Recurrent respiratory papillomatosis: a complex defect in immune responsiveness to human papillomavirus-6 and -11

Impact of HPV Types and Dendritic Cells on Recurrent Respiratory Papillomatosis' Aggressiveness

OBJECTIVE

This study assesses the associations between dendritic cells, HPV 6 and 11, and Recurrent Respiratory Papillomatosis (RRP) aggressiveness.

METHODS

The Derkay score was calculated using information obtained from the medical records. Biopsies from 36 patients with juvenile RRP (JRRP) and 43 adult RRP (ARRP) patients were analyzed under light microscopy, and their clinical data were collected. Immunohistochemical analysis using antibodies against CD83, CD1a, Factor XIIIa, and S100 was performed, and inflammatory cells were quantified. Data obtained were analyzed using the chi-squared test, in addition to the Mann-Whitney and Z tests for two proportions, considering a confidence interval of 95% and p < 0.05 as statistically significant.

RESULTS

A higher quantity of S100 was identified in the epithelium (p < 0.001) and in the conjunctive tissue (p = 0.027) among the ARRP cases, while CD83 (p = 0.025) and Factor XIIIa (p = 0.018), both in the epithelium, were identified among the JRRP cases. We observed significant association between a higher quantity of CD83 in the epithelium in the juvenile group with a low Derkay index (p = 0.034) and with HPV 6 (p = 0.039).

CONCLUSIONS

An increased quantity of dendritic cells is present in individuals diagnosed with RRP, regardless of age, and this may be related to the lower Derkay index, regardless of the HPV type detected.

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, 3 Laryngoscope, 134:5047-5053, 2024.

Characterization of HPV6/11-reactive T-cell subsets in papillomas of patients with juvenile-onset recurrent respiratory papillomatosis and identification of HPV11 E7-specific candidate TCR clonotypes

Juvenile-onset recurrent respiratory papillomatosis (JORRP) is caused by persistent infection of epithelial cells by low-risk human papillomavirus (HPV) types 6 and 11. While multiple infiltrated immune cells have been reported to mediate disease progress, knowledge of HPV-reactive T-cell subsets in papillomas remains elusive. Through single-cell RNA sequencing and RNA microarray, we found that CD8+ tissue-resident memory T (CD8+ TRM) cells with strong interferon-gamma (IFN-γ) production expanded, and were negatively correlated to the disease severity in the frequency of surgery. These IFN-γ+ CD8+ memory T cells were readily activated and expanded in vitro by autologous dendritic cells loaded with HPV11 E7 peptide pool. Moreover, T cell receptor (TCR) clonal expansion was observed in JORRP papilloma tissues, indicating a biased TCR repertoire toward HPV-specific recognition. Finally, we identified and characterized HPV11 E7-specific candidate TCR clonotypes from IFN-γ+ CD8+ memory T cells, suggesting their potential application in TCR-engineered T cells (TCR-T) therapy for HPV11-related diseases. Our findings provided insights into the specific local immune response to HPV6/11 infection and highlighted the importance of IFN-γ+ CD8+ TRM cells in anti-HPV6/11 T-cell immunity.IMPORTANCEThe persistent recurrence of human papillomavirus (HPV) 6/11 infection in papillomas underscores the failure of local immune responses in patients with juvenile-onset recurrent respiratory papillomatosis (JORRP). Our previous study demonstrated that T cells constitute the predominant immune cell population in JORRP papilloma tissues. Understanding the T-cell-mediated immune responses within JORRP papilloma tissues is crucial for disease control. In the present study, we characterized CD8+ tissue-resident memory T (CD8+ TRM) cells as the primary T-cell subset responsible for local anti-HPV6/11 immunity. Moreover, we identified two HPV11 E7-specific candidate T cell receptor (TCR) clonotypes out of IFN-γ+ CD8+ memory T cells. Overall, our findings provided insights into the local immune responses to HPV6/11 infection and offered information for developing more effective immunotherapeutic strategies against JORRP.

Quantification and Functional Studies of Neutrophilic Cells Identifies Distinct Papilloma Phenotypes

OBJECTIVES

To characterize the distribution of immune cell subsets within laryngeal papillomas and to study the function of potentially immunosuppressive neutrophilic and regulatory T cells (Tregs).

METHODS

Fresh clinical papilloma specimens were collected at the time of surgery and studied with multiparameter flow cytometry. Papilloma infiltrating neutrophilic cells and Tregs were sorted and studied functionally with ex vivo T cell suppression assays.

RESULTS

Flow cytometric analysis of fresh laryngeal papillomas samples from 18 adult patients with recurrent respiratory papillomatosis revealed patterns in immune constituency between patients. Clearly divergent phenotypes based primarily on the degree of neutrophilic and T cell infiltration were identified. Relative neutrophilic cell enrichment and T cell depletion were observed in 50% of samples and neutrophilic cell depletion and T cell enrichment were observed in the others. Greater papilloma neutrophilic cell enrichment was positively associated with the number of clinically indicated interventions required in the 12 months prior to sample collection, linking papilloma neutrophil inflammation to disease severity. Functional assays revealed the ability of both papilloma infiltrating neutrophilic and Tregs to suppress T cell function at roughly equal magnitudes, but substantially increased infiltration of neutrophilic cells compared to Tregs across samples.

CONCLUSION

Neutrophilic cells are an important contributor to immunosuppression within the respiratory papilloma microenvironment. Given these data and the association between greater neutrophilic cell infiltration and lack of clinical response to therapeutic vaccination, additional study of strategies aimed at limiting neutrophilic cell infiltration or function within papillomas is warranted.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3238-3244, 2024.

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.

The role of HPV11 E7 in modulating STING-dependent interferon β response in recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP) is a rare benign tumor caused mainly by the infection of the respiratory tract epithelial cells by the human papillomavirus (HPV) type 6/11. However, the specific mechanisms underlying the inhibition of the host's innate immune response by HPV remain unclear. For this purpose, we employed single-cell RNA sequencing to analyze the states of various immune cells in RRP samples post-HPV infection and utilized a cellular model of HPV infection to elucidate the mechanisms by which HPV evades the innate immune system in RRP. The results revealed distinct immune cell heterogeneity in RRP and demonstrated that HPV11 E7 can inhibit the phosphorylation of the stimulator of interferon genes protein, thereby circumventing the body's antiviral response. In vitro co-culture experiments demonstrated that stimulation of macrophages to produce interferon-beta induced the death of HPV-infected epithelial cells, also reducing HPV viral levels. In summary, our study preliminarily identifies the potential mechanisms by which HPV evades the host's antiviral immune response, as well as the latent antiviral functions exhibited by activated macrophages. This research serves as an initial exploration of antiviral immune evasion in RRP, laying a solid foundation for investigating immunotherapeutic approaches for the disease.IMPORTANCESurgical tumor reduction is the most common treatment for recurrent respiratory papillomatosis (RRP). One of the characteristics of RRP is its persistent recurrence, and multiple surgeries are usually required to control the symptoms. Recently, some adjuvant therapies have shown effectiveness, but none of them can completely clear human papillomavirus (HPV) infection, and thus, a localized antiviral immune response is significant for disease control; after all, HPV infection is limited to the epithelium. Inhibition of interferon-beta (IFN-β) secretion by HPV11 E7 viral proteins in epithelial cells by affecting stimulator of interferon genes phosphorylation may account for the persistence of low-risk HPV replication in the RRP. Moreover, suppression of the IFN-I pathway in RRP cell types might provide clues regarding the hyporeactive function of local immune cells. However, activation of macrophage groups to produce IFN-β can still destroy HPV-infected cells.

Recurrent respiratory papillomatosis disease course in immunosuppressed populations

OBJECTIVE

Recurrent respiratory papillomatosis is a benign manifestation of human papillomavirus types 6 and 11 in the respiratory tract. Disease is recurrent, and factors predicting these recurrences and severity of disease are incompletely characterised. This retrospective cohort study examined the relationship of immunosuppression with recurrent respiratory papillomatosis morbidity.

METHODS

A retrospective cohort of 97 adult patients with recurrent respiratory papillomatosis treated at a tertiary referral centre from 2005 to 2020 was conducted. Measures assessed included inter-surgical interval, Voice Handicap Index ('VHI-10') and anatomical Derkay scores.

