Comparison of immediate colposcopy, repeat conventional cytology and hrHPV testing for the clinical management of ASC-US cytology in routine health services of Medellin, Colombia: The ASCUS-COL Trial

In the context of opportunistic cervical cancer screening settings of low-and-middle-income countries, little is known about the benefits of high-risk human papillomavirus (hrHPV) testing on high-grade cervical abnormality detection among women with atypical squamous cells of undetermined significance (ASC-US) cytology in routine clinical practice. We compared the effectiveness of immediate colposcopy (IC), conventional cytology at 6 and 12 months (colposcopy if ≥ASC-US) (RC), and hrHPV testing (colposcopy if hrHPV-positive) (HPV) to detect cervical intraepithelial neoplasia grade 2 or more severe diagnoses (CIN2+) among women aged 20-69 years with ASC-US in routine care. Participants (n=2,661) were evenly randomized into three arms (n=882 IC, n=890 RC, n=889 HPV) to receive services by routine healthcare providers and invited to an exit visit 24 months after recruitment. Histopathology was blindly reviewed by a quality-control external panel (QC). The primary endpoint was the first QC-diagnosed CIN2+ or CIN3+ detected during three periods: enrolment (≤6 months for IC and HPV, ≤12 months for RC), follow-up (between enrolment and exit visit), and exit visit. The trial is completed. Colposcopy was done on 88%, 42%, and 52% of participants in IC, RC, and HPV. Overall, 212 CIN2+ and 52 CIN3+ cases were diagnosed. No differences were observed for CIN2+ detection (p=0.821). However, compared to IC, only HPV significantly reduced CIN3+ cases that providers were unable to detect during the 2-year routine follow-up (relative proportion 0.35, 95% CI 0.09-0.87). In this context, hrHPV testing was the most effective and efficient management strategy for women with ASC-US cytology.

Abstract 267: microRNA expression analysis in hrHPV positive FFPE tissues for the detection of cervical disease

Cervical cancer ranks first in cancer mortality among women of low-middle income countries where 80% of the 570,000 cases and 311,000 worldwide deaths estimated for 2018 occurred. Persistent infections with high-risk HPV (hrHPV) genotypes can lead to cervical high-grade lesions (Cervical Intraepithelial Neoplasia grade 2 or more severe disease, CIN-II+), that if left untreated progress to cancer. hrHPV test has high sensitivity but because many women infected with hrHPV genotypes will clear the infection spontaneously, it has low specificity to detect CIN-II+. MicroRNAs (miRNAs) are small RNAs that regulate gene expression and show differential profiles in cervical intraepithelial lesions. Our aim was to identify miRNAs differentially expressed in CIN-II+ and to evaluate their potential use as biomarkers to distinguish low from high-grade lesions in hrHPV positive women. Methods We compared the miRNAs expression pattern between Formalin-Fixed Paraffin-Embedded (FFPE) tissues from hrHPV positive women with low-grade lesions (n=10) and women with high-grade lesions (n=10) of Medellin, Colombia, using the QIAseq miRNA Library Kit (Qiagen) and sequencing reagents and protocols from Illumina. The miRNAs with low coefficient of variation and high fold change were further validated by RT-PCR (miR-133a-3p, 143-3p, 143-5p, 29a-3p and 30b-5p) using miRCURY LNA miRNA PCR kit (Qiagen) and SNORD44 as housekeeping gene. Receiver Operating Characteristic (ROC) analyses with 95% confidence interval of the area under the curve were used to evaluate the diagnostic accuracy of the 5 miRNA and their combinations and the maxim Youden index to determine the optimal specificity and sensitivity. Results The differential miRNAs expression analysis identified 25 miRNAs overexpressed in high- versus low-grade lesions. The relative expression by RT-PCR of 5 of those miRNAs was higher in high-grade when compared to low-grade, and the levels of miR-143-3p, 143-5p and 30b-5p increased with disease progression (from healthy, CIN-I, CIN-II, CIN-III+). ROC analyses showed that miR-143-5p and the combination with miR-133a-3p exhibits the highest AUC 79% (95% CI: 65-93). However, the highest sensitivity is given by miR-29a-3p, 87.50% (95% CI: 67.64 - 97.34), and the highest specificity is given by miR-30b-5p, 95.45% (95% CI: 77.16-99-88), with cut-offs of >1,157 and >3,345 respectively. In conclusion, we identified 25 candidate miRNAs biomarkers and validated 5 of them with good diagnostic performance to distinguish high-grade from low-grade cervical lesions. Further validation on a larger cohort of samples is needed to confirm the potential role of these microRNAs to triage HPV positive women.

