A non-radioactive PCR enzyme-immunoassay enables a rapid identification of HPV 16 and 18 in cervical scrapes after GP5+/6+ PCR

Human papillomavirus infection in women undergoing in-vitro fertilization: effects on embryo development kinetics and live birth rate

BACKGROUD

Several studies showed that human papillomavirus (HPV) affects male fertility, but its impact on female fertility and in vitro fertilization (IVF) outcome is not yet clear.

METHODS

Objective of this observational, prospective, cohort study was to evaluate the prevalence of HPV infection in women candidate to IVF, and the effects of HPV infection on the kinetic of embryonic development and on IVF outcome. A total number of 457 women candidate to IVF were submitted to HR-HPV test; among them, 326 underwent their first IVF cycle and were included in the analysis on IVF results.

RESULTS

8.9% of women candidate to IVF were HPV-positive, HPV16 being the most prevalent genotype. Among the infertility causes, endometriosis was significantly more frequent in HPV-positive than in negative women (31.6% vs. 10.1%; p < 0.01). Granulosa and endometrial cells resulted HPV-positive in 61% and 48% of the women having HPV-positive cervical swab, respectively. Comparing HPV-positive and negative women at their first IVF cycle, no significant difference was observed in the responsiveness to controlled ovarian stimulation (COS) in terms of number and maturity of retrieved oocytes, and of fertilization rate. The mean morphological embryo score was comparable in the two groups; embryos of HPV-positive women showed a quicker development in the early stages, with a significantly shorter interval between the appearance of pronuclei and their fusion. In the following days, embryo kinetic was comparable in the two groups until the early blastocyst stage, when embryos of HPV-positive women became significantly slower than those of HPV-negative women. Overall, these differences did not affect live birth rate/started cycle, that was comparable in HPV-positive and negative women (22.2 and 28.1%, respectively).

CONCLUSIONS

(a) the prevalence of HPV infection in women candidate to IVF is similar to that observed in the general female population of the same age range; (b) HPV infection migrates along the female genital apparatus, involving also the endometrium and the ovary, and perhaps participates in the genesis of pelvic endometriosis; (c) HPV slightly affects the developmental kinetic of in vitro-produced embryos, but does not exert an effect on live birth rate.

Sexual inactivity and occurrence of STIs in relation to weight status in women: Two large population-based studies

The aim of this study was to examine sexual inactivity and occurrence of selected sexually transmitted infections in relation to body mass index. We used data from two large Danish population-based cross-sectional studies conducted in 1991-1995 (HPV study: 6869 women, aged 22-32 years) and in 2004-2005 (Liva study: 19,484 women, aged 18-45 years). Data were collected using a structured interview and measured weight, height, high-risk human papillomavirus DNA, Chlamydia DNA for the HPV study and a structured questionnaire for the Liva study. Overweight and obese women were more likely to have had no lifetime sexual partner or no sexual partner in the last year, e.g., obese women had a threefold (95 percent CI: 1.95-5.04) odds ratio of having had no sexual partner in the last year compared to normal weight women. Additionally, overweight and obese women had a lower likelihood of genital warts and high-risk human papillomavirus infection. A similar tendency was found for self-reported Chlamydia, but not with presence of Chlamydia DNA. If higher likelihood of no lifetime or recent sexual partners among overweight and obese women reflects unmet sexual needs, it could give rise to concern because quality of sexual life is associated with general quality of life.

Prevalence of Human Papillomavirus Infection in Breast Cancer Cells from Thai Women

Breast cancer is the leading female cancer worldwide and is the most frequently diagnosed in Thai women. Its potential etiologic has not been clearly identified. Several recent reports could detect human papillomavirus (HPV) infection in breast cancer or benign breast lesions. HPV infection considered suggests being one of many risk factors for cancer development. The aim of this study was to determine the frequency of HPV infection in both breast cancer and benign breast lesion/tumor tissues. Seven hundred samples from Thai women were collected during 2013-2015 and statistically correlation between HPV infection, sociodemographic and histopathological parameters were also analyzed. HPV DNA detection and genotyping were performed by polymerase chain reaction and enzyme immunoassay, respectively. The results demonstrated that mean age of the patients were 41.76±12.53 years and 52.73±11.68 years for benign breast lesions/tumor and breast cancer samples, respectively. HPV DNA was detected in 25/700 (3.57%) samples, in which 10/350 (2.857%) from benign breast lesion/tumor samples and 15/350 (4.285%) from breast cancer samples. HPV 16 is the predominant types of this study, follow by HPV 33, 18, 35, 52. Most of HPV type detection samples belong to the high risk types, except 1/25 sample could be detected low risk type; HPV 6 which was presented as co-infection with the other high risk type. From sociodemographic and histopathological correlation analysis, all of studied parameters such as breast cancer history, hormone receptors status etc. did not show statistically significant correlated with HPV infection (P>0.05). In conclusion, the low frequency detection in this study suggests that HPV did not play the main important role for breast cancer development and represented highly controversial, but it may be causative agents of only a relative small proportion of all breast cancer or non-malignant breast lesion and it is the interesting data for further study in virus-associated cancer.

