Juvenile onset recurrent respiratory papillomatosis: What do we know in 2024 ?

Juvenile onset recurrent respiratory papillomatosis is a lifelong benign squamous lesion associated with HPV infection, particularly HPV6 and HPV11 genotypes. These lesions are rare, but can lead to laryngeal obturations, which can cause disabling dyspnea, or transform into squamous cell carcinoma. The aim here is to provide an epidemiological, biological and clinical overview of this pathology, particularly in children, in order to understand the issues at stake in terms of research and the development of medical and therapeutic management tools.

Histopathological Tracing of HPV Genotypes 6 and 11 in Pediatric Patients in Medical City with Chronic Palatine and Pharyngeal Tonsillitis.

BACKGROUND: HPVs are considered to have high-oncogenic risk. These genotypes have been proven to have a causal link to cancers, in pediatric and youth patients, with high rates of HPV presence in the tonsillar tissues. OBJECTIVE: A prospective case-control research for determining HPV 6/11 genotypes in tonsillar specimens of children who underwent operations in the otolaryngology departments of the Medical City Complex, Baghdad, Iraq, for their non-oncologic palatine and pharyngeal tonsillar hypertrophies. METHODS: This study enrolled 102 tonsillar tissues, 82 from pediatric patients aged from 4 to 12 years and who underwent tonsillectomies for non-oncologic palatine and pharyngeal tonsillar hypertrophies; 38 specimens were from single operations while 22 were multiple specimens from the same pediatric patients, represented as a total of 44 tissues). In addition, trimmed nasal tissues from 20 patients, with unremarkable pathological changes, were included as the control group. For HPV 6/11 DNA detection, specific DNA probes were used for the chromogenic in situ hybridization (CISH) technique. RESULTS: In the palatine tonsillar hypertrophied tissue group, 26.2% of the tissues revealed positive CISH signals for HPV 6/11 DNA. Regarding the pharyngeal tonsillar hypertrophied tissues, 22.5% of the specimens expressed positive CISH reactions. Among the 22 pediatric patients who had combined pharyngeal and palatine tonsillectomies, in 22.7% both sites expressed positive signals. No positive-CISH reactions were documented in the control nasal tissues. Statistically a significant difference was seen when compared to the control group. CONCLUSIONS: Significant rates of HPV were observed which pointed to the spread of HPV, among other STIs, and in mothers of at least this studied pediatric group. Also, this represented a critical mark as reservoir tissue sites, allowing transmission to other mucosal tissue localizations, playing part in their pathogenesis.

Human papillomavirus in men.

OBJECTIVE: To describe the clinical behavior of human papillomavirus in men. MATERIALS AND METHODS: Current international literature was reviewed to describe the clinical behavior of human papillomavirus in men. RESULTS: Internationally, the overall prevalence of HPV DNA is 50.8%, HPV considered high risk are 14 types. Prevalence of HPV DNA in invasive penile cancer ranges from 33.1% to 47%. HPV-16 has been the most frequent (68.3%), followed by HPV-6 (8.1%) and HPV-18 (6.9%). Positive HPV is described as an independent prognostic factor for cancer-specific survival. CONCLUSION: It is not clear why HPV infection has a predilection in specific areas of the genital tract. However, it is important to note that there are factors that increase the risk of HPV infection.

Transcriptomic Landscape of Gene Expression Profiles and Pathways in Juvenile-Onset Recurrent Respiratory Papillomatosis Tumor Tissues and Human Papillomavirus 6 and 11 E6- and E7-Overexpressing Head and Neck Squamous Cell Carcinoma Cell Lines.

