Human papillomavirus, viral load and proliferation rate in recurrent respiratory papillomatosis in response to alpha interferon treatment

Genomic Diversity of HPV6 and HPV11 in Recurrent Respiratory Papillomatosis: Association with Malignant Transformation in the Lungs and Clinical Outcomes

Recurrent respiratory papillomatosis (RRP) is a rare, proliferative disease caused by human papillomavirus 6 (HPV6) and HPV11. RRP can occasionally spread and undergo malignant transformation. We analysed samples across time for five RRP patients with malignant transformation and four with highly recurrent, non-malignant RRP by applying high-throughput sequencing. Patients with malignant transformation were infected by HPV11_A1/A2, while most non-malignant cases were associated with HPV6. Transient multiple infections with HPV6 and HPV11 were found in two patients, and resolved later to single infections. Viral genome loads were homogeneous across groups (median=78 viral genomes per human genome). Within-patient, we did not observe differences between the viral sequences in the papillomatous lesions and in the malignant tissue. Genetic analysis of the NLRP1 gene revealed no known mutations linked to idiopathic RRP, though some novel variants merit to be explored in larger cohorts. HPV11 infections appear associated with RRP malignant transformation in young patients. Multiple infections can occur in RRP, but within-patient viral diversity is minimal for a given genotype. Our results confirm the importance of viral genotype in disease prognosis and are consistent with growing evidence of HPV11 infections to be differentially associated with RRP malignant transformation in young patients.

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.

HPV associated with recurrent respiratory papillomatosis

Papillomaviruses are members of the Papillomaviridae family. Over 150 HPV types have been identified. Recurrent respiratory papillomatosis (RRP) is a chronic condition caused by HPV characterized by recurrent papillomas of the respiratory tract, mainly the larynx. During the early stages, the condition presents with hoarseness, while more advanced disease presents with stridor and respiratory distress. There is no specific cure and treatment consists of repeated surgical procedures to remove the papillomas. Most patients eventually go into remission, but some suffer for many years with this condition, which may be fatal. HPV-6 and HPV-11 are the HPV types most commonly associated with RRP. Although most studies have found RRP due to HPV-11 to be more aggressive than disease due to HPV-6, the variability in disease aggressiveness is probably multifactorial. Information regarding the current epidemiology, molecular diversity and host immune responses is important for strategizing ways to reduce disease. Data on HPV genotypes associated with RRP would provide valuable information for vaccination programs to reduce the incidence of these genotypes in mothers and, in the long term, reduce the incidence of RRP in children. This review focuses on HPV-6 and HPV-11 as the HPV types that cause RRP, and discusses the viral genome and replication, clinical presentation of RRP, current techniques of diagnosis and genotyping, and the molecular diversity of HPV-6 and HPV-11.

Human papillomavirus subtypes in oral lesions compared to healthy oral mucosa

BACKGROUND

Human papillomaviruses (HPV) are involved in the etiology of cervix cancer, but it is still unclear whether they play a role in related oral lesions.

OBJECTIVES

The presence of HPV in oral leukoplakia biopsies (n=50) and oral squamous carcinoma biopsies (n=50) was compared to normal oral mucosa swabs (n=50) for the purpose of indicating a possible etiological role for the virus.

STUDY DESIGN

DNA was extracted from tissue biopsies and from mucosa swabs of control samples. Nested PCR was performed with primers targeting conserved sequences within the capsid gene L1. PCR products were sequenced to identify the HPV genotype.

RESULT

The results reveal a profile of low-risk HPV genotypes in oral leukoplakia similar to that in healthy controls, while HPV was less frequently observed in oral squamous carcinoma.

CONCLUSIONS

HPV does not seem to represent an important causal factor for the development of oral leukoplakia or oral squamous carcinoma.

