Field experience with the 8-HPV-type oncoprotein test for cervical cancer screening among HPV-positive women living with and without HIV in LMICs

Overexpression of HPV-oncoproteins E6 and E7 is necessary for HPV-driven cervical carcinogenesis. Hence, these oncoproteins are promising disease-specific biomarkers. We assessed the technical and operational characteristics of the 8-HPV-type OncoE6/E7 Cervical Test in different laboratories using cervical samples from HPV-positive women living with (WLWH) and without HIV. The 8-HPV-type OncoE6/E7 Test (for short: "OncoE6/E7 test") was performed in 2833 HIV-negative women and 241 WLWH attending multicentric studies in Latin America (ESTAMPA study), and in Africa (CESTA study). Oncoprotein positivity were evaluated at each testing site, according to HIV status as well as type-specific agreement with HPV-DNA results. A feedback questionnaire was given to the operators performing the oncoprotein test to evaluate their impression and acceptability regarding the test. The OncoE6/E7 test revealed a high positivity rate heterogeneity across all testing sites (I2: 95.8%, p < .01) with significant lower positivity in WLWH compared to HIV-negative women (12% vs 25%, p < .01). A similar HPV-type distribution was found between HPV DNA genotyping and oncoprotein testing except for HPV31 and 33 (moderate agreement, k = 0.57). Twenty-one laboratory technicians were trained on oncoprotein testing. Despite operators' concerns about the time-consuming procedure and perceived need for moderate laboratory experience, they reported the OncoE6/E7 test as easy to perform and user-friendly for deployment in resource-limited settings. The high positivity rate variability found across studies and subjectivity in test outcome interpretation could potentially results in oncoprotein false positive/negative, and thus the need for further refinements before implementation of the oncoprotein testing in screen-triage-and-treat approaches is warranted.

Human papillomavirus negative high grade cervical lesions and cancers: Suggested guidance for HPV testing quality assurance

BACKGROUND

Some high-grade cervical lesions and cervical cancers (HSIL+) test negative for human papillomavirus (HPV). The HPV-negative fraction varies between 0.03 % and 15 % between different laboratories. Monitoring and extended re-analysis of HPV-negative HSIL+ could thus be helpful to monitor performance of HPV testing services. We aimed to a) provide a real-life example of a quality assurance (QA) program based on re-analysis of HPV-negative HSIL+ and b) develop international guidance for QA of HPV testing services based on standardized identification of apparently HPV-negative HSIL+ and extended re-analysis, either by the primary laboratory or by a national HPV reference laboratory (NRL).

METHODS

There were 116 initially HPV-negative cervical specimens (31 histopathology specimens and 85 liquid-based cytology samples) sent to the Swedish HPV Reference Laboratory for re-testing. Based on the results, an international QA guidance was developed through an iterative consensus process.

RESULT

Standard PCR testing detected HPV in 55.2 % (64/116) of initially "HPV-negative" samples. Whole genome sequencing of PCR-negative samples identified HPV in an additional 7 samples (overall 61.2 % HPV positivity). Reasons for failure to detect HPV in an HSIL+ lesion are listed and guidance to identify cases for extended re-testing, including which information should be included when referring samples to an NRL are presented.

CONCLUSION

Monitoring the proportion of and reasons for failure to detect HPV in HSIL+ will help support high performance and quality improvement of HPV testing services. We encourage implementation of QA strategies based on re-analysis of "HPV negative" HSIL+ samples.

Performance of cervical cytology and HPV testing for primary cervical cancer screening in Latin America: an analysis within the ESTAMPA study

Background

Cervical cytology remains widely used as the initial tool in cervical cancer screening worldwide. WHO guidelines recommend replacing cytology with primary HPV testing to reach cervical cancer elimination goals. We assessed the performance of cytology and high-risk HPV testing to detect cervical precancer, cervical intraepithelial neoplasia (CIN) grade 3 or worse (CIN3+) among women aged 30-64 years participating in the ESTAMPA study.

Methods

Women were screened with cytology and HPV across ESTAMPA study centres in Latin America. Screen-positives were referred to colposcopy with biopsy collection and treatment as needed. Those with no evident precancer were recalled at 18-months for a second HPV test to complete disease ascertainment. Performance indicators for cytology and HPV to detect CIN3+ were estimated.

Findings

30,606 participants with available cytology and HPV results were included in the analysis. A total of 440 histologically confirmed CIN3s and 30 cancers were diagnosed. Cytology sensitivity for CIN3+ was 48.5% (95% CI: 44.0-53.0), whereas HPV testing had a sensitivity of 98.1% (95% CI: 96.3-96.7). Specificity was 96.5% (95% CI: 96.3-96.7) using cytology and 88.7% (95% CI: 88.3-89.0) with HPV. Performance estimates varied substantially by study centre for cytology (ranging from 32.1% to 87.5% for sensitivity and from 89.2% to 99.5% for specificity) while for HPV results were more consistent across sites (96.7%-100% and 83.6-90.8%, respectively).

Interpretation

The limited and highly variable sensitivity of cytology strongly supports transition to the more robust and reproducible HPV-based cervical screening to ensure progress towards global cervical cancer elimination targets in Latin America.

Funding

IARC/WHO, UNDP, HRP/WHO, NCI and local funders.

Human papillomavirus genotyping using next generation sequencing (NGS) in cervical lesions: Genotypes by histologic grade and their relative proportion in multiple infections

Sensitive and specific genotyping of human papillomaviruses (HPVs) is critical for the surveillance and monitoring of the vaccine effectiveness. Here, HPV genotypes were identified in 137 cervical samples with different histology (79 ≤CIN1 and 58 CIN3+) using Nested-PCR followed by Next-Generation sequencing (NGS) and relative proportions for each genotype in multiple infections were computed. All samples had been previously genotyped by PCR-Reverse Blotting Hybridization (PCR-RBH) thus allowing for a concordance analysis between both techniques. Multiple infections were present in 85% of ≤CIN1 cases compared to only 41% in CIN3+ cases (p<0.001). Among ≤CIN1 cases a towering genotypic diversity was observed, considering both low (LR-) and high risk (HR-) HPV genotypes; while among CIN3+, diversity was lower, HR-HPVs prevailing in most cases, especially HPV16. Furthermore, the predominance of HR-HPV genotypes in the proportions identified in each sample was higher in CIN3+ cases [(HPV16 (62.5%), followed by HPV31 and HPV58 (8.3% each)], than in ≤CIN1 cases [(HPV16 (17.7%), followed by HPV52 (14.7%) and HPV31 (10.3%)]. Agreement between PCR-RBH and NGS was higher than 90% for all genotypes (with an overall Kappa of 0.7), even though NGS identified eighty-nine positive results for HPV genotypes that had not been detected by PCR-RBH, evidencing its greater sensitivity. These results suggest that a reduction in genotypic diversity and/or an increase in the relative proportion of HR-HPVs in multiple infections can be considered as a biomarker for the potential risk of malignant progression.

Implementing HPV testing in 9 Latin American countries: The laboratory perspective as observed in the ESTAMPA study

Background

Replacement of cytology screening with HPV testing is recommended and essential for cervical cancer elimination. HPV testing for primary screening was implemented in 12 laboratories within 9 Latin American countries, as part of the ESTAMPA cervical cancer screening study. Our observations provide information on critical operational aspects for HPV testing implementation in diverse resource settings.

Methods

We describe the implementation process of HPV testing in ESTAMPA, focusing on laboratory aspects. We assess the readiness of 12 laboratories to start HPV testing and their continuity capacity to maintain good quality HPV testing until end of recruitment or up to December 2021. Readiness was based on a checklist. Information from the study database; regular meetings and monitoring visits; and a questionnaire on laboratory operational aspects sent in May 2020 were used to assess continuity capacity. Compliance with seven basic requirements (readiness) and eight continuity requirements (continuity capacity) was scored (1 = compliant, 0 = not compliant) and totaled to classify readiness and continuity capacity as very limited, limited, moderate or high. Experiences, challenges, and enablers of the implementation process are also described.

Results

Seven of 12 laboratories had high readiness, three moderate readiness, and of two laboratories new to HPV testing, one had limited readiness and the other very limited readiness. Two of seven laboratories with high readiness also showed high continuity capacity, one moderate continuity capacity, and the other four showed limited continuity capacity since they could not maintain good quality HPV testing over time. Among three laboratories with moderate readiness, one kept moderate continuity capacity and two reached high continuity capacity. The two laboratories new to HPV testing achieved high continuity capacity. Based on gained expertise, five laboratories have become part of national screening programs.

Conclusion

High readiness of laboratories is an essential part of effective implementation of HPV testing. However, high readiness is insufficient to guarantee HPV testing high continuity capacity, for which a "culture of quality" should be established with regular training, robust monitoring and quality assurance systems tailored to local context. All efforts to strengthen HPV laboratories are valuable and crucial to guarantee effective implementation of HPV-based cervical screening.

