Type-specific Real-time PCR Research Articles

Presence of HPV with overexpression of p16INK4a protein and EBV infection in penile cancer-A series of cases from Brazil Amazon.

In Brazil, penile cancer (PC) is not uncommon. The highest incidence of PC is in the North and Northeast of the country. In addition to phimosis, the Human Papillomavirus (HPV) and Epstein-Baar Virus (EBV) infections are also related as risk factors for PC. The overexpression of p16INK4a is a surrogate sensitive marker of HPV infection in PC. To correlate p16INK4a overexpression and HPV infection status with EBV infection in a series of PC patients from the Amazon region. Tumor tissues from 47 PC cases were analyzed for the presence of HPV and EBV DNA by PCR. All PC patients were diagnosed between 2013 and 2018 at a public reference cancer center hospital in Manaus, Amazonas-Brazil. HPV was genotyped using E7 HPV16/HPV18 type-specific real-time PCR and the PapilloCheck® HPV-Screening assay. p16INK4a expression was evaluated by immunohistochemistry using the automated Ventana® BenchMark Ultra. The mean age of patients at the time of diagnosis was 57.4 years ±SD 17.8 ranging from 20 to 90 years old. Most of the patients (64%) came from rural areas of the Amazonas State. Thirty patients had phimosis (64%). Among the patients with phimosis, 43% (13/30) underwent circumcision, three during childhood and 10 in adulthood. 60% of the patients were smokers or ex-smokers. HPV infection was observed in 45% (21/47) of cases. HPV16 was detected in 13 patients (61%). Other HPV types detected were HPV 6, 11, 42, 51, 53, 68 and 44/55. EBV infection was observed in 30% (14/47) of the patients with PC. Co-infection with HPV and EBV was observed in 28% (6/21) cases. p16INK4a was only investigated in 26 samples. The p16INK4a overexpression was observed exclusively in HPV 16 positive cases and four HPV negative cases. In the survival analysis, the follow-up time was 35.4 months/patient. The mortality rate during the follow up time was 38%. p16INK4a positivity presented a high correlation to HPV 16 DNA detection, reinforcing its use as a surrogate marker for HPV-driven cancers. Infection with EBV was quite frequent and its role in epithelial penile oncogenesis needs to be demonstrated.

Human papillomavirus (HPV) 16 infection is not detected in rectal carcinoma

IntroductionPersistence of human papillomavirus (HPV) infections is associated with squamous cell carcinomas of different human anatomic sites. Several studies have suggested a potential role for HPV infection, particularly HPV16 genotype, in rectal cancer carcinogenesis.. The aim of this study was to assess the frequency of oncogenic HPV 16 viral DNA sequences in rectal carcinomas cases retrieved from the pathology archive of Braga Hospital, North Portuga.MethodsTaqMan-based type-specific real-time PCR for HPV 16 was performed using primers and probe targeting HPV16 E7 region.ResultsMost of the rectal cancer patients (88.5%, n = 206 patients), were symptomatic at diagnosis. The majority of the lesions (55.3%, n = 129) presented malignancies of polypoid/vegetant phenotype. 26.8% (n = 63) had synchronic metastasis at diagnosis. 26.2% (n = 61) patients had clinical indication for neoadjuvant therapy. Most patients with rectal cancer were stage IV (19.7% patients), followed by stage IIA (19.3%) and stage I (18.5%). All cases of the present series tested negative for HPV16.ConclusionThe total of negative tests for HPV 16 infection is a robust argument to support the assumption that HPV 16 infection, despite of previous evidences, is not involved in rectal cancer carcinogenesis and progression.