RESULTS

Bivariate analyses comparing average inter-surgical interval, Voice Handicap Index and Derkay scores in immunosuppressed and healthy patients were insignificant. When controlling for diabetes mellitus and comparing immunosuppressed to healthy patients, inter-surgical interval and Voice Handicap Index change were insignificant (p = 0.458 and p = 0.465, respectively).

CONCLUSION

Recurrent respiratory papillomatosis morbidity for immunosuppressed patients did not significantly differ from that of immunocompetent patients.

A Case of Malignant Transformation of Recurrent Respiratory Papillomatosis That Was Effectively Treated with Pembrolizumab

Introduction

Recurrent respiratory papillomatosis (RRP) is a benign tumor caused by the human papillomavirus that mainly occurs in the larynx; the tumor is known to show malignant transformation in a small percentage of cases. In this report, we describe a case of rapidly growing cervical metastasis due to malignant transformation of RRP that was successfully treated with pembrolizumab.

Case Presentation

A 79-year-old man diagnosed as having laryngeal papilloma was referred to our department, and we resected the tumor by transoral laser microsurgery (TLM). Postoperative histopathology showed papillary lesions with mild cellular atypia, suggestive of papilloma. Six years later, the patient visited our hospital again with worsening hoarseness of the voice and an enlarged papillary lesion of the larynx. We performed a second TLM and postoperative histopathological examination revealed a papillary squamous cell carcinoma. In the early postoperative period, the patient developed a recurrence at the primary site and received radiotherapy (70 Gy). Three months after the completion of radiotherapy, a rapidly enlarging metastatic lymph node was observed in the right cervical region, and we performed neck dissection. Five months after the surgery, a rapidly enlarging mass appeared in the anterior cervical subcutaneous region, and the patient received palliative radiation. Since an immunohistochemical examination of a specimen obtained at the time of neck dissection showed high PD-L1 expression, with a combined positive score of 100, the patient was initiated on treatment with pembrolizumab 1 month later. Although the patient developed fever and a skin rash as adverse events, the tumor disappeared almost entirely within 3 weeks. Thereafter, we have observed no evidence of recurrence for over 1 year.

Conclusion

The PD-1/PD-L1 pathway has been implicated in the tumorigenesis of RRP. This pathway may also play an important role in the malignant transformation of RRPs. Therefore, evaluation of tumor PD-L1 expression is recommended in these cases.

[Epidemiological features papillomatosis of the larynx in adults: a literature review]

The literature review presents current data on the epidemiology, drug, and surgical treatment of laryngeal papillomatosis in adults. Possible prospects for further study of the prevalence and incidence of the disease and provoking factors of recurrence of the disease for the development of possible preventive measures are considered.

Long-Term Follow-up of Parenteral Bevacizumab In Patients with Recurrent Respiratory Papillomatosis

OBJECTIVE

The clinical course of recurrent respiratory papillomatosis (RRP) varies from spontaneous remission to severe airway obstruction with wide variability in recurrence. Standard treatment involves debulking to improve voice and/or breathing. Non-surgical therapies are emerging in hopes of non-operative disease control. This retrospective review analyzes long-term safety, efficacy, and durability of clinical control in the largest reported series of parenteral bevacizumab in adults with RRP.

METHODS

Twenty-three patients with known RRP who have been receiving off-label systemic bevacizumab were included. Dosage, infusion interval, number of cycles, debulking requirements, subjective outcomes, adverse events, and reasons for treatment termination were investigated.

RESULTS

Patients have been followed for an average of 791.43 (21-1468) days. The most common starting dosing regimen was 15 mg/kg at 3 weeks in 11 followed by 10 mg/kg at 6 weeks intervals in 6 individuals. Long-term maintenance dosage varied with the least intensive regimen being 10 mg/kg at 14-week intervals. Subjective improvement of voice and/or breathing was reported in 18/23 subjects. The median time for patients that needed a procedure after treatment was 634 days. Procedures after infusions decreased from 3.08 ± 2.48 procedures in the year prior to 0.52 ± 1.12 during systemic Bevacizumab, and to 0.86 ± 2.05 after stopping bevacizumab. Therapy termination occurred in 8 subjects where only 3 were due to adverse events.

CONCLUSION

Parenteral bevacizumab remains a well-tolerated treatment for patients with recalcitrant RRP. There appears to be a durable reduction in the frequency of debulking surgery requirements although on a maintenance regimen. Laryngoscope, 133:2725-2733, 2023.

The Efficacy of Human Papillomavirus Vaccination as an Adjuvant Therapy in Recurrent Respiratory Papillomatosis

OBJECTIVE

To characterize the efficacy of human papillomavirus (HPV) vaccination as an adjuvant therapy in recurrent respiratory papillomatosis (RRP).

DATA SOURCES

PubMed, Embase, Cochrane, Google Scholar, ClinicalTrials.gov, and Web of Science databases were queried for articles published before April 2021.

REVIEW METHODS

All retrieved studies (n = 870) were independently analyzed by two reviewers according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement using predefined inclusion and exclusion criteria. 13 studies met inclusion criteria. A random-effects meta-analysis was performed to study intersurgical interval (ISI) and number of surgical procedures per year before and after vaccination.

RESULTS

The systematic review included 13 studies, comprising 243 patients. All studies utilized the Gardasil® quadrivalent vaccine, and one study (Yiu et al. 2019) utilized both the quadrivalent and Gardasil® 9-valent vaccines. Our meta-analysis included 62 patients with ISI data across 4 studies, and 111 patients with data on the number of surgical procedures per month across 7 studies. The mean number of surgical procedures decreased by 4.43 per year after vaccination (95% CI, -7.48 to -1.37). Mean ISI increased after vaccination, with a mean difference of 15.73 months (95% CI, 1.46-29.99). Two studies reported on HPV sero-conversion, with HPV seropositivity of 100% prior to vaccination and 25.93% after vaccination.

CONCLUSION

The addition of HPV vaccination was associated with an increase in time between surgeries and reduction in the number of surgical procedures required. HPV vaccination may be a beneficial adjuvant treatment for RRP.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:2046-2054, 2023.

Benralizumab as an Adjuvant Therapy for Recurrent Laryngeal Papillomatosis

Recurrent respiratory (RRP) or laryngeal papillomatosis is the result of human papillomavirus-mediated benign tumor growth on the larynx and is challenging to manage. Benralizumab is a monoclonal antibody targeted against the alpha subunit of the IL-5 receptor on eosinophils. A 61-year-old male patient presented with refractory RRP following multiple surgical excisions. His disease course improved substantially when benralizumab was added to his asthma regimen. There is no clear mechanistic role suggested for benralizumab directly treating RRP. This case may represent a novel application of benralizumab as an adjuvant treatment for patients with RRP and comorbid asthma. Laryngoscope, 133:863-865, 2023.

Involvement of TLR9 in priming the immune response in oral papillomatosis induced by low-risk HPV

Oral papillomatosis represents a benign lesion of the oral mucosa often induced by human papillomavirus (HPV) or having a non-infection local or general etiology. HPVs are very well adapted and efficient viruses able to produce changes in the immune system, endowed with the ability to replicate in the keratinocytes and to remain silent. The natural evolution of HPV infection is different, depending on the efficiency of the innate immune system. The purpose of this study was to explore Toll-like receptor 9 (TLR9) immunohistochemical expression in low-risk (LR)-HPV oral infection and its ability to facilitate an efficient immune response by activating the macrophages, which serve as main antigen-presenting cells. Samples of two groups of oral mucosae - LR-HPV-positive and HPV-negative - were processed for immunohistochemistry technique and incubated with antibody against TLR9 and cluster of differentiation 68 (CD68). Image analysis and morphometry were conducted to assess the intensity of TLR9 immune signal in the epithelium and the number of macrophages labeled by CD68. We found a statistically significant difference between macrophage count for the subjects in HPV-positive and HPV-negative groups; thought no significant differences of TLR9 immune signal was noted, which demonstrates a diminished immune response in HPV-positive group, probably influencing the time of lesion's clearance.