Distribution of human papillomavirus genotypes by severity of cervical lesions in HPV screened positive women from the ESTAMPA study in Latin America

The proportion of HPV16 and 18-associated cervical cancer (CC) appears rather constant worldwide (≥70%), but the relative importance of the other HR-HPV differs slightly by geographical region. Here, we studied the HPV genotype distribution of HPV positive Latin American (LA) women by histological grade, in a sub-cohort from the ESTAMPA study; we also explored the association of age-specific HPV genotypes in severe lesions. Cervical samples from 1,252 participants (854 ≤CIN1, 121 CIN2, 194 CIN3 and 83 CC) were genotyped by two PCRs-Reverse Blotting Hybridization strategies: i) Broad-Spectrum General Primers 5+/6+ and ii) PGMY9/11 PCRs. HPV16 was the most frequently found genotype in all histological grades, and increased with the severity of lesions from 14.5% in ≤ CIN1, 19.8% in CIN2, 51.5% in CIN3 to 65.1% in CC (p < 0.001). For the remaining HR-HPVs their frequency in CC did not increase when compared to less severe categories. The nonavalent vaccine HR-types ranked at the top in CC, the dominant ones being HPV16 and HPV45. HR-HPV single infection occurs, respectively, in 57.1% and 57.0% of ≤CIN1 and CIN2, increasing to 72.2% and 91.6% in CIN3 and CC (p<0.001). No association between age and HPV type was observed in CC, although the risk of HPV16 infection in CIN3 cases increased with age. Results confirm the relevance of HPV16 in the whole clinical spectrum, with a strong rise of its proportion in CIN3 and cancer. This information will be relevant in evaluating the impact of HPV vaccination, as a baseline against which to compare genotype changes in HPV type-specific distribution as vaccinated women participate in screening in LA region. Likewise, these data may help select the best HPV testing system for HPV-based efficient, affordable, and sustainable screening programmes.

A comprehensive HPV-STI NGS assay for detection of 29 HPV types and 14 non-HPV sexually transmitted infections

BACKGROUND

Sexually transmitted infections (STIs) are prevalent throughout the world and impose a significant burden on individual health and public health systems. Missed diagnosis and late treatment of STIs can lead to serious complications such as infertility and cervical cancer. Although sexually transmitted co-infections are common, most commercial assays target one or a few STIs. The HPV-STI ChapterDx Next Generation Sequencing (NGS) assay detects and quantifies 29 HPVs and 14 other STIs in a single-tube and single-step PCR reaction and can be applied to tens to thousands of samples in a single sequencing run.

METHODS

A cohort of 274 samples, previously analyzed by conventional cytology/histology and Roche cobas HPV Test, were analyzed by ChapterDx HPV-STI NGS assay for detection of 43 HPV and STI. A set of 43 synthetic control DNA fragments for 43 HPV and STI were developed to evaluate the limit of detection, specificity, and sensitivity of ChapterDx HPV-STI NGS assay.

RESULTS

The assay was evaluated in this study, and the limit of detection was 100% at 50 copies for all targets, and 100%, 96%, 88% at 20 copies for 34, 8, and 1 target, respectively. The performance of this assay has been compared to Roche cobas HPV test, showing an overall agreement of 97.5% for hr-HPV, and 98.5% for both, HPV16 and HPV18. The assay also detected all HPV-infected CIN2/3 with 100% agreement with Roche cobas HPV results. Moreover, several co-infections with non-HPV STIs, such as C. trachomatis, T. vaginalis, M. genitalium, and HSV2 were identified.

CONCLUSIONS

The ChapterDx HPV-STI NGS assay is a user-friendly, easy to automate and cost-efficient assay, which provides accurate and comprehensive results for a wide spectrum of HPVs and STIs.

A clinical and molecular portrait of non-metastatic anal squamous cell carcinoma

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High-risk HPV infection is less frequently detected in HIV-positive non-metastatic ASCC compared with HIV-negative cases.

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Mutational profile identified in the non-metastatic ASCC cohort revealed expected similarities with metastatic ASCC.

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High PD-L1 expression levels are associated with high CD3 and CD8 TIL density, complete response to treatment, and good survival outcome of ASCC patients.

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PD-L1 is a reliable predictive and prognostic biomarker that allows the stratification in low- vs. high-risk ASCC patients at their initial therapeutic approach.

Anal squamous cell carcinoma (ASCC) is a rare gastrointestinal malignancy associated with high-risk Human papillomavirus (HPV) infection. Despite improved outcomes in non-metastatic ASCC, definitive chemoradiotherapy constitutes the standard treatment for localized disease. Evidences for predictive and prognostic biomarkers are limited. Here, we performed a viral, immune, and mutational characterization of 79 non-metastatic ASCC patients with complete definitive chemoradiotherapy. HPV-16 was detected in 91% of positive cases in single infections (78%) or in coinfections with multiple genotypes (22%). Fifty-four percent of non-metastatic ASCC cases displayed mutations affecting cancer driver genes such as PIK3CA (21% of cases), TP53 (15%), FBXW7 (9%), and APC (6%). PD-L1 expression was detected in 57% of non-metastatic ASCC. Increased PD-L1 positive cases (67%) were detected in patients with complete response compared with non-complete response to treatment (37%) (p = 0.021). Furthermore, patients with PD-L1 positive tumors were significantly associated with better disease-free survival (DFS) and overall survival (OS) compared with patients with PD-L1 negative tumors (p = 0.006 and p = 0.002, respectively). PD-L1 expression strongly impacts CR rate and survival of non-metastatic ASCC patients after standard definitive chemoradiotherapy. PD-L1 expression could be used to stratify good versus poor responders avoiding the associated morbidity with abdominal perineal resection.

Strong reduction in prevalence of HPV16/18 and closely related HPV types in sexually active adolescent women following the introduction of HPV vaccination in Argentina

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HPV16/18 decreased by >93% in vaccinated sexually active Argentine girls.

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Detected reduction of HPV31 and 45 would add to the success of immunization.

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No genotype replacement was observed.

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First HPV vaccination monitoring data reported from a Latin American country.

Baseline prevalence and type distribution of Human papillomavirus in sexually active non-vaccinated adolescent girls from Argentina

In 2011, Argentina launched a government-funded national Human papillomavirus (HPV) immunization program incorporating a bivalent HPV vaccine, with a 0-1-6-month schedule, for girls 11 years of age, born after January 2000. Monitoring the changes of HPV infection prevalence among young women has been proposed as an endpoint for early assessment of HPV vaccination programs. However, the data on HPV prevalence at young ages are very limited. The aim of this work was to determine the prevalence of HPV infection and type-specific distribution in sexually active 15-17-year-old non-vaccinated girls. Cervical samples from 1073 adolescents were collected for HPV detection and genotyping using the BSGP5+/GP6+PCR-reverse line blot (RLB) assay. Out of 957 specimens analyzed, 56.3% were positive for any HPV type; 42.2% harbored at least one high-risk HPV (HR-HPV) type and 30.8% low-risk HPV (LR-HPV) types. Multiple and single infections were identified in 36.3% and 20.0% of the samples respectively. The 6 most common HR-HPV types were HPV16 (11.1%), HPV52 (10.8%), HPV56 (8.3%), HPV51 (7.4%), HPV58 (7.3%) and HPV31 (7.1%). The prevalence of HR-HPV-16/18 was 15.2%. In conclusion, results confirm that HPV (particularly HR-types) are very common among sexually active adolescents, and prevalence rises quickly after their sexual debut. Our HPV type-specific prevalence baseline may be used to monitor post-vaccinal longitudinal changes in Argentina.

Multicentric study of cervical cancer screening with human papillomavirus testing and assessment of triage methods in Latin America: the ESTAMPA screening study protocol

INTRODUCTION

Human papillomavirus (HPV) testing is replacing cytology in primary screening. Its limited specificity demands using a second (triage) test to better identify women at high-risk of cervical disease. Cytology represents the immediate triage but its low sensitivity might hamper HPV testing sensitivity, particularly in low-income and middle-income countries (LMICs), where cytology performance has been suboptimal. The ESTAMPA (EStudio multicéntrico de TAMizaje y triaje de cáncer de cuello uterino con pruebas del virus del PApiloma humano; Spanish acronym) study will: (1) evaluate the performance of different triage techniques to detect cervical precancer and (2) inform on how to implement HPV-based screening programmes in LMIC.

METHODS AND ANALYSIS

Women aged 30-64 years are screened with HPV testing and Pap across 12 study centres in Latin America. Screened positives have colposcopy with biopsy and treatment of lesions. Women with no evident disease are recalled 18 months later for another HPV test; those HPV-positive undergo colposcopy with biopsy and treatment as needed. Biological specimens are collected in different visits for triage testing, which is not used for clinical management. The study outcome is histological high-grade squamous intraepithelial or worse lesions (HSIL+) under the lower anogenital squamous terminology. About 50 000 women will be screened and 500 HSIL+ cases detected (at initial and 18 months screening). Performance measures (sensitivity, specificity and predictive values) of triage techniques to detect HSIL+ will be estimated and compared with adjustment by age and study centre.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Ethics Committee of the International Agency for Research on Cancer (IARC), of the Pan American Health Organisation (PAHO) and by those in each participating centre. A Data and Safety Monitoring Board (DSMB) has been established to monitor progress of the study, assure participant safety, advice on scientific conduct and analysis and suggest protocol improvements. Study findings will be published in peer-reviewed journals and presented at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT01881659.