Management of adult recurrent respiratory papillomatosis with oral acyclovir following micro laryngeal surgery: a case series

To demonstrate the role of oral acyclovir in monthly regimes after microdebrider assisted excision in 3 patients with adult recurrent respiratory papillomatosis (ARRP). Three patients with ARRP who presented to a tertiary referral hospital in stridor were initially treated with a tracheostomy in order to secure airway. On further evaluation by videolaryngoscopy extensive bilateral laryngeal papillomatosis was noted with history of similar conditions in the past for which they were repeatedly operated. They were admitted and underwent Microlaryngeal surgery and laryngeal microdebrider assisted surgery under general anesthesia. Post operatively a course of oral acyclovir at 800 mg/5 times/day for 5 days was administered. On repeat assessment with videolaryngoscopy at monthly intervals a complete remission of the disease was noted with no residual disease at the end of 1 year in 2 cases. One case had a recurrence. Renal parameters were monitored periodically. It may be concluded that the action of anti viral drugs at regular intervals in addition to a short course of oral steroids lead to rapid recovery and prevented latent virus activation within the laryngo tracheal system hence maintaining long term improvement. This can avoid multiple laryngeal surgeries, repeated respiratory emergencies and risk for malignant transformation in the future thereby reducing morbidity and effect on quality of life.

Recurrent respiratory papillomatosis: a rare chronic disease, difficult to treat, with potential to lung cancer transformation: apropos of two cases and a brief literature review

Recurrent respiratory papillomatosis (RRP), which is caused exclusively by human papilloma virus (HPV), is a rare condition characterized by recurrent growth of benign papillomata in the respiratory tract. The papillomata can occur anywhere in the aerodigestive tract but most frequently in the larynx, affecting both children and adults. The management of this entity remains still challenging since no specific definitive treatment exists. Nevertheless, novel surgical interventions as well as several adjuvant therapies have shown promising results in the long-term palliative management of this debilitating disease. Despite its mostly benign nature, RRP may cause significant morbidity and mortality because of its unpredictable clinical course and especially its tendency, albeit infrequent, for malignant transformation. In this article, we present two patients with RRP; one underwent bronchoscopic laser ablation in combination with inhaled interferon-alpha administration that led to a long-term regression of the disease while the other patient was diagnosed with transformation to squamous cell lung carcinoma with fatal outcome. We include a review of the current literature with special emphasis on RRP management and the potential role of HPV in the development of lung cancer.

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

Recurrent respiratory papillomatosis (RRP) is a rare disease of the larynx caused by infection with human papillomaviruses (HPV) -6 or -11, associated with significant morbidity and on occasion mortality. Here we summarize our current understanding of the permissive adaptive and innate responses made by patients with RRP that support chronic HPV infection and prevent immune clearance of these viruses. Furthermore, we provide new evidence of T(H)2-like polarization in papillomas and blood of patients with RRP, restricted CD4 and CD8 Vbeta repertoires, the effect of HPV-11 early protein E6 on T-cell alloreactivity, enriched Langerhans cell presence in papillomas, and evidence that natural killer cells are dysfunctional in RRP. We review the immunogenetic mechanisms that regulate the dysfunctional responses made by patients with RRP in response to HPV infection of the upper airway. In addition, we are identifying T-cell epitopes on HPV-11 early proteins, in the context of human leukocyte antigen (HLA) class II alleles enriched in RRP that should help generate a therapeutic vaccine. Taken together, RRP is a complex, multigene disease manifesting as a tissue and HPV-specific, immune deficiency that prevents effective clearance and/or control of HPV-6 and -11 infection.

Interferon-beta treatment increases human papillomavirus early gene transcription and viral plasmid genome replication by activating interferon regulatory factor (IRF)-1