PGE2 expression by HPV6/11-induced respiratory papillomas blocks NK cell activation in patients with recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP), a rare chronic disease caused primarily by human papillomavirus types 6 and 11, consists of repeated growth of premalignant papillomas in the airway. RRP is characterized by multiple abnormalities in innate and adaptive immunity. Natural killer (NK) cells play important roles in immune surveillance and are part of the innate immune responses that help prevent tumor growth. We identified that papillomas lack classical class I MHC and retain nonclassical class I MHC expression. Moreover, in this study, we have identified and characterized the mechanism that blocks NK cell targeting of papilloma cells. Here, we show for the first time that the PGE₂ secreted by papilloma cells directly inhibits NK cells activation/degranulation principally through the PGE₂ receptor EP2, and to a lesser extent through EP4 signaling. Thus, papilloma cells have a potent mechanism to block NK cell function that likely supports papilloma cell growth.

Prospective, Multi-Center Study of the Anatomic Distribution of Recurrent Respiratory Papillomatosis

OBJECTIVES/HYPOTHESIS

To create a model of the anatomic distribution, recurrence, and growth patterns of recurrent respiratory papillomatosis (RRP).

STUDY DESIGN

Prospective, multi-institutional cohort study.

METHODS

Adult patients with a diagnosis of RRP evaluated between August 1, 2018 and February 1, 2021 at six participating centers were invited to enroll. At each office or operating room encounter, laryngologists recorded the location and size of RRP lesions using a 22-region schematic. A generalized linear mixed effects model was used to compare region variations in lesion prevalence and recurrence.

RESULTS

The cohort comprised 121 patients: 74% were male, 81% had been diagnosed with adult-onset RRP, and a plurality (34%) had undergone 0 to 3 RRP interventions prior to enrollment. Across the study period, the odds of a lesion occurring in the glottis was significantly higher (odds ratio [OR]: 26.51; 95% confidence interval [CI]: 11.76-59.75, P < .001) compared with all other areas of the larynx and trachea. Within the true vocal folds, the membranous vocal folds had significantly higher odds (OR: 6.16; 95% CI: 2.66-14.30, P < .001) of lesion occurrence compared to the cartilaginous vocal folds. Despite these strong trends in lesion distribution, there were no differences in the odds of lesion recurrence, growth, or in the time to recurrence, between anatomic subsites.

CONCLUSIONS

RRP lesions are most likely to occur in the glottis, particularly the membranous vocal folds, compared with other regions of the larynx or trachea. However, all lesions demonstrate similar behavior with respect to recurrence, growth, and time to recurrence regardless of anatomic location.

LEVEL OF EVIDENCE

3 Laryngoscope, 132:2403-2411, 2022.

Trace Elements Levels in Serum of Patients with Recurrent Respiratory Papillomatosis

Recurrent respiratory papillomatosis (RRP) is a chronic airway disease characterized by unpredictable recurrences and relapses. Our study aimed to identify the role of trace elements, a proven risk factor for various malignancies, in the development of papilloma and to correlate their serum levels with various disease parameters. 32 RRP patients with 20 age-matched controls were recruited in the study. Analysis of serum trace elements was performed by atomic absorption spectrophotometry in whole blood samples from cases and controls. The serum levels of trace elements were correlated with age of onset, history of previous surgeries, tracheostomy status, Derkay's score, and presence of dysplasia. Among the 32 cases there were 18 males and 14 females with a mean age of 20.85 years (range: 3-60 years). The mean serum levels of Thallium, Zinc, and Gallium were higher among cases compared to their controls whereas the levels of Arsenic, Copper, Cobalt, Selenium, Cadmium, and Lead were higher in control subjects compared to RRP patients. There was a statistically significant correlation of serum level of Cobalt with more than 3 surgeries per year (p = 0.02), Gallium and Thallium with Derkay's score of more than 20 (p = 0.04 and 0.05) and Lead, Arsenic and Gallium with presence tissue dysplasia (p = 0.05, 0.04 and 0.04). Our study had shown a variable association of trace elements in RRP patients. The usefulness of these values need to be completely elucidated and our study calls for future investigations to identify the casual association of various trace elements in the pathogenesis of RRP.

Oropharyngeal tumor cells induce COX-2 expression in peripheral blood monocytes by secretion of IL-1α

Oropharyngeal squamous cell cancer (OPC) accounts for 3% of all cancers and greater than 1.5% of all cancer deaths in the United States, with marked treatment-associated morbidity in survivors. More than 80% of OPC is caused by HPV16. Tumors induced by HPV have been linked to impaired immune functions, with most studies focused on the local tumor microenvironment. Fewer studies have characterized the effects of these tumors on systemic responses in OPC, especially innate responses that drive subsequent adaptive responses, potentially creating feed-back loops favorable to the tumor. Here we report that elevated plasma levels of PGE2 are expressed in half of patients with OPC secondary to overexpression of COX-2 by peripheral blood monocytes, and this expression is driven by IL-1α secreted by the tumors. Monocytes from patients are much more sensitive to the stimulation than monocytes from controls, suggesting the possibility of enhanced immune-modulating feed-back loops. Furthermore, control monocytes pre-exposed to PGE2 overexpress COX-2 in response to IL-1α, simulating responses made by monocytes from some OPC patients. Disrupting the PGE2/IL-1α feed-back loop can have potential impact on targeted medical therapies.

Systematic review of the use of human papillomavirus vaccine as adjuvant therapy for juvenile-onset recurrent respiratory papillomatosis

INTRODUCTION

Juvenile-onset RRP (JoRRP) is considered a rare disease with high morbidity and healthcare costs. The management of RRP has received much scientific attention in recent years and several treatment methodologies have been explored, including therapeutic use of HPV vaccine. There has been increasing interest in the off-label use of the vaccine in virus-induced disease processes such as RRP, due to its immunomodulatory effect and activating role on the innate and adaptive immune system. This review explores the efficacy of the HPV vaccination as a therapeutic tool in the pediatric population.

METHODS

The review of the English literature included three electronic databases, PubMed, SCOPUS, and Cochrane, without publication date restrictions. Studies and reports identified by the database search were reviewed and assessed by two independent reviewers.

RESULTS

The literature searches identified 768 unique citations, from which 204 duplicates were removed (n = 564). A total of 547 articles were excluded as they did not meet our inclusion criteria. A total of 12 studies (3 experimental studies, 3 case series, 6 case reports) that met the inclusion criteria and reported one or more of the outcomes of interest were included for our review. The assessment of the outcome measures evaluated (number of surgeries during the follow-up period, ISI, SPM, Derkay or severity scores, and remission status) revealed that eight out of 12 studies included in the review showed varying degrees of potential benefits from the administration of the vaccine as a treatment modality compared to surgical interventions and/or concurrent adjuvant therapies alone.

CONCLUSION

We conclude that while the therapeutic use of HPV vaccination has shown promise for some JoRRP patients, it overall remains uncertain with the currently available data. There is a need for a prospective multi-centric trial with a larger sample size to fully characterize the potential use of the vaccine in the management of JoRRP.

