Pitfalls in the epidemiologic classification of human papillomavirus types associated with cervical cancer using polymerase chain reaction: driver and passenger

Current updates on the structural and functional aspects of the CRISPR/Cas13 system for RNA targeting and editing: A next‑generation tool for cancer management (Review)

For centuries, a competitive evolutionary race between prokaryotes and related phages or other mobile genetic elements has led to the diversification of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR‑associated sequence (Cas) genome‑editing systems. Among the different CRISPR/Cas systems, the CRISPR/Cas9 system has been widely studied for its precise DNA manipulation; however, due to certain limitations of direct DNA targeting, off‑target effects and delivery challenges, researchers are looking to perform transient knockdown of gene expression by targeting RNA. In this context, the more recently discovered type VI CRISPR/Cas13 system, a programmable single‑subunit RNA‑guided endonuclease system that has the capacity to target and edit any RNA sequence of interest, has emerged as a powerful platform to modulate gene expression outcomes. All the Cas13 effectors known so far possess two distinct ribonuclease activities. Pre‑CRISPR RNA processing is performed by one RNase activity, whereas the two higher eukaryotes and prokaryotes nucleotide‑binding domains provide the other RNase activity required for target RNA degradation. Recent innovative applications of the type VI CRISPR/Cas13 system in nucleic acid detection, viral interference, transcriptome engineering and RNA imaging hold great promise for disease management. This genome editing system can also be employed by the Specific High Sensitivity Enzymatic Reporter Unlocking platform to identify any tumor DNA. The discovery of this system has added a new dimension to targeting, tracking and editing circulating microRNA/RNA/DNA/cancer proteins for the management of cancer. However, there is still a lack of thorough understanding of the mechanisms underlying some of their functions. The present review summarizes the recent updates on the type VI CRISPR/Cas system in terms of its structural and mechanistic properties and some novel applications of this genome‑editing tool in cancer management. However, some issues, such as collateral degradation of bystander RNA, impose major limitations on its in vivo application. Furthermore, additional challenges and future prospects for this genome editing system are described in the present review.

Advances in application of CRISPR-Cas13a system

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) and CRISPR-associated (Cas) proteins serve as an adaptive immune system that safeguards prokaryotes and some of the viruses that infect prokaryotes from foreign nucleic acids (such as viruses and plasmids). The genomes of the majority of archaea and about half of all bacteria contain various CRISPR-Cas systems. CRISPR-Cas systems depend on CRISPR RNAs (crRNAs). They act as a navigation system to specifically cut and destroy foreign nucleic acids by recognizing invading foreign nucleic acids and binding Cas proteins. In this review, we provide a brief overview of the evolution and classification of the CRISPR-Cas system, focusing on the functions and applications of the CRISPR-Cas13a system. We describe the CRISPR-Cas13a system and discuss its RNA-directed ribonuclease function. Meanwhile, we briefly introduce the mechanism of action of the CRISPR-Cas13a system and summarize the applications of the CRISPR-Cas13a system in pathogen detection, eukaryotes, agriculture, biosensors, and human gene therapy. We are right understanding of CRISPR-Cas13a has been broadened, and the CRISPR-Cas13a system will be useful for developing new RNA targeting tools. Therefore, understanding the basic details of the structure, function, and biological characterization of CRISPR-Cas13a effector proteins is critical for optimizing RNA targeting tools.

Novel Vaccine Strategies and Factors to Consider in Addressing Health Disparities of HPV Infection and Cervical Cancer Development among Native American Women

Cervical cancer is the 4th most common type of cancer in women world-wide. Many factors play a role in cervical cancer development/progression that include genetics, social behaviors, social determinants of health, and even the microbiome. The prevalence of HPV infections and cervical cancer is high and often understudied among Native American communities. While effective HPV vaccines exist, less than 60% of 13- to 17-year-olds in the general population are up to date on their HPV vaccination as of 2020. Vaccination rates are higher among Native American adolescents, approximately 85% for females and 60% for males in the same age group. Unfortunately, the burden of cervical cancer remains high in many Native American populations. In this paper, we will discuss HPV infection, vaccination and the cervicovaginal microbiome with a Native American perspective. We will also provide insight into new strategies for developing novel methods and therapeutics to prevent HPV infections and limit HPV persistence and progression to cervical cancer in all populations.