Citation Format: Martha I. Gonzalez, Jone Garai, Jovanny Zabaleta, Gloria I. Sanchez. microRNA expression analysis in hrHPV positive FFPE tissues for the detection of cervical disease [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 267.

Psychosocial impact of inclusion of HPV test on the management of women with atypical squamous cells of undetermined significance: a study within a randomised pragmatic trial in a middle-income country

Objective: To assess the psychosocial impact of human papillomavirus (HPV) testing, colposcopy, and Pap-smear, as triage strategies after a Pap-smear with atypical squamous cells of undetermined significance (ASCUS). We also sought to evaluate the psychosocial impact based on the results of the strategies. Methods: Nested within a randomised pragmatic trial, which compared an immediate colposcopy, repeat Pap-smear, and high risk HPV test, we enrolled 675 women between 2012 and 2014. Participants completed surveys at enrollment, two weeks after triage test results, and 1 year thereafter to assess cervical cancer and HPV knowledge, self-esteem, anxiety and HPV impact (HIP). Results: Knowledge, self-esteem, anxiety and HIP improved with no differences among arms. At the baseline, 31.4% and 32.7% of the participants had state anxiety and trait anxiety, respectively, which decreased to 10.7% and 13.3% in the last survey. Compared to HPV-negative women, HPV-positive women in the second survey had worse HIP scores (HPV-: M 22.9 [SD: 15.20]; HPV+: M 35.9 [SD: 19.91]; p < 0.001), trait anxiety (HPV-: M 15.4 [SD 12.73]; HPV+: M 22.9 [SD 13.29]; p = 0.001), and state anxiety (HPV-: M 10.7 [SD 11.25]; HPV+: M 21.4 [SD 14.81]; p < 0.001). Conclusions: HPV testing as a triage strategy for women with ASCUS does not differ from colposcopies or Pap-smears in terms of psychosocial outcomes.

Factors related to inter-observer reproducibility of conventional Pap smear cytology: a multilevel analysis of smear and laboratory characteristics

OBJECTIVE

To identify factors that influence the inter-observer reproducibility of the routine, conventional Pap smear cytology (Pap smear test) in a network of certificated laboratories in a middle-income Latin American country.

METHODS

Twenty-six laboratories provided each an average of 26 negative for malignancy (NILM) and high-grade squamous intraepithelial lesion (HSIL) Pap smears. An external panel reviewed the slides. The kappa index and multilevel logistic regression were used to estimate the reproducibility and odds ratios (OR) of a false result with 95% confidence intervals (95% CI), respectively. Results are presented for laboratories that collect (collector laboratories) and do not collect (non-collector laboratories) samples.

RESULTS

The agreements ranged widely (median kappa 0.51, range 0.16-0.70). The overall false-positive (FP) and false-negative (FN) rates were 31% (95% CI 27-35) and 11% (95% CI 7-17). Among collector laboratories (N = 14), a bigger sample collection volume decreased the probability of a FP (OR-adjusted 0.05, 95% CI 0.02-0.1) whereas the number of quality defects (OR-adjusted 1.67, 95% CI 1.25-2.24), high workload (OR-adjusted 5.52, 95% CI 3.85-7.92) and collection by cytotechnologists (OR-adjusted 1.28, 95% CI 1.15-1.42) or health professionals (OR-adjusted 2.26, 95% CI 2.04-2.49) instead of nursing assistants increased it. Among non-collector laboratories (N = 9), the FP rate increased with the number of quality defects (OR-adjusted 1.86, 95% CI 1.06-3.26) but decreased if the samples were collected by health professionals instead of nursing assistants (OR-adjusted 0.37, 95%CI 0.17-0.80). No significant associations were observed for FN.