Restricted Recruitment of NK Cells with Impaired Function Is Caused by HPV-Driven Immunosuppressive Microenvironment of Papillomas in Aggressive Juvenile-Onset Recurrent Respiratory Papillomatosis Patients

Laryngopharynx epithelium neoplasia induced by HPV6/11 infection in juvenile-onset recurrent respiratory papillomatosis (JO-RRP) causes a great health issue characteristic of frequent relapse and aggressive disease progression. Local cell-mediated immunity shaped by the recruitment and activation of cytotoxic effector cells is critical for viral clearance. In this study, we found that NK cells in the papillomas of aggressive JO-RRP patients, in contrast to massive infiltrated T cells, were scarce in number and impaired in activation and cytotoxicity as they were in peripheral blood. Data from cell infiltration analysis indicated that the migration of NK cell to papilloma was restricted in aggressive JO-RRP patients. Further study showed that the skewed chemokine expression in the papillomas and elevated ICAM-1 expression in hyperplastic epithelia cells favored the T cell but not NK cell recruitment in aggressive JO-RRP patients. In parallel to the increased CD3⁺ T cells, we observed a dramatical increase in Tregs and Treg-promoting cytokines such as IL-4, IL-10 and TGFβ in papillomas of aggressive JO-RRP patients. Our study suggested that likely initialized by the intrinsic change in neoplastic epithelial cells with persistent HPV infection, the aggressive papillomas built an entry barrier for NK cell infiltration and formed an immunosuppressive clump to fend off the immune attack from intra-papillomas NK cells. IMPORTANCE Frequent relapse and aggressive disease progression of juvenile-onset recurrent respiratory papillomatosis (JO-RRP) pose a great challenge to the complete remission of HPV 6/11 related laryngeal neoplasia. Local immune responses in papillomas are more relevant to the disease control considering the locale infected restriction of HPV virus in epitheliums. In our study, the restricted NK cell number and reduced expression of activating NKp30 receptor suggested one possible mechanism underlying impaired NK cell defense ability in aggressive JO-RRP papillomas. Meanwhile, the negative impact of HPV persistent infection on NK cell number and function represented yet another example of a chronic pathogen subverting NK cell behavior, affirming a potentially important role for NK cells in viral containment. Further, the skewed chemokine/cytokine expression in the papillomas and the elevated adhesion molecules expression in hyperplastic epithelia cells provided important clues for understanding blocked infiltration and antiviral dysfunction of NK cells in papilloma.

Expanded Basal Compartment and Disrupted Barrier in Vocal Fold Epithelium Infected with Mouse Papillomavirus MmuPV1

Laryngeal infection with low-risk human papillomaviruses can cause recurrent respiratory papillomatosis (RRP), a disease with severe effects on vocal fold epithelium resulting in impaired voice function and communication. RRP research has been stymied by limited preclinical models. We recently reported a murine model of laryngeal MmuPV1 infection and disease in immunodeficient mice. In the current study, we compare quantitative and qualitative measures of epithelial proliferation, apoptosis, differentiation, and barrier between mice with MmuPV1-induced disease of the larynx and surrounding tissues and equal numbers of uninfected controls. Findings supported our hypothesis that laryngeal MmuPV1 infection recapitulates many features of RRP. Like RRP, MmuPV1 increased proliferation in infected vocal fold epithelium, expanded the basal compartment of cells, decreased differentiated cells, and altered cell–cell junctions and basement membrane. Effects of MmuPV1 on apoptosis were equivocal, as with RRP. Barrier markers resembled human neoplastic disease in severe MmuPV1-induced disease. We conclude that MmuPV1 infection of the mouse larynx provides a useful, if imperfect, preclinical model for RRP that will facilitate further study and treatment development for this intractable and devastating disease.

A Novel In Vivo Model of Laryngeal Papillomavirus-Associated Disease Using Mus musculus Papillomavirus

Recurrent respiratory papillomatosis (RRP), caused by laryngeal infection with low-risk human papillomaviruses, has devastating effects on vocal communication and quality of life. Factors in RRP onset, other than viral presence in the airway, are poorly understood. RRP research has been stalled by limited preclinical models. The only known papillomavirus able to infect laboratory mice, Mus musculus papillomavirus (MmuPV1), induces disease in a variety of tissues. We hypothesized that MmuPV1 could infect the larynx as a foundation for a preclinical model of RRP. We further hypothesized that epithelial injury would enhance the ability of MmuPV1 to cause laryngeal disease, because injury is a potential factor in RRP and promotes MmuPV1 infection in other tissues. In this report, we infected larynges of NOD scid gamma mice with MmuPV1 with and without vocal fold abrasion and measured infection and disease pathogenesis over 12 weeks. Laryngeal disease incidence and severity increased earlier in mice that underwent injury in addition to infection. However, laryngeal disease emerged in all infected mice by week 12, with or without injury. Secondary laryngeal infections and disease arose in nude mice after MmuPV1 skin infections, confirming that experimentally induced injury is dispensable for laryngeal MmuPV1 infection and disease in immunocompromised mice. Unlike RRP, lesions were relatively flat dysplasias and they could progress to cancer. Similar to RRP, MmuPV1 transcript was detected in all laryngeal disease and in clinically normal larynges. MmuPV1 capsid protein was largely absent from the larynx, but productive infection arose in a case of squamous metaplasia at the level of the cricoid cartilage. Similar to RRP, disease spread beyond the larynx to the trachea and bronchi. This first report of laryngeal MmuPV1 infection provides a foundation for a preclinical model of RRP.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Hypopharynx, Larynx, Trachea and Parapharyngeal Space

In this article, we review the chapter on tumors of the larynx, hypopharynx, trachea and parapharyngeal space in the new edition of the WHO book, focusing on the new developments in comparison to the previous edition. Squamous cell carcinoma (SCC) and its variants are by far the most common malignancies at these locations, with very limited new insights. The most important is the introduction of new targeted treatment-checkpoint inhibitors, with a new task for pathologists, who may help to predict the response to treatment by analyzing the expression of targeted proteins in biopsy samples. Precancerous lesions remain a controversial topic and, similarly to other organs, it is acceptable to use the terms "dysplasia" or "squamous intraepithelial lesion" (SIL), but there is a slight difference between low-grade dysplasia and low-grade SIL: in the former, mild atypia must be present, while the latter also includes hyperplastic epithelium without atypia. Two approaches have been proposed: a two-tiered system with low- and high-grade dysplasia/SIL and a three-tiered system with an additional category, carcinoma in situ. We are still searching for reliable diagnostic markers to surpass the subjectivity in biopsy diagnosis, with a few potential candidate markers on the horizon, e.g., stem cell markers. Other tumors are rare at these locations, e.g., hematolymphoid, neuroendocrine and salivary gland neoplasms, and are no longer included in Chapter 3. They must be diagnosed according to criteria described in specific chapters. The same holds true for soft tissue tumors, with the exception of cartilaginous neoplasms, which are still included in Chapter 3.

A review of the risk factors associated with juvenile-onset recurrent respiratory papillomatosis: genetic, immune and clinical aspects

BACKGROUND

Juvenile-onset recurrent respiratory papillomatosis (JoRRP) is one of the most common benign lesions of hyperplastic respiratory epithelial tissue in children and is predominantly caused by human papillomaviruses (HPVs) 6 and 11. The clinical course of the disease is variable, and some patients even develop a malignancy. The purpose of this review was to summarize the related factors affecting the disease course in patients with JoRRP.

DATA SOURCES

We used databases, including PubMed and Google Scholar, to search for publications on factors associated with the genetic, immune, and clinical aspects of JoRRP. The most relevant articles to the scope of this review were chosen for analysis.

RESULTS

Mother-to-child transmission is the most important mode of disease transmission; other factors, such as immune condition or genetic susceptibility, may be important determinants of JoRRP occurrence. Genetically, the presence of DRB1*0301 and HPV 6/11 E6/E7 is associated with a more severe disease. Immunewise, patients have an enhanced T helper 2-like response. In addition, regulatory T cells are enriched in tumors and may become one of the effective prognostic indicators. For clinical characteristics, patients infected with HPV-11 have more aggressive disease. However, compared with HPV type, age at first onset is a more important factor related to the aggressiveness of JoRRP. Furthermore, socioeconomic status may also affect the course.

CONCLUSIONS

Genetic, immune, and some clinical factors have been noted to play an important role in the course of JoRRP. Exploring definite influencing factors will be an important direction of research in the future.

HPV and Recurrent Respiratory Papillomatosis: A Brief Review

Recurrent Respiratory Papillomatosis (RRP) is a rare but severe manifestation of human papillomavirus (HPV). As our knowledge about HPV infections has expanded, it has become possible to understand the course of RRP disease and unravel plausible efficient methods to manage the disease. However, the surge in reports on HPV has not been accompanied by a similar increase in research about RRP specifically. In this paper, we review the clinical manifestation and typical presentation of the illness. In addition, the pathogenesis and progression of the disease are described. On the other hand, we discuss the types of treatments currently available and future treatment strategies. The role of vaccination in both the prevention and treatment of RRP will also be reviewed. We believe this review is essential to update the general knowledge on RRP with the latest information available to date to enhance our understanding of RRP and its management.