The distribution and pathogenic risk of non-9-valent vaccine covered HPV subtypes in cervical lesions

Human papillomavirus (HPV) infection is the main cause of female precancerous lesions and cervical cancer. The development and application of HPV prophylactic vaccines have been recognized as a major effective intervention for the control of cervical lesions. However, the infection rate and clinical characters of non-9-valent vaccine covered HPV subtypes are still worth studying. In this retrospective study, we included patients diagnosed and treated in the Department of Gynecology of Shanghai General Hospital between January 2017 and February 2021. The clinical features of non-9-valent vaccine covered HPV subtypes were explored in 2179 patients who have normal results, 338 patients with cervical intraepithelial neoplasia 1 (CIN1), and 153 patients with ≥CIN2. Univariate analysis showed that compared to the normal cervix group, age ≥50, pregnancy ≥5, delivery ≥3, menopause, no condom use, and cervical transformation zone type III were risk factors for CIN1 or ≥CIN2 (p < 0.05). Thirty-one percent of CIN1 and 26% of ≥CIN2 were attributed to HPV51, HPV53, HPV56, and HPV68. Multivariate analysis revealed that HPV53, HPV81, age, menopause, cervical transformation area and involved glands were independent risk factors for ≥CIN2 group compared to the CIN1 group (p < 0.05). Additionally, among the 14 non-9-valent vaccine covered HPV subtypes, the infection rates of HPV53, 56, 51, and 68 were higher in this study. In conclusion, our study demonstrated the distribution and pathogenic risk of non-9-valent vaccine covered HPV subtypes in cervical lesions. These findings might supply a foundation for optimizing cervical cancer prevention in the post-vaccine era.

Sex difference in the immunogenicity of the quadrivalent Human Papilloma Virus vaccine: Systematic review and meta-analysis

BACKGROUND

Immunological differences between males and females in response to viral vaccines are well known. This the first review to examine them for the Human Papilloma Virus.

METHODS

We conducted a systematic review and meta-analysis of the immunogenicity of the Quadrivalent Human Papilloma Virus Vaccine qHPVV. We searched Medline, Embase, and CENTRAL for trials published until September 17, 2019. Inclusion criteria were 3-doses and reporting geometric mean titers (GMTs). We performed random-effects meta-analyses and meta-regression separated by age group and sex.

RESULTS

Our search yielded 1809 unique studies. 334 full texts were screened and data from 18 studies were extracted. Females had higher pooled geometric mean titers than males in all age groups. Log transformed GMTs in male children (<16) years were: against HPV6: 6·62 (95% CI 6·29-6·94; I² = 86·0%), against HPV11: 7·07 (95% CI 6·90-7·23; I² = 63.1%), against HPV16: 8·53 (95% CI 8·28-8·78; I² = 73·0%), and against HPV18 7·21 (95% CI 7·08-7·34; I² = 26·4%). In females: against HPV6 7·10 (95% CI 6·79-7·41; I² = 96·6%), HPV11: 7·32 (95% CI 7·15-7·50; I² = 90·6%), HPV16: 8·71 (95% CI 8·52-8·91; I² = 90·2%), and HPV18 7·35 (95% CI 7·11-7·58; I² = 92·7%). In the meta-regression, the sexual difference was significant for HPV6 (p = 0·022) with a similar tendency for HPV11 (p = 0·066) and HPV18 (p = 0·079). Immunogenicity was significantly higher in children (<16) than in adults (p < 0·001).

CONCLUSION

Females have higher antibody titers against HPV after receiving the qHPVV than do males. The difference is bigger in low-risk HPV strains. Adjusting the doses and schedules for each sex should be explored further.