Detection and Type-Distribution of Human Papillomavirus in Vulva and Vaginal Abnormal Cytology Lesions and Cancer Tissues from Thai Women

Vulva and Vaginal cancers are rare among all gynecological cancers worldwide, including Thailand, and typically affect women in later life. Persistent high risk human papillomavirus (HR-HPV) infection is one of several important causes of cancer development. In this study, we focused on HPV investigation and specific type distribution from Thai women with abnormality lesions and cancers of the vulva and Vaginal. A total of ninety paraffin-embedded samples of vulva and Vaginal abnormalities and cancer cells with histologically confirmed were collected from Thai women, who were diagnosed in 2003-2012 at the National Cancer Institute, Thailand. HPV DNA was detected and genotyped using polymerase chain reaction and enzyme immunoassay with GP5+/ bio 6+ consensus specific primers and digoxigenin-labeled specific oligoprobes, respectively. The human β-globin gene was used as an internal control. Overall results represented that HPV frequency was 16/34 (47.1%) and 8/20 (40.0%) samples of vulva with cancer and abnormal cytology lesions, respectively, while, 3/5 (60%) and 16/33 (51.61%) samples of Vaginal cancer and abnormal cytology lesions, respectively, were HPV DNA positive. Single HPV type and multiple HPV type infection could be observed in both type of cancers and abnormal lesion samples in the different histological categorizes. HPV16 was the most frequent type in all cancers and abnormal cytology lesions, whereas HPV 18 was less frequent and could be detected as co-infection with other high risk HPV types. In addition, low risk types such as HPV 6, 11 and 70 could be detected in Vulva cancer and abnormal cytology lesion samples, whereas, all Vaginal cancer samples exhibited only high risk HPV types; HPV 16 and 31. In conclusion, from our results in this study we suggest that women with persistent high risk HPV type infection are at risk of developing vulva and Vaginal cancers and HPV 16 was observed at the highest frequent both of these, similar to the cervical cancer cases. Although the number of samples in this study was limited and might not represent the overall incidence and prevalence in Thai women, but the baseline data are of interest and suggest further study for primary cancer screening and/or developing the efficiency of prophylactic HPV vaccines in Thailand.

Mutation analysis of genes in the EGFR pathway in Head and Neck cancer patients: implications for anti-EGFR treatment response

Background

Targeted therapy against the Epidermal Growth Factor Receptor (EGFR) is among the most promising molecular therapeutics for Head and Neck Squamous Cell Carcinoma (HNSCC). However, drug resistance limits the clinical efficacy of anti-EGFR monoclonal antibodies and no predictive biomarker has entered the clinic yet.

Methods

A retrospective clinical study was performed utilizing pathological specimens from 52 newly diagnosed HNSCC patients. These patients were screened for mutations in EGFR and KRAS. Tyrosine kinase mutations in EGFR and KRAS mutations were evaluated by high resolution melting analysis (HRMA), whereas EGFRvIII was determined using one-step real-time PCR. Finally, patient samples were screened for HPV-DNA by GP5+/6+ PCR. Survival analysis was performed using Kaplan-Meier analysis and significance was calculated using log-rank statistic.

Results

In our study population no EGFRvIII mutations were present. However, two silent mutations were found; T785T in exon 20 and R836R in exon 21 of the EGFR gene. Additionally, HRMA revealed an abnormal KRAS melting pattern in 7.0% of the samples. However, the KRAS StripAssay could confirm only one sample with a G12S mutation and none of these samples could be confirmed by direct sequencing. HPV DNA was present in 3/25 larynx and 9/27 oropharynx tumors.

Conclusion

The low rate of EGFR and KRAS mutations in this Belgian HNSCC population suggests that these genes will probably not play a major role in predicting response to anti-EGFR therapy in HNSCC. Hence, other predictive markers need to be discovered in order to optimize EGFR targeting therapy.

Chlamydia trachomatis and risk of cervical intraepithelial neoplasia grade 3 or worse in women with persistent human papillomavirus infection: a cohort study

OBJECTIVES

Some studies suggest that Chlamydia trachomatis (CT) enhances cervical carcinogenesis; however, a possible confounding effect of persistent human papillomavirus (HPV) infection was not addressed. We examined the potential role of CT infection in the development of subsequent cervical intraepithelial neoplasia grade 3 or worse (CIN3+) in women with prevalent HPV infection and in a subgroup of women with persistent HPV infection.

METHODS

Participants in this population-based cohort study underwent a structured interview, including history of CT infection, and subsequently cervical exfoliated cells were obtained for HPV DNA and CT DNA testing. Women with high-risk HPV DNA infection and no prevalent cervical disease constituted the overall study population (n=1390). A subgroup of women with persistent HPV infection (n=320) was also identified. All women were passively followed for development of cervical lesions in the national Pathology Data Bank. HRs and 95% CIs for CIN3+ during follow-up (up to 19 years) were estimated in an accelerated failure time model.

RESULTS

Women who reported more than one CT infection had a statistically significantly increased risk of CIN3+ (high-risk HPV-positive, HR=2.51, 95% CI 1.44 to 4.37) (persistent HPV infection, HR=3.65, 95% CI 1.53 to 8.70). We found no association between CT DNA and subsequent risk of CIN3+ among women who were HPV-positive or had a persistent HPV infection at baseline.

CONCLUSIONS

Repeated CT infections increased the risk of CIN3+ among women with prevalent as well as persistent high-risk HPV infection.