Juvenile-onset recurrent respiratory papillomatosis (JORRP) is the most common benign laryngeal neoplasm in children and is considered to be primarily caused by human papillomavirus (HPV) types 6 and 11. In the present study, we performed RNA sequencing (RNA-seq) of 8 tumors and 4 adjacent nontumor tissues to explore the transcriptional profiles of JORRP tumors. A total of 1,151 upregulated genes involved in the interleukin-17 (IL-17) signaling pathway and 1,620 downregulated genes involved in dysregulated inflammatory responses were reported. Immunohistochemistry (IHC) assays confirmed the upregulation of IL-17C in JORRP tumors compared with paired adjacent nontumor tissues. Real-time PCR (RT-PCR) assays showed positive correlations between CXCL1 (CXC chemokine ligands 1) and CXCL8 and the Derkay Clinic Score of JORRP patients. We further overexpressed the HPV6 or HPV11 E6 and E7 oncogenes in SNU-1076 head and neck squamous cell carcinoma (HNSCC) cell lines and carried out RNA-seq. We found that HPV6-E6-E7 gene overexpression resulted in only 16 upregulated genes and 1 downregulated gene; however, HPV11-E6-E7 gene overexpression resulted in 1,776 upregulated genes and 461 downregulated genes compared with the control cell lines. The differentially expressed genes (DEGs) of HPV11-E6-E7 gene overexpression were positively enriched in the DNA replication-related terms by Gene Ontology (GO) analysis and the IL-17 signaling pathway by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Taken together, our present findings revealed IL-17 signaling pathway-related gene profiles that might contribute to disease pathogenesis and that the HPV11 E6 and E7 oncogenes promote disease progression by enhancing tumor growth and activating the IL-17 signaling pathway in JORRP patients. IMPORTANCE Juvenile-onset recurrent respiratory papillomatosis (JORRP) is primarily caused by human papillomavirus 6 (HPV6) and HPV11 infection; however, the gene signatures of tumors are currently less understood. In the present study, we performed RNA sequencing and found upregulated genes associated with the IL-17 signaling pathway and downregulated genes associated with inflammatory-related pathways. Further RNA sequencing was performed in HPV6-E6-E7- or HPV11-E6-E7-overexpressing SNU-1076 HNSCC cells lines to explore the potential pathogenic molecular mechanisms of HPV virus. We found that HPV11-E6-E7 overexpression resulted in gene expression related to DNA replication and the IL-17 signaling pathway. Our results suggested enriched that the IL-17 signaling pathway resulting from HPV11 infection might contribute to JORRP pathogenesis.

Comprehensive multiomic characterization of human papillomavirus-driven recurrent respiratory papillomatosis reveals distinct molecular subtypes.

Recurrent respiratory papillomatosis (RRP) is a debilitating neoplastic disorder of the upper aerodigestive tract caused by chronic infection with low-risk human papillomavirus types 6 or 11. Patients with severe RRP can require hundreds of lifetime surgeries to control their disease and pulmonary papillomatosis can be fatal. Here we report the comprehensive genomic and transcriptomic characterization of respiratory papillomas. We discovered and characterized distinct subtypes with transcriptional resemblance to either a basal or differentiated cell state that associate with disease aggressiveness and differ in key molecular, immune and APOBEC mutagenesis profiles. Through integrated comparison with high-risk HPV-associated head and neck squamous cell carcinoma, our analysis revealed divergent molecular and immune papilloma subtypes that form independent of underlying genomic alterations. Cumulatively our results support the development of dysregulated cellular proliferation and suppressed anti-viral immunity through distinct programs of squamous cell differentiation and associated expression of low-risk HPV genes. These analyses provide insight into the pathogenesis of respiratory papillomas and provide a foundation for the development of therapeutic strategies.

Genomic diversity of human papillomavirus type 6 from patients with condyloma acuminatum in Eastern China.