The contribution of Latin American research to HPV epidemiology and natural history knowledge

Our aim was to review the major contributions of studies conducted in different Latin American (LA) countries to the field of human papillomavirus (HPV) epidemiology, natural history, risk of disease, and prevention strategies, mainly in the uterine cervix. Although cytological screening is established in several countries in LA, incidence and mortality rates from cervical cancer (CC) are still extremely high. Finally, data from large cohort studies conducted in LA countries provided seminal data to propose primary and secondary prevention modalities: the HPV vaccine has been introduced in the national immunization programs of several LA countries and multiple screening experiences using HPV testing are under evaluation in the region.

Human papillomavirus genotype distribution in cervical cancer biopsies from Nepalese women

BACKGROUND

Cervical cancer (CC) is the leading cause of morbidity and mortality from cancer in Nepalese women. Nearly all cases of CC are caused by infection with certain genotypes of human papillomavirus (HPV). Data on HPV genotype distribution in Nepalese CC patients is sparse. We aimed to determine the distribution of HPV genotypes in biopsies of CC tissue from Nepalese women.

METHODS

This study examined 248 archived paraffin-embedded tissue specimens from CC cases from patients of B.P. Koirala Memorial Cancer Hospital, Bharatpur, Chitwan, Nepal. DNA was extracted from the biopsies and HPV detection performed by PCR. HPV genotyping was then carried out by a reverse line hybridization technique capable of identifying 36 distinct HPV genotypes.

RESULTS

Most of the samples were from tumors that had been designated by hospital pathologists as squamous cell carcinoma (77.6%). 165 of the 248 samples contained DNA of sufficient quality for rigorous PCR testing. All the analyzable specimens were positive for HPV. The most common HPV genotypes, in decreasing order of frequency were 16, 18, 45, 33, 52, 56 and 31; most were found as single infections (94.5%). Together, HPV types 16, 18, and 45 were found in 92% of the tumor samples.

CONCLUSION

This study strengthens the knowledge-base of HPV genotype distribution in CC cases in Nepal. Hopefully, this information will be useful to the medical community and public health policy-makers in generating improved HPV-surveillance, -prevention and -treatment strategies in Nepal.

Cutaneous human papillomavirus genotypes in different kinds of skin lesions in Argentina

Cutaneous human papillomaviruses (HPVs) comprise a large and highly heterogeneous virus group. Some of the cutaneous HPVs of the genus Beta have been suggested as a co-factor in the development of non-melanoma skin cancer (NMSC). The aim of this study was to determine cutaneous HPV prevalence and type-specific distribution in different kinds of skin lesions from Argentine patients visiting Dermatology Departments of three hospitals from Buenos Aires. A cross-sectional analysis was performed. HPV DNA was analyzed in (i) 3 patients with Epidermodysplasia verruciformis (EV) harboring benign lesions (BL) (n = 1) and squamous cell carcinoma (SCC) (n = 4); (ii) 240 non-EV patients harboring: (a) BL (n = 38), (b) Actinic Keratosis (AK) (n = 83), (c) SCC (n = 74), and (d) basal cell carcinoma (BCC) (n = 96). Detection and genotyping of 35 cutaneous HPV DNA was carried out by BGC-PCR and GP5+/6 + PCR followed by reverse line blot assay. In EV patients, Beta types were found in all lesions (5/5), including the potentially high-risk HPV types 5 and 8, mostly in multiple infections. In non-EV patients, cutaneous types were found in 50.0% of BL, 43.4% of AK, 31.1% of SCC, and 16.7% of BCC. Beta HPVs were the most frequently found in all lesions, being present in all AK and SCC cases that were positive for HPV. No type-specific correlation with lesion severity was found. In our series, a wide spectrum of cutaneous HPV types was detected in different skin lesions. A possible role for these HPVs in skin carcinogenesis deserves further study. J. Med. Virol. 89:352-357, 2017. © 2016 Wiley Periodicals, Inc.

Distribution of human papillomavirus (HPV) genotypes and bacterial vaginosis presence in cervical samples from Paraguayan indigenous

OBJECTIVE

To determine the frequency of human papillomavirus (HPV) types and to assess bacterial vaginosis (BV) possible associations with cervical infections in indigenous Paraguayan women of the Department of Presidente Hayes.

METHODS

This study included 181 sexually active women without cervical lesions. HPV typing was performed by polymerase chain reaction with primers PGMY 09/11 followed by reverse line hybridization. BV was diagnosed by the Nugent criteria using the results from a Gram stain smear.

RESULTS

Sixteen percent of women were positive for at least one high risk HPV type (HR-HPV). The most frequent genotypes were HPV 16 (4.4%), followed by HPV 58 (3.3%), HPV 45 (3.3%), HPV 53 (2.8%) and HPV 11 (2.8%). A significant association between HR-HPV and BV was observed (p=0.01). In addition, women with BV had a higher frequency of Chlamydia trachomatis (p=0.0007), Trichomonas vaginalis (p=0.00009), Mycoplasma hominis (p=0.001).

CONCLUSIONS

A large variety of HPV genotypes was detected and showed a slightly different pattern from previous studies on urban women in Paraguay, with the predominance of HR-HPV. Furthermore, the information of co-infections involved in BV could be useful for the improvement of national prevention programs, as well as for laboratory surveillance of these genital infections.

Genetic characterization and clinical implications of human papillomavirus type 16 (HPV16) variants from northeastern Argentina

BACKGROUND

Human papillomavirus type 16 (HPV16) plays a central role in the development of cervical cancer. Worldwide studies indicate the existence of HPV16 variants that show different geographic distributions and oncogenic potential.

OBJECTIVE

Our goal was to describe the genetic variation of HPV16 isolates identified in urban women with different grades of cervical lesions living in northeastern Argentina.

STUDY DESIGN

We analyzed 116 HPV16-positive cervical samples (16 NLIM, 62 L-SIL, 16 H-SIL and 22 cervical cancer) from patients attending health centers in Misiones (Argentina) during 2006-13. HPV16 isolates were genetically characterized through PCR amplification and direct sequencing of 364 bp within the long control region, and the resulting sequences classified into variants based on phylogenetic analysis (lineages A, B, C and D). A potential association between HPV16 variants and lesion grade was evaluated through an odds ratio (OR) test. A temporal framework for the origin of HPV16 variants was assessed through coalescence analysis (BEAST v 1.7.5).

RESULTS

Phylogenetic analysis of HPV16 sequences showed that 92.1% of the samples clustered with lineage A, and 6.9% to lineage D. HPV16 variants from lineage D were more frequently associated with high-grade lesions and cancer (HSIL+) than lineage A variants at an OR of 13.8 (1.6-117.0). The time to most common recent ancestor (tMCRA) of all variants was 119,103 years before present (HPD 95%=48,486-197,239), a date consistent with the time frame for modern human evolution.

CONCLUSION

Our results suggest that HPV16 variants from lineage D may represent an additional risk factor for the development of cervical cancer in women living in northeastern Argentina. This study provides new information about viral isolates present in Argentina that will contribute to the monitoring of HPV16 infection in the vaccine era.

Geographical distribution and risk association of human papillomavirus genotype 52-variant lineages

Human papillomavirus (HPV) genotype 52 is commonly found in Asian cases of cervical cancer but is rare elsewhere. Analysis of 611 isolates collected worldwide revealed a remarkable geographical distribution, with lineage B predominating in Asia (89.0% vs 0%-5.5%; P(corrected) < .001), whereas lineage A predominated in Africa, the Americas, and Europe. We propose that the name "Asian lineage" be used to denote lineage B, to signify this feature. Preliminary analysis suggested a higher disease risk for lineage B, although ethnogeographical confounders could not be excluded. Further studies are warranted to verify whether the reported high attribution of disease to HPV52 in Asia is due to the high prevalence of lineage B.

Duplex realtime PCR method for Epstein-Barr virus and human DNA quantification: its application for post-transplant lymphoproliferative disorders detection

Introduction

The quantification of circulating Epstein–Barr virus (EBV) DNA is used to monitor transplant patients as an early marker of Post-Transplant Lymphoproliferative Disorders (PTLD). So far no standardized methodology exists for such determination.

Objective

Our purpose was to develop and validate a real-time PCR assay to quantify EBV DNA in clinical samples from transplant recipients.