237. Adenovirus Types in Children with Acute Respiratory Illnesses in Nashville Over Two Respiratory Seasons

BackgroundHuman adenovirus (HAdV) types 1–7, 11, 14, 16, and 21 within species B, C, and E are commonly associated with acute respiratory illnesses (ARI) in children. We sought to compare demographics, clinical characteristics, and outcomes of HAdV types with children who presented with fever and/or respiratory symptoms.MethodsChildren < 18 years with fever and/or ARI seen at Vanderbilt Children’s Hospital inpatient and emergency department settings from December of 2016 to October of 2018 were enrolled. Interviews and chart abstraction were conducted. Mid-turbinate nose and throat swab specimens were collected and tested by real-time RT-PCR for common respiratory viruses including HAdV. HAdV molecular typing was performed by type-specific real-time PCR assays for types 1–7, 11, 14, 16, and 21 targeting the hexon gene using published methods.ResultsOf 5111 ARI cases, 206 (4%) were HAdV-positive with a median age of 16 months (IQR 9–30); 57% male, 47% White, 40% Black, 33% Hispanic, 20% admitted, and 24% of hospitalized required oxygen support. Of the 206, 186 (90%) were able to be typed with more than one types detected in 13 (7%) cases. Distribution of HAdV types among single detections (n = 173) is shown in Figure 1; HAdV-1 and HAdV-2 were most common. Children with HAdV-2 were younger (median age 12 months vs. 15 months (HAdV-1) and 59 months (all other types), P < 0.001), and those with HAdV-1 were less likely to be male (44% vs. 65% for both HAdV-2 and other types, P = 0.029). Figure 2 displays HAdV detections over time, with winter and early spring peaks. Co-detection with other respiratory viruses occurred in 47% of cases; the most common among typable HAdV were rhinovirus/enterovirus in 30/186 (16%) and RSV in 19/186 (10%). Distribution among HAdV types is shown in Figure 3.ConclusionHAdV-1 and HAdV-2 were more prevalent than other HAdV types over two respiratory seasons in the Nashville area with peak cases in December-March. Children with HAdV-1 and HAdV-2 had some demographic differences. Further studies with a larger sample size for HAdV typing are needed in the pediatric population to determine whether additional clinically-relevant differences between HAdV types exist. Disclosures All authors: No reported disclosures.

Human Papillomavirus Viral Load and Transmission in Young, Recently Formed Heterosexual Couples.

We studied the association between human papillomavirus (HPV) viral load (VL) and HPV concordance. The HITCH cohort study included young, heterosexual, recently formed, sexually active couples. Questionnaires and genital samples were collected at 0 and 4 months. Samples were tested for HPV DNA by polymerase chain reaction (PCR; Linear Array). VLs of HPV6/11/16/18/31/42/51 were quantified using type-specific real-time PCR. Correlations between VL and type-specific HPV prevalence and incidence were evaluated using multilevel, mixed-effects linear/logistic regression models. We included 492 couples. VLs were higher in penile than vaginal samples. VL at subsequent visits correlated significantly within men (r, 0.373), within women (r, 0.193), and within couples (r range: 0.303-0.328). Men with high VL had more type-specific persistent HPV infections (odds ratio [OR], 4.6 [95% confidence interval {CI}, 2.0-10.5]). High VL in men was associated with prevalent (OR, 5.3 [95% CI, 2.5-11.2]) and incident (OR, 6.7 [95% CI, 1.5-30.7]) type-specific HPV infections in their partner. Women's VL was associated with type-specific HPV prevalence in their partner at the same (OR, 5.9) and subsequent (OR, 4.7) visit. Persistent HPV infections have limited VL fluctuations. VL between sex partners are correlated and seem predictive of transmission episodes.

Human papillomavirus DNA detection in plasma and cervical samples of women with a recent history of low grade or precancerous cervical dysplasia.