Immunogenetics and human papillomavirus (HPV) in male genital lichen sclerosus (MGLSc)

BackgroundThe pathogenesis of male genital lichen sclerosus (MGLSc) is controversial. Incriminated factors include infection with human papillomavirus (HPV) and autoimmunity (e.g. Human Leukocyte Antigen [HLA]). To address the roles of HLA and HPV in MGLSc we studied adult Caucasian males with a clinical and histological diagnosis of MGLSc. The men in the study attended two specialised Male Genital Dermatoses Clinics between July 2011 and September 2012 and were selected and phenotyped from the clinical records. DNA was extracted from blood and paraffin-embedded biopsy sections, for HLA and HPV typing, respectively. HLA allele frequencies were compared with those derived from the UK-based Caucasian population. Eighty-eight cases of MGLSc were identified. HPV DNA was detected in 33/88 (37.5%) cases of MGLSc. HPV16 was the most prevalent type found: 11/88 (12.5%) MGLSc. No statistically significant HLA associations were established but HLA-B*35, -B*51, -C*15, -DRB1*04, -DRB1*10 (predisposition) and -DQA1*01 (protection) were revealed as alleles of interest. HPV16-associated MGLSc cases showed no statistically significant association with HLA genotype. The relationship between HPV and MGLSc suggests a passenger effect rather than a pathogenic role. HLA is not associated with MGLSc nor co-existent HPV16.

PCR-RFLP assay as an option for primary HPV test

Persistent human papillomavirus (HPV) infection is an essential factor of cervical cancer. This study evaluated the analytical performance of restriction fragment length polymorphism polymerase chain reaction (PCR-RFLP) assay compared to PapilloCheck^® microarray to identify human papilloma virus (HPV) in cervical cells. Three hundred and twenty-five women were analyzed. One sample was used for conventional cytology and another sample was collected using BD SurePath™ kit for HPV tests. Eighty samples (24.6%) were positive for HPV gene by PCR-Multiplex and were then submitted to PCR-RFLP and PapilloCheck^® microarray. There was a genotyping agreement in 71.25% (57/80) on at least one HPV type between PCR-RFLP and PapilloCheck^® microarray. In 22 samples (27.5%), the results were discordant and those samples were additionally analyzed by DNA sequencing. HPV 16 was the most prevalent HPV type found in both methods, followed by HPVs 53, 68, 18, 39, and 66 using PCR-RFLP analysis, and HPVs 39, 53, 68, 56, 31, and 66 using PapilloCheck^® microarray. In the present study, a perfect agreement using Cohen's kappa (κ) was found in HPV 33 and 58 (κ=1), very good for HPV 51, and good for types 16, 18, 53, 59, 66, 68, 70, and 73. PCR-RFLP analysis identified only 25% (20/80) HPV coinfection, and PapilloCheck^® microarray found 62.5% (50/80). Our Cohen's kappa results indicate that our in-house HPV genotyping testing (PCR-RFLP analysis) could be applied as a primary HPV test screening, especially in low income countries. If multiple HPV types are found in this primary test, a more descriptive test, such as PapilloCheck^® microarray, could be performed.

HPV types in cervical cancer tissue in South Africa: A head-to-head comparison by mRNA and DNA tests

Accurate identification of human papillomavirus (HPV)-types in cervical cancer tissue may be important for tailoring tests for primary screening and types to be included in a vaccine. The aim of this study was to compare test-performance of a 45-type HPV deoxyribonucleic acid (DNA)-test with a 9-type HPV messenger ribonucleic acid (mRNA)-test in cervical cancer tissues.In a case-series design 188 women with diagnosed cervical cancer during the period January 2008 to July 1, 2011 at the Gynaecological Oncology Unit, University of Pretoria, South Africa were recruited to the study. After cases with negative internal controls for DNA/mRNA detection (n = 18) and unconfirmed histology (n = 3) of cervical cancer were excluded, 167 women remained eligible for analysis. We compared 45 DNA-types detected through general primer (GP)5/6 polymerase chain reaction (PCR) and reverse line blot (RLB) genotyping with a modified version of the mRNA test PreTect HPV-Proofer detecting 9 genotypes (16, 18, 31, 33, 35, 45, 51, 52, 58).Histological types were 92.2% squamous cell carcinoma, 4.8% adenocarcinoma, and 3.0% adenosquamous carcinoma. Overall, HPV was detected in 95.2% (159/167) of specimens. The DNA- and mRNA tests each rendered 153/167 (91.6%) HPV positive results. When restricting the analysis to the 9 high-risk HPV-types included in the mRNA test, 91.6% (153/167) and 88.0% (147/167) were positive by the mRNA- and DNA-tests (P = .28), respectively. After hierarchical categorization of 9 comparable types, we found concordance in 66 of 67 specimens for HPV16, 25 of 27 specimens for HPV18, 19 of 21 specimens for HPV45, and only in 33 of 45 for HPV31, 33, 35, 51, 52, 58. The positivity rate for the HPV types 16, 18, and 45 and the positivity rate for HPV 16, 18, 45, 33 and 35 by both tests was 66% to 68% and 80% to 83%, respectively.Overall and when considering established high-risk types, the mRNA test has at least as high detection rate as the DNA test. The mRNA test can be an appropriate research tool to describe causative HPV-types in cervical cancer tissue for health care planning purposes.