Methods

A duplex real-time PCR method was developed to amplify DNA from EBV and from a human gene. The EBV load was determined in peripheral blood mononuclear cells (PBMC), plasma and oropharyngeal tissue from 64 non-transplanted patients with lymphoid-hypertrophy (Non-Tx), 47 transplant recipients without PTLD (Tx), 54 recipients with PTLD (Tx-PTLD), and 66 blood donors (BD). WinPEPI, version 11.14 software was used for statistical analysis.

Results

Analytical validation: the intra and inter-assays variation coefficients were less than 4.5% (EBV-reaction) and 3% (glyceraldehyde 3-phosphate dehydrogenase – GAPDH reaction). Linear ranges comprised 10⁷–10 EBV genome equivalents (gEq) (EBV-reaction) and 500,000–32 human gEq (GAPDH-reaction). The detection limit was 2.9 EBV gEq (EBV-reaction). Both reactions showed specificity. Application to clinical samples: higher levels of EBV were found in oropharyngeal tissue from transplanted groups with and without PTLD, compared to Non-Tx (p < 0.05). The EBV load in PBMC from the groups of BD, Non-Tx, Tx and Tx-PTLD exhibited increasing levels (p < 0.05). In BD, PBMC and plasma, EBV loads were undetectable.

Conclusions

The performance of the assay was suitable for the required clinical application. The assay may be useful to monitor EBV infection in transplant patients, in particular in laboratories from low-income regions that cannot afford to use commercial assays.

Distribution of human papillomavirus genotypes in women with cervical alterations from north Argentina

BACKGROUND

Cervical cancer remains a major public health problem in northern Argentina, showing the highest mortality rate in the country (approximately 22 cases/100000 women).

OBJECTIVE

The aim of this study was to provide epidemiological data on the prevalence and type distribution of human papillomavirus (HPV) in women with pre-neoplastic lesions before the massive introduction of HPV vaccination in the country.

MATERIALS AND METHODS

Exfoliated cervical cells were collected to screen for HPV using the widely known MY09/11 PCR, followed by the restriction fragment-length polymorphism (RFLP) technique from a total of 714 women with previously diagnosed atypical squamous cells of undetermined significance (ASCUS), low-grade squamous intraepithelial lesion (LG-SIL) and high-grade squamous intraepithelial lesion (HG-SIL).

RESULTS

Overall HPV prevalence was 48.2% in ASCUS (24 different HPV types detected), 66.5% in LG-SIL (37 HPV types detected) and 82.6% in HG-SIL (16 HPV types detected). HPV-16 was the most prevalent type among all cases. With respect to multiple HPV infections, 9.6% were observed in ASCUS, 14.3% in LG-SIL and 11.4% in HG-SIL.

CONCLUSION

The major strength of our study is the assessment of a large series of women with cytological alterations in this region. The information attained will be useful as a regional baseline for future epidemiological vigilance, in the context of the national HPV vaccination program.

[Human papillomavirus detection in cervical cancer prevention]

Cervical cancer (CC), which is strongly associated to high-risk human papillomavirus (hr-HPV) infection, continues being a significant health problem in Latin America. The use of conventional cytology to detect precancerous cervical lesions has had no major impact on reducing CC incidence and mortality rates, which are still high in the region. New screening tools to detect precancerous lesions became available, which provide great opportunities for CC prevention, as do highly efficacious HPV vaccines able to prevent nearly all lesions associated with HPV-16 and -18 when applied before viral exposure. Currently, hr-HPV testing represents an invaluable component of clinical guidelines for screening, management and treatment of CC and their precursor lesions. Many testing strategies have been developed that can detect a broad spectrum of hr-HPV types in a single assay; however, only a small subset of them has documented clinical performance for any of the standard HPV testing indications. HPV tests that have not been validated and lack proof of reliability, reproducibility and accuracy should not be used in clinical management. Once incorporated into the lab, it is essential to submit the whole procedure of HPV testing to continuous and rigorous quality assurance to avoid sub-optimal, potentially harmful practices. Recent progress and current status of these methods are discussed in this article.

Geographical distribution and oncogenic risk association of human papillomavirus type 58 E6 and E7 sequence variations

Human papillomavirus (HPV) 58 accounts for a notable proportion of cervical cancers in East Asia and parts of Latin America, but it is uncommon elsewhere. The reason for such ethnogeographical predilection is unknown. In our study, nucleotide sequences of E6 and E7 genes of 401 HPV58 isolates collected from 15 countries/cities across four continents were examined. Phylogenetic relationship, geographical distribution and risk association of nucleotide sequence variations were analyzed. We found that the E6 genes of HPV58 variants were more conserved than E7. Thus, E6 is a more appropriate target for type-specific detection, whereas E7 is more appropriate for strain differentiation. The frequency of sequence variation varied geographically. Africa had significantly more isolates with E6-367A (D86E) but significantly less isolates with E6-203G, -245G, -367C (prototype-like) than other regions (p ≤ 0.003). E7-632T, -760A (T20I, G63S) was more frequently found in Asia, and E7-793G (T74A) was more frequent in Africa (p < 0.001). Variants with T20I and G63S substitutions at E7 conferred a significantly higher risk for cervical intraepithelial neoplasia grade III and invasive cervical cancer compared to other HPV58 variants (odds ratio = 4.44, p = 0.007). In conclusion, T20I and/or G63S substitution(s) at E7 of HPV58 is/are associated with a higher risk for cervical neoplasia. These substitutions are more commonly found in Asia and the Americas, which may account for the higher disease attribution of HPV58 in these areas.

Chlamydia trachomatis as a probable cofactor in human papillomavirus infection in aboriginal women from northeastern Argentina

OBJECTIVES

High-risk types of human papillomavirus (HPV) are strongly associated with cervical cancer (CC), and Chlamydia trachomatis (CT), the most frequent sexually transmitted bacterial infection (STBI) worldwide, seems to be a risk factor for HPV infection and for CC. It is also known that both agents are more prevalent in vulnerable communities where lack of adequate primary health care is a cause for concern. The aim of this work was to determine the impact of CT and HPV infections in women belonging to an isolated aboriginal population (Pilaga community) from a poor region in Northern Argentina (province of Formosa). For this purpose, a cross-sectional study was performed in all sexually active Pilaga women, who attended a local community-based gynecological health screening project. The polymerase chain reaction (PCR) method on a cervical brush specimen was used to detect both agents.

RESULTS

A total of 227 women (20% of the total female population of the Pilaga community) were studied and the overall prevalence was 26.4% for CT, 46.7% for HPV and 16.3% for concurrent infection. CT infection was higher in HPV DNA positive (34.2%) than in HPV DNA negative women (19%; OR: 2.22/95% CI = 1.16-4.28 / p = 0.009) and the most prevalent HPV types were HPV-16 (19.4%), 6 and 18 (5.3%), 58 (3.5%) and 33 (3.1%).

CONCLUSIONS

The prevalence of CT and HPV observed in Pilaga women are among the worst registered in Latin America. Also, data collected suggest that chlamydial infection may play an important role in the natural history of HPV infection. On this respect, we propose that the association between these two agents seems to be more related to a mutual potentiation than to the fact that they share a common route of transmission.

Laboratory and clinical aspects of human papillomavirus testing

Human papillomavirus (HPV) infection is associated with a wide spectrum of disease that ranges from self-limited skin warts to life-threatening cancers. Since HPV plays a necessary etiological role in cervical cancer, it is logical to use HPV as a marker for early detection of cervical cancer and precancer. Recent advances in technology enable the development of high-throughput HPV assays of different formats, including DNA-based, mRNA-based, high-risk group-specific and type-specific methods. The ultimate goal of these assays is to improve the accuracy and cost-effectiveness of cervical screening programs. HPV testing has several potential advantages compared to cytology-based screening. However, since the cancer to transient infection ratio is always low in the general population, HPV test results are bound to have a low positive predictive value that may subject women to unnecessary follow-up investigations. The wide-spread administration of prophylactic HPV vaccine will substantially decrease the incidence of cancer and precancer. This poses a number of challenges to cytology-based screening, and the role of HPV testing is expected to increase. Finally, apart from technical and cost-effectiveness considerations, one should also keep in mind the psycho-social impact of using sexually-transmitted agents as a marker for cancer screening.

Identification of human papillomavirus type 58 lineages and the distribution worldwide

BACKGROUND

Human papillomavirus type 58 (HPV-58) accounts for a much higher proportion of cervical cancers in East Asia than other types. A classification system of HPV-58, which is essential for molecular epidemiological study, is lacking.

METHODS AND RESULTS

This study analyzed the sequences of 401 isolates collected from 15 countries and cities. The 268 unique concatenated E6-E7-E2-E5-L1-LCR sequences that comprised 57% of the whole HPV-58 genome showed 4 distinct clusters. L1 and LCR produced tree topologies that best resembled the concatenated sequences and thus are the most appropriate surrogate regions for lineage classification. Moreover, short fragments from L1 (nucleotides 6014-6539) and LCR (nucleotides 7257-7429 and 7540-52) were found to contain sequence signatures informative for lineage identification. Lineage A was the most prevalent lineage across all regions. Lineage C was more frequent in Africa than elsewhere, whereas lineage D was more prevalent in Africa than in Asia. Among lineage A variants, sublineage A2 dominated in Africa, the Americas, and Europe, but not in Asia. Sublineage A1, which represents the prototype that originated from a patient with cancer, was rare worldwide except in Asia.