OBJECTIVE: Human papillomavirus type 6 (HPV6) is the major etiological agent of anogenital warts both men and women. However, there is limited data on its genomic characterization in mainland China. The aim of this study was to understand the complete genomic diversity of HPV6 from patients with condyloma acuminatum (CA) and to explore the prevalence of different variant lineages/sublineages in eastern China. METHODS: CA samples were collected in 3 hospitals in Shandong Province, China from January 2020 to March 2021. DNA extraction, PCR amplification, Sanger sequencing and sequence assembly were performed on HPV6-positive samples. The complete genomes obtained in this study were analyzed phylogenetically with global HPV6 sequences in GenBank database using MEGA 11. RESULTS: A total of 55 complete genomic sequences of HPV6 were obtained in this study. They were classified as HPV6 variant lineage A (n = 20), sublineage B1 (n = 34) and sublineage B3 (n = 1) by phylogenetic analysis. Sequence alignment showed E1, E5A, E5B, L1, L2, LCR were relatively highly variable regions for sublineage B1 whereas E1, E5A, L2 for lineage A. Both phylogenetic trees of lineage A and sublineage B1 composed of two main branches. Chinese sequences of lineage A segregated into the major branch while those in sublineage B1 belonged to both branches. Genomic divergence between sequences from China and other countries was 0.00% - 0.33% in lineage A and 0.00% - 0.40% in sublineage B1. CONCLUSIONS: This is the first study on HPV variant lineages circulating in mainland China. The results revealed that lineage A and sublineage B1 were prevalent and they had different highly variable regions. Further surveillance is needed to understand the dynamic change of different variants in the population.

Role of human papillomavirus 6 & 11 in condyomata acuminata in Indian patients.

BACKGROUND: Condylomata acuminata, commonly known as genital wart is a sexually transmitted disease caused by Human Papillomavirus (HPV). The positivity of HPV6/11 in condylomata acuminata in western literature varies from 80-90% however, there is a paucity of Indian literature. AIM: The aim of the present study was to determine the role of HPV 6 & 11 in Condylomata acuminata in Indian patients. METHODS: A total of 22 formalin fixed parafilm embedded (FFPE) tissue was collected from the cases of condylomata acuminata which was histologically diagnosed and was used to detect HPV 6 and 11 by PCR. RESULTS: Of these 14/22 patients (63.6%) were positive for HPV 6 or 11; HPV 6 alone in eight (36.3%) and HPV 11 in six (27.2%). CONCLUSION: The high HPV 6 and 11 PCR positivity suggests their definitive role in causation of condylomas cases. This important HPV infection is preventable by prophylactic vaccination.

Anogenital giant condyloma in an infant with liver transplantation.

Human papillomavirus (HPV) types 6 and 11 were detected in a 3-year-old girl with extensive anogenital condylomata. Although sexual abuse must be considered, non-sexual transmission is evident in at least 57% of children with anogenital warts. Perinatal transmission may occur in approximately 24.5% of infants born to HPV-positive mothers. We present an immunosuppressed child with giant condylomata and discuss transmission, work up, and treatment.

A novel recombinant protein vaccine containing the different E7 proteins of the HPV16, 18, 6, 11 E7 linked to the HIV-1 Tat (47-57) improve cytotoxic immune responses.

OBJECTIVES: Human papillomavirus infection (HPV) is the most common viral infection which is causes of cervical, penal, vulvar, anal and, oropharyngeal cancer. E7 protein of HPV is a suitable target for induction of T cell responses and controlling HPV-related cancer. The aim of the current study was to designed and evaluated a novel fusion protein containing the different E7 proteins of the HPV 16, 18, 6 and 11, linked to the cell-penetrating peptide HIV-1 Tat 49-57, in order to improve cytotoxic immune responses in in-vitro and in-vivo. RESULTS: In this study whole sequence of HPV16,18,6,11 E7-Tat (47-57) and HPV16,18,6,11 E7 cloned into the vector and expressed in E. coli (BL21). The purified protein was confirmed by SDS page and western blotting and then injected into the C57BL/6 mice. The efficiency of the fusion protein vaccine was assessed by antibody response assay, cytokine assay (IL-4 and IFN-γ), CD + 8 cytotoxicity assay and tumor challenge experiment. Result showed that fusion proteins containing Adjuvant (IFA,CFA) could express higher titer of antibody. Also, we showed that vaccination with E7-Tat and, E7-Tat-ADJ induced high frequencies of E7-specific CD8 + T cells and CD107a expression as well as IFN-γ level and enhanced long-term survival in the therapeutic animal models. CONCLUSION: Our finding suggested that this novel fusion protein vaccine was able to induce therapeutic efficacy and immunogenicity by improving CD8 + T cell in TC-1 tumor bearing mice; so this vaccine may be appreciated for research against HPV and tumor immunotherapies.