CONCLUSIONS

Staff in charge of cervical sampling significantly determined the reproducibility of the Pap smear test, but this depended on whether the laboratory collects samples or read samples collected elsewhere.

Unexpected inverse correlation between Native American ancestry and Asian American variants of HPV16 in admixed Colombian cervical cancer cases

BACKGROUND

European (E) variants of HPV 16 are evenly distributed among world regions, meanwhile Non-European variants such as European-Asian (EAs), Asian American (AA) and African (Af) are mostly confined to Eastern Asia, The Americas and African regions respectively. Several studies have shown that genetic variation of HPV 16 is associated with the risk of cervical cancer, which also seems to be dependent on the population. This relationship between ethnicity and variants have led to the suggestion that there is co-evolution of variants with humankind. Our aim was to evaluate the relationship between the individual ancestry proportion and infection with HPV 16 variants in cervical cancer.

METHODS

We examined the association between ancestry and HPV 16 variants in samples of 82 cervical cancer cases from different regions of Colombia. Individual ancestry proportions (European, African and Native American) were estimated by genotyping 106 ancestry informative markers. Variants were identified by PCR amplification of the E6 gene, followed by reverse line blot hybridization (RLB) with variants specific probes.

RESULTS

Overall European (E) and Asian American (AA) variants frequency was 66.5% and 33.5% respectively. Similar distribution was observed in cases with higher proportions of European or African ancestry. A higher Native American ancestry was significantly associated with higher frequency of E variants (median ancestry>23.6%, Age and place of birth adjusted OR: 3.55, 95% CI: 1.26-10.03, p=0.01). Even further, an inverse geographic correlation between Native American ancestry and frequency of infections with AA variants was observed (ρ=-0.825, p=0.008). Regions with higher proportion of Native American ancestry had a lower frequency of AA variants of HPV 16.

CONCLUSIONS

This study suggests replacement of AA variants by E variants of human papillomavirus 16 in cervical cancer cases with high Native American ancestry.

Immunosuppression in cervical cancer with special reference to arginase activity

INTRODUCTION

Cervical cancer is characterized by an immunosuppressive microenvironment and a Th2-type cytokine profile. Expression of arginase (ASE), the enzyme that converts L-arginine into L-ornithine and urea, is stimulated by Th2-type cytokines.

OBJECTIVE

To assess the association of ASE activity and L-Arg metabolism products with cervical cancer.

METHODS

Sera of 87 and 41 women with histologically confirmed by colposcopy-directed biopsy SCC and CIN3 respectively and 79 with normal cytology or Low-Grade Squamous Intraepithelial Lesion (LSIL), were evaluated. Cytokines were measured using Milliplex Human cytokine/chemokine kit. Arginase (ASE) activity was determined using an enzymatic assay. Levels of L-arginine, L-ornithine, putrescine and spermine were determined by HPLC.

RESULTS

Significantly higher levels of ASE activity were observed in women with CIN3 (age-adjusted OR: 24.3; 95%CI: 3.82-155) and SCC (AOR: 9.8; 95%CI: 2.34-40.8). As expected, possibly due to high levels of ASE activity, higher levels of l-Arg were negatively associated with CIN3 (AOR: 0.03; 95%CI: 0.004-0.19) and SSC (AOR: 0.06; 95%CI: 0.02-0.24). Consistent with the role of ASE in the conversion of L-arginine to L-ornithine and polyamine production therefrom, women with cervical cancer had higher levels of spermine and putrescine. A correlation analysis revealed a significant albeit weak relationship between high levels of IL-10 and high levels of ASE (Pearson r=0.32, p-value=0.003) in women with cervical cancer.