Characterization of two new monoclonal antibodies against human papillomavirus type 16 L1 protein

Background

Human papillomavirus type 16 (HPV16) infection is implicated in cervical carcinogenesis. This study aimed to characterize two new monoclonal antibodies (mAbs) against HPV L1 protein.

Methods

The immunocompetence of AE3 and AG7 mAbs for HPV L1 protein was evaluated by Western blot analysis, immunostaining, hemagglutination inhibition assay, and ELISA. The heavy chain variable region (VH) and light chain variable region (VL) of AE3 and AG7 mAbs were sequenced and analyzed.

Results

Both mAbs specifically recognized HPV16 L1 and virus-like particles (VLPs). Both the affinity and the titer of AE3 mAb were higher than that of AG7. There were differences in sequences in the complementary determining regions (CDR) 2 and 3 of VL, as well as in the CDR1 and CDR3 of VH. The two mAbs have distinct predicted three-dimensional structures.

Conclusions

We characterized two mAbs neutralizing antibodies for HPV L1 protein, which would help develop genetic-engineered neutralizing antibodies against HPV16 for diagnostic and therapeutic purposes.

Human papillomavirus and the risk of Barrett's esophagus

Human papillomavirus (HPV) is strongly associated with squamous esophageal cancer. The potential role of HPV in Barrett's esophagus (BE) has been examined but remains unclear. The aim of the study was to determine the prevalence of HPV in esophageal and gastric tissues obtained from patients with and without BE. We designed a cross-sectional study was conducted with prospective enrollment of eligible patients scheduled for esophagogastroduodenoscopy (EGD). All participants had biopsies of endoscopic BE, squamous-lined esophagus, and stomach. Immunohistochemistry (IHC) on formalin-fixed and paraffin-embedded tissue was conducted using monoclonal antibodies. Polymerase chain reaction (PCR) for HPV was performed on DNA extracted from esophageal biopsies snapped frozen within 30 minutes after endoscopic capture. The Roche HPV Linear Array Assay with PGMY primers that has high sensitivity for detecting 37 types of HPV was used. A total of 127 subjects were included: 39 with definitive BE had IHC done on samples from non-dysplastic BE, squamous esophagus, gastric cardia, and gastric body; and 88 control patients without BE had IHC done on squamous esophageal samples, gastric cardia, and gastric body. HPV was not detected in any of the samples in either group. For confirmation, HPV DNA PCR was performed on randomly selected samples from 66 patients (both esophagus and BE from 13 patients with BE, and 53 esophagus from patients without BE); no sample had HPV DNA detected via PCR in the presence of adequate quality control. HPV infection does not play a role in the formation of non-dysplastic Barrett's esophagus in men in the United States.