Preliminary study on human papillomavirus frequency and specific type-distribution in vulva cancer from Thai women

Vulva cancer is rare among all gynecological cancer worldwide, including Thailand, and mainly affects older women. Persistent high risk type infection of human papillomavirus (HPV) is the one important factor for developing cancer. In this study, we focused on HPV DNA investigation and type-specific distribution of HPV in 25 formalin-fixed paraffin-embedded (FFPE) samples collected from Thai women with vulva cancer histologically confirmed by the National Cancer Institute, Thailand, during 2003-2011. HPV DNA detection and genotyping were undertaken with polymerase-chain reaction and enzyme-immunoassay using GP5+/bio6+ consensus specific primers and digoxigenin-labeled specific oligoprobes, respectively. Human β-globin genes was used as the internal control. Our results showed that 44% (11/25) of all vulva cancer samples were HPV-positive. All of them are high risk HPV type infection, detected as single (63.64%, 7/11) and/or double infections (4/11, 36.36%). HPV 16 was the most common type identified in vulva cancer, followed by HPV 35, 33, 18 and 58. In conclusion, this study presented that HPV-16 is observed at the highest frequency in this cancer, similar to cervical cancer, with HPV 18 being less frequent. Although the sample size was small and could not represent overall incidence and prevalence in Thai women, these preliminary data for vulva cancer are of interest since they reinforce the necessity for HPV screening or vaccination in Thailand.

The Prevalence of the Human Papillomavirus in Cervix and Vagina in Low-risk and High-risk Populations

Concordance of HPV between vagina and cervix may be influenced by sample taking and by differences in flow of cervical epithelial cells. To investigate the latter aspect, from 96 women visiting their general practitioner, and 63 sex workers visiting a STI clinic, both vaginal and cervical samples for HPV detection were obtained by the doctor to standardize sample taking. To identify factors that may influence the flow of cervical epithelial cells to the vagina, a questionnaire on intimate hygiene was obtained. The overall HPV prevalence was 22.8%; 14.3% in the general population (14.3% in the cervix, 11.9% in the vagina), compared with 34.4% in sex workers (31.1% in the cervix, 27.9% in the vagina). There was excellent agreement between HPV prevalence in vaginal and cervical samples. The overall agreement was 94.5% (kappa = 0.83, 95% CI: 0.77-0.89); in the general population agreement reached 97.6%, compared with 90.0% in sex workers. Vaginal infection may influence concordance, but for validation of this finding larger studies are necessary. The high concordance found between HPV prevalence in vagina and cervix warrants further study of the applicability of self-sampling to improve coverage rates by attracting women who would otherwise not obtain a pap test.

Activating NK cell receptor ligands are differentially expressed during progression to cervical cancer

Human papillomavirus-induced cervical carcinomas often show impaired expression of MHC class I molecules resulting in the inability of tumor cells to directly present viral peptides to cytotoxic T lymphocytes. Loss of MHC class I expression combined with the expression of activating NK cell receptor ligands renders tumor cells potentially susceptible to NK cell attack. Thus, in this study, we analyzed the expression of activating NK cell receptor ligands, NK cell accumulation and activation status in situ in normal ectocervical tissue (NCT), cervical intraepithelial neoplasia (CIN) and squamous cervical carcinoma (CxCa). We observed that expression of the DNAM-1 ligand CD155 was frequently upregulated in CxCa, but not in CIN. The NKG2D ligand MICA was upregulated in fewer CxCa biopsies. In contrast, another NKG2D ligand ULBP2 was preferentially expressed in differentiated epithelial cells of NCT. Increased numbers of NK cells were detected in CIN as compared to NCT and CxCa. Expression of activating NK cell receptor ligands combined with loss of MHC class I was not correlated with enhanced NK cell accumulation or activation status. Furthermore, we demonstrate that cervical cancer cell lines are killed by the NK cell line, NKL, in a NKG2D- and DNAM-1-dependent manner in vitro. Since a significant number of CxCa biopsies showed low MHC class I expression combined with high expression of one or more of the tested activating NK cell receptor ligands, we conclude that CxCa might be a promising target for NK cell-based adoptive immunotherapy.

PreTect HPV-Proofer: real-time detection and typing of E6/E7 mRNA from carcinogenic human papillomaviruses

Monitoring human papillomavirus (HPV) E6/E7 mRNA expression may provide an accurate and informative diagnostic approach for detection of oncogene activity related to the development of severe dysplasia or cervical carcinoma. A multiplex nucleic acid sequence based amplification (NASBA) assay, utilizing molecular beacon probes for real-time detection was developed for the identification of E6/E7 mRNA from HPV types 16, 18, 31, 33 and 45. The assay is called PreTect HPV-Proofer and this report describes the development and the analytical performance of the assay. The reproducibility of PreTect HPV-Proofer with regard to a positive result was found to be between 96 and 100%, depending on HPV type. The melting temperature for the different molecular beacons was in the range of 48-55 degrees C, indicating conformational stability, i.e. the molecular beacons will not get activated by the 41 degrees C annealing temperature, but will be activated by the annealing to the target itself. The limit of detection for HPV 16 was ten SiHa or CaSki cells and for HPV 18 one HeLa cell. No cross reactivity was observed with E6/E7 mRNA from the other tested HPV types. mRNA from cervical cells was also successfully amplified after more than one year of storage. In conclusion, the PreTect HPV-Proofer assay, individually identifying E6/E7 mRNA expression from five carcinogenic HPV types, is a reproducible assay that may serve as a valuable tool in monitoring HPV infections producing proteins with a transforming potential.

Combined Pap and HPV testing in primary screening for cervical abnormalities: Should HPV detection be delayed until age 35?