Circulating HPV DNA has been previously described in women with advanced stages of cervical cancer and has been suggested to be a prognostic marker of disease recurrences and metastases. Only a few studies have reported the presence of HPV DNA in bloodstream of patients with low grade or precancerous cervical lesions. This study aimed to define if HPV DNA could be detected in plasma samples of 120 women referred for a recent history of cervical dysplasia who presented with lesions ranging from High Squamous Intraepithelial Lesion (H-SIL) to regressed normal cytology. HPV DNA detection was carried out in both plasma and cervical samples using type-specific real-time quantitative PCR assays identifying oncogenic HPV 16, 18, 31, 33, 45, 51 and 52.Overall, 34.2% (41/120) of plasma samples were shown to be positive for HPV DNA detection; HPV 45 (46.3%), HPV-51 (29.6%), and HPV 16 (18.5%) were the most frequently identified genotypes. The rate of HPV detection in paired cervical and plasma samples increased with advancing disease stage, ranging from 15.4% in women with regressed lesions to 38.9% in women with HSIL; HPV 16 resulted the most common genotype identified in women found to be HPV DNA positive in both cervical and plasma samples. Moreover, HPV 16 showed the highest median viral load value in both cervical and plasma samples, with 48,313 copies/104 cells and 1,099 copies/ml, respectively.Results obtained in this study confirm that HPV DNA can be detected and quantified in plasma samples of women with asymptomatic cervical infection. Further knowledge on HPV dissemination through the blood stream of women with cervical lesions would be very important in better understanding the natural history of HPV infection as well as its potential role in other distant tumors.

Molecular characterization, prevalence and clinical relevance of Phodopus sungorus papillomavirus type 1 (PsuPV1) naturally infecting Siberian hamsters (Phodopus sungorus).

Phodopus sungorus papillomavirus type 1 (PsuPV1), naturally infecting Siberian hamsters (Phodopus sungorus) and clustering in the genus Pipapillomavirus (Pi-PV), is only the second PV type isolated from the subfamily of hamsters. In silico analysis of three independent complete viral genomes obtained from cervical adenocarcinoma, oral squamous cell carcinoma and normal oral mucosa revealed that PsuPV1 encodes characteristic viral proteins (E1, E2, E4, E6, E7, L1 and L2) with conserved functional domains and a highly conserved non-coding region. The overall high prevalence (102/114; 89.5 %) of PsuPV1 infection in normal oral and anogenital mucosa suggests that asymptomatic infection with PsuPV1 is very frequent in healthy Siberian hamsters from an early age onward, and that the virus is often transmitted between both anatomical sites. Using type-specific real-time PCR and chromogenic in situ hybridization, the presence of PsuPV1 was additionally detected in several investigated tumours (cervical adenocarcinoma, cervical adenomyoma, vaginal carcinoma in situ, ovarian granulosa cell tumour, mammary ductal carcinoma, oral fibrosarcoma, hibernoma and squamous cell papilloma) and normal tissues of adult animals. In the tissue sample of the oral squamous cell carcinoma individual, punctuated PsuPV1-specific in situ hybridization spots were detected within the nuclei of infected animal cells, suggesting viral integration into the host genome and a potential etiological association of PsuPV1 with sporadic cases of this neoplasm.

Human Papillomavirus (HPV) Infection: Molecular Epidemiology, Genotyping, Seroprevalence and Associated Risk Factors among Arab Women in Qatar.

Human Papillomavirus (HPV) infections are known to cause cervical cancer worldwide, however, limited information is currently available on prevalence, types distribution and risk factors for HPV infection in the Arab countries. We conducted a cross-sectional observational study exclusively of women of Arabic origin residing in Qatar (n = 406) who were selected from the Women’s Hospital at Hamad Medical Corporation (HMC) and Health Centers of the Primary Health Care Corporation in Doha, Qatar over the period March 2013 to August 2014. Socio-demographic, behavioral and clinical data were collected. Four hundred and six cervical smears and 292 blood samples were included in the study. HPV typing was done using HPV type-specific primers-based real-time PCR, and Sanger sequencing. HPV-IgG and IgM were quantified using ELISA assays. The prevalence of HPV infection amongst Qatari and non-Qatari Arab women were 9.8% and 6.1%, respectively and 7.6% and 16.7% in women with normal and abnormal cytology, respectively. HPV 81 was the most commonly found genotype in women with normal cytology (34.5%), whereas HPV 81, 16 and 59 in women with abnormal cytology (25.0% each). All the HPV DNA positive women were seronegative and HPV-IgG prevalence was higher in Qatari women than in non-Qatari Arab women. None of the studied factors had any significant association with HPV-DNA positivity or HPV-IgG seropositivity. The overall identified HPV DNA prevalence and HPV seroprevalence among Arab women in Qatar were on the low side compared to global levels.