CONCLUSION

This study indicates that ASE activity and L-Arg degradation mechanisms of immunosuppression are present in cervical cancer. The results foster research in the design of possible strategies to inhibit ASE activity for therapy of cervical cancer.

Human papillomavirus types in cases of squamous cell carcinoma of head and neck in Colombia

Estimating the type-specific prevalence of human papillomavirus (HPV) in head and neck cancer (HNSCC) is helpful in predicting the impact of HPV immunization.

Objective

To estimate the overall prevalence, and gender and age-specific prevalence of HPV in HNSCC.

Method

This cross sectional retrospective study was carried out in four pathology laboratories of Medellin, Colombia. HPV testing was performed by GP5+/6+ PCR-based RLB and HPV 16 and 18 type-specific PCR.

Results

175 primary HNSCC cases consecutively diagnosed between 1999 and 2008 with confirmed diagnosis and amplifiable DNA were included. Overall HPV prevalence was 18.9%. HPV was found in 23.9%, 17.5% and 13.3% of the oral cavity, larynx and oropharynx cases respectively. Among HPV positive cases, 82% were HPV 16 and 18% were HPV 18. No other HPV genotypes were identified. Most patients were males. Male patients were younger that their female counterparts, particularly in oral cavity cancer cases.

Conclusion

HPV 16 and 18 genotypes were found in nearly 20% of HNSCC cases in Colombian patients. The impact of HPV vaccination for the prevention of HNSCC in this population deserves further evaluation.

Human papillomavirus genotype detection in recurrent respiratory papillomatosis (RRP) in Colombia

BACKGROUND

Knowledge on human papillomavirus (HPV) genotype distribution in recurrent respiratory papillomatosis (RRP) is essential to assess the impact of HPV vaccine. It is provided information for Colombia.

METHODS

In all, 189 RRP primary cases diagnosed between 1985 and 2009 were identified from 5 pathology laboratories of Cali and Medellin, Colombia. HPV DNA testing in 129 cases that fulfilled inclusion criteria (available paraffin blocks, amplifiable DNA, and confirmed histologic diagnosis of RRP) was performed by the SPF-10/LiPA25 assay (version 1).

RESULTS

Of all cases 36.1% were juvenile (<12 years old) and a majority of adults were males (p = .09); 95% of cases were HPV positive. HPV 6, 11, and 16 contributed to 69%, 27.1%, and 7.8% of all HPV positive cases. Twelve cases (9.3%) showed multiple infections; 8 of these were HPV 6 or 11 positive.

CONCLUSIONS

HPV prophylactic vaccine including HPV 6 and 11 may have a major impact against RRP.

Location and Density of Immune Cells in Precursor Lesions and Cervical Cancer

Only a small proportion of women infected with Human Papillomavirus (HPV) develop cervical cancer. Host immune response seems to play a role eliminating the viral infection and preventing progression to cancer. Characterization of tumor infiltrating lymphocytes (TILs) in cervical pre-neoplastic lesions and cervical cancer may be helpful to understand the mechanisms that mediate this protection. The aim of this study was to determine if there are differences in the localization and density (cells/mm(2)) of CD8+ T-cells, CD4+ T-cells and Tregs (CD25 + Foxp3+) in cervical pre-neoplastic lesions and cervical cancer. Immunohistochemical analysis of sections of 96 (26 CIN1, 21 CIN2, 25 CIN3, and 24 SCC) samples revealed that regardless of CIN grades, CD8+ T-cells are more abundant than CD4+, CD25+ and Foxp3+ cells in both the stroma and epithelium. There was a higher density of CD8+ cells in the stroma of cervical cancer compared to CIN3 (OR = 4.20, 95% CI 1.2-15), CIN2 (OR = 7.86, 95% CI 1.7-36.4) and CIN1 (OR = 4.25, 95% CI 1.1-17). Studies evaluating whether these cells are recruited before or after cancer progression will be helpful to understand the role of these cells in the natural history of HPV-induced lesions.