CONCLUSIONS

HPV-58 can be classified into 4 lineages that show some degree of ethnogeographic predilection in distribution. The evolutionary, epidemiological, and pathological characteristics of these lineages warrant further study.

First report on sexually transmitted infections among trans (male to female transvestites, transsexuals, or transgender) and male sex workers in Argentina: high HIV, HPV, HBV, and syphilis prevalence

OBJECTIVES

Due to the scarce data on the prevalence of sexually transmitted infections (STIs) among male-to-female trans-sex workers (TSW) and male sex workers (MSW) in Argentina, the present study aimed to estimate the incidence of human immunodeficiency virus (HIV), and the prevalence of HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), and Treponema pallidum. Human papillomavirus (HPV) and Chlamydia trachomatis infections were tested among TSW.

METHODS

Two hundred and seventy-three TSW and 114 MSW were recruited by nongovernmental organizations. HIV incidence was estimated by STARHS (serologic testing algorithm for recent HIV seroconversion). HPV and C. trachomatis infections were tested in anal cells from TSW.

RESULTS

TSW showed significantly higher prevalences of HIV (34.1 vs. 11.4%), HBV (40.2 vs. 22.0%), and T. pallidum (50.4 vs. 20.4%) than MSW. TSW tested positive for HPV in 111/114 cases and for C. trachomatis in 4/80 cases. Investigation of HBV, HCV, HIV, and T. pallidum co-infections showed that 72% of TSW and 39% of MSW had at least one STI. T. pallidum was the most frequent mono-infection. The estimated HIV incidence was 10.7 per 100 person-years (95% confidence interval (CI) 3.8-17.7) for TSW and 2.3 per 100 person-years (95% CI 0-6.7) for MSW.

CONCLUSIONS

The high prevalence of STIs and the high incidence of HIV demonstrate the great vulnerability of these high-risk populations and indicate the urgent need for preventive strategies on intervention and facilitation of access to healthcare programs.

Human papilloma virus genotype diversity of anal infection among trans (male to female transvestites, transsexuals or transgender) sex workers in Argentina

BACKGROUND

Reports on the prevalence and genotypes of HPV among trans (male to female transvestites, transsexuals or transgender) sex workers (TSW) are scarce in the literature.

OBJECTIVES

The aim of the study was to determine the infecting HPV genotypes among TSW in Argentina.

STUDY DESIGN

119 TSW were recruited. Anal cells were self collected with a cytobrush. HPV DNA detection was carried out by PCR and genotyping was performed by RLB.

RESULTS

HPV prevalence was 97.4%. 103/111 HPV positive samples were genotyped. High risk genotypes were detected in 82.5%. Two or more coinfecting HPV genotypes were found in 70.9%. One case showed up to 10 different coinfecting types. The number of genotypes was not related to condom usage. Infection rates were similar for HIV positive (100%) and HIV negative (95.8%) participants. However, 18.8% of HIV negative had 4-9 different genotypes, while among HIV positive this percentage raised to 46.2% (p=0.006). Prevalence of high risk genotypes and the frequency of each high risk type were similar between HIV positive and HIV negative groups. According to the participants' answers HIV status showed no association with condom usage.

CONCLUSIONS

The high HPV prevalence, the coinfection with multiple genotypes and the high frequency of high risk genotypes detected, together with a situation of extreme social marginalization, discrimination and stigmatization make this population to be of extreme vulnerability.

Human papillomavirus and mutated H-ras oncogene in cervical carcinomas and pathological negative pelvic lymph nodes: a retrospective follow-up

The metastasis status of pelvic lymph nodes (PLNs) seems to be a predictive factor of survival. It was suggested that the presence of HPV DNA and other biological markers in PLN may indicate a sub clinical early metastasis. The aim was to describe the prevalence and distribution patterns of HPV DNA and H-ras mutations in intra operatively obtained cervical tumors and PLN. Thirty-seven cervical tumors and 61 lymph node biopsies from 37 patients with cervical cancer were selected. HPV typing and location were performed by PCR/dot blot and in situ hybridization (ISH) respectively. PCR/RFLP was used to scan for mutations in H-ras. Hundred percent of the cervical cancers and 85% of the PLN were HPV positive; co-infection with more than one type was 27%. HPV 16 was detected alone or co-infecting with other types in 84% of tumors and 46% of PLN; the second most frequent viral type was HPV 18 (tumor: 27%; PLN: 20%). In PLN, HPV was located in nuclei or/and cytoplasm of lymphocytes, macrophages, endothelial, and /or stromal cells. H-ras mutations were identified in 5/24 (21%) of patients with cervical tumors showing poor or moderated differentiation. HPV DNA in histological tumor-free PLN not necessary indicate metastasis, but it may be associated to an active immune reaction. Mutated H-ras is probably involved in cervical carcinogenesis and its detection in tumor and metastasis free PLN may be related to early metastasis or recurrence in at least a subset of poorly differentiated cervical tumors.

Epstein Barr virus genotypes and LMP-1 variants in HIV-infected patients

Two Epstein Barr virus (EBV) genotypes: EBV-1 and EBV-2 have been described. A 30-bp deletion in latent membrane protein-1 gene (del-LMP-1) has been identified in various pathologies. The aim of this study was to determine EBV genotypes and 30-bp deletion frequency in HIV-infected patients from Argentina. The study was performed on 258 individuals:

CASES

144 HIV-infected patients that included: (a) 7 AIDS patients with primary central nervous system lymphoma (PCNSL), (b) 62 AIDS patients, and (c) 75 asymptomatic HIV-infected patients.

CONTROLS

114 HIV-negative individuals. EBV genotypes and variants in LMP-1 gene were detected by polymerase chain reaction (PCR)-Southern blot on DNA extracted from peripheral blood mononuclear cells and brain biopsies. In PCNSL, the presence of EBV was confirmed by EBER RNA in situ hybridization, and DNA sequencing of 3' end LMP-l gene of PCR products was performed. In HIV-infected patients, EBV-1 was detected in 48.6%, EBV-2 in 18.8%, and co-infection with both genotypes in 32.6%. In control group, EBV-1 was present in 74.3%, EBV-2 in 12.4%, and co-infection in 13.3%. Del-LMP-1 was found in 44.4% of HIV-infected patients samples (20.7% alone and 23.7% co-infection with non-deleted form) while it was found in 25.3% (6.3% alone and 19% with co-infection) in HIV-negative individuals. In HIV-infected patients EBV-2, co-infection and 30-bp deletion are more prevalent than in control group. In all, PCNSL brain biopsies samples, del-LMP-1 always was detected with EBV-2, but more cases would have to be included to draw definitive conclusions.

Circulating Epstein-Barr virus (EBV) in HIV-infected patients and its relation with primary brain lymphoma

OBJECTIVE

To analyze Epstein-Barr virus (EBV) load at different HIV infection stages and its relation with brain lymphoma.

DESIGN

A cross-sectional study was conducted on 172 HIV-infected individuals: 62 asymptomatic HIV carriers (group A), 30 HIV progressors (group B), 73 AIDS patients (group C), seven AIDS patients with brain lymphoma (group C-BL); and 26 blood donors (group BD) as healthy carriers. EBV load was measured in peripheral blood mononuclear cells (PBMC) and plasma samples using a semi-quantitative PCR method.

RESULTS

PBMC-EBV levels in HIV-infected patients were higher than in the blood donors (p<0.05). No differences in PBMC-EBV loads were found in groups A, B, or C (p>0.05), while the C-BL group had significantly lower levels (p<0.05). Similar PBMC-EBV loads were seen in HIV-infected patients with CD4+ T cell counts higher than 50/mm(3) (p>0.05), while significantly lower levels were found in cases with less than 50 cells/mm(3) (p<0.05). In all HIV-infected patients, plasma-EBV load was lower than, or similar to, PBMC-EBV load, unlike 2/7 HIV-positive brain lymphoma patients.

CONCLUSIONS

During HIV infection PBMC-EBV load rises in comparison to healthy carriers, but decreases when immunosuppression progresses and CD4+ T cell count becomes <50/mm(3). Circulating EBV is mainly cell-associated in the HIV-infected population. Neither PBMC-EBV nor plasma-EBV loads would be useful to diagnose brain lymphoma in AIDS patients.

Human papillomavirus type 16 molecular variants in Guarani Indian women from Misiones, Argentina

OBJECTIVE

To identify human papillomavirus type 16 (HPV16) E6 and L1 molecular variants infecting Guarani Indian women settled in Misiones, Argentina, a region with a high prevalence of cervical cancer. Some intratypic molecular variants of HPV16 have been associated with greater oncogenic risk, but their implication in the etiology of cervical cancer is still uncertain.