In 2003, the United States Food and Drug Administration has approved the Hybrid Capture 2 assay for use with a Pap test to adjunctively screen women of 30 years and older for the presence of high-risk human papillomavirus (HR-HPV) infection. Although the predictive power of a negative test is strong, the number of false-positives may still be high. We investigated HPV prevalence in relation to age in a group of 2293 women, aged between 20 and 50, with normal cytology. Overall HR-HPV prevalence was 6.9% (95%CI=5.9-8.0%). Regression analysis using 5-year intervals showed that the HR-HPV prevalence did not significantly decline up to age 34, whereas it declined significantly after age 35. This would suggest that postponing HPV detection in primary screening from age 30 to 35 would result in a decrease of almost 50% of the number of women with normal cytology and a transient HPV infection. However, larger scale studies are required to confirm this finding.

HPV16 semiquantitative viral load and serologic biomarkers in oral and oropharyngeal squamous cell carcinomas

A considerable subset of oropharyngeal squamous cell carcinomas (SCCs) are positive for human papillomavirus (HPV); however, delineating etiologically-associated HPV infections from SCCs with concurrent HPV infection unrelated to tumorigenesis is challenging. Viral load assessment in biopsy specimens may help facilitate such differentiation. HPV16 viral load and serologic markers were assessed among oral and oropharyngeal cases from a multinational study conducted by the International Agency for Research on Cancer (IARC). HPV16 viral load, measured semiquantitatively by PCR-enzyme immunoassay, was dichotomized as high or low based on the median optical density value. Serologic antibodies to HPV16 virus-like particles (VLPs) and to HPV16 E6 and E7 proteins were measured by ELISA. Compared to HPV DNA-negative cases (n = 852), HPV16 DNA-positive cases with high viral load (n = 26) were significantly more likely to originate in the oropharynx (odds ratio [OR], 12.0; 95% confidence interval [CI], 5.2-27.5) and, after adjustment for tumor site (AdjOR), have antibodies against HPV16 VLPs (AdjOR, 14.6; 95% CI, 6.0-35.6), E6 (AdjOR, 57.6; 95% CI, 21.4-155.3) and E7 (AdjOR, 25.6; 95% CI, 9.3-70.8). HPV16 DNA-positive cases with low viral load (n = 27) were more commonly oropharyngeal (OR, 2.7; 95% CI, 1.1-6.2) and seropositive for HPV16 VLPs (AdjOR, 2.7; 95% CI, 1.1-6.9), E6 (AdjOR, 3.0; 95% CI, 0.7-14.0) and E7 (AdjOR, 3.5; 95% CI, 0.7-16.3), compared to HPV DNA-negative cases; the associations, however, were neither as strong nor as significant as the associations for high viral load. As there appears to be a strong association between HPV16 serologic markers and viral load, in the absence of data on serologic markers, HPV16 viral load may be used to help delineate the subset of HPV16 DNA-positive oral and oropharyngeal cancers that may be the consequence of HPV infection.

Does human papillomavirus play a role in the development of bladder transitional cell carcinoma? A comparison of PCR and immunohistochemical analysis

AIM

To investigate the role of human papillomavirus (HPV) in the development of bladder transitional cell carcinoma (TCC).

METHODS

Seventy eight paraffin wax embedded TCC samples were tested for the presence of HPV by two methods. First, immunohistochemistry was carried out using a polyclonal antibody capable of detecting the capsid protein of all known papillomaviruses. The second method was a consensus GP5+/6+ primer mediated polymerase chain reaction (PCR) technique, with the products analysed by both agarose gel electrophoresis and an enzyme immunoassay using type specific oligonucleotide probes for 10 different mucosal genotypes. To exclude false negative results because of the poor quality of DNA extracted from paraffin wax embedded samples, the series was extended to include 20 further blocks for which the corresponding snap frozen unfixed tissue was available.

RESULTS

The two methods produced contrasting results, with 47 of the 78 samples positive for HPV antigen and none positive for HPV DNA. HPV DNA was not detected in the 20 additional paraffin wax embedded TCCs or in the 20 paired unfixed samples. In contrast, HPV DNA was amplified by PCR from all six of the paraffin wax embedded cervical carcinoma and anogenital wart control samples.

CONCLUSION

The disparity between the two sets of results is probably caused by false positives resulting from the non-specificity of the polyclonal antibody used for immunohistochemistry. These results suggest that HPV is unlikely to play an aetiological role in the development of bladder TCC.

Distribution of HPV infection and tumour markers in cervical intraepithelial neoplasia from cone biopsies of Mozambican women

AIMS

To evaluate human papillomavirus (HPV) infection in whole cervical cone specimens with cervical intraepithelial neoplasia (CIN). In addition, to evaluate the relation between the presence of CIN lesions and HPV infection and the expression of Ki-67, p53, cytokeratins, Gp230 glycoprotein, and simple mucin-type carbohydrates.

METHODS

Cervical cone specimens from five patients with CIN were studied. For each specimen, serial sections encompassing the whole cone were collected (52 samples). HPV infection and HPV types were detected by the polymerase chain reaction and enzyme immunoassay. The expression of Ki-67, p53, cytokeratins, Gp230, and simple mucin-type carbohydrates was examined immunohistochemically.

RESULTS

All cases showed high risk HPV types, namely types 16, 33, 35, and 58. Four of the five patients were infected by multiple viral types. HPV-58 was always seen in CIN III, whereas HPV-35 was more frequent in CIN I. The expression of Ki-67 and p53 was higher in CIN III lesions. The expression of cytokeratins 8 and 17 showed complete or almost complete overlap with CIN III. Altered expression of Gp230, Tn, and sialyl-T was often seen in all grades of CIN.