Higher micronutrient intake is associated with human papillomavirus-positive head and neck cancer: a case-only analysis

No studies have investigated dietary differences between head and neck squamous cell carcinoma (HNSCC) patients with human papillomavirus (HPV)-positive tumors and patients with HPV-negative tumors. This study was designed to investigate the relationship between diet and HPV status in HNSCC patients. Cases of HNSCC were recruited from 2 clinical centers participating in the University of Michigan Head and Neck Specialized Program of Research Excellence (SPORE). HPV tissue genotyping was performed, and epidemiological and dietary data collected. Multivariable logistic regression tested whether pretreatment consumption of 12 selected micronutrients was significantly associated with HPV-positive status in 143 patients newly diagnosed with cancer of the oral cavity or pharynx. After controlling for age, sex, body mass index, tumor site, cancer stage, problem drinking, smoking, and energy intake, significant and positive associations were observed between vitamin A, vitamin E, iron, β-carotene, and folate intake and HPV-positive status (P(trend) < 0.05), suggesting that diet may be a factor in the improved prognosis documented in those with HPV-positive HNSCC. Dietary differences by HPV status should be considered in prognostic studies to better understand the influence of diet on HNSCC survival.

Clinical evaluation of polymerase chain reaction reverse hybridization assay for detection and identification of human papillomavirus type 16 variants

BACKGROUND

Isolates of HPV16 comprise six variants: European (Eu), Asian (As), Asian-American (AA), North American (NA), African-1 (AF1), and African-2 (AF2) with different carcinogenic potentials. Highly reliable automatable techniques for HPV variant genotyping would be helpful to confirm the role of variants in cervical cancer in large epidemiological studies.

OBJECTIVE

To validate the performance of a novel assay for identification of HPV16 variants.

STUDY DESIGN

The test is a multiplex PCR amplifying four small fragments from the E6 open reading frame (ORF). Variants are identified in a reverse hybridization assay with variant specific probes. The novel assay was compared to sequence analysis of the E6 ORF in 68 clinical samples. In addition, HPV16 variant distribution was studied in 218 cervical samples from women with normal cytology, squamous cell carcinoma (SCC) and adenocarcinoma of countries in Africa, Asia and South-America.

RESULTS

There was 95.6% agreement between the test and sequencing. Analysis of the clinical panel including 218 positive samples revealed worldwide distribution patterns of HPV16 variants. Finally, a threefold increased risk for SCC with grouped Eu and As variants in South-American countries as compared to controls was found, although the association was not statistically significant.

CONCLUSIONS

The novel assay is a reliable and simple technique, distribution patterns of HPV16 variants in different world regions and disease associations could be established and it may be useful in further epidemiological studies investigating the role of HPV16 variants in cervical carcinogenesis.

Abstract A86: Higher micronutrient intake is associated with human papillomavirus-positive head and neck cancer: A case-only analysis