Quantitative real-time PCR assays for detection and type-specific identification of the endemic species C human adenoviruses

Human adenoviruses (HAdVs) are medically important respiratory pathogens. Among the 7 recognized species (A–G), species C HAdVs (serotypes 1, 2, 5 and 6) are globally endemic and infect most people early in life. Species C HAdV infections are most often subclinical or mild and can lead to persistent shedding from the gastrointestinal and upper respiratory tracts. They can also cause severe disseminated disease in newborn and immunocompromised persons, where rapid and quantitative detection and identification of the virus would help guide therapeutic intervention. To this end, we developed quantitative type-specific real-time PCR (qPCR) assays for HAdV-1, -2, -5 and -6 targeting the HAdV hexon gene. All type-specific qPCR assays reproducibly detected as few as 5 copies/reaction of quantified hexon recombinant plasmids with a linear dynamic range of 8 log units (5–5×107 copies). No non-specific amplifications were observed with concentrated nucleic acid from other HAdV types or other common respiratory pathogens. Of 199 previously typed HAdV field isolates and positive clinical specimens, all were detected and correctly identified to type by the qPCR assays; 10 samples had 2 HAdV types and 1 sample had 3 types identified which were confirmed by amplicon sequencing. The species C HAdV qPCR assays permit rapid, sensitive, specific and quantitative detection and identification of four recognized endemic HAdVs. Together with our previously developed qPCR assays for the epidemic respiratory HAdVs, these assays provide a convenient alternative to classical typing methods.

Development of a novel multiplex type-specific quantitative real-time PCR for detection and differentiation of infections with human papillomavirus types HPV2, HPV27, and HPV57

The present study describes the development and evaluation of the first multiplex type-specific quantitative real-time PCR (RT-PCR), enabling simple, rapid, sensitive, and specific concurrent detection and differentiation of human papillomavirus (HPV) types HPV2, 27, and 57 in a single PCR reaction. The HPV2/27/57 multiplex RT-PCR with a dynamic range of seven orders of magnitude (discriminating 10 to 108 viral genome equivalents/reaction) has an analytical sensitivity of at least 10 viral copies of each targeted HPV type/reaction, and no cross-reactivities were observed among the included targets. All three primer/probe combinations were efficient in amplifying 500 copies of targeted DNA in a background of 108, 107, 500, 100, and 10 copies of non-targeted viral DNA/reaction, and the performance of the HPV2/27/57 multiplex RT-PCR was additionally not affected by the presence of background human genomic DNA. When testing DNA isolates obtained from fresh-frozen tissue specimens of various children's warts, the results of the HPV2/27/57 multiplex RT-PCR were completely in line with the results of the conventional Low-risk Alpha-PV PCR. The newly developed HPV2/27/57 multiplex RT-PCR is an appropriate test for use in routine clinical laboratory settings and for studies focusing on the molecular epidemiology, pathogenesis, and natural history of HPV2/27/57-related lesions.

Type specific Real time PCR for detection of human herpes virus 6 in schizophrenia and bipolar patients: a case control study.

BackgroundSchizophrenia (SC) and bipolar disorder (BD) are among the most devastating diseases worldwide. There are several lines of evidence suggesting that viruses may play significant roles in the etiology of these mental disorders. The aim of this study was the detection of HHV-6A/B in the peripheral blood mononuclear cells (PBMC) of SC and BD patients versus the healthy control (HC) subjects using a new method of type-specific Real time PCR analysis.MethodsA type-specific Real time PCR was performed for simultaneous detection and typing of HHV-6A/B in the PBMCs of 120 SC and BD patients and 75 HCs.ResultsOnly one case of HHV-6B out of 120 (0.8 %) SC and BD patients and two cases of HHV-6A (2.7 %) in 75 HCs were detected.ConclusionsThe low levels of HHV-6 detection in PBMCs, severely limited the capacity of this study to investigate the association between the presence of HHV-6 and BD or SC in this population, thus no conclusions can be drawn in this regard. Meanwhile this study introduces a Real time PCR based method for type specific detection of HHV-6A/B in clinical samples.