CONCLUSIONS

When whole cervical cone specimens are evaluated the rate of multiple HPV infection is very high. The expression of cytokeratins 8 and 17 is a useful marker of CIN III.

Factors predicting successful DNA recovery from archival cervical smear samples

Polymerase chain reaction (PCR)-based DNA testing of archival cervical smear slides is a useful method of retrospectively establishing the presence of the human papillomavirus (HPV) in cervical cells. A cellular DNA recovery test is performed in parallel to HPV DNA testing to ensure that sufficient cells are present and purification of sample DNA has been successfully performed. Previous studies have not comprehensively assessed DNA recovery rates in slides older than 13 years. We undertook a study to determine the factors impacting DNA recovery in 436 UK slides dating from 11 to 33 years prior to testing. Overall, a low cellular DNA recovery success rate of 29% was obtained but a strong trend was observed with increasing recovery rates the older the slides (P < 0.001). Recovery rates increased from 22% in the most recent slides collected from 1988 to 1992, to 61% in the oldest slides, collected in 1970-72. It is likely that fixation compounds incorporating acetic acid, introduced in the UK through the 1980s, have compromised subsequent attempts at PCR amplification. These findings emphasize the importance of the original fixation method in the success of DNA recovery from archival smear samples.

Characterization of human papillomavirus infection, P53 and Ki-67 expression in cervix cancer of Mozambican women

In this study, we aimed at evaluating the distribution of HPV types and the expression of P53 and Ki-67 in cervix carcinomas of Mozambican women. Fourty-seven invasive carcinomas, 10 CIN III, and 10 normal cervix were studied. P53 and Ki-67 expression was examined immunohistochemically. HPV infection and HPV types were detected by PCR (GP5+/bio-GP6+) and enzyme-immunoassay, respectively. Expression of P53 and Ki-67 and detection of HPV were as follows: normal cervix--0%, 10%, and 0%, respectively; CIN III--10%, 0%, and 100%, respectively; invasive carcinomas--50%, 55.5%, and 70%, respectively. HPV 16 was identified in 54% of invasive carcinomas, HPV 31, 33, 35, and 45 in 23%, "unidentified" HPV in 19%, and HPV 18 in 4% of invasive carcinomas. No significant associations were observed between P53 expression, Ki-67 expression, and HPV infection. In conclusion, we observed a high frequency of HPV infection in CIN III lesions and invasive carcinomas from Mozambican women, with HPV 16 representing the most frequent viral type. HPV status was not related to P53 and Ki-67 expression. Both P53 and Ki-67 are associated with invasive cervix carcinomas, mainly of the squamous keratinizing histotype.

Human papillomavirus in a rural community in Zimbabwe: The impact of HIV co-infection on HPV genotype distribution

Cervical cancer is a leading cause of cancer-related deaths in developing countries, and the human papillomavirus (HPV) is linked etiologically to cervical cancer. Hence, a vaccine which prevents HPV-associated cervical cancer would have the most impact in developing countries, including the African continent. The type-specific immune response towards HPV virus-like particles, in combination with geographical variation in the prevalence of HPV, necessitates the presence of multiple HPV type antigens in a single vaccine cocktail in order to provide relevant protection. We aimed to investigate whether co-infection with HIV, which is highly prevalent in Africa, plays a role in HPV genotype distribution. After informed consent, HPV detection by GP5+/6+ PCR and HIV detection by serology was carried out on 236 women from the rural north-western part of Zimbabwe. The prevalence of HPV was higher in HIV positive women (54%) than in HIV negative women (27%). Certain HPV types (HPV types 11, 39, 43, 51, and 59, P-values ranging from 0.017 to 0.067) occurred more frequently in HIV positive women. Only high-risk HPV, and not HIV, was associated significantly with cervical intraepithelial neoplasia in multiple regression analysis. In conclusion, a high prevalence of HPV was found in a rural community, where regular Papanicolaou (Pap) smears would be a logistic and economic impossibility, but where free vaccination programmes against other infections are already established. The results suggest that HIV co-infection may have an impact on HPV genotype distribution.

Can cervical cancer screening be stopped at 50? The prevalence of HPV in elderly women

Although the relation between cervical cancer and the human papillomavirus (HPV) has been established beyond doubt, the introduction of HPV detection in cervical cancer screening is halted, primarily by the high rate of false positivity in relation to morbidity, since the majority of women infected with HPV will not develop lesions. To counteract overconsumption of cervical cancer screening in elderly women, we wanted to test the hypothesis that women of 50 years or older who are HPV-negative and have a cytologically normal smear might be encouraged to refrain from further screening. As a first step, the prevalence of high-risk HPV in a population of 1,936 women of 50 years and older was investigated. After an initial decline, a slightly higher prevalence can be seen with increasing age. There is a decrease in the prevalence of multiple infections with age, paralleled by an increase in single infections, especially of HPV type 16 in the eldest-age group. However, neither the decrease in multiple infections nor the increase in single infections is statistically significant. The data obtained in this study show that, even in the presence of a slight increase in the HPV prevalence in elderly women, approximately 94% of the elderly women can be withdrawn from the cervical cancer screening. However, a follow-up study will be necessary to determine the frequency of (re)infection as well as the course of an HPV infection in elderly women.

