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, 2024.

Adjuvant Human Papillomavirus Vaccination in Recurrent Respiratory Papilloma Patients Older than 45

OBJECTIVES

The primary objective was to examine the intersurgical interval (ISI) of recurrent respiratory papillomatosis (RRP) in patients older than 45 years before and after a Gardasil vaccination series.

METHODS

We conducted a retrospective chart review of adult patients >45 years of age diagnosed with RRP from 2012 to 2022. Patients were excluded if they did not receive at least two doses of the Gardasil vaccine series or if they underwent two or fewer surgeries during the study period.

RESULTS

Thirteen patients met the inclusion criteria, 11 males and two females. The age at initial diagnosis ranged from 46 to 80 years, with a mean of 59 years. There was a significant increase in the average ISI, from 126 ± 87 days pre-vaccination compared to 494 ± 588 days post-vaccination (p < 0.01). The average number of surgeries per patient was 6.8 ± 2.4 over an average follow-up of 49.7 ± 30.3 months.

CONCLUSION

Adjuvant Gardasil use in RRP patients older than 45 years significantly increases the ISI. Current CDC recommendations include only patients ages 9 to 45, but this study provides evidence that RRP patients outside this age range may benefit from adjuvant HPV vaccination.

LEVEL OF EVIDENCE

4 Laryngoscope, 2024.

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.

Use of extracorporeal membrane oxygenation during resection of recurrent laryngeal papillomatosis: A case report

RATIONALE

Recurrent laryngeal papillomatosis (RLP) is a common benign tumor in the larynx of children, which is characterized by high recurrence rate and rapid growth, leading to clinical symptoms such as hoarseness and difficulty breathing. Low-temperature plasma radiofrequency ablation (RFA) is the main treatment, but ventilation problems are often encountered during surgery.

PATIENT CONCERNS

We report a case of a 2-year-old child with RLP who underwent low-temperature plasma RFA with the assistance of a laryngoscope. However, the surgery had to be temporarily stopped due to ventilation difficulties and difficulty in maintaining blood oxygen saturation during the procedure.

DIAGNOSIS

The child was diagnosed with RLP.

INTERVENTIONS

The child underwent low-temperature plasma RFA supported by laryngoscopy assisted by ECMO.

OUTCOMES

Despite ventilation problems during surgery, the use of ECMO support helped maintain good oxygen saturation in the child and provided a clear surgical field, enabling the tumor to be quickly and cleanly removed. Therefore, the use of ECMO provided critical support during the surgery.

LESSONS

This case highlights the importance of airway management during laryngeal papillomatosis surgery. A thorough airway assessment should be performed before anesthesia, and early use of ECMO can reduce harm to the child and ensure the child's safety.

Utility of CK8, CK10, CK13, and CK17 in Differential Diagnostics of Benign Lesions, Laryngeal Dysplasia, and Laryngeal Squamous Cell Carcinoma

There are no reliable immunohistochemical markers for diagnosing laryngeal squamous cell carcinoma (SCC) or diagnosing and grading laryngeal dysplasia. We aimed to evaluate the diagnostic utility of CK8, CK10, CK13, and CK17 in benign laryngeal lesions, laryngeal dysplasia, and laryngeal SCC. This retrospective study included 151 patients diagnosed with laryngeal papilloma, laryngeal polyps, laryngeal dysplasia, and laryngeal SCC who underwent surgical treatment between 2010 and 2020. Immunohistochemistry (IHC) was carried out using specific monoclonal antibodies against CK8, CK10, CK13, and CK17. Two experienced pathologists performed semi-quantitative scoring of IHC positivity. The diagnostic significance of the markers was analyzed. CK13 showed a sensitivity of 100% and a specificity of 82.5% for distinguishing between laryngeal SCC and laryngeal dysplasia and benign lesions. CK17 showed a sensitivity of 78.3% and specificity of 57.1% for the detection of laryngeal SCC vs. laryngeal dysplasia. CK10 showed a sensitivity of 80.0% for discriminating between low-grade and high-grade dysplasia, and a specificity of 61.1%. Loss of CK13 expression is a reliable diagnostic tool for diagnosing laryngeal lesions with malignant potential and determining resection lines. In lesions with diminished CK13 expression, CK17 could be used as an auxiliary immunohistochemical marker in diagnosing laryngeal SCC. In CK13-negative and CK17-positive lesions, CK10 positivity could be used to determine low-grade dysplasia. CK8 is not a useful IHC marker in differentiating between benign laryngeal lesions, laryngeal dysplasia, and laryngeal SCC.