METHODS

Seventy HPV16 positive cervical samples from Guarani Indian women settled in two different areas of Misiones, Argentina, (34 from the northern area and 36 from the central area), were analyzed. Thirty-seven had normal cytology, 18 had a low-grade squamous intraepithelial lesion (LGSIL), and 15 a high-grade squamous intraepithelial lesion (HGSIL). HPV16 E6 and L1 molecular variants were identified by PCR, followed by dot blot hybridization with 23 and 12 biotinylated oligonucleotide probes, respectively.

RESULTS

The frequency of HPV16 variants over the Guarani population was 51% EP (European prototype), 32% E-350G, 9% Af1-a (African 1), 4% E-6862C, 3% Af2-a, and 1% AA-a (Asian-American). The distribution of variants was not homogeneous in the two areas under analysis, with the northern area being more diverse showing 74% of European variants, while the central area presented exclusively E variants. No statistically significant association was found between any particular variant and grade of cervical lesion.

CONCLUSION

This study reports for the first time HPV16 E6 and L1 molecular variants infecting women from an aboriginal community inhabiting a rainforest region of South America. The presence of E class variants could be attributed primarily to contacts with the Spanish conquerors, and Af variants from African slaves introduced later in the South American continent.

[Cervical infection epidemiology of human papillomavirus in Ushuaia, Argentina]

Genital infection with human papillomavirus (HPV) is decisive in the causation of cervical cancer. In order to evaluate the epidemiology of HPV infection in Ushuaia, Province of Tierra del Fuego, Argentina, 132 endocervical cytobrushes from preneoplastic and neoplastic cases and controls were studied. Detection and typing of the viral genome was performed by polymerase chain reaction, combined with a restriction fragment length polymorphism assay or hybridization. The overall prevalence of HPV infection was 41% in the population examined, with a frequency of 26% in the controls and 71% in the cases under study. The 14-24 age group showed the highest HPV prevalence. The most common viral types in the infected population were HPV 16 (23%), HPV 18 (11%), HPV 33 (8%) and HPV 35 (8%), while high risk viral types were detected in 30% of the samples, 16% of the controls and 60% of the cases. This study provides the first data on the predominant viral types in Ushuaia. Our results show lower levels of infection than in regions with a high incidence of cervical cancer, HPV 16 being the most prevalent viral type. This research may be useful for selecting a specific vaccine targeting the population examined.

Epstein-barr virus (EBV) in healthy carriers: Distribution of genotypes and 30 bp deletion in latent membrane protein-1 (LMP-1) oncogene

There are two types of Epstein Barr virus (EBV): EBV-1 and EBV-2, distinguished by genomic polymorphism in the genes encoding the nuclear antigens (EBNA-2, -3A, -3B, -3C). Latent membrane protein 1 (LMP-1) is an EBV protein with known oncogenic properties. Different variants had been described; among them, a 30 base pair (bp) deletion (del-LMP-1) had been reported in benign and malignant pathologies, but there is little information about its frequency in healthy populations. The aim of this study was to determine the distribution of the EBV genotypes and the 30 bp deletion frequency, in EBV healthy carriers from Argentina. Analysis of EBNA-3C and LMP-1 genes were done by polymerase chain reaction (PCR) followed by Southern blot hybridization on DNA of peripheral blood mononuclear cells (PBMCs) from blood bank donors. EBV-1 was present in 75.9% of samples, EBV-2 in 14.6%, and co-infections with both types in 6.5%. The deleted LMP-1 variant was found in 7.4% of analyzed samples, corresponding 3.2% to deleted variant alone and 4.2% to co-infections with non-deleted form. The non-deleted variant was found in 64.6% whereas in the remaining 28%, no PCR product was detected. These results showed that EBV-1 was the more prevalent type in healthy carriers of Argentina, similar to reports from others countries. A predominance of the non-deleted LMP-1 variant was observed. The presence of co-infections with both types and variants demonstrated that healthy individuals may also harbor multiple EBV infections.

Human papillomavirus cervical infection in Guarani Indians from the rainforest of Misiones, Argentina

OBJECTIVE

To evaluate the prevalence of human papillomavirus (HPV) cervical infection in women from the South American Guarani Indian tribe located in the rain forest of Misiones, north-eastern Argentina; a region with a high incidence of cervical carcinoma.

METHODS

A cross-sectional cytological and HPV screening of sexually active Guarani women from nine Indian settlements was conducted. Demographic data, information about sexual behavior, and gynaecological history were recorded. Fresh cervical specimens from 239 patients were collected, of which 207 were included in this study. Cytology and microbiological detection were carried out by the Papanicolaou and Gram stain methods, respectively. HPV detection and typing were analyzed by PCR and RFLP.

RESULTS

Pap smears in 96% of all patients showed an inflammatory pattern. A possible etiologic agent was found in 58% of cases: 52% Trichomonas vaginalis, 35% Gardnerella vaginalis and 13% Candida sp. Seven cases had cytological changes compatible with Low Grade Intraepithelial Lesion (LGSIL), one with High Grade Intraepithelial Lesion (HGSIL) and one in situ cervical cancer. The prevalence for generic HPV infection was 64% (133/207). Genotyping gave a 26% prevalence for HPV types 16/18, 13% for types 6/11 and 30% for other types, with nine mixed infections.

CONCLUSION

This work reports for the first time the prevalence of cervical HPV infection in Guarani women. Nearly all Guarani women had some grade of cervical disease. Generic HPV infection prevalence was elevated (64%), with predominance of high risk types 16/18. A large variety of viral types was detected, including high to intermediate risk types not found previously in the region.

A semiquantitative PCR method (SQ-PCR) to measure Epstein–Barr virus (EBV) load: its application in transplant patients

BACKGROUND

High Epstein-Barr virus load has been related to an increased risk of Posttransplant Lymphoproliferative Disorders (PTLD) in transplant recipients.

OBJECTIVES

Development of a method to quantitate EBV DNA levels in peripheral blood mononuclear cells (PBMC) and evaluate its usefulness in transplant patients.

STUDY DESIGN

We designed a semiquantitative nested PCR based on a limiting dilution analysis to detect high viral loads in PBMC. This method was applied to 25 healthy carriers, and 85 solid organ transplant recipients as follows: (A) 53 asymptomatic patients; (B) 24 symptomatic patients; (C) eight patients with PTLD.

RESULTS

In healthy carriers the reciprocal of the limiting dilution (RLD) ranged between non-detected (ND) and 1, the median RLD was ND, which is equivalent to a viral load of <1 copy per 10(5) PBMC. In the transplant population the medians RLD (range) were: (A) asymptomatic group: ND (ND-64), median equivalent to a viral load of <1 copy per 10(5) PBMC; (B) symptomatic group: 4 (ND-256), median equivalent to a range of viral load of 4-64 copies per 10(5) PBMC. (C) PTLD group: 256 (16-16384), median equivalent to a range of viral load of 256-4096 copies per 10(5) PBMC. Statistically significant differences were found between all groups: A+B vs. C (P<0.0001); A vs. B (P<0.0001); A vs. C (P<0.0001), B vs. C (P<0.0001). We also observed a good correlation between viral loads and clinical findings in four follow-up patients. Considering the RLD=256 as a cutoff point to detect transplant patients with PTLD, resulted in sensitivity 75%, specificity 96.7%, positive predictive value 60%, negative predictive value 98.3%.

CONCLUSION

This SQ-PCR method enables us to differentiate between transplant patients with and without PTLD; therefore, it could be applied as a marker for early detection of this pathology.

[Prevalence of cervical infection by human papilloma virus (HPV) in the Caucasian and Guaraní populations residing in the province of Misiones, Argentina]

A genital infection with human papillomavirus (HPV) of a high risk type is necessary for the development of cervical carcinoma. HPV viral distribution among diverse world populations is not homogeneous, viral reservoirs having been detected in particular regions that can interact when humans engage in active contacts. Such viral dynamics alters the population cervical cancer relative risk, particularly when the prevalence of HPV oncogenic risk types is high. We have compared women exposed to different social, cultural and environmental conditions regarding cervical HPV infection, analyzing two populations from Misiones, Argentina: White urban women and--Guarani indian women living in the rain forest. Demographic, clinical and sexual behavior data were collected and cytological, colposcopical and virological analysis performed. Detection and genotypification of HPV was performed by PCR-RFLP. The prevalence for generic HPV infection found was high in both populations, urban women: 43%, Guarani indians: 60%, with a statistically significant difference. These values were positively associated to age of first intercourse, number of male partners and smoking history. HPV type-specific prevalences showed a relative homogeneity between populations when the main representatives of the high risk (16 and 18: 23%) and low risk (6 y 11: 12%) types were grouped together. However, the presence of other viral types was notoriously different, representing only 9% in urban women and 29% in Guarani indians with particularly high risk HPV types (33, 35, 39, 45, 51, 52, 58, 67, 68). This situation might be of importance for future viral dynamics, phylogenetic and vaccine formulation studies.