The Use of the Antigenic Protein HPV6 L1 to Induce the Synthesis of Interferon, CD4 and CD8 T Lymphocytes, and Granzyme B in Blood and Splenocytes of Mice in Order to Develop a Broad Vaccine against Anogenital Papillomatoses

The antigenic protein HPV6 L1 was synthesized in the plant expression system based on transgenic tomato fruit during the development of an oral vaccine against anogenital papillomaviruses. In experiments on mice immunization, new data on the induction of the T-cell immune response were obtained, which were recorded by the results of activation of the synthesis of interferon, CD4 and CD8 T lymphocytes, and granzyme B secreted by them in peripheral mononuclear blood cells and splenocytes of mice that were previously vaccinated with the vaccine material of tomato fruit with the HPV6 L1 gene.

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.

Pharmacotherapy for recurrent respiratory papillomatosis (RRP): a treatment update

Introduction: Recurrent respiratory papillomatosis is a rare human papillomavirus (HPV)-induced condition where warts grow within the airway and especially the larynx to effect voice and restrict breathing.Areas covered: A PubMed search using the following search terms was performed: respiratory papillomatosis and cidofovir, alpha-interferon, bevacizumab, PD1, and HPV vaccines. Surgery remains the mainstay of treatment. There has been a change in options available for adjuvant therapies with systemic bevacizumab and the potential benefits of prophylactic HPV vaccine. Despite efforts to identify a drug therapy to control RRP, no therapy yet remains which is predictable and effective in all. The current status of therapeutic vaccines and immunotherapy is discussed.Expert opinion: The current adjuvant therapies do offer a reasonable expectation of control but the effect for the individual is unpredictable despite the therapies being based on good science. The current therapies would allow an escalating treatment strategy to be formulated, however a single therapy is unlikely to be curative. Multi-center trials are required such that adequate numbers to show an effect are achieved.

The Synthesis of Main Capsid Protein of Anogenital Type HPV6 L1 in Plant Expression System on the Basis of Tomato Fruits

The anogenital type HPV6 L1 major capsid protein was synthesized in a plant expression system on the basis of tomato fruits. The content of HPV6 L1 reached 380 μg per 1 mg of total soluble protein of raw fruit mass, which was represented as a single band with a molecular mass of 56 kDa on the SDS electrophoregram. When orally administrated to mice, the vaccine material from the tomato fruit transgenic for HPV6 L1 induced highly effective antibody immune response with a high titer. The cross-reactivity during the interaction of the antibody to the HPV6 L1 protein from peripheral blood serum of mice vaccinated with HPV6 L1 with the antigenic proteins HPV16 L1, HPV18 L1, HPV31 L1, and HPV45 L1 was found. This is promising for creating a vaccine with a broad reactivity against dangerous anogenital papillomatoses and cervical cancer.

An updated review of the epidemiological factors associated with recurrent respiratory papillomatosis

OBJECTIVES

To identify studies evaluating the epidemiology of recurrent respiratory papillomatosis (RRP), including patient demographics, human papillomavirus (HPV) immunology, clinical course, surgical and medical treatments, and psychosocial factors.

METHODS

A systematic literature search through PubMed was performed to identify studies evaluating the epidemiological factors associated with RRP. All studies were screened through a priori selection criteria using the titles and abstracts.

RESULTS

A total of 208 studies were identified, of which 54 met eligibility criteria and were included in the review.

CONCLUSIONS

RRP is a rare disease most commonly caused by HPV 6 and 11. It is characterized by recurring benign papillomatous lesions in the respiratory tract, particularly the larynx. Existing evidence about disease risk factors is limited but includes both maternal HPV infection and patient smoking and sexual behaviors. Disease management involves a combination of routine surgical and medical treatment. Surgical techniques include CO2-laser, sharp dissection, coblation, microdebridement, and photoangiolytic laser. Medical treatments which have been found to facilitate disease control off-label include interferon-alpha (IFN-α), indole-3-carbinol, acyclovir, bevacizumab, retinoids, and the Gardasil and mumps vaccines. Many patients suffer from additional psychosocial challenges related to their diagnosis. Current disease knowledge remains limited, and more robust controlled trials about risk factors, medical therapies, and surgical options are needed.

LEVEL OF EVIDENCE

5.

Laryngopharyngeal Reflux and Inflammatory Responses in Mucosal Barrier Dysfunction of the Upper Aerodigestive Tract

The upper aerodigestive tract (UAT) is the first line of defense against environmental stresses such as antigens, microbes, inhalants, foods, etc., and mucins, intracellular junctions, epithelial cells, and immune cells are the major constituents of this defensive mucosal barrier. Laryngopharyngeal reflux (LPR) is recognized as an independent risk factor for UAT mucosal disorders, and in this review, we describe the components and functions of the mucosal barrier and the results of LPR-induced mucosal inflammation in the UAT. We discuss the interactions between the refluxate and the mucosal components and the mechanisms through which these damaging events disrupt and alter the mucosal barriers. In addition, we discuss the dynamic alterations in the mucosal barrier that might be potential therapeutic targets for LPR-induced disorders.

Parenteral Bevacizumab for the Treatment of Severe Respiratory Papillomatosis in an Adult Population

OBJECTIVES/HYPOTHESIS

Recurrent respiratory papillomatosis (RRP) is a rare, potentially life-threatening, disease that impacts the voice, breathing, and quality of life of patients. Frequent surgical interventions may be needed to control symptoms. We examined the safety and efficacy of utilizing parenteral bevacizumab in the management of severe RRP in adults.

STUDY DESIGN

This is a retrospective review of clinical management approaches in a group of patients with severe RRP defined as having a high disease burden, frequent need for debridement, and/or tracheobronchial disease. Patients were initially treated with 15 mg/kg of bevacizumab at 3-week intervals. Bevacizumab dosing and frequency was then individually titrated down.

RESULTS

Fourteen adults received a median of 8.5 (range 2-17) bevacizumab infusions over approximately 24 months. All had a history of laryngeal RRP with 6/14 having additional tracheobronchial lesions. Patients required a median of 4 (range 2-11) procedures in the year prior to treatment. Only 3/10 (30%) patients who continued therapy required any additional procedures. Bevacizumab administration was generally well tolerated, with four patients discontinuing therapy. Medical reasons included severe epistaxis and hypertension and thrombocytopenia in an individual with systemic lupus erythematosus. Common side effects included hypertension (grade 2), headache (grades 1-2), elevated creatinine (grades 1-2), and epistaxis (grade 3).

CONCLUSIONS

Intravenous bevacizumab for the primary treatment of severe RRP in adults appears clinically effective and safe. Expected and typically mild side effects related to bevacizumab were observed. Continued investigation of bevacizumab through a prospective clinical trial is warranted.

LEVEL OF EVIDENCE

4. Laryngoscope, 131:E921-E928, 2021.

Juvenile-Onset Recurrent Respiratory Papillomatosis Aggressiveness: In Situ Study of the Level of Transcription of HPV E6 and E7

Simple Summary

Juvenile-onset recurrent respiratory papillomatosis (JoRRP) is a condition related to HPV 6 and 11 infection which is characterized by the repeated growth of benign exophytic papilloma in the respiratory tract of children. Disease progression is unpredictable leading sometimes to airway compromise and death. The aim of this study was to explore p16^INK4a and expression of the RNA of HPV genes E6 and E7 with a chromogenic in situ hybridization (CISH) as biomarkers of JoRRP aggressiveness on a bicentric cohort of forty-eight children. CISH was scored semi-quantitatively as high (2+ score) and low (1+ score) levels of transcription of E6 and E7. Patients with a 2+ score had a more aggressive disease compared to those with a 1+ score. These data are a first step towards the use of biomarkers predictive of disease severity in JoRRP, this could improve the disease management, for example, by implementing adjuvant treatment at the early stages.