Development of Antibodies against HPV-6 and HPV-11 for the Study of Laryngeal Papilloma

Laryngeal papilloma (LP), which is associated with infection by human papillomavirus (HPV)-6 or -11, displays aggressive growth. The precise molecular mechanism underlying the tumorigenesis of LP has yet to be uncovered. Building on our earlier research into HPV-6, in this study, the viral gene expression of HPV-11 was investigated by quantitative PCR and DNA/RNA in situ hybridization. Additionally, newly developed antibodies against the E4 protein of HPV-6 and HPV-11 were evaluated by immunohistochemistry. The average viral load of HPV-11 in LP was 1.95 ± 0.66 × 10⁵ copies/ng DNA, and 88% of HPV mRNA expression was found to be E4, E5a, and E5b mRNAs. According to RNA in situ hybridization, E4 and E5b mRNAs were expressed from the middle to upper part of the epithelium. E4 immunohistochemistry revealed a wide positive reaction in the upper cell layer in line with E4 mRNA expression. Other head and neck lesions with HPV-11 infection also showed a positive reaction in E4 immunohistochemistry. The distribution pattern of HPV DNA, viral mRNA, and E4 protein in LP with HPV-11 infection was quite similar to that of HPV-6. Therefore, it might be possible to apply these E4-specific antibodies in other functional studies as well as clinical applications, including targeted molecular therapies in patients with HPV-6 and HPV-11 infection.

Immune delineation of laryngeal papilloma reveals enhanced neutrophil associated gene profile

Laryngeal papilloma (LP) is a rare benign disease, caused by recurrent multisite papillomas that are referred to as recurrent respiratory papillomatosis (RRP). RRP is caused primarily by two types of human papillomavirus (HPV): HPV6 and HPV11. The immune dysregulation within the microenvironment of the lesions has been shown to likely play a role in the development of RRP. The present study aimed at analyzing the transcriptional profile of immune response genes and cancer-related genes in the LP microenvironment. We used the NanoString^® nCounter^® analysis system to study expression of 730 genes among seven paired samples of LP and healthy laryngeal (HL) tissue. qRT-PCR and flow cytometric analysis was performed to confirm identified transcripts and follow-up scores of infiltrating immune cells, respectively. In total, 113 differentially expressed transcripts were detected of which 37 showed increased expression levels and 76 decreased expression levels in the LP samples compared to the HL samples (fold change ≥ 2). Transcripts with increased expression levels included S100As (A7, A8, and A12), CEACAM1, neutrophil activation associated cytokines (IL8), chemokines (CXCL6), and IL receptors, e.g., IL4R. Transcripts with decreased expression in LP were associated with innate and adaptive immunity. Overall, HPV6 and 11 were present in 67% and 33% of the patients, respectively. There was a significant increase in neutrophils and a significant decrease in CD8⁺ T cells in LP. LP samples display an immune profile characterized by enhanced expression of neutrophilic markers and significantly reduced T cell-associated markers.

