A review of methods for detect human Papillomavirus infection

Duplex Real-time PCR assay and SYBR green I melting curve analysis for molecular identification of HPV genotypes 16, 18, 31, 35, 51 and 66

Long-term infection with high-risk HPV genotypes is the leading cause of cervical cancer. In the present study a Duplex Real-time PCR assay was developed in order to identify HPV types 16, 18, 31, 35, 51 and 66 in three reactions, through SYBR green I melting curve analysis. The method utilizes type-specific primer sets that allowed the amplification of highly conserved regions of L1 gene. Reconstitution experiments were conducted by using HPV DNA plasmids in order to determine the sensitivity of the assay. The newly designed assay has a limit of detection of 10 copies per reaction. The most prevalent HPV genotype in single and in multiple HPV infections was HPV16 followed by HPV18, HPV51, HPV31, HPV35 and HPV66. The proposed method is a simple, specific, sensitive and cost-effective assay that can be easily incorporated in small and medium size laboratories for the rapid identification of the most clinically important HPV genotypes.

Human papilloma virus and squamous cell carcinoma of the anus

The incidence of anal cancer is increasing. In the UK, the incidence is estimated at approximately 1.5 per 100,000. Most of this increase is attributed to certain at-risk populations. Persons who are human immunodeficiency virus (HIV)-positive and men who have sex with men (MSM), Organ transplant recipients, women with a history of cervical cancer, human papilloma virus (HPV), or cervical intraepithelial neoplasia (CIN) are known to have a greater risk for anal cancer. This paper will focus on HPV as a risk factor for anal intraepithelial neoplasia (AIN) and discusses the etiology, anatomy, pathogenesis, management of squamous cell carcinoma (SCC) of the anus.

Association between cervical lesion grade and micronucleus frequency in the Papanicolaou test

The aim of this study was to evaluate the association between the frequency of micronuclei (MN) and the cellular changes detected in the conventional Papanicolaou test. One hundred and seventy-four Papanicolaou test smears with cellular changes were examined. MN screening was done in cytopathological smears by counting 1,000 cervical cells in a light microscope. MN frequencies were significantly higher in the group with cellular changes compared to the control group (p < 0.001). The mean MN frequencies were 0.95 ± 1.12 (mean ± SD) in the control group (n = 223), 2.98 ± 1.20 in individuals with atypical squamous cells of undetermined significance (ASC-US) (n = 50), 4.04 ± 1.45 in cervical intraepithelial neoplasia (CIN) I (n = 52), 5.97 ± 1.83 in CIN II (n = 30), 7.29 ± 1.55 in CIN III (n = 17) and 8.64 ± 1.55 in invasive cancer (n = 25). These findings suggest that MN monitoring should be included as an additional criterion for the early detection of cytogenetic damage in routine examinations. This monitoring should be done in the same smear as used for cytopathological examination. More specific and systematic studies are necessary to confirm this proposal.

Concurrent oral human papilloma virus infection in patients with recurrent respiratory papillomatosis: a preliminary study

OBJECTIVES/HYPOTHESIS

To determine oral human papilloma virus (HPV) colonization in patients with adult-onset recurrent respiratory papillomatosis (AO-RRP) and their long-term partners.

STUDY DESIGN

Prospective, cohort study

METHODS

Patients with pathology-confirmed AO-RRP and a small cohort of their long-term partners were subjected to a standardized oral rinse and swab protocol to obtain oral epithelial cells. DNA from these samples was extracted and subjected to both qualitative analyses via multiplex polymerase chain reaction as well as to a commercially available linear array assay for the determination of specific HPV subtypes.

RESULTS

Samples were collected from 27 patients with AO-RRP and six long-term sexual partners. Qualitative analysis of agarose gel products using a multiple genotype primer cocktail suggested the presence of HPV DNA in oral rinse or swabs in 26 patients (96%) and four partner samples (67%). A subset of these positive patient samples was then subjected to genotyping; a spectrum of HPV subtypes was observed. Interestingly, HPV81 was identified in many samples.

CONCLUSION

Recent data suggest that less than 7% of the general population is HPV positive in the oral cavity. Our data suggest that the oral colonization rate is much higher in patients with AO-RRP. Additionally, long-term sexual partners of patients with RRP had a much higher rate of HPV positivity. These preliminary data may have implications for viral transmission and provide a framework for enhanced patient education as well as further investigation.

