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

Recurrent Laryngeal Papillomatosis in Denmark from 1994 to 2021: A Nationwide Register Study

OBJECTIVES

The aim of this study is to describe the incidence and demographics of laryngeal papillomatosis (LP) in Denmark, including sex and age distribution, recurrence rates, and HPV subtypes, using a new method of register identification.

METHODS

The data were extracted from the Danish Pathology Data Bank using SNOMED codes instead of the usual method using ICD codes from the Danish National Health Register. The derived pathology records were manually verified by three medical doctors. The study period was 1994-2021. Patients were categorized according to age as either juvenile-onset RRP (JoRRP) if <18 years or adult-onset RRP (AoRRP) if 18 years or older.

RESULTS

We identified 1819 RRP patients (JoRRP: 56; AoRRP:1763). The overall incidence per 100,000 inhabitants were 0.17 for JoRRP and 1.45 for AoRRP. The vast majority (72%) of the patients were male, but there was no significant difference in age at onset of RRP or recurrence rates between the sexes. Children below 3 years of age had the highest recurrence probability. Extracting data using SNOMED codes resulted in a positive predictive value of 99% regarding total number of biopsies and 98% regarding individuals. The incidence decreased throughout the study period.

CONCLUSION

Comparable incidence and recurrence rates of RRP were found between Denmark and Norway. In this study, the Danish Pathology Register was found to be a highly valuable method for identifying LP patients. The effect of the nationwide HPV vaccination program can be evaluated using this method as the vaccinated cohort is starting to grow older and reproduce.

LEVEL OF EVIDENCE

Retrospective registry-based national cohort study, level of evidence 3 Laryngoscope, 2024.

Transcriptomic landscape of gene expression profiles and pathways in JORRP tumor tissues and HPV6/11 E6-E7-overexpressing HNSCC 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 1151 upregulated genes involved in the IL-17 signaling pathway and 1620 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 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 1776 upregulated genes and 461 downregulated genes compared with the control cell lines. The 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 JORRP is primarily caused by HPV 6 and HPV11 infection, however, the gene signatures of tumor are less understood currently. In the present study, we performed RNA-sequencing and found up-regulated genes associated with "IL-17 signaling pathway" and down-regulated genes associated with inflammatory-related pathways. Further RNA-sequencing was performed in HPV6-E6-E7 or HPV11-E6-E7 over-expressing SNU-1076 HNSCC cells lines to explore the potential pathogenic molecular mechanisms of HPV virus. We found HPV11-E6-E7 over-expression resulted in gene expressions related to DNA replication and IL-17 signaling pathway. Our results suggested enriched IL-17 signaling pathway resulted from HPV11 infection might contribute to JORRP pathogenesis.

Recurrent respiratory papillomatosis: clinical characteristics and viral genotyping in a Brazilian population

This study presents 25 cases of recurrent respiratory papillomatosis (RRP) that occurred in Sao Luis, Maranhao State, Northeast region, Brazil, between January 2007 and December 2018. Sociodemographic and clinical profile of patients as well as human papillomavirus (HPV) infection status were evaluated. Clinical and histopathological data were collected from the patients' medical records. For the HPV infection analysis, DNA was extracted and subjected to amplification by a nested polymerase chain reaction. Viral genotyping was performed by automated sequencing. The median age of patients was 12.40 ± 12.6. years, and the juvenile form of the disease (68%) was the predominant form of disease. Female participants were predominant (60%), and they were from cities located in the interior of the State (60%). The most common clinical manifestation was dysphonia; recurrence was observed in most cases (56%), and tracheostomy was necessary in seven patients (26.9%). When comparing the RRP forms, patients in the juvenile-RRP group had higher recurrence rates and need of tracheostomy than those in the adult-RRP group. The viral genotyping analysis revealed that 47.8% of patients had low-risk HPVs, whereas 13.1% had high-risk HPVs, and in 39.1% of patients the viral genotype was not obtained. HPV-6 was the most prevalent type and Juvenile-RRP was more prevalent in our population. HPV was present at a high rate, and HPV-6 was the predominant genotype. This study serves as the basis for further studies to be conducted in the Brazilian population. Our findings aid the better understanding of RRP, possibly suggesting some prognostic factors associated with the disease aggressiveness.

HPV-Associated Benign Squamous Cell Papillomas in the Upper Aero-Digestive Tract and Their Malignant Potential

Squamous cell papilloma (SCP) in the upper aero-digestive tract is a rare disease entity with bimodal age presentation both at childhood and in adults. It originates from stratified squamous and/or respiratory epithelium. Traditionally, SCPs have been linked to chemical or mechanical irritation but, since the 1980s, they have also been associated with human papillomavirus (HPV) infection. Approximately 30% of the head and neck SCPs are associated with HPV infection, with this association being highest for laryngeal papillomas (76–94%), followed by oral (27–48%), sinonasal (25–40%), and oropharyngeal papillomas (6–7%). There is, however, a wide variation in HPV prevalence, the highest being in esophageal SCPs (11–57%). HPV6 and HPV11 are the two main HPV genotypes present, but these are also high-risk HPVs as they are infrequently detected. Some 20% of the oral and oropharyngeal papillomas also contain cutaneous HPV genotypes. Despite their benign morphology, some SCPs tend to recur and even undergo malignant transformation. The highest malignant potential is associated with sinonasal inverted papillomas (7–11%). This review discusses the evidence regarding HPV etiology of benign SCPs in the upper aero-digestive tract and their HPV-related malignant transformation. In addition, studies on HPV exposure at an early age are discussed, as are the animal models shedding light on HPV transmission, viral latency, and its reactivation.

HPV Type-Specific Prevalence a Decade after the Implementation of the Vaccination Program: Results from a Pilot Study

Human papillomavirus infection is a cause of the development of invasive cervical cancer. Three types of vaccine are currently available to prevent precancerous/cancerous lesions due to persistent infection, which is supported mainly by 7 different high-risk genotypes. The aim of this pilot study was to acquire preliminary data on type-specific prevalence 10 years after the implementation of the HPV vaccination program in Italy, in order to subsequently plan appropriate observational studies in the Italian population. First-voided urine samples were collected from 393 consenting subjects, both females and males, aged 18–40 years, and HPV DNA was detected by PCR amplification of a 450 bp L1 fragment. All amplified products were genotyped by means of the Restriction Fragment Length Polymorphism (RFLP) method. The female population was divided into three cohorts (“vaccine-eligible”, “pre-screening” and “screening” cohorts) according to the preventive intervention scheduled by age; males were included in the same three cohorts according to their year of birth. The overall prevalence of HPV infection was 19%, being higher in females than in males (22.1% vs. 13.6%, p = 0.03729). In the female population, 10 years after the start of the national immunization program, we observed a reduction in the prevalence of vaccine types and the number of circulating genotypes, especially in the “vaccine-eligible” cohort. The frequency of HPV vaccine types increased with age, particularly in males in the “pre-screening” and “screening” cohorts. Our study highlights the importance of monitoring HPV infection in both genders, to validate the effect of the HPV vaccination program.