Identification of a Novel Human Papillomavirus, Type HPV199, Isolated from a Nasopharynx and Anal Canal, and Complete Genomic Characterization of Papillomavirus Species Gamma-12.

The novel human papillomavirus type 199 (HPV199) was initially identified in a nasopharyngeal swab sample obtained from a 25 year-old immunocompetent male. The complete genome of HPV199 is 7,184 bp in length with a GC content of 36.5%. Comparative genomic characterization of HPV199 and its closest relatives showed the classical genomic organization of Gammapapillomaviruses (Gamma-PVs). HPV199 has seven major open reading frames (ORFs), encoding five early (E1, E2, E4, E6, and E7) and two late (L1 and L2) proteins, while lacking the E5 ORF. The long control region (LCR) of 513 bp is located between the L1 and E6 ORFs. Phylogenetic analysis additionally confirmed that HPV-199 clusters into the Gamma-PV genus, species Gamma-12, additionally containing HPV127, HV132, HPV148, HPV165, and three putative HPV types: KC5, CG2 and CG3. HPV199 is most closely related to HPV127 (nucleotide identity 77%). The complete viral genome sequence of additional HPV199 isolate was determined from anal canal swab sample. Two HPV199 complete viral sequences exhibit 99.4% nucleotide identity. To the best of our knowledge, this is the first member of Gamma-PV with complete nucleotide sequences determined from two independent clinical samples. To evaluate the tissue tropism of the novel HPV type, 916 clinical samples were tested using HPV199 type-specific real-time PCR: HPV199 was detected in 2/76 tissue samples of histologically confirmed common warts, 2/108 samples of eyebrow hair follicles, 2/137 anal canal swabs obtained from individuals with clinically evident anal pathology, 4/184 nasopharyngeal swabs and 3/411 cervical swabs obtained from women with normal cervical cytology. Although HPV199 was found in 1.4% of cutaneous and mucosal samples only, it exhibits dual tissue tropism. According to the results of our study and literature data, dual tropism of all Gamma-12 members is highly possible.

Evaluation of human papillomavirus type replacement postvaccination must account for diagnostic artifacts: masking of HPV52 by HPV16 in anogenital specimens.

It has been hypothesized that, following a reduction in human papillomavirus (HPV) vaccine-targeted genotypes, an increase in prevalence of other HPV types may occur due to reduced competition during natural infection. Any apparent postvaccination increase must be distinguished from diagnostic artifacts consequent to consensus PCR assays failing to detect HPV types present in low copy numbers in coinfected specimens (under the assumption that with a drop in vaccine-preventable types there may be increased detection of previously "masked" types). We reanalyzed anogenital specimens to evaluate unmasking of HPV52 that may be caused by elimination of HPV16. Using highly sensitive type-specific real-time HPV52 PCR, we retested 1,200 anogenital specimens (all HPV52 negative according to consensus PCR assays) from six epidemiologic studies (200 specimens/study; 100 HPV16(+)/study). Multivariate logistic regression, with adjustment for age and number of sexual partners, was used to evaluate the association between HPV16 positivity and detection of HPV52. In our pooled analysis (n = 1,196), the presence of HPV16 was positively associated with HPV52 detection [adjusted OR, 1.47; 95% confidence interval (CI), 0.76-2.82]. In our separate (study specific) analyses, a statistically significant association was observed in one study that included HIV-infected males (HIPVIRG study; adjusted OR, 3.82; 95% CI, 1.19-12.26). We observed a positive association between HPV16 viral load (tertiles) and detection of HPV52 (P for trend = 0.003). These results indicate that diagnostic artifacts, resulting from unmasking of HPV52, may occur in some settings in the evaluation of HPV type replacement. Additional studies exploring the extent and severity of unmasking are needed.