LEVEL OF EVIDENCE

4.

Comparing the Cervista HPV HR test and Hybrid Capture 2 assay in a Dutch screening population: improved specificity of the Cervista HPV HR test by changing the cut-off

The diagnostic performance of the widely-used Cervista HPV HR test was compared to the Hybrid Capture 2 (HC2) test in a Dutch population-based cervical cancer screening program. In 900 scrapings of women with normal cytomorphology, specificity was 90% (95%CI: 87.84–91.87) for the Cervista HPV HR test and 96% (95%CI: 94.76–97.37) for the HC2 test with 93% agreement between both tests (κ = 0.5, p<0.001). The sensitivity for CIN2+ using 65 scrapings of women with histological-confirmed CIN2+ was 91% (95%CI: 80.97–96.51) for the Cervista HPV HR test and 92% (95%CI: 82.94–97.43) for the HC2 test with 95% agreement between both tests (κ = 0.7, p<0.001). Fifty-seven of 60 HC2 negative/Cervista positive cases tested HPV-negative with PCR-based HPV assays; of these cases 56% were defined as Cervista triple-positive with FOZ values in all 3 mixes higher than the second cut-off of 1.93 (as set by manufacturer). By setting this cut-off at 5.0, specificity improved significantly without affecting sensitivity. External validation of this new cut-off at 5.0 in triple-positive scrapings of women selected from the SHENCCASTII database revealed that 22/24 histological normal cases now tested HPV-negative in the Cervista HPV HR test, while CIN2+ lesions remained HPV-positive. The intra-laboratory reproducibility of the Cervista HPV HR test (n = 510) showed a concordance of 92% and 93% for cut-off 1.93 and 5.0 (κ = 0.83 and κ = 0.84, p<0.001) and inter-laboratory agreement of the Cervista HPV HR test was 90% and 93% for cut-off 1.93 and 5.0 (κ = 0.80 and κ = 0.85, p<0.001). In conclusion, the specificity of the Cervista HPV HR test could be improved significantly by increasing the second cut-off from 1.93 to 5.0, without affecting the sensitivity of the test in a population-based screening setting.

Detection of HPV16 African variants and quantitative analysis of viral DNA methylation in oropharyngeal squamous cell carcinomas

BACKGROUND

HPV16 is the most prevalent genotype in oropharyngeal squamous cell carcinomas (OPSCCs), but there are few information about intratype variants prevalence and their clinical relevance in these tumors. Moreover, since HPV DNA detection alone is not sufficient to determine a favorable prognosis for OPSCCs, additional diagnostic/prognostic biomarkers are necessary.

OBJECTIVES

To assess the prevalence of HPV intratype variants and evaluate the role of HPV16 DNA methylation as prognostic marker in OPSCCs.

STUDY DESIGN

We analyzed 81 biopsies of OPSCCs for HPV detection and genotyping with a pyrosequencing-based HPV DNA-test. We also quantified viral DNA methylation frequency in the LCR by pyrosequencing in patients with transcriptionally-active HPV16-infection, analyzing it in function of available clinical/virological data.

RESULTS

The overall HPV prevalence was 74.1% and HPV16 was confirmed the most prevalent genotype (51/60, 85.0%). Interestingly, we detected, for the first time, HPV16 African variants in 10/51 cases (19.6%), pointing out their clinical relevance also out of the anogenital district. Regarding viral DNA methylation, the E2BS1 showed a significantly higher mean methylation frequency compared to E2BS3/4, as previously observed in high-grade precancerous lesions of the uterine cervix. On the other hand, patient with a mean methylation frequency in the early promoter >10% showed only a tendency to have a worse prognosis.

CONCLUSIONS

Our results highlight both the involvement of HPV16 African variants in OPSCCs development and the necessity of further studies to deepen the role of viral methylation in these tumors, in order to better define similarities/differences compared to cervical cancer.

Persistence of microbial contamination on transvaginal ultrasound probes despite low-level disinfection procedure

AIM OF THE STUDY

In many countries, Low Level Disinfection (LLD) of covered transvaginal ultrasound probes is recommended between patients' examinations. The aim of this study was to evaluate the antimicrobial efficacy of LLD under routine conditions on a range of microorganisms.