Coordinated Expression of HPV-6 Genes with Predominant E4 and E5 Expression in Laryngeal Papilloma

Laryngeal papilloma (LP) associated with human papillomavirus (HPV)-6 or -11 infection shows aggressive growth. However, the detailed molecular mechanism of virus-driven tumorigenesis has not been uncovered fully. HPV-6 viral gene expression and dynamic alterations were investigated with in situ localization of viral DNA and RNA in 13 patients with HPV-6-infected laryngeal papilloma. The average viral load was 4.80 × 10⁵ ± 1.86 × 10⁵ copies/ng DNA. E4, E5a, and E5b mRNAs accounted for 96% of the expression of 9 mRNAs. The alteration of viral DNA load during recurrence paralleled the mRNA expression levels, and the expression of all mRNAs showed a similar curve. E4, E5a, and E5b were expressed in the middle to upper part of the epithelium and were co-expressed in the same cells. E4 immunohistochemistry demonstrated an extensively positive reaction in the upper cell layer in accordance with E4 mRNA expression. These results suggest that individual viral genes are coordinately expressed for viral replication, virus release, and immunosurveillance avoidance. The newly developed E4-specific monoclonal antibody can be applied to further functional studies and clinical applications such as targeted molecular therapies.

Steering Sheath for 2-Nostril Transnasal Office Laryngoscopy

OBJECTIVE

The aim was to study the feasibility of performing office-based laryngeal procedures employing a flexible hollow steerable sheath placed contralateral to the nostril through which a standard flexible video endoscope is placed.

METHODS

The study design included simulation of transnasal endoscopic laryngeal procedures evaluating the use of a flexible steering sheath in laboratory and clinic settings. Transnasal laryngeal procedures were performed in an otolaryngology office setting employing an airway-management-trainer mannequin and then repeated in a human cadaver lab with standard transnasal flexible video laryngoscopy. Video documentation assessed use of a lever-manipulated deflecting ureteral access sheath with an inner diameter of 2.97 mm, an outer diameter of 4.95 mm, and a length of 45 cm. Simulated transnasal laryngoscopy procedures deployed devices through the deflecting sheath to mimic vocal fold needle injection, biopsy with forceps, balloon dilation, and laser treatment to identify strengths and shortcomings to the technology and technique.

RESULTS

Simulation was successful in appropriately directing instrumentation for all procedures tested. Shortcomings included limitations in steering capacity, greater length to the sheath than desirable for laryngeal procedures, and the need for additional assistants to perform procedures.

CONCLUSION

Steering sheath technology is applicable to enhance in-office transnasal laryngoscopy procedures.

Inverted schneiderian papilloma of the supraglottis: Case report

Inverted schneiderian papillomas are rare benign tumors, most often arising from the sinonasal mucosa. We describe a case of a 59-year-old female with an inverted papilloma of the supraglottis. This is the first reported case of a supraglottic-presenting inverted papilloma. Although rare, this case demonstrates that these tumors should be considered during workup of supraglottic laryngeal masses. Laryngoscope, 127:2830-2832, 2017.

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.

Immunologic responses to a novel DNA vaccine targeting human papillomavirus-11 E6E7

OBJECTIVES/HYPOTHESIS

Recurrent respiratory papillomatosis (RRP) is a benign disease caused by human papillomavirus (HPV) types 6 and 11. Although a prophylactic vaccine against RRP is available, a therapeutic vaccine is needed to treat those already infected. The objective of our study was to design and test a DNA vaccine targeting HPV11 proteins.

STUDY DESIGN

Preclinical scientific investigation.

METHODS

A DNA vaccine encoding the HPV11 E6 and E7 genes linked to calreticulin (CRT) was generated. Immunologic response to the HPV11 CRT/E6E7 vaccine was measured by vaccinating C57BL/6 mice via electroporation and measuring CD8 + T cell responses from harvested splenocytes. A tumor cell line containing HPV11-E6E7 was created, and the ability of novel DNA vaccine to control tumor growth was measured in vivo.

RESULTS

Our vaccine generated a significant and specific CD8 + T-cell response against the HPV11-E6aa41-70 peptide. The CD8 + T-cell responses did not recognize E7 epitopes, indicating E6 immunodominance. CD8 + responses were augmented in the CRT-linked vaccine compared to a control non-CRT vaccine. The HPV11 CRT/E6E7 vaccine was used to treat mice inoculated with a HPV11 E6E7 expressing tumor cell line after temporary CD3 depletion to facilitate tumor growth. Vaccinated mice had a significantly lower tumor growth rate (P = .029) and smaller tumor volumes compared to control mice, indicating an augmented immunologic response in vaccinated mice.