Evidence that alpha-9 human papillomavirus infections are a major etiologic factor for oropharyngeal carcinoma in black South Africans

Human papillomavirus (HPV) infection, most commonly genotype 16 of the alpha-9 family, is implicated in the etiology of a subset of oropharyngeal squamous cell carcinomas (OPSC) worldwide. Data are scarce regarding OPSC in South Africans, and three prior studies suggest no significant etiologic role for HPV. We aimed to investigate for evidence of HPV etiology in OPSCs from black South Africans by polymerase chain reaction (PCR) methodologies with determination of HPV subtype by sequencing, in situ hybridization (ISH), and p16INK4a immunohistochemistry (IHC), as a surrogate marker for an HPV-driven tumor. It was hypothesized that HPV-driven tumors would be positive by PCR plus IHC and/or ISH whereas OPSCs with HPV background infections (HPV-passenger) would be positive by PCR alone. Formalin-fixed, paraffin embedded tissues from 51 OPSCs collected between 2005 and 2010 from 41 patients were analyzed for HPV by GP5?6? PCR (targeting the HPV L1 region), pU-1M/pU- 2R PCR (targeting the HPV E6/E7 region) and HPV-31 specific PCR (targeting the E5 region), chromogenic ISH, and p16INK4a IHC. All cases positive by PCR were subject to sequencing to determine HPV genotype. The patient mean age was 58.0 years and 88 % were male. Of the 51 evaluable tumors, 48 (94.1 %) were positive for HPV DNA by PCR: 25 (49.1 %) met criteria for an HPV-driven tumor, 23 (45.1 %) for HPV-passenger, and 3 (5.9 %) were HPV unrelated. Sequencing of the PCR-positive cases revealed the following genotypes: combined HPV-16 and 31 (41.7 %), HPV-31 (25.0 %), HPV-16 (22.9 %), combined HPV-16 and 18 (6.3 %), and a single case each of HPV 18 and HPV 33. Studies via ISH were negative in all cases. In accordance with worldwide trends but contrary to prior South African data, HPV likely plays an etiologic role in a significant subset (at least 49.1 %) of OPSC in black South Africans. We found that the alpha-9 HPV family, particularly HPV-16 and 31 either in combination or separately, to predominate in our sample tumors. The use of multiple PCR primers increased sensitivity of viral detection, and a HPV-31 specific primer confirmed the presence of this genotype in many samples. Further studies including HPV E6/E7 mRNA assays are needed to better elucidate the pathogenic role of HPV in black South African OPSCs.

Nogo-B promotes the epithelial-mesenchymal transition in HeLa cervical cancer cells via Fibulin-5

Cervical cancer is a common malignancy in women worldwide, and the occurrence of invasion and metastasis is the major cause for most cancer-related deaths. Epithelial-mesenchymal transition (EMT) has been implicated in the metastasis of primary tumors and provides molecular mechanisms for cervical cancer metastasis. We previously reported that Nogo-B mediates cell motility by binding Fibulin-5. Herein, we show that the increased expression of Nogo-B is correlated with the degree of cervical cancer metastasis. In HeLa cervical cancer cells, overexpression of Nogo-B induces the EMT and promotes cell migration and invasion, while inhibiting cell adhesion. Furthermore, we found that Nogo-B accumulates and co-localizes with Fibulin-5 in pseudopods, and the downstream effects of overexpression of Nogo-B on cell motility could be partially abolished by RNA interference against Fibulin-5. These results suggest that Nogo-B functions as an inducer of cervical cancer metastasis and that this effect is mediated, at least in part, through Fibulin-5.

Identification of miR-23a as a novel microRNA normalizer for relative quantification in human uterine cervical tissues

Quantitative real-time RT-PCR (RT-qPCR) is being widely used in microRNA expression research. However, few reports detailed a robust identification and validation strategy for suitable reference genes for normalisation in microRNA RT-qPCR studies. The aim of this study was to identify the most stable reference gene(s) for quantification of microRNA expression analysis in uterine cervical tissues. A microarray was performed on 6 pairs of uterine cervical tissues to identify the candidate reference genes. The stability of candidate reference genes was assessed by RT-qPCR in 23 pairs of uterine cervical tissues. The identified most stable reference genes were further validated in other cohort of 108 clinical uterine cervical samples: (HR-HPV- normal, n=21; HR-HPV+ normal, n=19; cervical intraepithelial neoplasia [CIN], n=47; cancer, n=21), and the effects of normalizers on the relative quantity of target miR-424 were assessed. In the array experiment, miR-26a, miR-23a, miR-200c, let-7a, and miR-1979 were identified as candidate reference genes for subsequent validation. MiR-23a was identified as the most reliable reference gene followed by miR-191. The use of miR-23a and miR-191 to normalize expression data enabled detection of a significant dereg-ulation of miR-424 between normal, CIN and cancer tissue. Our results suggested that miR-23a and miR-191 are the optimal reference microRNAs that can be used for normalization in profiling studies of cervical tissues; miR-23a is a novel microRNA normalizer.