Abstract

Juvenile-onset recurrent respiratory papillomatosis (JoRRP) is a condition related to HPV 6 and 11 infection which is characterized by the repeated growth of benign exophytic papilloma in the respiratory tract. Disease progression is unpredictable: some children experience minor symptoms, while others require multiple interventions due to florid growth. The aim of this study was to explore the biomarkers of JoRRP severity on a bicentric cohort of forty-eight children. We performed a CISH on the most recent sample of papilloma with a probe targeting the mRNA of the E6 and E7 genes of HPV 6 and 11 and an immunostaining with p16^INK4a antibody. For each patient HPV RNA CISH staining was assessed semi-quantitatively to define two scores: 1+, defined as a low staining extent, and 2+, defined as a high staining extent. This series contained 19 patients with a score of 1+ and 29 with a score of 2+. Patients with a score of 2+ had a median of surgical excision (SE) per year that was twice that of patients with a score of 1+ (respectively 6.1 versus 2.8, p = 0.036). We found similar results with the median number of SE the first year. Regarding p16^INK4a, all patients were negative. To conclude, HPV RNA CISH might be a biomarker which is predictive of disease aggressiveness in JoRRP, and might help in patient care management.

Identification of 11 Different HPV Subtypes in Adult Patients With Recurrent Respiratory Papillomatosis

OBJECTIVE

To define the human papillomavirus (HPV) subtypes seen in a large adult population with traditionally defined recurrent respiratory papillomatosis.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary care laryngology practice.

SUBJECTS AND METHODS

All patients had a firm diagnosis of recurrent respiratory papillomatosis defined by (1) visually obvious papillomas, (2) recurrence requiring multiple surgeries, and (3) pathology diagnosis of "papilloma." Each patient had also undergone HPV subtyping. Age, sex, presence of malignancy, and HPV subtypes were tabulated and correlated with long-term patient outcomes.

RESULTS

A total of 184 patients were identified who fulfilled the above criteria. In total, 87.0% (160) had a low risk subtype; 9.2% had an alternative subtype. These consisted of subtypes 16, 18, 31, 44, 45, 55, and 70. Four patients (2.2%) had combinations of subtypes, with 1 patient with HPV 11 and 16, 1 patient with HPV 11 and 76, 1 patient with 11 and 84, and 1 patient with 18 and 45. Finally, 3.8% of patients were HPV negative, despite fulfilling all 3 criteria listed above.

CONCLUSION

In the patient population above, almost 10% of patients had an HPV subtype other than 6 and 11. This suggests that traditionally defined recurrent respiratory papillomatosis (RRP) can be caused by HPV subtypes other than 6 and/or 11. In addition, the clinical course of persons with this definition of RRP appears to vary by subtype, and this information may offer the ability to nuance follow-up instructions, reducing in particular the burden placed upon patients who have RRP caused by subtypes 6 and 11.

Human genetic dissection of papillomavirus-driven diseases: new insight into their pathogenesis

Human papillomaviruses (HPVs) infect mucosal or cutaneous stratified epithelia. There are 5 genera and more than 200 types of HPV, each with a specific tropism and virulence. HPV infections are typically asymptomatic or result in benign tumors, which may be disseminated or persistent in rare cases, but a few oncogenic HPVs can cause cancers. This review deals with the human genetic and immunological basis of interindividual clinical variability in the course of HPV infections of the skin and mucosae. Typical epidermodysplasia verruciformis (EV) is characterized by β-HPV-driven flat wart-like and pityriasis-like cutaneous lesions and non-melanoma skin cancers in patients with inborn errors of EVER1-EVER2-CIB1-dependent skin-intrinsic immunity. Atypical EV is associated with other infectious diseases in patients with inborn errors of T cells. Severe cutaneous or anogenital warts, including anogenital cancers, are also driven by certain α-, γ-, μ or ν-HPVs in patients with inborn errors of T lymphocytes and antigen-presenting cells. The genetic basis of HPV diseases at other mucosal sites, such as oral multifocal epithelial hyperplasia or juvenile recurrent respiratory papillomatosis (JRRP), remains poorly understood. The human genetic dissection of HPV-driven lesions will clarify the molecular and cellular basis of protective immunity to HPVs, and should lead to novel diagnostic, preventive, and curative approaches in patients.

Altered Monocyte and Langerhans Cell Innate Immunity in Patients With Recurrent Respiratory Papillomatosis (RRP)

The micromilieu within respiratory papillomas supports persistent human papillomavirus (HPV) infection and disease recurrence in patients with recurrent respiratory papillomatosis (RRP). These patients show polarized (T_H2-/Treg) adaptive immunity in papillomas and blood, enriched immature Langerhans cell (iLC) numbers, and overexpression of cyclooxygenase-2/prostaglandin E₂ (PGE₂) in the upper airway. Blood monocyte-derived, and tissue-derived iLCs from RRP patients and controls were now studied to more fully understand innate immune dysregulation in RRP. Patients' monocytes generated fewer iLCs than controls, due to a reduced fraction of classical monocytes that generated most but not all the iLCs. Prostaglandin E₂, which was elevated in RRP plasma, reduced monocyte-iLC differentiation from controls to the levels of RRP patients, but had no effect on subsequent iLC maturation. Cytokine/chemokine responses by iLCs from papillomas, foreskin, and abdominal skin differed significantly. Freshly derived tissue iLCs expressed low CCL-1 and high CCL-20 mRNAs and were unresponsive to IL-36γ stimulation. Papilloma iLCs uniquely expressed IL-36γ at baseline and expressed CCL1 when cultured overnight outside their immunosuppressive microenvironment without additional stimulation. We conclude that monocyte/iLC innate immunity is impaired in RRP, in part due to increased PGE₂ exposure in vivo. The immunosuppressive papilloma microenvironment likely alters iLC responses, and vice versa, supporting T_H2-like/Treg HPV-specific adaptive immunity in RRP.

Immune Therapy Targeting E6/E7 Oncogenes of Human Paillomavirus Type 6 (HPV-6) Reduces or Eliminates the Need for Surgical Intervention in the Treatment of HPV-6 Associated Recurrent Respiratory Papillomatosis

: Background: Recurrent respiratory papillomatosis (RRP) is a rare disorder characterized by the generation of papillomas of the aerodigestive tract, usually associated with human papilloma virus (HPV) subtypes 6, 11. INO-3106 is a DNA plasmid-based immunotherapy targeting E6 and E7 proteins of HPV6, in order to create a robust immune T cell response.

METHODS

Testing of INO-3016 in animal models confirmed immunogenicity of the DNA-based therapy. A single-site open-label Phase 1 study was initiated for patients with HPV6-positive RRP. Patients were dosed with INO-3106 with or without INO-9012, a DNA plasmid immunotherapy that encodes IL-12, delivered intramuscularly (IM) in combination with electroporation (EP) with the CELLECTRA^® device. Patients received an escalating dose of INO-3106, 3 mg once and then 6 mg for three additional doses, each dose three weeks apart, with the third and fourth doses co-administered with INO-9012. The primary objective of the study was to evaluate the safety and tolerability of INO-3106 with and without INO-9012. The secondary objective was to determine cellular immune responses to INO-3106 with and without INO-9012. Exploratory objectives included preliminary clinical efficacy to the therapy.

RESULTS

Three patients were enrolled in this study, of which two had RRP. Study therapy was well-tolerated, with no related serious adverse events and all related adverse events (AEs) were low-grade. Injection site pain was the most common related AE reported. Immunogenicity was evidenced by multiple immune assays showing engagement and expansion of an HPV6-specific cellular response, including cytotoxic T cells. Preliminary efficacy was demonstrated in patients with RRP in the form of reduction in need for surgical intervention for papilloma growth. Prior to intervention, both patients required surgical intervention approximately every 180 days. One patient demonstrated a greater than three-fold increase in surgery avoidance (584 days) and the other patient remains completely surgery-free as of the last contact at 915 days, a greater than 5-fold increase in surgery interval.

CONCLUSION

INO-3106 with and without INO-9012 was well tolerated, immunogenic and demonstrated preliminary efficacy in patients with HPV6-associated RRP aerodigestive lesions. Further clinical study is indicated.

Role of epstein-barr virus in the severity of recurrent respiratory papillomatosis

OBJECTIVE

The objective was to investigate the prevalence of the Epstein-Barr virus (EBV) and its association with human papilloma virus (HPV) detection, clinicopathological features, and the severity of recurrent respiratory papillomatosis (RRP).