Prevalence of human papillomavirus 6 and 11 variants in recurrent respiratory papillomatosis.

Human papillomavirus (HPV) types 6 and 11 are the etiological agents of recurrent respiratory papillomatosis (RRP). We examined the prevalence and distribution of HPVs 6 and 11 genetic variants in juvenile onset (JORRP) and adult onset (AORRP) laryngeal papillomas. Cases of JORRP and AORRP were collected, retrospectively. HPV detection and genotyping were accessed by polymerase chain reaction-sequencing in 67 RRP samples. Overall, the most prevalent HPV-6 variants were from B1 (55.8%) and B3 (27.9%) sublineages, whereas among HPV-11 positive samples A2 (62.5%) variants were predominant. A higher prevalence of HPV-6 B1 was observed in JORRP (83.3% B1 and 16.7% B3), compared with AORRP cases (58.3% B1 and 41.7% B3). HPV-11 A2 variants were more prevalent both in JORRP (57.2%) and in AORRP cases (70.0%). Nevertheless, with the exception that HPV-6 B1 were significantly less likely to recur, there was a lack of association between any particular HPVs 6 or 11 variant and clinicopathological features. Our data do not support an association between HPVs 6 and 11 variability and RRP.

HPV genotype is a prognosticator for recurrence of respiratory papillomatosis in children.

OBJECTIVES: This study aimed to compare the prognosis according to age, genotype or human papillomavirus (HPV) variant in patients with recurrent respiratory papillomatosis (RRP). DESIGN: Non-concurrent cohort. PARTICIPANTS: Forty one patients with RRP. SETTING: Tertiary referral hospital. MAIN OUTCOME MEASURES: Disease severity was defined by the number of surgeries performed, and Derkay score at surgeries, obtained from medical records. HPV was detected and genotyped, and HPV-6 variants were also assessed. RESULTS: Fifteen (36.58%) individuals belonged to the juvenile RRP group (JoRRP, less than 18 years), while 26 patients (63.41%) were allocated at the adult group (AoRRP, equal or more than 18 years). JoRRP patients needed, in average, a higher number of surgeries to control the disease than AoRRP patients (mean difference: 3.36). Also, JoRRP patients showed a higher Derkay score at each surgery (mean difference: 3.76). There was no significant difference in the number of surgeries when we compared patients infected with HPV-6 or HPV-11, neither in accordance to HPV-6 variants. Patients with HPV-11 presented a higher mean Derkay score at surgery than those with HPV-6 (mean difference: 4.39); when co-variated by age, we observed that this difference occurred only among JoRRP patients (mean difference: 6.15). CONCLUSIONS: Age of onset of RRP has an important impact on number of surgeries to control disease. Patients with JoRRP and HPV-11 tend to present worse Derkay score at each surgery. HPV genotype among adults and HPV-6 variants had no impact on the outcome of the disease.

Contemporary human papillomavirus genotyping and correlations to peniscopy, cytology, and histopatology on over 1000 males.

OBJECTIVES: To explore male human papillomavirus (HPV) contemporary genotyping epidemiology and correlations to peniscopy, cytology, and histopatology. METHODS: Medical records of patients who had been submitted to HPV infection screening with genotyping, peniscopy, cytology, and histopathology in a period of 2 years were reviewed. Frequency analysis and correlations between the diagnostic tools were established. RESULTS: Genotype of 1132 men resulted in 69.2% (784) positivity for HPV DNA, 78% classified as high risk of oncogenesis. Co-infections occurred in 429 (54.7%) and the most frequently identified types were HPV-6, HPV-42, and HPV-16, in 133 (17%), 94 (12%), and 86 (11%) patients, respectively. Positive/negative predictive values of peniscopy, cytology, and histopathology were 83/31%, 92/32%, and 87/33%, respectively. As a result, though significant, the correlations between genotype and non-molecular tests were poor. CONCLUSIONS: In the current contemporary representative male cohort, over two thirds are positive for human HPV DNA, 78% of high risk and with over half co-infections. Though significant, its correlation with non-molecular tests is poor and while the positive predictive values of peniscopy, cytology, and histopatology are between 83% and 92%, their negative predictive values are as low as 31% to 33%.