CONCLUSIONS

A DNA vaccine targeting HPV11 E6E7 generates a specific HPV11 CD-8 + T-cell response capable of reducing the growth of HPV11-expressing tumors. DNA vaccines are a promising immunologic strategy for treating RRP.

LEVEL OF EVIDENCE

NA. Laryngoscope, 127:2713-2720, 2017.

Systemic bevacizumab for recurrent respiratory papillomatosis: A national survey

OBJECTIVES/HYPOTHESIS

Aggressive laryngeal, tracheal, and pulmonary papilloma is an extremely challenging clinical problem without proven treatment options. A recent German report documented promising results with systemic bevacizumab. The objective of this study is to report the initial experience of this novel treatment in the United States for recurrent respiratory papillomatosis (RRP).

STUDY DESIGN

Cases series.

METHODS

Electronic survey of the RRP Task Force of the American Society of Pediatric Otolaryngology, American Broncho-Esophagological Association, and physicians known to the authors to have used systemic bevacizumab for RRP.

RESULTS

Eleven completed surveys were obtained. In three cases, systemic bevacizumab was considered clinically but not administered. Eight patients were treated with systemic bevacizumab, all for aggressive papillomatosis uncontrolled by surgical and adjuvant therapy, including seven of eight with pulmonary disease. Treatment dosing ranged from 5 to 10 mg/kg every 2 to 4 weeks, with all patients responding (7/8 partial response, 1/8 complete response). In four patients who had postbevacizumab chest imaging, three demonstrated improvement of disease and one stabilization. Treatment interval could be lengthened in seven patients and clinical response maintained. One patient with long-standing pulmonary disease (>10 years) was diagnosed with malignant transformation while on treatment, and bevacizumab was discontinued in lieu of other chemotherapeutic agents. All other patients continue on systemic bevacizumab with minimal complications (hemoptysis n = 1, proteinuria n = 1).

CONCLUSIONS

Systemic bevacizumab appears to have significant promise in the most treatment-resistant and aggressive forms of papillomatosis with a low complication profile. These results suggest bevacizumab should be studied in a formal clinical trial for RRP.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:2225-2229, 2017.

[Photodynamic therapy by topical drup for the treatment of juvenile onset laryngeal papillomatosis]

Objective:To observe the therapeutic effect of photodynamic therapy(PDT) on the treatment of juvenile onset laryngeal papillomatosis. Method:Twenty-eight cases of children with laryngeal papilloma were treated,only 2 cases for the first time, and the rest were repeatedly treated outside our hospital, the average hospital surgery were more than 4 times. Under self retaining laryngoscope and microscope and endoscope assisted by semiconductor laser and plasma and cold instrument method，visible tumor resection and local affixed deposited 20% 5-aminolevulinic acid(photosensitizer) 3 hours later, with 635 nm semiconductor laser photodynamic,200-280 mW and can volume density of 80 to 120 J/cm², 20 min irradiation. PDT should be repeated after 25 days until no visible tumor.Then,2 times PDT must be done. Result:In 28 cases, 24 cases were followed up for more than 1 years(12 cases were followed up for 3 years),19 had no recurrence, the cure rate was 79.2%(19/24)；5 cases recurrence, and the recurrence rate was 20.8%(5/24)，among them,2 cases were abandoned because of the relapse，the other 3 cases were cure after 3 times of PDT.The main complications were adhesion of larynx. Conclusion:The preliminary effect of PDT by topical drug for the treatment of juvenile onset laryngeal papillomatosis is encouraging. The principle of PDT and the principle of the recurrence of laryngeal papilloma in children were also introduced in this paper.

Anatomic Derkay Score Is Associated with Voice Handicap in Laryngeal Papillomatosis in Adults

OBJECTIVE

The Derkay staging system quantifies recurrent respiratory papillomatosis (RRP) severity based on involvement of laryngeal structures. Despite its broad use in the laryngology literature, the association between Derkay score and voice-related quality of life has not previously been studied. It is hypothesized that Derkay score positively correlates with the Voice Handicap Index-10 (VHI-10).