Comparison of three commercially available peptide-based immunoglobulin G (IgG) and IgA assays to microimmunofluorescence assay for detection of Chlamydia trachomatis antibodies

Three commercially available, peptide-based enzyme-linked immunosorbent assay (ELISA) systems (Chlamydia trachomatis IgG and IgA EIA [CT-EIA; Labsystems OY, Helsinki, Finland], SeroCT IgG and IgA [SeroCT; Savyon Diagnostics Ltd., Ashdod, Israel], and Chlamydia trachomatis IgG and IgA pELISA [CT pELISA; Medac, Wedel, Germany]) were evaluated for the detection of serum immunoglobulin G (IgG) and IgA antibodies specific for Chlamydia trachomatis and compared to the "gold standard" assay, the microimmunofluorescence (MIF) assay. Serological responses were analyzed in 149 women aged 20 to 30 years. Cervical swabs obtained from these women were examined for C. trachomatis by PCR, and 43 were found to be positive. The overall seroprevalence rates detected by CT-EIA, SeroCT, CT pELISA, and the MIF assay were 42, 42, 35, and 39%, respectively, for IgG and 7, 7, 3, and 7%, respectively, for IgA. The IgG seroprevalence rates for the PCR-positive women were two to three times higher than those for the PCR-negative women, i.e., 72 versus 29%, 72 versus 29%, 47 versus 26%, and 74 versus 25% for CT-EIA, SeroCT, CT pELISA, and the MIF assay, respectively. After discrepancy analysis, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the IgG assays; for CT-EIA they were 84.7, 98.6, 98.4, and 86.7%, respectively; for CT pELISA they were 71.4, 97.3, 96.2, and 78.3%, respectively; for SeroCT they were 84.7, 98.6, 98.4, and 86.3%, respectively; and for the MIF assay they were 79.2, 83.1, 98.3, and 83.1%, respectively. In conclusion, these peptide-based ELISA systems for the serological detection of C. trachomatis infection performed as well as the MIF assay. Since these tests are less time-consuming, less expensive, and easier to perform than the MIF assay, they might be useful in the serodiagnosis of chlamydial infection.

A quantitative polymerase chain reaction-enzyme immunoassay for accurate measurements of human papillomavirus type 16 DNA levels in cervical scrapings

A quantitative polymerase chain reaction-enzyme immunoassay (Q-PCR-EIA) was developed to measure the amount of human papillomavirus (HPV) 16 DNA per genome equivalent in cervical scrapings. The quantitative approach was based on a combined competitive PCR for both HPV 16, using the general primer GP5+/6+ PCR, and beta-globin DNA. The two competitive PCRs involve co-amplification of target sequences and exogenously added DNA constructs carrying a rearranged 30 bp sequence in the probe-binding region. The accuracy of quantification by combining the two competitive PCR assays was validated on mixtures of HPV 16 containing cervical cancer cells of CaSki and SiHa cell lines. Comparison of this fully quantitative PCR assay with two semi-quantitative HPV PCR assays on a series of crude cell suspensions from HPV 16 containing cervical scrapings revealed remarkable differences in the calculated relative HPV load between samples. We found evidence that correction for both intertube variations in PCR efficiency and number of input cells/integrity of DNA significantly influence the outcome of studies on viral DNA load in crude cell suspensions of cervical scrapings. Therefore, accurate measurements on viral DNA load in cervical scrapings require corrections for these phenomena, which can be achieved by application of this fully quantitative approach.

Monitoring of epstein-barr virus DNA load in peripheral blood by quantitative competitive PCR

A competitive quantitative PCR (Q-PCR) assay combined with simple silica-based DNA extraction was developed for monitoring of Epstein-Barr virus (EBV) DNA load in unfractionated peripheral blood. The Q-PCR is based on competitive coamplification of a highly conserved 213-bp region of the EBNA-1 open reading frame with an internal standard (IS), added in a known concentration. The IS has the same amplicon length and base composition as the wild-type (WT) EBNA-1 amplicon but differs in 23 internally randomized bases. Competitive coamplification yields two PCR products that are quantified by enzyme immunoassay or by electrochemiluminescence detection, with probes specific for the 23 differing internal nucleotides. The Q-PCR has a sensitivity of 10 copies of either WT or IS plasmid DNA. The Q-PCR was validated by quantification of known amounts of plasmid containing the WT EBNA-1 target. Furthermore, we determined EBV genome copy numbers in different cell lines. For EBV quantification in clinical samples, DNA was isolated from lysed whole blood by silica-affinity purification. Forty-six percent of healthy donor peripheral blood samples were positive by Q-PCR. In most of these samples, viral load was less than 2,000 EBV copies/ml of blood. In peripheral blood samples from two AIDS-related non-Hodgkin's lymphoma patients, elevated EBV loads (up to 120,000 copies/ml) were observed, which decreased upon therapy. In Burkitt's lymphoma patients, up to 4,592,000 EBV genome copies/ml of blood were detected. In conclusion, the EBNA-1-based Q-PCR assay provides a reproducible, accurate, and easy method for studying the relationship between EBV load and clinical parameters.

Reliable high risk HPV DNA testing by polymerase chain reaction: an intermethod and intramethod comparison

BACKGROUND

The development of a reproducible, sensitive, and standardised human papillomavirus (HPV) polymerase chain reaction (PCR) test is required to implement HPV testing in cervical cancer screening programmes and for triaging women with mild to moderate dysplasia.