Mitochondrial somatic mutations and the lack of viral genomic variation in recurrent respiratory papillomatosis.

Recurrent Respiratory Papillomatosis (RRP) is a rare disease of the aerodigestive tract caused by the Human Papilloma Virus (HPV) that manifests as profoundly altered phonatory and upper respiratory anatomy. Current therapies are primarily symptomatic; enhanced insight regarding disease-specific biology of RRP is critical to improved therapeutics for this challenging population. Multiplex PCR was performed on oral rinses collected from twenty-three patients with adult-onset RRP every three months for one year. Twenty-two (95.6%) subjects had an initial HPV positive oral rinse. Of those subjects, 77.2% had an additional positive oral rinse over 12 months. A subset of rinses were then compared to tissue samples in the same patient employing HPViewer to determine HPV subtype concordance. Multiple HPV copies (60-787 per human cell) were detected in RRP tissue in each patient, but a single dominant HPV was found in individual samples. These data confirm persistent oral HPV infection in the majority of patients with RRP. In addition, three novel HPV6 isolates were found and identical HPV strains, at very low levels, were identified in oral rinses in two patients suggesting potential HPV subtype concordance. Finally, somatic heteroplasmic mtDNA mutations were observed in RRP tissue with 1.8 mutations per sample and two nonsynonymous variants. These data provide foundational insight into both the underlying pathophysiology of RRP, but also potential targets for intervention in this challenging patient cohort.

Neutralization sites of human papillomavirus-6 relate to virus attachment and entry phase in viral infection.

Human papillomavirus type 6 (HPV6) is the major etiologic agent of genital warts and recurrent respiratory papillomatosis. Although the commercial HPV vaccines cover HPV6, the neutralization sites and mode for HPV6 are poorly understood. Here, we identify the HPV6 neutralization sites and discriminate the inhibition of virus attachment and entry by three potent neutralizing antibodies (nAbs), 5D3, 17D5, and 15F7. Mutagenesis assays showed that these nAbs predominantly target surface loops BC, DE, and FG of HPV6 L1. Cryo-EM structures of the HPV6 pseudovirus (PsV) and its immune complexes revealed three distinct binding modalities - full-occupation-bound to capsid, top-center-bound-, and top-rim-bound to pentamers - and illustrated a structural atlas for three classes of antibody-bound footprints that are located at center-distal ring, center, and center-proximal ring of pentamer surface for 5D3, 17D5, and 15F7, respectively. Two modes of neutralization were identified: mAb 5D3 and 17D5 block HPV PsV from attaching to the extracellular matrix (ECM) and the cell surface, whereas 15F7 allows PsV attachment but prohibits PsV from entering the cell. These findings highlight three neutralization sites of HPV6 L1 and outline two antibody-mediated neutralization mechanisms against HPV6, which will be relevant for HPV virology and antiviral inhibitor design. HighlightsMajor neutralization sites of HPV6 were mapped on the pseudovirus cryo-EM structuremAb 15F7 binds HPV6 capsid with a novel top-rim binding modality and confers a post-attachment neutralizationmAb 17D5 binds capsid in top-centre manner but unexpectedly prevents virus from attachment to cell surface.

E6 and E7 gene polymorphisms in human papillomavirus Type-6 identified in Southwest China.