Detection of major HPVs by a new multiplex real-time PCR assay using type-specific primers

In this study, we aimed to develop a cost-effective, practical, and sensitive method to be used for the diagnosis of HPV infections. The presence of HPV-DNA was investigated in cervical smear samples using three different methods: MY09/11 consensus PCR, TaqMan-based type-specific real-time PCR, and SYBR Green-based multiplex PCR. Of the 315 samples, 21.6% (68/315) were HPV-DNA positive by using at least one of the three methods. The relative sensitivities of MY09/11 PCR, type-specific PCR, and multiplex PCR were found to be 86.8% (59/68), 91.2% (62/68), and 91.2% (62/68), respectively. Genotyping analyses were successfully carried out in 62 of 68 HPV-DNA positive samples, and 77 isolates (8 low-risk and 69 high-risk HPV) were identified, while six samples were determined to be positive by consensus PCR only and could not be genotyped. The type distribution of the 69 high-risk HPV strains was as follows: 37.7% HPV 16, 13.0% HPV 52, 11.6% HPV 58, 7.2% HPV 18, 7.2% HPV 31, 7.2% HPV 68, 4.3% HPV 35, 4.3% HPV 39, 4.3% HPV 82, 1.4% HPV 33, and 1.4% HPV 45. Our data suggests that the diagnosis of HPV infections using only consensus PCR may lead to epidemiologically significant data loss, and that our multiplex PCR is more sensitive than consensus PCR and lower in cost than the type-specific PCR. We believe that the SYBR Green-based multiplex PCR may be useful and cost-effective for other microbiological fields. In addition, type-specific screening of HPV-DNA gives more reliable results, but it may also be used in combination with consensus PCR if the type spectrum of the test is not large enough.

Determination of Viral Load by Quantitative Real-Time PCR in Herpes Simplex Encephalitis Patients

Objective: Human herpesviruses cause various acute, subacute, and chronic disorders of the central nervous system and peripheral nervous systems in adults and children. The objective of the present study is to summarize the experience gained with the estimation of viral load in the central nervous system of children and adults with herpes simplex encephalitis (HSE) admitted to a neurological institute at Nagpur, India, by quantitative real-time PCR (qPCR) assay within the past 4 years. Methods: The qPCR assay was evaluated retrospectively in 242 cerebrospinal fluid (CSF) samples from patients. Evaluation of possible relationships was done between the herpes simplex virus (HSV) DNA concentration in CSF with that of patients' clinical and laboratory manifestations. The prevalence of the type of HSV in the study population was also determined using type-specific real-time PCR analysis. Results and Conclusions: Real-time analysis using type-specific primers revealed the presence of predominantly HSV-1 genotype in the study population. The qPCR results show that in patients with higher viral loads in their CSF, a greater number of cases were associated with the presence of lesions in the brain as revealed by computed tomography/magnetic resonance imaging scan. They required acyclovir therapy for a longer duration and had a poorer clinical outcome than the patients with lower viral loads in their CSF.

Quantitative Real-Time PCR Assay Panel for Detection and Type-Specific Identification of Epidemic Respiratory Human Adenoviruses

Outbreaks of human adenovirus (HAdV) acute respiratory illness (ARI) have been well documented among civilians and unvaccinated military recruits. Among the 7 recognized HAdV species (A to G), species B (particularly serotypes 3, 7, 11, 14, and 21) and E (serotype 4) have more often been associated with epidemic ARI. Rapid detection and type-specific identification of these viruses would enhance outbreak response and help guide prevention and control measures. To this end, we developed type-specific real-time quantitative PCR (qPCR) assays for HAdV types 3, 4, 7, 11, 14, 16, and 21 targeting the HAdV hexon gene. All type-specific qPCR assays reproducibly detected as few as 10 copies/reaction of quantified hexon recombinant plasmids with a linear dynamic range of 8 log units (10(1) to 10(8) copies); in contrast, a generic qPCR assay that detects all HAdV types run concurrently detected between 10 and 100 copies/reaction, depending on the virus type. No nonspecific amplifications were observed with concentrated nucleic acid from 51 HAdV prototype strains or other common respiratory pathogens. All members of a panel of 137 previously typed HAdV field isolates and positive clinical specimens were correctly characterized by the type-specific qPCR assays; two different HAdV types were detected in three of the clinical specimens and confirmed by amplicon sequencing. The qPCR assays permit sensitive, specific, and quantitative detection and identification of seven clinically important respiratory HAdVs and should provide a convenient adjunct to classical typing methods for a rapid response to HAdV outbreaks.