METHODS

Cases of juvenile recurrent respiratory papillomatosis (JRRP) (n = 36) and adult recurrent respiratory papillomatosis (ARRP) (n = 44) were collected retrospectively and subdivided into low- and high-risk severity groups based on the Derkay score. We performed HPV detection and genotyping using a reverse hybridization protocol and investigated the presence of EBV by polymerase chain reaction (PCR) and in situ hybridization. CD21 levels were accessed by immunohistochemistry.

RESULTS

All samples were HPV-positive, including 49 cases of HPV 6, 26 cases of HPV 11, four cases of HPV 6 and 11 coinfections, and one case of HPV 16. EBV-DNA was detected in nine samples by PCR, although none of the cases were positive by means of in situ hybridization. CD21 immunoexpression was not statistically associated with any of the variables analyzed. HPV 6 detection was significantly higher in ARRP cases (P = 0.03), whereas HPV 11 was more prevalent in JRRP cases (P = 0.02) and was even more prevalent in JRRP cases of greater severity (Derkay laryngoscopic scale ≥20) (P = 0.04).

CONCLUSION

The presence of EBV does not seem to play an important role in the progression/severity of RRP.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:E611-E618, 2020.

Abnormal Activation of Myeloid Dendritic Cells in JORRP Patients and Associated with Disease Activity

BACKGROUND

Representing the first line of host defense against virus infections and an essential link between innate and adaptive immune response, the role of dendritic cells (DCs) in peripheral blood of juvenile-onset recurrent respiratory papillomatosis (JORRP) patients and association with disease activity were still not established.

MATERIALS AND METHODS

In our present study, 28 JORRP patients and 28 age and sex matched healthy controls were enrolled. The percentage, phenotype and cytokine secretion of DC and was measured by flow cytometry. Plasma cytokine were detected by the enzyme-linked immunosorbent assay (ELISA).

RESULTS

We found that the percentage of myeloid DC (mDC) was significantly lower in JORRP patients compared to healthy controls and was negatively correlated with interval times, but not surgical times or disease onset. Moreover, the activation marker, CD40 and CD86 was significantly up-regulated on the surfaces of mDC in JORRP patients compared with healthy controls. Neither the percentage nor activation of plasmacytoid DC (pDC) showed statistical difference between JORRP patients and healthy controls. HLA-DR expression on both mDC and pDC was down-regulated in JORRP group and negatively correlated with surgical times. Antigen presenting ability of DC was greatly impaired in JORRP patients of higher number of operations and shorter interval time. Plasma IL-10 as well as IL-10 secreted by mDC was higher in JORRP patients compared with healthy control. Finally, we detected an up-regulated TLR2 and TLR4 expression on mDCs and TLR4 expression was positively correlated with HLA-DR expression on mDC of JORRP patients.

CONCLUSION

Our results demonstrate an abnormal TLR2 and TLR4 expression in mDCs may contribute to suppressive immune response to HPV6 or HPV11 infection and associated with disease activity in JORRP patients.

Immunological tolerance of low-risk HPV in recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP) is characterized by benign exophytic lesions of the respiratory tract caused by the human papillomavirus (HPV), in particular low-risk HPV6 and HPV11. Aggressiveness varies greatly among patients. Surgical excision is the current standard of care for RRP, with adjuvant therapy used when surgery cannot control disease recurrence. Numerous adjuvant therapies have been used to control RRP with some success, but none are curative. Current literature supports a polarization of the adaptive immune response to a T helper type 2 (Th2)-like or T regulatory phenotype, driven by a complex interplay between innate immunity, adaptive immunity and HPV6/11 proteins. Additionally, certain immunogenetic polymorphisms can predispose individuals to an HPV6/11-tolerant microenvironment. As a result, immunomodulatory efforts are being made to restore the host immune system to a more balanced T cell phenotype and clear viral infection. Literature has shown exciting evidence for the role of HPV vaccination with Gardasil or Gardasil-9 as both primary prevention, by decreasing incidence through childhood vaccinations, and secondary prevention, by treating active RRP disease. Multi-institution randomized clinical trials are needed to better assess their efficacy as treatment for active disease. Interestingly, a DNA vaccine has recently shown in-vitro success in generating a more robust CD8⁺ T cell response. Furthermore, clinical trials for programmed death 1 (PD-1) inhibitors are under investigation for RRP management. Molecular insights into RRP, in particular the interplay between RRP and the immune system, are needed to advance our understanding of this disease and may lead to the identification of immunomodulatory agents to better manage RRP.

Homozygous NLRP1 gain-of-function mutation in siblings with a syndromic form of recurrent respiratory papillomatosis

Juvenile-onset recurrent respiratory papillomatosis (JRRP) is a rare and debilitating childhood disease that presents with recurrent growth of papillomas in the upper airway. Two common human papillomaviruses (HPVs), HPV-6 and -11, are implicated in most cases, but it is still not understood why only a small proportion of children develop JRRP following exposure to these common viruses. We report 2 siblings with a syndromic form of JRRP associated with mild dermatologic abnormalities. Whole-exome sequencing of the patients revealed a private homozygous mutation in NLRP1, encoding Nucleotide-Binding Domain Leucine-Rich Repeat Family Pyrin Domain-Containing 1. We find the NLRP1 mutant allele to be gain of function (GOF) for inflammasome activation, as demonstrated by the induction of inflammasome complex oligomerization and IL-1β secretion in an overexpression system. Moreover, patient-derived keratinocytes secrete elevated levels of IL-1β at baseline. Finally, both patients displayed elevated levels of inflammasome-induced cytokines in the serum. Six NLRP1 GOF mutations have previously been described to underlie 3 allelic Mendelian diseases with differing phenotypes and modes of inheritance. Our results demonstrate that an autosomal recessive, syndromic form of JRRP can be associated with an NLRP1 GOF mutation.

Hoarseness in children

Hoarseness or dysphonia are terms used to describe a change in the quality of the voice. The voice quality can be raspy, breathy, strained, fatigued, rough, tremulous or weak. There may be a change in pitch, restriction of range, voice breaks, decreased projection, or abnormal resonance. It is important to remember that a voice disorder is not a disease in itself but rather a presentation of an underlying pathology. Clinicians' knowledge of paediatric hoarseness is limited as it can be difficult to examine children using fibreoptic laryngoscopy and the child may not comprehend the need for detailed examination. However, paediatric flexible naso-laryngoscopy provides a dynamic view of the laryngeal anatomy and function. Recent advances in diagnostic equipment, pharmacology and therapeutics mean that this problem can be managed more successfully but it still remains a challenge. This article discusses the presentation, aetiology and management of hoarseness in children.

Safety and clinical activity of PD-L1 blockade in patients with aggressive recurrent respiratory papillomatosis

Background

Recurrent respiratory papillomatosis (RRP) is a human papillomavirus (HPV)-driven disorder that causes substantial morbidity and can lead to fatal distal airway obstruction and post-obstructive pneumonias. Patients require frequent surgical debridement of disease, and no approved systemic adjuvant therapies exist.

Methods

A phase II study was conducted to investigate the clinical activity and safety of programmed death-ligand 1 (PD-L1) blockade with avelumab in patients with RRP.

Results

Twelve patients were treated. All patients with laryngeal RRP displayed improvement in disease burden, and 5 of 9 (56%) displayed partial responses. None of 4 patients with pulmonary RRP displayed a response. Using each patient’s surgical history as their own control, patients required fewer surgical interventions after avelumab treatment (p = 0.008). A subset of partial responders developed HPV-specific reactivity in papilloma-infiltrating T-cells that correlated with reduced HPV viral load and an increased Tissue Inflammation Signature.

Conclusions

Avelumab demonstrated safety and clinical activity in patients with laryngeal RRP. Further study of immune checkpoint blockade for RRP, possibly with longer treatment duration or in combination with other immunotherapies aimed at activating antiviral immunity, is warranted.

Trial registration

NCT, number NCT02859454, registered August 9, 2016.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0603-3) contains supplementary material, which is available to authorized users.