BACKGROUND: Human papillomavirus type-6 (HPV6) is the major etiological agent of anogenital warts both men and women. The present study aimed to characterize the genetic diversity among HPV6 in Southwest China, and to investigate the origin of, selective pressure experienced by, and impact of the resultantly identified genetic variants on the HPV6 secondary structure. METHODS: Phylogenetic trees were constructed by Maximum-likelihood and the Kimura 2-parameters methods by Molecular Evolutionary Genetics Analysis version 6.0. The diversity of secondary structure was analyzed by PSIPred software. The selection pressures acting on the E6/E7 genes were estimated by Phylogenetic Analyses by Maximum Likelihood version 4.8 software. RESULTS: HPV6 was the most prevalent low risk HPV type in southwest China. In total, 143 E6 and E7 gene sequences of HPV6 isolated from patients were sequenced and compared to GenBank HPV6 reference sequence X00203. The results of these analyses revealed that both the HPV6 E6 and E7 were highly conserved within the analyzed patient samples, and comprised only 3 types of variant sequence, respectively. Furthermore, the analysis of HPV6 E6 and E7 sequences revealed seven/five single-nucleotide mutations, two/four and five/one of which were non-synonymous and synonymous, respectively. The phylogenetic analyses of the E6 and E7 sequences indicated that they belonged to sub-lineage A1 and sub-lineage B1, whereas the selective pressure analyses showed that only the E7 mutation sites 4R, 34E, and 52F were positive selection. CONCLUSIONS: HPV6 (detection rate = 13.10%) was very prevalent in southwest China, both the HPV6 E6 and E7 sequences were highly conserved within the analyzed patient samples in southwest China, indicating that the low risk HPV6 can adapt to the environment well without much evolution.

Expression of toll-like receptors in non-endemic nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a malignant disease with an enigmatic etiology. NPC associates with Epstein-Barr virus (EBV) and human papillomaviruses (HPVs), while immunological factors also play a role in carcinogenesis. Toll-like receptors (TLRs) are pattern recognition receptors that participate in the immunological defence against pathogens, but their functions are also linked to cancer. METHODS: In our whole population-based study, we retrieved 150 Finnish NPC cases and studied their tumour samples for TLR1, TLR2, TLR4, TLR5, TLR7, and TLR9 expressions by immunohistochemistry, and for the presence of EBV and high-risk HPVs with EBV RNA and HPV E6/E7 mRNA in situ hybridizations. In addition, we analyzed the TLR expression patterns according to age, tumour histology, EBV/HPV status, and outcome. RESULTS: We found that all TLRs studied were highly expressed in NPC. Viral status of the tumours varied, and 62% of them were EBV-positive, 14% HPV-positive, and 24% virus-negative. The tumours with strong TLR2nucl or TLR5 expression were mostly virus-negative or HPV-positive keratinizing squamous cell carcinomas, and the patients with these tumours were significantly older than those with mild or negative TLR2nucl/TLR5 expression. In Kaplan-Meier analysis, the patients with strong TLR5 expression had worse survival compared to the patients with negative or mild TLR5 expression, but the results were linked to other patient and tumour characteristics. In multivariable-adjusted Cox regression analysis, the patients with positive TLR7 tumour expression had better overall survival than those with no TLR7 expression. The 5-year overall survival rates according to TLR7 expression were 66% (mild), 52% (moderate or strong), and 22% (negative). CONCLUSIONS: TLRs are highly expressed in non-endemic NPC. Intensity of TLR2 and TLR5 expressions correlate with viral status, and TLR7 seems to be an independent prognostic factor of non-endemic NPC.

The interaction of high and low-risk human papillomavirus genotypes increases the risk of developing genital warts: A population-based cohort study.

Cervical cancer is among the most common type of cancers in women and is associated with human papillomavirus (HPV) infection. Genital warts are also reported to be linked with HPV infection types 11 and 6. In turn, clinical characteristics and morphological features of warts may be useful in the prediction of prognosis and in making treatment decisions. Thus, we have investigated the association of high and low-risk HPVs genotype with genital wart risk, as well as pathological and cytological information in cases recruited from a population-based cohort study of 1380 patients. Patients infected with HPV genotype 6 or 11 had an increased risk of having warts, with OR of 2.34 (95% CI: 0.955-5.737, P = 0.06). Also, this association was enhanced in the presence of high plus low-risk HPV for having genital wart (OR: 2.814; 95%: 1.208-6.55, P = 0.017) and cases having high-risk HPV (OR: 2.329; 95% CI: 1.029-5.269, P = 0.042). Moreover, we observed patients with genital warts having CIN2/3, indicating the importance of informing the physician to the patient to prevent more severe lesions. Our data demonstrated that patients with both low/high-risk HPV types had an increased risk of developing genital warts and persistent infection with HPV was a necessary precursor for the increase in cervical lesions.