While tobacco and concurrent alcohol use account for the majority of head and neck squamous cell carcinomas (HNSCC), human papillomavirus (HPV)-16 contributes to a distinct subtype of the disease. HPV-positive HNSCC cases have better prognoses and typically occur in younger individuals with lower exposure to tobacco and alcohol and higher socioeconomic status (SES) when compared to those with more strongly tobacco-related, HPV-negative HNSCC. As dietary quality is associated with SES, patients with HPV-positive tumors also may have higher intake of micronutrients. This study was conducted to better understand the relationship between diet and HPV status among HNSCC patients. Subjects were recruited from two clinical centers participating in the University of Michigan Head and Neck Specialized Program of Research Excellence (SPORE). HPV genotyping was performed in DNA extracted from micro-dissected tissue and epidemiologic and dietary data collected. Multivariable logistic regression tested whether pretreatment consumption of 12 selected micronutrients was significantly associated with HPV status in 143 patients newly diagnosed with cancer of the oral cavity or pharynx. After controlling for age, sex, body mass index, tumor site, cancer stage, problem drinking, smoking and energy intake, a significant and positive association was observed between HPV-positive status and increasing quartiles of vitamin A, vitamin E, iron, β-carotene and folate intake (Ptrend&lt;0.05). Patients with HPV-positive cancers have higher intakes of selected micronutrients compared to patients with HPV-negative tumors, suggesting that diet may be a factor in the improved prognosis documented in those with HPV-positive HNSCC. Dietary differences by HPV status should be considered in prognostic studies to better understand the influence of diet on HNSCC survival.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A86.

Molecular epidemiology of human immunodeficiency virus-infected individuals in Medellin, Colombia

To study the molecular epidemiology of human immunodeficiency virus type 1 (HIV-1) strains in Medellín, Colombia, 115 HIV-1-positive individuals who were recruited from an HIV outpatient hospital (Universitario San Vicente de Paul) during the period from July 2001 to January 2002 were genotyped. All samples were analyzed by envelope heteroduplex mobility assay and found to be subtype B. Twenty-four samples were randomly selected for sequencing of the protease and the reverse transcriptase regions; all isolates were found to be subtype B. Phylogenetic analysis of seven nearly full-length genomes showed that all samples were subtype B. This study shows that the HIV epidemic in Colombia continues to be dominated by the subtype B virus. The predominance of subtype B genotypes of HIV-1 strains in Medellín resembles what is seen in the nearby countries of Peru, Ecuador, and Venezuela.

Worldwide genomic diversity of the high-risk human papillomavirus types 31, 35, 52, and 58, four close relatives of human papillomavirus type 16

Among the more than one hundred formally described human papillomavirus (HPV) types, 18 are referred to as high-risk HPV types due to their association with anogenital cancer. Despite pathogenic similarities, these types form three remotely related taxonomic groups. One of these groups is called HPV species 9 and is formed by HPV-16, the most common and best-studied type, together with HPV-31, -33, -35, -52, -58, and -67. Previous worldwide comparisons of HPV-16 samples showed about 2% nucleotide diversity between isolates, which were subsequently termed variants. The distribution of divergent variants has been found to correlate frequently with the geographic origin and the ethnicity of the infected patients and led to the concept of unique African, European, Asian, and Native American HPV-16 variants. In the current study, we address the question of whether geography and ethnicity also correlate with sequence variations found for HPV-31, -35, -52, and -58. This was done by sequencing the long control region in samples derived from Europe, Asia, and Africa, and from immigrant populations in North and South America. We observed maximal divergence between any two variants within each of these four HPV types ranging from 1.8 to 3.6% based on nucleotide exchanges and, occasionally, on insertions and deletions. Similar to the case with HPV-16, these mutations are not random but indicate a relationship between the variants in form of phylogenetic trees. An interesting example is presented by a 16-bp insert in select variants of HPV-35, which appears to have given rise to additional variants by nucleotide exchanges within the insert. All trees showed distinct phylogenetic topologies, ranging from dichotomic branching in the case of HPV-31 to star phylogenies of the other three types. No clear similarities between these types or between these types and HPV-16 exist. While variant branches in some types were specific for Europe, Africa, or East Asia, none of the four trees reflected human evolution and spread to the extent illustrated by HPV-16. One possible explanation is that the rare HPV types that we studied spread and thereby diversified more slowly than the more abundant HPV-16 and may have established much of today's variant diversity already before the worldwide spread of humans 100,000 years ago. Most variants had prototypic amino acid sequences within the E6 oncoprotein and a segment of the L1 capsid protein. Some had one, two, or three amino acid substitutions in these regions, which might indicate biological and pathogenic diversity between the variants of each HPV type.