MATERIALS AND METHODS

Samples were taken over a six month period in a private French Radiology Center. 300 specimens derived from endovaginal ultrasound probes were analyzed after disinfection of the probe with wipes impregnated with a quaternary ammonium compound and chlorhexidine. Human papillomavirus (HPV) was sought in the first set of s100 samples, Chlamydia trachomatis and mycoplasmas were searched in the second set of 100 samples, bacteria and fungi in the third 100 set samples. HPV, C. trachomatis and mycoplasmas were detected by PCR amplification. PCR positive samples were subjected to a nuclease treatment before an additional PCR assay to assess the likely viable microorganisms. Bacteria and fungi were investigated by conventional methods.

RESULTS

A substantial persistence of microorganisms was observed on the disinfected probes: HPV DNA was found on 13% of the samples and 7% in nuclease-resistant form. C. trachomatis DNA was detected on 20% of the probes by primary PCR but only 2% after nuclease treatment, while mycoplasma DNA was amplified in 8% and 4%, respectively. Commensal and/or environmental bacterial flora was present on 86% of the probes, occasionally in mixed culture, and at various levels (10->3000 CFU/probe); Staphylococcus aureus was cultured from 4% of the probes (10-560 CFU/probe). No fungi were isolated.

CONCLUSION

Our findings raise concerns about the efficacy of impregnated towels as a sole mean for disinfection of ultrasound probes. Although the ultrasound probes are used with disposable covers, our results highlight the potential risk of cross contamination between patients during ultrasound examination and emphasize the need for reviewing the disinfection procedure.

Human papillomavirus genomics: past, present and future

Human papillomaviruses (HPV) are a group of divergent DNA viruses, of which a select few evolutionarily related HPVs have emerged to be highly oncogenic and of significant medical importance. Essentially all cases of cervical cancer, as well as a subset of other anogenital and oral cancers are caused by this limited set of HPV types. At present, over 150 HPV types have been identified and may be classified into genera, species and types based upon comparison of the viral genome. Established nucleotide phylogenies sort the highly pathogenic HPV types to the genus Alphapapillomavirus (α-PV). A species group includes viral types with 60-70% genomic nucleotide similarity that share a most-recent common ancestor; for example the species group's alpha-9 (HPV16-related) and alpha-7 (HPV18-related), contain the majority of known oncogenic HPV types. Genomes from the same HPV type with 1-10% nucleotide differences designate HPV variant lineages. The established nucleotide variations observed in extant HPV genomes have been fixed through evolutionary processes prior to human population expansion and global dissemination. To characterize viral types and variants associated with pathology for clinical applications (e.g. screening), molecular epidemiological studies have proven essential for identifying links between HPV natural history and carcinogenicity. This chapter presents a historical account of HPV genomics in the context of major discoveries and advances over the past 2 thousand years.

Viral involvement in the pathogenesis and clinical features of ophthalmic pterygium (Review)

Pterygium is a potentially vision-threatening fibrovascular lesion originating from the conjunctiva that often extends on the corneal surface. Although it has been extensively studied, its pathogenesis has yet to be fully elucidated. Recent evidence on molecular genetic abnormalities in pterygium suggested neoplastic changes of limbal stem cells potentially associated with exposure to ultraviolet (UV) light. Human papillomavirus (HPV) is an oncogenic virus, associated with squamo-proliferative lesions of the anogenital region, skin and oropharynx. Several studies have shown HPV involvement in the pathogenesis of conjunctival neoplastic lesions, including papilloma and squamous cell carcinoma. The involvement of HPV as a co-factor in the pathogenesis of pterygium, although suggested by several studies using PCR and immunohistochemical techniques, remains controversial. Moreover, a marked variation in the prevalence of HPV in ophthalmic pterygium has been reported by different studies. Ethnic susceptibility and methodological differences in the detection of HPV may account for this variation. Surgical excision, often using sophisticated techniques, is the standard current method of therapy for pterygium. However, recurrences are frequent and recurrent lesions tend to be more aggressive. If indeed HPV is involved in pterygium pathogenesis or recurrence, anti-viral medications or vaccination may be new options in pterygium therapy.