Lack of Association between Human Papillomavirus Types 6 and 11 Genetic Variants and Cervical Abnormalities: The Ludwig-McGill Cohort Study.

BACKGROUND: Human papillomavirus (HPV) types 6 and 11 are mainly associated with the development of genital warts and recurrent respiratory papillomatosis. We examined intratypic genetic variability of both viral types with the development of cervical cytologic abnormalities in Brazilian women. METHODS: We used PCR sequencing to characterize variants of HPVs 6 and/or 11 in cervical swabs from women in the Ludwig-McGill Cohort Study. We used a binomial generalized estimating equations (GEE) model with logit link to estimate odds ratios (OR) and 95% confidence intervals (CI) for the associations between HPV 6 and 11 variants and cytologic abnormalities. RESULTS: B1 and B3 HPV6 and A2 HPV11 variants were the most common isolates identified. Compared with HPV6-negative women, the ORs among women harboring HPV6 B1 or B3 variants were 6.3 (95% CI, 2.3-17.0) and 2.3 (95% CI, 0.6-9.7) for atypical cells of undetermined significance (ASCUS)/low squamous intraepithelial lesions (LSIL), respectively, and 1.7 (95% CI, 0.6-5.1) and 1.2 (95% CI, 0.3-4.7) for ASCUS/LSIL/high squamous intraepithelial lesions (HSIL). Respective ORs were 5.0 (95% CI, 1.7-14.6) and 2.8 (95% CI, 1.0-8.1) upon comparing women with HPV11 A2 variants to HPV11-negative women. All associations disappeared when adjusting for coinfections with high-risk HPV types. CONCLUSIONS: Our data do not support an association between low-risk HPVs 6 and 11 genetic variability and cervical abnormalities. IMPACT: Risk of cervical cytologic abnormalities is not affected by intratypic polymorphism in HPVs 6 and 11.

Comparative analysis of human papillomavirus type 6 complete genomes originated from head and neck and anogenital disorders.

It is increasingly recognized that fundamental differences exist between high-risk and low-risk human papillomavirus (HPV) genotypes regarding interactions with the host. This study aims to join the recently emerging efforts to uncover these differences at the complete genome level and to study how they may influence the disease caused. Sixteen samples of thirteen patients with various HPV6-mediated benign mucosal disorders (nine recurrent respiratory papillomatoses with 2-8 recurrences, one condyloma acuminatum and three premalignant lesions of the genital mucosa) were sampled to determine the complete virus genomes. We collected the 197 HPV6 complete genomes deposited in the GenBank for cluster analysis to determine (sub)lineages. Genome polymorphisms were determined against the reference sequences of the (sub)lineages. Genome polymorphisms of the long control region (LCR) were tested for putative transcription factor binding sites; their functional analysis was performed by transient transfection of cloned whole LCRs into HEp-2 cells using a luciferase reporter system. Genomes from the same patients were always identical. Three, nine and one patients carried HPV6 lineage A, sublineage B1 and B2 variants, respectively. The three lineage A sequences were highly similar to each other, but distinct from the reference genome. A unique non-synonymous single nucleotide polymorphism (SNP) was found in the E5a open reading frame (ORF). Sublineage B1 genomes were more diverse, exhibited unique non-synonymous SNPs in the LCR and the E2/E4, L1, L2 ORFs. LCR activity of lineage A and sublineage B1 differed significantly; activity of one sublineage B1 LCR exhibiting two unique SNPs was significantly higher than that of other B1 LCR variants, close to the mean of LCR activities of lineage A variants. Different HPV6 lineages showed marked differences in variability patterns of the different genome regions. This may be involved in the differences in their distribution in different diseases or patient populations.