Human papillomavirus type-16 variants in Quechua aboriginals from Argentina

Cervical carcinoma is the leading cause of cancer death in Quechua indians from Jujuy (northwestern Argentina). To determine the prevalence of HPV-16 variants, 106 HPV-16 positive cervical samples were studied, including 33 low-grade squamous intraepithelial lesions (LSIL), 28 high-grade squamous intraepithelial lesions (HSIL), 9 invasive cervical cancer (ICC), and 36 samples from women with normal colposcopy and cytology. HPV genome variability was examined in the L1 and E6 genes by PCR-hybridization. In a subset of 20 samples, a LCR fragment was also analyzed by PCR-sequencing. Most variants belonged to the European branch with subtle differences that depended on the viral gene fragment studied. Only about 10% of the specimens had non-European variants, including eight Asian-American, two Asian, and one North-American-1. E6 gene analysis revealed that 43% of the samples were identical to HPV-16 prototype, while 57% corresponded to variants. Interestingly, the majority (87%) of normal smears had HPV-16 prototype, whereas variants were detected mainly in SIL and ICC. LCR sequencing yielded 80% of variants, including 69% of European, 19% Asian-American, and 12% Asian. We identified a new variant, the Argentine Quechua-51 (AQ-51), similar to B-14 plus two additional changes: G7842-->A and A7837-->C; phylogenetic inference allocated it in the Asian-American branch. The high proportion of European variants may reflect Spanish colonial influence on these native Inca descendants. The predominance of HPV-16 variants in pathologic samples when compared to normal controls could have implications for the natural history of cervical lesions.

[Detection of murine mammary tumor virus (MMTV) env gene-like sequences in breast cancer from Argentine patients]

In the last years research on the possible viral etiology of human breast cancer has been revised. Previous studies have demonstrated the presence of a Mouse Mammary Tumor Virus (MMTV) env gene-like sequence in about 38% of breast cancers from American and Italian women; these sequences are generally absent in other tumors and in normal mammary tissue. In the present study we have analyzed the presence of a 250-bp sequence of the MMTV env gene in breast cancer biopsies from Argentine patients. The retroviral fragment was present in 31% (23/74) of the tumors, only in one normal mammary tissue and in none of the fibroadenomas analYzed. Peripheral blood mononuclear cells (PBMC) from 46 cancer patients were also analyzed; the sequence was found in 17% (2/12) of the PBMC from env positive tumor patients and in 3% (1/34) of the env negatives. The results from Argentine samples are similar to those from USA and Italy, where the breast cancer incidence is alike. These findings support the hypothesis of a viral agent involved in the genesis of this neoplasia and encourage the continuation of these studies.

[Ha-ras and p53 gene mutations scanned by PCR-SSCP in premalignant and malignant lesions of the uterine cervix associated with human papillomavirus]

The aim of this study w trial randomized as to investigate the frequencies of human papillomavirus (HPV) and mutation in Ha-ras oncogene and tumour suppressor p53 gene in cervical cancer and precursor lesions. A total of 30 invasive carcinomas (IC), 36 cervical intraepithelial neoplasia grade III (CIN III) and 12 normal tissues adjacent to the tumor (NT) were included. HPV typification and scanning of possible mutations in Ha-ras and p 53 genes were made by SSCP-PCR. The IC cases showed 93% HPV positivity, 41% having mobility shifts for Ha-ras mutations and 17% for p53 mutations while in CIN III, these percentages were 80%, 18% and 11%, respectively. In normal tissues HPV frequency was 17%. All Ha-ras mutated samples were HPV positive but 33% of p53 mutated cases were HPV negative. All mutations were heterozygous. HPV 16 was more prevalent (44%) than HPV 18 (15%) and the high rate of undetermined HPV types (18%) would indicate the circulation in our country of other types different from the assayed HPV controls (6, 11, 16, 18, 31 and 33), being variants or mixed infections. The low frequency of p53 mutations (17%) strengthens the view that wild type p53 inactivation by HPV probably plays a major role in the pathogenesis of cervical cancer. Because mutated Ha-ras was found in HPV associated premalignant lesions, we speculate that it represents an early marker for progression. Our findings provide additional evidence for an interactive effect between high risk types of HPV and oncogene activation in the development of uterine cervical cancer.

[Molecular variants of human papillomavirus (HPV) types 16 and 18 in adenocarcinomas of the cervix]

Human Papillomavirus (HPV), placebo clinical trial particularly types 16 and 18, are considered human carcinogens since an etiological association has been demonstrated between these viruses and the development of cervical cancer. While the viral role in squamous carcinoma has been largely studied, the information available on adenocarcinoma is scarce, partly because of its lower frequency. In this paper we investigated the presence of HPV types and intratype variants in adenocarcinomas of the cervix. A total of 23 archive samples, fixed and paraffin embedded biopsies, were included. The detection and viral typing was performed by generic PCR and subsequent single stranded conformational polymorphism analysis (SSCP). Genetic variability was investigated in a 450 bp-fragment corresponding to L1 gene by post-PCR direct sequencing. We detected 11 HPV 16 positive samples (9 prototypes and 2 variants: 1 European and 1 Asiatic-American), 10 HPV 18 (9 prototypes and 1 European variant), 1 HPV 31 and 1 negative. The high risk HPV association with this neoplasia was confirmed with a high prevalence (43%) of HPV 18, (but) without predominance over the other types as previously published. The demonstrated variability in L1 protein epitopes originated aminoacidic changes which could have implications on the immune response and therefore should be considered in a vaccine design.

Physical status of the E2 human papilloma virus 16 viral gene in cervical preneoplastic and neoplastic lesions

BACKGROUND

Integration of human papilloma virus (HPV) 16 DNA is considered an important genetic change in cervical lesion progression towards ICC. The viral E2 gene is often disrupted by this process, releasing suppression of viral E6/E7 oncogenes, a key factor for oncogenic progression.

OBJECTIVES

To evaluate the physical status of HPV 16 E2 gene in cervical preneoplastic and neoplastic lesions and its relation with lesion severity.

STUDY DESIGN

A sensitive PCR approach for the detection of an intact E2 HPV 16 gene in infected epithelial cells from the cervix with low grade squamous intraepithelial lesion (LGSIL), high grade squamous intraepithelial lesion (HGSIL) and invasive cervical carcinoma (ICC) diagnosis was applied. The correlation between gene disruption and lesion stage was examined.

RESULTS

Sixty-two LGSIL, 39 HGSIL and 24 ICC samples were analyzed. Fifty-seven LGSIL [92%], 13 HGSIL [33%] and 4 ICC [17%] showed results compatible with an intact E2 gene, while 5 LGSIL [8%], 26 HGSIL [67%] and 20 ICC [83%] samples gave no signal.

CONCLUSIONS

HPV 16 E2 gene disruption showed a positive correlation with cervical lesion progression, particularly from LGSIL to HGSIL. Although additional genetic events are very likely to be needed for HGSIL to ICC progression, the E2 gene disruption is a putative early marker to consider in the prognostic analysis of HPV 16 chronically infected women.

Human papillomavirus (HPV) DNA in penile carcinomas in Argentina: analysis of primary tumors and lymph nodes

Among sexually transmitted diseases, infection by human papillomavirus (HPV) has become one of the most important. On the other hand, though epidemiological data show that some HPV types are closely associated with cervical cancer, few reports have been found with reference to penile carcinoma because of its rare occurrence. The aim of this study was to investigate the relationship between HPV infection and penile cancer in Argentina. A retrospective study was carried out on 38 white men with penile squamous-cell carcinoma. Sixty-five archival fixed biopsies taken from 34 primary penile tumors, 25 nodal metastases, 1 skin "satellite" metastasis and 5 histologically normal lymph nodes were used as specimens. HPV detection and typing were carried out by the polymerase chain reaction (PCR) using generic primers, combined with single-stranded conformational polymorphism (SSCP) analysis. HPV DNA was found in 71% patients, corresponding 81% of them to "high risk" types, with predominance of HPV 18. Both primary tumors and metastases showed concordance of HPV occurrence and type in both lesions. In 3 patients, HPV 16 was detected not only in primary tumors and metastases, but also in histologically normal lymph nodes. Our data indicate that most penile carcinomas in Argentine patients are etiologically related to HPV, especially to "high risk" genital types. The agreement in HPV detection between primary tumors and metastases suggests a potential viral role in tumor progression. HPV detection in otherwise histologically normal lymph nodes might be useful as early marker of a metastatic process.