Comparison of oncogenic HPV type‐specific viral DNA load and E6/E7 mRNA detection in cervical samples: Results from a multicenter study

High-risk human papillomavirus (HR-HPV) genotype viral load and E6/E7 mRNA detection are proposed as surrogate markers of malignant cervical lesion progression. Currently, the use of commercially available DNA-based or mRNA-based tests is under investigation. In this study, the viral DNA load and E6/E7 mRNA detection of the five most common HR-HPV types detected in cervical cancer worldwide were compared in 308 cervical samples by using in-house type-specific quantitative real-time PCR assays and PreTect HPV-Proofer test, respectively. Sensitivity and negative predictive values were higher for the HPV-DNA assays combined (95.0% and 96.0%, respectively) than the RNA assays (77.0% and 88.0%, respectively); conversely, the mRNA test showed a higher specificity and higher positive predictive value (81.7% and 66.9%, respectively) than the DNA test (58.6% and 52.5%, respectively) for detecting histology-confirmed high-grade cervical intraepithelial neoplasia. A significantly higher association between viral DNA load and severity of disease was observed for HPV 16 and 31 (γ = 0.62 and γ = 0.40, respectively) than for the other HPV types screened. A good degree of association between the two assays was found for detection of HPV 16 (k = 0.83), HPV 18 (k = 0.72), HPV 33 (k = 0.66), and HPV 45 (k = 0.60) but not for HPV 31 (k = 0.24). Sequence analysis in L1 and E6-LCR regions of HPV 31 genotypes showed a high level of intra-type variation. HR-HPV viral DNA load was significantly higher in E6/E7 mRNA positive than negative samples (P < 0.001), except for HPV 31. These findings suggest that transcriptional and replicative activities can coexist within the same sample.

Clinical Validation of a Type-Specific Real-Time Quantitative Human Papillomavirus PCR against the Performance of Hybrid Capture 2 for the Purpose of Cervical Cancer Screening

To be acceptable for use in cervical cancer screening, a new assay that detects DNA of high-risk human papillomavirus (hrHPV) types must demonstrate high reproducibility and performance not inferior to that of a clinically validated HPV test. In the present study, a real-time quantitative PCR (qPCR) assay targeting the E6 and E7 genes of hrHPV was compared with Hybrid Capture 2 (hc2) in a Belgian cervical cancer screening setting. In women >30 years old, the sensitivity and specificity for intraepithelial neoplasias of grade 2 or worse (93 cases of cervical intraepithelial neoplasias of grade 2 or worse (CIN2+) and 1,207 cases of no CIN or CIN1) were 93.6% and 95.6%, respectively, and those of hc2 were 83.9% and 94.5%, respectively {relative sensitivity of qPCR/hc2 = 1.12 [95% confidence interval (CI), 1.01 to 1.23]; relative specificity = 1.01 [95% CI, 0.99 to 1.03]}. A score test showed that the sensitivity (P < 0.0001) and specificity (P < 0.0001) of the qPCR assay were not inferior to those of hc2 at the required thresholds of 90% and 98%, respectively. The overall agreement of hrHPV positivity between the two runs of the qPCR tests was 98.7% (95% CI, 97.5 to 99.4%), with a kappa value of 0.96 (95% CI, 0.83 to 1.00). The qPCR assay used in this study can be considered a reliable HPV assay that fulfills the clinical validation criteria defined for use in cervical cancer screening.