Clinical Activity of Nivolumab for Human Papilloma Virus-Related Juvenile-Onset Recurrent Respiratory Papillomatosis

BACKGROUND

Juvenile-onset recurrent respiratory papillomatosis (JO-RRP) is a human papilloma virus-mediated progressive benign neoplasm that affects children and young adults. Primary management consists of regular surgical debulking to maintain airway patency and vocal function. Like condyloma acuminata, JO-RRP is associated with immune dysregulation, and T cells isolated from papillomas express an anergic phenotype. Therefore, we hypothesized that programmed death protein 1 axis inhibition could stabilize tumor growth.

MATERIALS AND METHODS

We treated two patients with refractory JO-RRP using nivolumab, with the primary objective of assessing clinical activity. We explored baseline papilloma features using immunohistochemistry and comprehensive genomic profiling.

RESULTS

Both patients experienced symptomatic improvement, and interval laryngoscopies revealed a reduction in papillomatosis burden. One patient has not required subsequent surgical debridement for almost 2 years. On pathologic examination of pretreatment papillomas from both cases, infiltrating T cells were evident in the papilloma stroma, and papilloma programmed death ligand 1 expression was absent. Papilloma mutational load ranged between three and six mutations per megabase for each case. From on-treatment biopsy tissue, a higher amount of intraepithelial T cells and programmed death ligand 1 expression were detected in the papilloma.

CONCLUSION

Nivolumab appears to have promising activity in JO-RRP, and further clinical investigation with more patients in clinical trials is warranted.

IMPLICATIONS FOR PRACTICE

To the authors' knowledge, this article is the first report describing clinical activity with a programed cell death-1 (PD-1) inhibitor to treat a rare but detrimental type of respiratory tract epithelial neoplasm that afflicts young adults. Two patients were treated, and tumor features, such as mutational load, were examined with the intent to stimulate future hypotheses for translational research. The safety and activity of PD-1 inhibitors in this population still need to be corroborated in clinical trials and should not yet be adopted into clinical practice.

A new cell culture model to genetically dissect the complete human papillomavirus life cycle

Herein, we describe a novel infection model that achieves highly efficient infection of primary keratinocytes with human papillomavirus type 16 (HPV16). This cell culture model does not depend on immortalization and is amenable to extensive genetic analyses. In monolayer cell culture, the early but not late promoter was active and yielded a spliced viral transcript pattern similar to HPV16-immortalized keratinocytes. However, relative levels of the E8^E2 transcript increased over time post infection suggesting the expression of this viral repressor is regulated independently of other early proteins and that it may be important for the shift from the establishment to the maintenance phase of the viral life cycle. Both the early and the late promoter were strongly activated when infected cells were subjected to differentiation by growth in methylcellulose. When grown as organotypic raft cultures, HPV16-infected cells expressed late E1^E4 and L1 proteins and replication foci were detected, suggesting that they supported the completion of the viral life cycle. As a proof of principle that the infection system may be used for genetic dissection of viral factors, we analyzed E1, E6 and E7 translation termination linker mutant virus for establishment of infection and genome maintenance. E1 but not E6 and E7 was essential to establish infection. Furthermore, E6 but not E7 was required for episomal genome maintenance. Primary keratinocytes infected with wild type HPV16 immortalized, whereas keratinocytes infected with E6 and E7 knockout virus began to senesce 25 to 35 days post infection. The novel infection model provides a powerful genetic tool to study the role of viral proteins throughout the viral life cycle but especially for immediate early events and enables us to compare low- and high-risk HPV types in the context of infection.

Current cell culture models for the study of the human papillomavirus (HPV) life cycle depend on immortalized keratinocytes harboring episomal HPV genomes. However, the requirement for immortalization restricts the study to only a few HPV types and does not allow investigating immediate early events of the viral life cycle. Despite many efforts, efficient infection of primary keratinocytes has not been achieved until now. Using pre-binding of virus to extracellular matrix deposited by keratinocytes, we now achieve very efficient infection of primary keratinocytes. The infection model allows studying the complete viral lifecycle. It could be extended to HPV types that do not immortalize keratinocytes and allows an extensive genetic screen of the contributions of viral factors throughout the viral lifecycle. It should aid the investigations of processes leading to HPV-induced immortalization.

Current and future management of recurrent respiratory papillomatosis

Objectives

Recurrent respiratory papillomatosis (RRP) is a chronic disease of the respiratory tract that occurs in both children and adults. It is caused by the human papillomavirus (HPV), in particular low‐risk HPV6 and HPV11, and aggressiveness varies among patients. RRP remains a chronic disease that is difficult to manage. This review provides perspectives on current and future management of RRP.

Results

The current standard of care is surgical excision, with adjuvant therapies as needed. Surgical management of RRP has evolved with the introduction of microdebriders and photoangiolytic lasers; the latter can now be used in the office setting. Numerous adjuvant pharmacologic therapies have been utilized with some success. Also, exciting preliminary data show that HPV vaccines may prolong the time to recurrence in the RRP population. There is also optimism that wide‐spread HPV vaccination could reduce RRP incidence indirectly by preventing vertical HPV transmission to newborns.

Conclusion

To date, the biology of RRP is not well understood, although it has been noted to become more aggressive in the setting of immune suppression. Additional research is needed to better understand immune system dysfunction in RRP such that immunomodulatory approaches may be developed for RRP management.

Level of Evidence

4

The PD-1 and PD-L1 pathway in recurrent respiratory papillomatosis

OBJECTIVES/HYPOTHESIS

Generation of an immunosuppressive microenvironment may enable a persistent human papillomavirus infection in the setting of an otherwise normal immune system. We hypothesized that expression of the T-lymphocyte co-inhibitory receptor programmed death 1 (PD-1) and its ligand PD-L1 would be increased in the recurrent respiratory papillomatosis (RRP) microenvironment compared to normal controls.

STUDY DESIGN

Case-control study.

METHODS

Formalin-fixed paraffin-embedded respiratory papilloma and normal controls were obtained under institutional review board approval, stained for CD4, CD8, FoxP3, and PD-1, and scored by automated cell count. PD-L1 staining was scored by a blinded pathologist using an adjusted inflammation score that accounted for epithelial and immune infiltrate.

RESULTS

Thirty-nine RRP cases and seven controls were studied. All immunologic markers demonstrated significantly increased staining in RRP specimens compared to normal controls (all P < .01). PD-1 correlated with both CD4 (P < .0001) and CD8 (P < .001) cell counts. Epithelial staining for PD-L1 (68%) and PD-L1+ infiltrating immune cells (76%) were observed in the majority of papilloma samples. The strongest staining for PD-L1 was usually observed in the basal papilloma layer adjacent to the immunologic infiltrate in the vascular core. Disease severity inversely correlated with CD8 cell counts (P = .01). A correlation between disease severity and other immunologic markers was not observed.

CONCLUSIONS

Most RRP specimens demonstrate PD-1 T-lymphocyte infiltration and PD-L1 expression on both papilloma and infiltrating immune cells. This study suggests that this checkpoint pathway may be contributing to local immunosuppression in RRP, and opens the door for clinical trials utilizing PD-blocking monoclonal antibodies.

LEVEL OF EVIDENCE

NA Laryngoscope, 128:E27-E32, 2018.

HLA-DRB1 and HLA-DQB1 alleles in Chinese Han patients with Juvenile-Onset recurrent respiratory papillomatosis

Juvenile-Onset recurrent respiratory papillomatosis (JORRP) is a rare benign neoplasm of the respiratory mucosa caused by human papilloma virus. Previous studies on the possible associations between HLA alleles and JORRP have shown various results in different ethnic groups. The present study aims to investigate the association between JORRP and HLA class II DRB1and DQB1 alleles in Chinese Han children. We found that the frequencies of HLA-DRB1*03:01 (pc = 0.0378, OR = 4.8) and HLA-DQB1*02:01 (pc = 0.021, OR = 4.8) alleles were significantly higher in patients with JORRP than in controls. In addition, HLA-DRB1*03:01 allele significantly correlated with aggressive JORRP (r = 0.467, p = 0.009). This was the first study on the HLA alleles in Chinese Han patients with JORRP. Future studies are required to further elucidate the correlation of HLA class II alleles and susceptibility to JORRP.