Discrimination of 'driver' and 'passenger' HPV in tonsillar carcinomas by the polymerase chain reaction, chromogenic in situ hybridization, and p16(INK4a) immunohistochemistry

Human papillomavirus (HPV) positive tonsillar squamous cell carcinoma (TSCC) is associated with a favorable clinical outcome. However, the HPV detected in a given tumor may be causal (driver HPV) or an incidental bystander (passenger HPV). There is a need to discriminate these forms of HPV in TSCCs to understand their impact on HPV as a biomarker for use in TSCC patient management. This study has compared the polymerase chain reaction (PCR), chromogenic in situ hybridization (CISH), and p16(INK4a) immunohistochemistry in the assessment of HPV status in TSCC. Archival specimens of TSCC from thirty patients were investigated. HPV was detected by PCR in 25/30 (83.3%) tumors; HPV16 (70.0%) and HPV52 (6.7%) were the most common types. HPV was corroborated by CISH in 22/25 (88.0%) specimens; integrated HPV was implicated by the presence of punctate signals in each of these cases. p16(INK4a) staining was found in 20/22 (90.9%) HPV PCR positive samples; two PCR/CISH HPV positive cases were p16(INK4a) negative and two HPV negative samples were p16(INK4a) positive. These data suggest that a minority of HPV positive TSCCs are positive for passenger HPV and that two or more assays may be required for diagnosing driver HPV status. Further studies are required to exam whether oropharyngeal tumors positive for passenger HPV have a less favorable prognosis than tumors that are driver HPV positive. The clinical significance of TSCCs that test HPV negative/p16(INK4a) positive, PCR and CISH HPV positive/p16 (INK4a) negative, or PCR HPV positive/p16 (INK4a) and CISH negative, also requires further investigation.

HPV is detectable in virtually all abnormal cervical cytology samples after reinvestigation of HPV negatives with multiple alternative PCR tests

The demonstration of human papillomavirus (HPV) in 99.7% of cervical carcinoma surgical specimens from around the world required investigations by multiple alternative polymerase chain reaction (PCR) assays. A similar approach may therefore be necessary to best characterize HPV prevalence and genotype distribution among cervical cytology samples. In an earlier study, 752 of 799 (94.1%) abnormal and 82 of 300 (27.3%) normal cytology specimens tested HPV positive after PCR using GP5+/6+primers. This study has reinvestigated the "HPV negative" abnormal samples (20 atypical squamous cells of undetermined significance, 5 low-grade squamous intraepithelial lesion, 14 atypical squamous cells, cannot exclude HSIL, 6 high-grade squamous intraepithelial lesion) and an age-matched cohort of "HPV negative" normal (negative for an intraepithelial lesion or malignancy) samples by PCR using PGMY09/11, FAP59/64, and LCR-E7 primers. PGMY09/11-GP5+/6+ nested PCR was performed on samples that were HPV negative by PGMY09/11 PCR. After the first 3 assays, HPV was detected in 41 of 45 (91.1%) abnormal and in 10 of 47 (21.3%) normal samples (P<0.0001). Eighteen HPV genotypes were detected and in some samples the genotype that was identified differed between the tests. The nondetection of common HPV genotypes (eg, HPVs 6, 11, 16, and 18) was notable. High-grade histopathology was found for 2 patients with HPV52-positive cytopathology. Combined with our earlier study, HPV (40 different genotypes) is shown in 99.5% of abnormal samples (99.8% inclusive of the nested PCR data). These findings show that HPV genotype and prevalence estimates are dependent on the method(s) of detection and indicate that suboptimal analytical sensitivity for one or more of the less common high-risk HPV genotypes could lead to impaired clinical sensitivity. HPV may be causal in almost every instance of abnormal cervical cytology; however, passenger HPV that is incidental to an abnormality may also have been detected.