AIMS

To determine the intermethod agreement between different GP5+/6+ and MY09/11 PCR based protocols for the detection and typing of high risk (HR) HPV DNA in cervical smears and to assess the intramethod reproducibility of the GP5+/6+ PCR enzyme immunoassay (EIA) for HR-HPV detection.

METHODS

For the intermethod comparison, crude aliquots of 20 well characterised cervical smears comprising five HPV negative samples, and six and nine samples containing single and multiple HPV infections, respectively, were coded and sent from reference laboratory (A) to three other laboratories. One of these (laboratory B) used the GP5+/6+ PCR-EIA and was provided with standard protocols. Another laboratory (C) used GP5+/6+ PCR combined with sequence analysis and type specific PCR, whereas two laboratories (D and E) used MY09/11 PCR followed by restriction fragment length polymorphism (RFLP) analysis for the detection and typing of HR-HPV. The intramethod agreement of GP5+/6+ PCR-EIA was analysed in a subsequent study with four other laboratories (F to I) on crude aliquots of 50 well characterised cervical smears, consisting of 32 HR-HPV positive and 18 HPV negative samples. Standardised protocols, primers, and probes were also provided by the reference laboratory for HR-HPV detection.

RESULTS

In the intermethod comparison, pairwise agreement of the different laboratories with reference laboratory A for the detection of HR-HPV varied between 75% and 100% (kappa values: 0.5 to 1). Typing data revealed a broader range in pairwise agreement rates between 32% and 100%. The highest agreement was found between laboratories A and B using standardised protocols and validated reagents. In the intramethod evaluation, pairwise comparison of the laboratories F to I with reference laboratory A revealed excellent agreement rates from 92% to 100% (kappa values: 0.88 to 1.0) with an overall sensitivity of 97.5% (195/200) and specificity of 99.5% (199/200).

CONCLUSIONS

The detection of HR-HPV as a group is highly reproducible with GP5+/6+ PCR-EIA provided that standardised protocols and validated reagents are used.

Nonisotopic detection and typing of human papillomavirus DNA in genital samples by the line blot assay. The Canadian Women's HIV study group

The line blot assay, a gene amplification method that combines PCR with nonisotopic detection of amplified DNA, was evaluated for its ability to detect human papillomavirus (HPV) DNA in genital specimens. Processed samples were amplified with biotin-labeled primers for HPV detection (primers MY09, MY11, and HMB01) and for beta-globin detection (primers PC03 and PC04). Amplified DNA products were hybridized by a reverse blot method with oligonucleotide probe mixtures fixed on a strip that allowed the identification of 27 HPV genotypes. The line blot assay was compared to a standard consensus PCR test in which HPV amplicons were detected with radiolabeled probes in a dot blot assay. Two hundred fifty-five cervicovaginal lavage specimens and cervical scrapings were tested in parallel by both PCR tests. The line blot assay consistently detected 25 copies of HPV type 18 per run. The overall positivity for the DNA of HPV types detectable by both methods was 37.7% (96 of 255 samples) by the line blot assay, whereas it was 43. 5% (111 of 255 samples) by the standard consensus PCR assay. The sensitivity and specificity of the line blot assay reached 84.7% (94 of 111 samples) and 98.6% (142 of 144 samples), respectively. The agreement for HPV typing between the two PCR assays reached 83.9% (214 of 255 samples). Of the 37 samples with discrepant results, 33 (89%) were resolved by avoiding coamplification of beta-globin and modifying the amplification parameters. With these modifications, the line blot assay compared favorably to an assay that used radiolabeled probes. Its convenience allows the faster analysis of samples for large-scale epidemiological studies. Also, the increased probe spectrum in this single hybridization assay permits more complete type discrimination.

Detection and quantitation of human papillomavirus by using the fluorescent 5' exonuclease assay

A method for the detection and quantitation of oncogenic human papillomavirus (HPV) was developed by using the fluorescent 5' exonuclease assay. The method is based on the amplification of a 180-bp fragment from the 3' part of the E1 open reading frame in a single PCR with type-specific probes for HPV types 16, 18, 31, 33, and 35. The probes can be used separately or in combinations of up to three probes per assay. Quantitation over a range of 10(1) to 10(6) initial HPV copies was possible by using real-time detection of the accumulation of fluorescence with cycle number. Reconstitution experiments, performed to mimic mixed infections, showed that individual HPV types can be detected down to a ratio of about 1% in a mixture. The performance of the assay depends on DNA quality, the presence of PCR inhibitors, and the number of different probes used simultaneously. This homogeneous assay provides a fast and sensitive way of screening for oncogenic HPV types in biopsy specimens as well as cervical smear samples. The closed-tube nature of the assay and the inclusion of uracil N'-glycosylase reduces cross contamination of PCR products to a minimum. A similar assay for beta-actin was used in parallel for quantitation of genomic DNA. After normalizing the samples for genomic DNA content, the mean number of HPV copies per cell could be calculated.

Distribution of 14 high risk HPV types in cervical intraepithelial neoplasia detected by a non-radioactive general primer PCR mediated enzyme immunoassay

AIM

To evaluate the presence of high risk human papillomaviruses (HPV) in cervical smears showing intraepithelial neoplasia (CIN).

METHODS

The presence of 14 high risk HPV was evaluated in 114 cervical smears with CIN of different degrees, by comparing a non-radioactive polymerase chain reaction (PCR) enzyme immunoassay (EIA) with conventional PCR followed by radioactive Southern blot hybridisation. General primer PCR amplicons detecting low risk and high risk HPV were typed for 14 different high risk HPV types (HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68) by a non-radioactive PCR-EIA. Virus load of HPV 16 positive CIN was assessed using the semiquantitative PCR-EIA.