Interferons (IFNs) have been used to treat mucosal lesions caused by human papillomavirus (HPV) infection, such as intraepithelial precursor lesions to cancer of the uterine cervix, genital warts or recurrent respiratory papillomatosis, to potentially reduce or eliminate replicating HPV plasmid genomes. Mucosal HPVs have evolved mechanisms that impede IFN-β synthesis and downregulate genes induced by IFN. Here we show that these HPV types directly subvert a cellular transcriptional response to IFN-β as a potential boost in infection. Treatment with low levels of human IFN-β induced initial amplification of HPV-16 and HPV-11 plasmid genomes and increased HPV-16 or HPV-31 DNA copy numbers up to 6-fold in HPV-immortalized keratinocytes. IFN treatment also increased early gene transcription from the major early gene promoters in HPV-16, HPV-31 and HPV-11. Furthermore, mutagenesis of the viral genomes and ectopic interferon regulatory factor (IRF) expression in transfection experiments using IRF-1 ^−/− , IRF-2 ^−/− and dual knockout cell lines determined that these responses are due to the activation of IRF-1 interaction with a conserved interferon response element demonstrated in several mucosal HPV early gene promoters. Our results provide a molecular explanation for the varying clinical outcomes of IFN therapy of papillomatoses and define an assay for the modulation of the HPV gene program by IFNs as well as other cytokines and signaling molecules in infection and therapy.

Age of child, more than HPV type, is associated with clinical course in recurrent respiratory papillomatosis

Background

RRP is a devastating disease in which papillomas in the airway cause hoarseness and breathing difficulty. The disease is caused by human papillomavirus (HPV) 6 or 11 and is very variable. Patients undergo multiple surgeries to maintain a patent airway and in order to communicate vocally. Several small studies have been published in which most have noted that HPV 11 is associated with a more aggressive course.

Methodology/Principal Findings

Papilloma biopsies were taken from patients undergoing surgical treatment of RRP and were subjected to HPV typing. 118 patients with juvenile-onset RRP with at least 1 year of clinical data and infected with a single HPV type were analyzed. HPV 11 was encountered in 40% of the patients. By our definition, most of the patients in the sample (81%) had run an aggressive course. The odds of a patient with HPV 11 running an aggressive course were 3.9 times higher than that of patients with HPV 6 (Fisher's exact p = 0.017). However, clinical course was more closely associated with age of the patient (at diagnosis and at the time of the current surgery) than with HPV type. Patients with HPV 11 were diagnosed at a younger age (2.4y) than were those with HPV 6 (3.4y) (p = 0.014). Both by multiple linear regression and by multiple logistic regression HPV type was only weakly associated with metrics of disease course when simultaneously accounting for age.

Conclusions/Significance Abstract

The course of RRP is variable and a quarter of the variability can be accounted for by the age of the patient. HPV 11 is more closely associated with a younger age at diagnosis than it is associated with an aggressive clinical course. These data suggest that there are factors other than HPV type and age of the patient that determine disease course.

Juvenile recurrent respiratory papillomatosis: still a mystery disease with difficult management

Juvenile recurrent respiratory papillomatosis (RRP) is the most common benign neoplastic disease of the larynx in children and adolescents and has a significant impact on patients and the health care system with a cost ranging from $60,000 to $470,000 per patient. The aim of this paper is to review the current literature on RRP and summarize the recent advances. RRP is caused by human papillomavirus (HPV; mainly by types 6 and 11). Patients suffer from wart-like growths in the aerodigestive tract. The course of the disease is unpredictable. Although spontaneous remission is possible, pulmonary spread and malignant transformation have been reported. Surgical excision, including new methods like the microdebrider, aims to secure an adequate airway and improve and maintain an acceptable voice. Repeated recurrences are common and thus overenthusiastic attempts to eradicate the disease may cause serious complications. When papillomas recur, old and new adjuvant methods may be tried. In addition, recent advances in immune system research may allow us to improve our treatment modalities and prevention strategies. A new vaccine is under trial to prevent HPV infection in women; the strongest risk factor for juvenile RRP is a maternal history of genital warts (transmitted from mother to child during delivery). Better understanding of the etiology of the disease and the knowledge of all available therapies is crucial for the best management of the affected patients.

Papillomavirus and treatment

Human papillomaviruses (HPVs) are small DNA viruses responsible for a broad range of clinical presentations, characterized histologically by the proliferation of epithelial cells. HPVs are responsible for benign as well as malignant lesions, the most frequent of the latter being cervical carcinoma. A better knowledge of the immunobiology of these lesions allowed the development of prophylactic vaccines (for the most frequent genital types) that are presently under evaluation. The present paper describes different approaches for the treatment of HPV lesions, still mostly based on surgery, and underlines the importance of developing adjuvant therapies.