Type-specific human papillomavirus detection in cervical smears in Romania

Although Romania has one of the highest incidence of cervical cancer in Europe (30 new cases/100 000 women), little is known about the distribution of the human papillomaviruses (HPV) genotypes in this population. We seek to determine the distribution of HPV genotypes in women with normal and abnormal cervical cytology. We analyzed 460 cervical cytology specimens from women who self-referred to the gynecologic clinic. HPV was detected and genotyped using the commercially available INNOLiPA (INNOGENETICS NV) kit based on the reverse hybridization principle. HPV DNA was detected in 279 cases (60.7%) with a median age of 32.9 years. In HGSIL (High Grade Squamous Intraepithelial Lesion) cytology, the presence of HPV DNA was confirmed in 82.7% of cases. The most frequent high-risk genotype was HPV16, found in 32.6% of HPV-positive samples. The next common high-risk genotypes were HPV18, HPV31 and HPV51. Our findings on the distribution and frequency of the HPV genotypes in Romanian population confirmed the utility of the current available HPV vaccines, HPV16 and 18 being detected in 28.7% of cases in the investigated area.

Screening for human papillomavirus in basaloid squamous carcinoma: utility of p16(INK4a), CISH, and PCR

This study compares p16( INK4a) immunohistochemistry (IHC), HPV chromogenic in situ hybridization (ISH), and HPV polymerase chain reaction (PCR) genotyping for detection of HPV infection in basaloid squamous carcinoma (BSCC). A retrospective histopathological analysis of 40 BSCC from a single institution was carried out. p16 IHC, HPV DNA extraction and ISH, and HPV PCR genotyping were performed, and there was excellent agreement between all 3 methods of HPV detection. Analysis of variance yielded no significant differences between the results of the 3 tests ( P = .354) and Pearson product-moment correlation coefficients calculated for each pair of tests demonstrated direct correlation (r = .61 for PCR and IHC, r = .61 for PCR and ISH, and r = 1.00 for ISH and IHC). This supports the use of p16(INK4a) IHC as an initial screening tool for HPV infection in BSCC, while definitive evidence of HPV DNA can be sought subsequently with PCR or CISH.

HPV DNA is associated with a subset of Schneiderian papillomas but does not correlate with p16(INK4a) immunoreactivity

This study investigated the role of human papillomavirus (HPV) in Schneiderian papillomas (SPs) to determine whether HPV is associated with the pathogenesis of particular histologic subtypes and whether p16(INK4a) can be used as a surrogate marker for HPV detection. Twenty-seven papilloma specimens (19 inverted [IPs], 6 exophytic [EPs], 1 oncocytic [OP] and 1 mixed) were collected from 23 patients. Purified SP DNA extracts were tested for HPV by PCR using GP5 +/GP6 + primers; HPV genotyping was performed by dot blot hybridization. PCR positive specimens were screened for HPV by biotinyl-tyramide-based chromogenic in situ hybridization (CISH). Immunohistochemsistry (IHC) for the HPV L1 capsid protein and for p16(INK4a) was performed on all specimens. HPV was detected by PCR in 16/27 (59.3%) SPs; 9/19 (47.4%) IPs; 6/6 (100%) EPs [p = 0.051], and 1/1 (100%) mixed SP. HPV was not detected in the single OP. High risk genotypes were detected in 4/9 IPs (44.4%) and 0/6 EPs (0%) [p = 0.10]. Seven of 16 PCR positive SPs were also CISH positive for HPV: 5/6 EPs (83.3%) and 1/9 IP (11.1%) [p = 0.01]. IHC for the L1 capsid protein was positive in 2 SPs (1 EP and 1 mixed). p16(INK4a) staining was seen in 14/16 (87.5%) PCR positive SPs and in 10/11 (90.9%) PCR negative SPs (p = 1.00). In summary, this study demonstrates a strong association between HPV and EPs, however, its role in IPs remains less well-defined. Further, p16(INK4a) is not a useful surrogate marker for HPV detection across the various SPs.