The impact of cidofovir treatment on viral loads in adult recurrent respiratory papillomatosis

Cidofovir is an antiviral agent used in the therapy of recurrent respiratory papillomatosis (RRP). In this study, we hypothesized that cidofovir is effective in decreasing the viral load of human papillomavirus (HPV). We established a type specific real-time PCR and measured HPV DNA loads. The course of viral load of HPV types 6 and 11 after repeated applications of cidofovir intralesionally was compared to the clinical outcome using a modified Derkay score. In 6 of the 8 (75 %) patients, we detected HPV 6. In 2 (25 %) patients, we detected HPV 11. In all of the patients, the viral load and the modified Derkay score decreased significantly during the treatment. We conclude that viral load of HPV can be monitored using the technique described here. Cidofovir in combination with surgical debulking reduces the viral load in patients with RRP. Relapses of the symptoms cannot be avoided but might be delayed.

The 2010 Global Proficiency Study of Human Papillomavirus Genotyping in Vaccinology

Accurate and internationally comparable human papillomavirus (HPV) DNA genotyping is essential both for evaluation of HPV vaccines and for effective monitoring and implementation of vaccination programs. The World Health Organization (WHO) HPV Laboratory Network (LabNet) regularly issues international proficiency studies. The 2010 HPV genotyping proficiency panel for HPV vaccinology contained 43 coded samples composed of purified plasmids of 16 HPV types (HPV types 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68a and 68b) and 3 coded extraction controls. Proficient typing was defined as detection in both single and multiple infections of 50 international units (IU) of HPV type 16 (HPV-16) and HPV-18 DNA and 500 genome equivalents (GE) for the other 14 HPV types. Ninety-eight laboratories worldwide submitted a total of 132 data sets. Twenty-four different HPV genotyping assay methods were used, with Linear Array being the most commonly used. Other major assays used were a line blot assay (Inno-LiPa), CLART, type-specific real-time PCR, PCR Luminex, and different microarray assays. Altogether, 72 data sets were proficient for detection of more than 1 type, and only 26 data sets proficiently detected all 16 HPV types. The major oncogenic HPV types, 16 and 18, were proficiently detected in 95.0% (114/120) and 87.0% (94/108) of data sets, respectively. Forty-six data sets reported multiple false-positive results and were considered nonproficient. A trend toward increased sensitivity of assays was seen for the 41 laboratories that participated in both 2008 and 2010. In conclusion, continued global proficiency studies will be required for establishing comparable and reliable HPV genotyping services for vaccinology worldwide.

High-throughput detection, genotyping and quantification of the human papillomavirus using real-time PCR

The establishment of the causal relationship between high-risk human papillomavirus (HR-HPV) infection and cervical cancer and its precursors has resulted in the development of HPV DNA detection systems. Currently, real-time PCR assays for the detection of HPV, such as the RealTime High Risk (HR) HPV assay (Abbott) and the cobas® 4800 HPV Test (Roche Molecular Diagnostics) are commercially available. However, none of them enables the detection and typing of all HR-HPV types in a clinical high-throughput setting. This paper describes the laboratory workflow and the validation of a type-specific real-time quantitative PCR (qPCR) assay for high-throughput HPV detection, genotyping and quantification. This assay is routinely applied in a liquid-based cytology screening setting (700 samples in 24 h) and was used in many epidemiological and clinical studies. The TaqMan-based qPCR assay enables the detection of 17 HPV genotypes and β-globin in seven multiplex reactions. These HPV types include all 12 high-risk types (HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59), three probably high-risk types (HPV53, 66 and 68), one low-risk type (HPV6) and one undetermined risk type (HPV67). An analytical sensitivity of ≤100 copies was obtained for all the HPV types. The analytical specificity of each primer pair was 100% and an intra- and inter-run variability of <6.4% was observed. The type-specific real-time PCR approach enables detection of 17 HPV types, identification of the HPV type and determination of the viral load in a single sensitive assay suitable for high-throughput screening.