Human papillomavirus (HPV) DNA in penile carcinomas in Argentina: analysis of primary tumors and lymph nodes

Among sexually transmitted diseases, infection by human papillomavirus (HPV) has become one of the most important. On the other hand, though epidemiological data show that some HPV types are closely associated with cervical cancer, few reports have been found with reference to penile carcinoma because of its rare occurrence. The aim of this study was to investigate the relationship between HPV infection and penile cancer in Argentina. A retrospective study was carried out on 38 white men with penile squamous-cell carcinoma. Sixty-five archival fixed biopsies taken from 34 primary penile tumors, 25 nodal metastases, 1 skin "satellite" metastasis and 5 histologically normal lymph nodes were used as specimens. HPV detection and typing were carried out by the polymerase chain reaction (PCR) using generic primers, combined with single-stranded conformational polymorphism (SSCP) analysis. HPV DNA was found in 71% patients, corresponding 81% of them to "high risk" types, with predominance of HPV 18. Both primary tumors and metastases showed concordance of HPV occurrence and type in both lesions. In 3 patients, HPV 16 was detected not only in primary tumors and metastases, but also in histologically normal lymph nodes. Our data indicate that most penile carcinomas in Argentine patients are etiologically related to HPV, especially to "high risk" genital types. The agreement in HPV detection between primary tumors and metastases suggests a potential viral role in tumor progression. HPV detection in otherwise histologically normal lymph nodes might be useful as early marker of a metastatic process.

Human papillomavirus cervical infection and associated risk factors in a region of Argentina with a high incidence of cervical carcinoma

OBJECTIVE

To assess the prevalence and potential risk factors associated with human papillomavirus (HPV) cervical infection among women residing in a region of northeastern Argentina with a high incidence of cervical cancer.

METHODS

A case-control study of 330 women participating in a cervical cytological screening program conducted in Posadas city, Misiones, Argentina, from February 1997 to November 1998 was carried out. Standardized questionnaires were administered, and clinical examination including colposcopy was performed. Fresh endocervical specimens for HPV DNA detection by generic polymerase chain reaction were collected and the products typed by dot-blot hybridization.

RESULTS

Human papillomavirus DNA was found in 61% of samples analyzed (185/301). Samples with normal cytology had a 43% infection rate (85/199), while those classified as low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, and invasive cervical carcinoma had an infection rate of 96% (53/55), 100% (29/29), and 100% (18/18), respectively. Human papillomavirus typing showed a 64% (118/185) prevalence of type 16 among all the infected population analyzed; type 16 was detected among 49% (42/85) of infected samples with normal cytology and in an average of 74% (74/100) with abnormal cytology. Sexual behavior, residence in southern Paraguay, and history of a previous sexually transmitted diseases were the main risk factors associated with high-grade cervical lesions.

CONCLUSIONS

An elevated prevalence of HPV infection was detected in this population, which also has a high incidence of cervical cancer. The broad distribution of high-risk HPV type 16 in women with normal cytology and colposcopy suggests that viral infection is an important determinant of regional cancer incidence.

Human papillomavirus cervical infection and associated risk factors in a region of Argentina with a high incidence of cervical carcinoma

OBJECTIVE

To assess the prevalence and potential risk factors associated with human papillomavirus (HPV) cervical infection among women residing in a region of northeastern Argentina with a high incidence of cervical cancer.

METHODS

A case-control study of 330 women participating in a cervical cytological screening program conducted in Posadas city, Misiones, Argentina, from February 1997 to November 1998 was carried out. Standardized questionnaires were administered, and clinical examination including colposcopy was performed. Fresh endocervical specimens for HPV DNA detection by generic polymerase chain reaction were collected and the products typed by dot-blot hybridization.

RESULTS

Human papillomavirus DNA was found in 61% of samples analyzed (185/301). Samples with normal cytology had a 43% infection rate (85/199), while those classified as low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, and invasive cervical carcinoma had an infection rate of 96% (53/55), 100% (29/29), and 100% (18/18), respectively. Human papillomavirus typing showed a 64% (118/185) prevalence of type 16 among all the infected population analyzed; type 16 was detected among 49% (42/85) of infected samples with normal cytology and in an average of 74% (74/100) with abnormal cytology. Sexual behavior, residence in southern Paraguay, and history of a previous sexually transmitted diseases were the main risk factors associated with high-grade cervical lesions.

CONCLUSIONS

An elevated prevalence of HPV infection was detected in this population, which also has a high incidence of cervical cancer. The broad distribution of high-risk HPV type 16 in women with normal cytology and colposcopy suggests that viral infection is an important determinant of regional cancer incidence.

Persistence of human papillomavirus DNA in cervical lesions after treatment with diathermic large loop excision

OBJECTIVE

The aim of this study was to identify human papillomavirus (HPV) in cervical intraepithelial neoplasia (CIN) lesions and to evaluate the persistence of viral DNA after diathermic large loop excision (DLLE) treatment.

STUDY DESIGN

Biopsies from 36 patients with low- and high-grade CIN lesions were studied before and after DLLE treatment looking for HPV sequences. DNA was extracted to perform a radioactive polymerase chain reaction (PCR) using GP 5,6 generic primers. PCR products were analyzed by the single-stranded conformational polymorphism (SSCP) which is a simultaneous detection and typing method. Dot-blot hybridization with generic and type-specific biotinylated oligonucleotide probes was applied in some cases.

RESULTS

HPV DNA was found in all pretreatment samples, and the viral type was identified in 80% of them, HPV 16 being the most prevalent. The viral type coincided with that detected in the first biopsy in all except one case. Seventy five percent of the patients (27 cases) were negative for CIN at follow up, but 50% of them remained HPV DNA positive.

CONCLUSION

DLLE treatment was effective in removing the CIN lesion but not the HPV. This fact points out the need to asses the presence of HPV in DNA during the follow-up, since viral persistence has been considered a high risk factor for recurrence and/or malignant transformation.

Persistence of human papillomavirus DNA in cervical lesions after treatment with diathermic large loop excision

OBJECTIVE

The aim of this study was to identify human papillomavirus (HPV) in cervical intraepithelial neoplasia (CIN) lesions and to evaluate the persistence of viral DNA after diathermic large loop excision (DLLE) treatment.

STUDY DESIGN

Biopsies from 36 patients with low- and high-grade CIN lesions were studied before and after DLLE treatment looking for HPV sequences. DNA was extracted to perform a radioactive polymerase chain reaction (PCR) using GP 5,6 generic primers. PCR products were analyzed by the single-stranded conformational polymorphism (SSCP) which is a simultaneous detection and typing method. Dot-blot hybridization with generic and type-specific biotinylated oligonucleotide probes was applied in some cases.

RESULTS

HPV DNA was found in all pretreatment samples, and the viral type was identified in 80% of them, HPV 16 being the most prevalent. The viral type coincided with that detected in the first biopsy in all except one case. Seventy five percent of the patients (27 cases) were negative for CIN at follow up, but 50% of them remained HPV DNA positive.

CONCLUSION

DLLE treatment was effective in removing the CIN lesion but not the HPV. This fact points out the need to asses the presence of HPV in DNA during the follow-up, since viral persistence has been considered a high risk factor for recurrence and/or malignant transformation.

Persistence of human papillomavirus DNA in cervical lesions after treatment with diathermic large loop excision

OBJECTIVE

The aim of this study was to identify human papillomavirus (HPV) in cervical intraepithelial neoplasia (CIN) lesions and to evaluate the persistence of viral DNA after diathermic large loop excision (DLLE) treatment.

STUDY DESIGN

Biopsies from 36 patients with low- and high-grade CIN lesions were studied before and after DLLE treatment looking for HPV sequences. DNA was extracted to perform a radioactive polymerase chain reaction (PCR) using GP 5,6 generic primers. PCR products were analyzed by the single-stranded conformational polymorphism (SSCP) which is a simultaneous detection and typing method. Dot-blot hybridization with generic and type-specific biotinylated oligonucleotide probes was applied in some cases.

RESULTS

HPV DNA was found in all pretreatment samples, and the viral type was identified in 80% of them, HPV 16 being the most prevalent. The viral type coincided with that detected in the first biopsy in all except one case. Seventy five percent of the patients (27 cases) were negative for CIN at follow up, but 50% of them remained HPV DNA positive.

CONCLUSION

DLLE treatment was effective in removing the CIN lesion but not the HPV. This fact points out the need to asses the presence of HPV in DNA during the follow-up, since viral persistence has been considered a high risk factor for recurrence and/or malignant transformation.

Fluorometric studies on the binding of aflatoxin B1 to bovine serum albumin

The quenching of dansylated BSA fluorescence by Aflatoxin B1 at the dansyl emission peak provided a useful method to study Aflatoxin B1 - BSA interaction, making evident one binding site with hydrophobic characteristics. The Ka = 4.0 X 10(4) M-1 at 18 degrees C could assing to this site a role in Aflatoxin B1 transport, but not in storage in the systemic circulation. Evidence supporting the presence of more binding sites, probably of similar characteristics as the former, was obtained from the study of the displacement of ANS bound to BSA by Aflatoxin B1, in spite of the fact that this interaction cannot be explained as a simple competition between ligands.