Molecular epidemiology of sexually transmitted human papillomavirus in a self referred group of women in Ireland

Background

Human papillomavirus (HPV) causes cervical cancer and external genital warts. The purpose of this study is to document the genotype distribution of HPV in females aged between 18 and 34 who self-referred to an STI clinic with visible external genital warts (EGW). Scrapings were taken from visible external genital warts (EGW). These scrapings were analysed by PCR for the presence of HPV DNA. Positive samples were then genotyped by means of a commercially available assay (LiPA). A comparison of genotyping results determined by the LiPA assay and direct amplicon DNA sequencing was also performed.

Results

Ninety-two patients out of 105 samples (88%) had detectable levels of HPV DNA. The majority of individuals with EGW (66%) showed the presence of two or more genotypes. The most common HPV genotypes present in the study population were HPV-6, HPV-11, HPV-16, HPV-18, HPV-33 and HPV-53. Potential effects of vaccination on HPV molecular epidemiology indicate that 40% of the patients could have been protected from the high risk genotypes HPV-16 and HPV-18.

Conclusion

This is the first report of the molecular epidemiology of external genital warts in women aged between 18 and 34 from Ireland based on results from a LiPA assay. The study shows that most individuals are infected with multiple genotypes including those with high oncogenic potential and that the newly available HPV vaccines could have a significant impact on prevalence of the most common HPV genotypes in this study population.

Validation of the SPF10 LiPA human papillomavirus typing assay using formalin-fixed paraffin-embedded cervical biopsy samples

Lower levels of performance of human papillomavirus (HPV) typing assays in studies using formalin-fixed paraffin-embedded (FFPE) tissue compared to those using exfoliated cervical cells have been reported. The interpretation of current studies is limited by bias in inclusion criteria, sample matching, and methods of cell collection. We aimed to validate FFPE tissue for typing by the use of the SPF(10) LiPA assay, comparing cervical scrapings to punch and cone biopsy specimens. We examined 165 paired cervical scraping and FFPE punch biopsy samples, and 66 paired FFPE punch and cone biopsy samples. HPV typing was performed using the SPF(10) LiPA assay. Kappa statistics were used to measure interrater agreement. The overall agreement with respect to HPV status was 100%. For 74.5% of subjects (kappa = 0.6147), the same numbers of HPV types were detected in scraping and biopsy specimens. The overall positive typing agreement was 95.4% (range, 93.4 to 97.3) for 441 out of 484 individual HPV type analyses. Agreement was good for HPV-39, -42, -43, and -70 (kappa = 0.6506 to 0.7166), excellent for HPV-6, -16, -18, -31, -33, -35, -40, -51, -52, -56, -58, and -66 (kappa = 0.8499 to 0.9665), and absolute for HPV-11, -44, -45, -53, and -68. In 43.9% of cases (kappa = 0.247), the same numbers of HPV types were found in punch and cone biopsy specimens. Overall positive agreement for typing was 86.8% (range, 82.5 to 91.1) for 204 out of 266 individual HPV type analyses. More infections by HPV-18, -33, -51, and -52 were detected in cone specimens. HPV typing by SPF(10) LiPA performed equally well for cervical scraping specimens and standard pathological material. Some viral types are preferentially detected in cone specimens, likely reflecting better sampling of diseased epithelium and endocervix tissue.

Rapid detection of human papilloma virus using a novel leaky surface acoustic wave peptide nucleic acid biosensor

A novel leaky surface acoustic wave (LSAW) bis-peptide nucleic acid (bis-PNA) biosensor with double two-port resonators has been constructed successfully for the quantitative detection of human papilloma virus (HPV). The bis-PNA probe can directly detect HPV genomic DNA without polymerase chain reaction (PCR) amplification, and it can bind to the target DNA sequences more effectively and specifically than a DNA probe. When the concentrations varied from 1 pg/L to 1000 microg/L, with 100 microg/L being the optimal, a typical linearity was found between the quantity of target and the phase shifts. The detection limit was 1.21 pg/L and the clinical specificity was 97.22% of that of real-time PCR. The bis-PNA probe was able to distinguish sequences that differ only in one base. Both the intraassay and interassay coefficients of variance (CVs) were <10%, and the biosensor can be regenerated for ten times without appreciable loss of activity. Therefore, this technical platform of LSAW biosensor can be applied to clinical samples for direct HPV detection.