified, cervical cancer burden. Improving cervical cancer prevention, through screening and HPV vaccination, is an important public health issue for Mongolia.

Homogeneous amplification of genital human alpha papillomaviruses by PCR using novel broad-spectrum GP5+ and GP6+ primers.

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 < or = 1,000 plasmid copies in the presence of 100 ng cellular DNA was obtained. Additionally, we integrated an internal beta-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 beta-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 beta-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.

T25 repeat in the 3' untranslated region of the CASP2 gene: a sensitive and specific marker for microsatellite instability in colorectal cancer.

DNA mismatch repair deficiency is observed in about 10% to 15% of all colorectal carcinomas and in up to 90% of hereditary nonpolyposis colorectal cancer (HNPCC) patients. Tumors with mismatch repair defects acquire mutations in short repetitive DNA sequences, a phenomenon termed high-level microsatellite instability (MSI-H). The diagnosis of MSI-H in colon cancer is of increasing relevance, because MSI-H is an independent prognostic factor in colorectal cancer, seems to influence the efficacy of adjuvant chemotherapy, and is the most important molecular screening tool to identify HNPCC patients. To make MSI typing feasible for the routine pathology laboratory, highly reproducible and cost effective laboratory tests are required. Here, we describe a novel T25 mononucleotide marker in the 3'untranslated region of the CASP2 gene (CAT25) that displayed a quasimonomorphic repeat pattern in normal tissue of 200 unrelated individuals of Caucasian origin. In addition, CAT25 was monomorphic also in all tested donors of African and Asian origin (n = 102 and n = 79, respectively) and thus differs from the most commonly used markers BAT25 and BAT26. Without the analysis of corresponding normal tissue, CAT25 correctly detected 56 of 57 colorectal cancer specimens classified as MSI-H by using the standard National Cancer Institute/International Collaborative Group-HNPCC marker panel. Combined with the standard markers BAT25 and BAT26 in a multiplex PCR, all MSI-H colorectal cancer samples were typed correctly. No false-positive results were obtained in 60 non-MSI-H control colorectal cancer specimens. These data suggest that CAT25 should be included into novel marker panels for microsatellite testing thus allowing for a significant reduction of the complexity and costs of MSI typing. Moreover, CAT25 represents a highly promising marker for early detection of colorectal cancer in HNPCC germ line mutation carriers.