Worldwide genomic diversity of the human papillomaviruses-53, 56, and 66, a group of high-risk HPVs unrelated to HPV-16 and HPV-18

Among more than 200 human papillomavirus (HPV) types presumed to exist, 18 "high-risk" HPV types are frequently found in anogenital cancer. The best studied types are HPV-16 and 18, which are only distantly related to one another and form two separate phylogenetic branches, each including six closely related types. HPV-30, 53, 56, and 66 form a third phylogenetic branch unrelated to HPV-16 and 18. Worldwide comparison of HPV-16 and 18 isolates revealed a distribution of variant genomes that correlated with the geographic origin and the ethnicity of the infected cohort and led to the concept of unique African, European, Asian, and Native American HPV-16 and 18 variants. Here, we address the question whether similar phylogenies are found for HPV-53, 56, and 66 by determining the sequence of the long control regions (LCR) of these HPVs in samples from Europe, Asia, and Africa, and from immigrant societies in North and South America. Phylogenetic trees calculated from point mutations and a few insertions/deletions affecting 2-4.2% of the nucleotide sequences were distinct for each of the three HPVs and divergent from HPV-16 and 18. In contrast to the "star-phylogenies" formed by HPV-16 and 18 variants, 44 HPV-53 isolates represented nine variants, which formed two deep dichotomic branches reminiscent of the beginning split into two new taxa, as recently observed for subtypes of HPV-44 and 68. A total of 66 HPV-56 isolates represented 17 variants, which formed three branches preferentially containing European, Asian, and African variants. Variants of a fourth branch, deeply separated from the other three, were characterized by a 25 bp insertion and created a dichotomy rather than star-like phylogeny. As it contained isolates from cohorts in all continents, it may have evolved before the spread of humans into all continents. 18 of 31 HPV-66 isolates represented the prototype clone, which was found in all parts of the world, while the remaining 13 clones formed 11 branches without any geographic association. Our findings confirm the notion of a quantitatively limited genomic diversity of each HPV type with some correlation to the geographic origin of the sample. In addition, we observed in some variants of these three HPV types mutations that affect the amino acid sequence of the E6 oncoproteins and the L1 capsid protein, supporting the possibility of immunogenic and oncogenic diversity between variants of any HPV type.

Prevalences, genotypes, and risk factors for HIV transmission in South America

HIV cross-sectional studies were conducted among high-risk populations in 9 countries of South America. Enzyme-linked immunosorbent assay screening and Western blot confirmatory testing were performed, and env heteroduplex mobility assay genotyping and DNA sequencing were performed on a subset of HIV-positive subjects. HIV prevalences were highest among men who have sex with men (MSM; 2.0%-27.8%) and were found to be associated with multiple partners, noninjection drug use (non-IDU), and sexually transmitted infections (STIs). By comparison, much lower prevalences were noted among female commercial sex workers (FCSWs; 0%-6.3%) and were associated mainly with a prior IDU and STI history. Env subtype B predominated among MSM throughout the region (more than 90% of strains), whereas env subtype F predominated among FCSWs in Argentina and male commercial sex workers in Uruguay (more than 50% of strains). A renewed effort in controlling STIs, especially among MSM groups, could significantly lessen the impact of the HIV epidemic in South America.

Clinical, histopathological and virological findings in patients with focal epithelial hyperplasia from Colombia

BACKGROUND

Focal epithelial hyperplasia (FEH) is a rare oral HPV-related disease, highly prevalent in certain ethnic communities. A previous study found 7.5% prevalence among school children from the Indian community Embera-Chami in Colombia.

OBJECTIVE

To determine the prevalence and Human Papillomavirus (HPVs)-type in children with FEH.

MATERIALS AND METHODS

One hundred and thirty-eight students were screened. All FEH samples were HPV-tested by two PCR-based systems.