RESULTS

Histological evaluation confirmed CIN I in 49 cases (mean age 29.0 years, range 17 to 52), CIN II in 31 cases (mean age 30.8 years, 18 to 54), and CIN III in 34 cases (mean age 31.1 years, 16 to 57). The non-radioactive PCR-EIA showed an overall agreement rate of 90% (kappa value 0.75) when compared with conventional general primer PCR followed by radioactive Southern blot hybridisation. High risk HPVs were detected in 47% of CIN I, 77% of CIN II, and 97% of CIN III (p < or = 0.02). HPV types 39, 51, 56, and 58 were found in CIN I exclusively (between 2% and 8%). HPV 16 and HPV 31 were detected in 12% and 2% of CIN I, 35% and 21% of CIN II, and 74% and 13% of CIN III, respectively (p < or = 0.03 and p < or = 0.04). The virus load estimated by the semiquantitative PCR-EIA of HPV 16 was similar in CIN I, CIN II, and CIN III.

CONCLUSIONS

The PCR-EIA has high clinical sensitivity for detecting CIN II/III (90%). There was a significantly higher prevalence rate of HPV 16 and 31 in CIN III than in CIN I and II.

Immunoglobulin G responses against human papillomavirus type 16 virus-like particles in a prospective nonintervention cohort study of women with cervical intraepithelial neoplasia

BACKGROUND

Infection with cancer-linked human papillomavirus (HPV) types such as HPV type 16 (HPV16) is the most important risk factor in the development of cervical cancer. It has been shown that immunoglobulin G (IgG) antibody responses against HPV16 virus-like particles (VLPs) are specifically associated with genital HPV16 infection.

PURPOSE

The aim of this study was to determine the temporal relationships between the presence of HPV16 VLP-specific IgGs, HPV16 infection patterns, and the course of premalignant cervical disease.

METHODS

Plasma samples from 133 women who had been diagnosed originally with mild to moderate cervical dyskaryosis and enrolled in a prospective non-intervention cohort study conducted in Amsterdam, The Netherlands, from 1991 through 1996 were analyzed for the presence of HPV16 VLP-specific IgGs by use of an enzyme-linked immunosorbent assay. A detailed analysis was performed on 43 women with different HPV16 infection patterns during a follow-up period of 10-34 months. Progression or regression of cervical intraepithelial neoplasia (CIN) lesions was monitored by cytologic and colposcopic testing at intervals of 3-4 months. HPV typing in cervical smears was performed by use of a polymerase chain reaction-based assay. Statistical analysis of the serologic data was performed by use of the Mann-Whitney U test or 2 x 2 table analyses.

RESULTS

The presence of HPV16 VLP-specific IgGs in the plasma of the patients was found to be associated with the presence of HPV16 DNA in the cervical smear. Significantly higher proportions of patients with persistent HPV16 infections (i.e., who were polymerase chain reaction positive in three to 11 consecutive tests) than of patients with cleared HPV16 infections were found to be positive for the presence of HPV16 VLP-specific IgGs (18 [69.2%] of 26 versus nine [28.1%] of 32, respectively; P = .003). HPV16 VLP-specific IgGs were consistently detected in all women (n = 11) who were persistently HPV16 DNA positive during follow-up and whose disease ultimately progressed to CIN III (histologically diagnosed severe dysplasia or carcinoma in situ).

CONCLUSION

HPV16 VLP-specific IgG responses are present in the plasma of a majority of patients with persistent HPV16 infections and histologically confirmed high-grade lesions but only in a smaller subset of patients with cleared HPV16 infections and either normal cervical histology or low-grade CIN lesions.

IMPLICATIONS

These results suggest that HPV16 VLP-specific antibodies are not responsible for the clearance of virally induced CIN lesions but that they might, in patients with persistent HPV16 infections, be indicative of an increased cervical cancer risk.

A general primer GP5+/GP6(+)-mediated PCR-enzyme immunoassay method for rapid detection of 14 high-risk and 6 low-risk human papillomavirus genotypes in cervical scrapings

Two cocktails of digoxigenin-labeled human papillomavirus (HPV) type-specific oligonucleotide probes and an enzyme immunoassay (EIA) were used as a basis to developed a group-specific detection method for 14 high-risk (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68) and 6 low-risk (types 6, 11, 40, 42, 43, and 44) HPVs, following a general primer GP5+/bioGP6(+)-mediated PCR. The sensitivity of this high-risk/low-risk (HR/LR) HPV PCR-EIA ranged from 10 to 200 HPV copies, depending on the HPV type. Comparison of HR/LR HPV PCR-EIA with radioactive Southern blot hybridization using a general probe on the same PCR products derived from 417 cytomorphologically abnormal cervical scrapings resulted in an overall agreement of 96% between the two methods. Complete concordance between group-specific HR/LR detection and individual typing results for both single and multiple infections indicate the strong specificity of this HR/LR HPV PCR-EIA. Multiple infections could be predicted by comparing PCR-EIA optical density values of the cocktail probes with one of the individual oligonucleotide probes. This novel HR/LR PCR-EIA allows accurate and rapid identification of high-risk and low-risk HPV types in cervical scrapings and will facilitate HPV detection in HPV mass-screening programs.