RESULTS

We identified 18 FEH cases. beta-globin amplification was obtained in 15 cases and nine were HPV-55-positive by the HPV-PCR-hybridization method. Nine cases (50%) were HPV-13-positive by the GP5+/GP6+-based method. Twelve cases (80%) were HPV-positive by one or the other method. Forty-four percent and 88% of interviewed parents reported family histories of FEH and toothbrush sharing, respectively.

CONCLUSIONS

Human Papillomavirus-DNA was identified in the majority of FEH cases and HPV-13 was the only genotype involved. Frequent familiar infection suggests interfamiliar transmission, genetic predisposition or infection susceptibility among family members.

Immunogenicity and protective efficacy of a Plasmodium yoelii Hsp60 DNA vaccine in BALB/c mice

The gene encoding the 60-kDa heat shock protein of Plasmodium yoelii (PyHsp60) was cloned into the VR1012 and VR1020 mammalian expression vectors. Groups of 10 BALB/c mice were immunized intramuscularly at 0, 3, and 9 weeks with 100 microg of PyHsp60 DNA vaccine alone or in combination with 30 microg of pmurGMCSF. Sera from immunized mice but not from vector control groups recognized P. yoelii sporozoites, liver stages, and infected erythrocytes in an indirect fluorescent antibody test. Two weeks after the last immunization, mice were challenged with 50 P. yoelii sporozoites. In one experiment the vaccine pPyHsp60-VR1012 used in combination with pmurGMCSF gave 40% protection (Fisher's exact test; P = 0.03, vaccinated versus control groups). In a second experiment this vaccine did not protect any of the immunized mice but induced a delay in the onset of parasitemia. In neither experiment was there any evidence of a protective effect against the asexual erythrocytic stage of the life cycle. In a third experiment mice were primed with PyHsp60 DNA, were boosted 2 weeks later with 2 x 10(3) irradiated P. yoelii sporozoites, and were challenged several weeks later. The presence of PyHsp60 in the immunization regimen did not lead to reduced blood-stage infection or development of parasites in hepatocytes. PyHsp60 DNA vaccines were immunogenic in BALB/c mice but did not consistently, completely protect against sporozoite challenge. The observation that in some of the PyHsp60 DNA vaccine-immunized mice there was protection against infection or a delay in the onset of parasitemia after sporozoite challenge deserves further evaluation.

Plasmodium yoelii: cloning and characterization of the gene encoding for the mitochondrial heat shock protein 60

Heat shock proteins are a highly conserved group of proteins required for the correct folding, transport, and degradation of other proteins in vivo. The Hsp70, Hsp90, and Hsp60 families are among the most widely studied families. Hsp60 is found in eubacteria, mitochondria, and chloroplasts, where, in cooperation with Hsp10, it participates in protein folding and translocation of proteins to the organelles. We have cloned and characterized the Hsp60 gene of Plasmodium yoelii (PyHsp60). PyHsp60 is a single-copy gene, located on chromosome 9, 10, or 11. The PyHsp60 cDNA sequence showed an open reading frame of 1737 nucleotides that codes for a polypeptide of 579 amino acids, with 93% amino acid identity to Plasmodium-falciparum Hsp60 (PfHsp60). Cloning and sequencing of a genomic PCR clone showed the presence of a 201-bp intron, located 141 bp downstream of the ATG codon. A single, heat-inducible, 2.3-kb transcript was detected in Northern blots of RNA isolated from blood stage parasites. Mouse antisera raised against a DNA vaccine vector that expresses PyHsp60 recognized sporozoites and liver- and blood-stage parasites by indirect fluorescent antibody test (IFAT). By Western blot, these antisera reacted with the mycobacterial Hsp65 and recognized a protein of approximately 65 kDa in P. yoelii sporozoites and P. falciparum blood stages. These results show that PyHsp60 and PfHsp60 genes are homologous and that of the PyHsp60 gene encodes a heat-inducible, intracellular protein that is expressed in several of the developmental stages of P. yoelii.