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary medical center.

SUBJECTS AND METHODS

Forty-six adult RRP patients treated from 2007 to 2013 at a tertiary medical center were included. Anatomic Derkay scores at the time of each RRP procedure were calculated. VHI-10 scores obtained within 30 days preceding the procedures were used to assess for correlation between Derkay staging system and VHI-10.

RESULTS

Ninety-three procedures performed on 46 patients met inclusion criteria. Mean Derkay score was 11.9 (range, 2-28), and mean VHI-10 was 18.0 (range, 0-40). There was a significant positive correlation between Derkay score and VHI-10 (Spearman coefficient r = 0.42, P < .0001).

CONCLUSION

The anatomic burden of RRP as assessed by Derkay staging system is positively correlated with voice-related quality of life as quantified by the VHI-10.

Is recurrent respiratory papillomatosis a manageable or curable disease?

OBJECTIVES

Recurrent respiratory papillomatosis (RRP) is a relatively rare disease with potentially devastating consequences for the patient. The purpose of this study was to evaluate the patterns of recurrence of RRP after surgery and determine the effectiveness of combined concurrent adjuvant therapy.

METHODS

A total of 86 patients were diagnosed with and operated on for RRP. The clinical characteristics of 29 of the 86 patients who had undergone operations at other hospitals and who were followed up for >2 years were evaluated retrospectively. A combined concurrent adjuvant therapy was performed with microlaryngeal surgery, 585-nm pulsed dye laser (PDL) application, and an intralesional cidofovir injection. To evaluate the recurrence pattern, the larynx was divided into 10 subsites, and patients were investigated for the frequency of recurrence at the subsites after the operation.

RESULTS

Twenty-nine subjects required a mean of 3.0 operations to achieve complete remission for 2 years. The most common subsites for recurrence were the anterior commissure, subglottis, and epiglottis according to increasing number of operations. The subsites of recurrence tended to be closely correlated with the laryngeal submucosal glandular density distribution. A complete en-bloc layer excision, including the submucosal glands, using cold instruments decreased the recurrence rate of RRP. Applying PDL minimized scarring and provided significant posttreatment voice-quality improvement.

CONCLUSIONS

The results of the recurrent pattern analysis suggest that a combined concurrent adjunctive treatment might be promising as a cure for RRP and restoration of vocal function after treatment.

LEVEL OF EVIDENCE

4. Laryngoscope, 126:1359-1364, 2016.

Anesthesia management in a child with laryngeal papilloma causing near complete airway obstruction

Recurrent respiratory papillomatosis (RRP) is a rare, chronic disease of viral etiology affecting most commonly larynx. A 5-year-old child with stridor was posted for microlaryngoscopic excision of laryngeal papilloma. We discuss the perioperative management of case with the various ventilation strategies. In child with stridor intubation remains the safest option. It is suggested to maintain spontaneous ventilation until intubation as mask ventilation could be difficult.

Low expression of nuclear Toll-like receptor 4 in laryngeal papillomas transforming into squamous cell carcinoma

OBJECTIVE

The malignant transformation rate of recurrent respiratory papillomatosis (RRP), a disease caused by human papillomavirus (HPV), has varied significantly. Cells of the human immune system express toll-like receptors (TLRs) that recognize particles from viruses and bacteria; TLRs are also present on tumor cells, and down-regulation of TLRs has been shown during the progression of HPV-associated neoplasia. The aim of this study was to determine the malignant transformation rate of laryngeal papillomas (LPs) and analyze the potential of TLR2, TLR4, and TLR9 immunoexpression as indicators of the increased cancer risk.

STUDY DESIGN

Retrospective case-control study.

SETTING

Department of Otorhinolaryngology-Head and Neck Surgery, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.

SUBJECTS AND METHODS

We reviewed all patients with RRP treated for LPs between 1975 and 2011. Data from the Finnish Cancer Registry confirmed the number of patients diagnosed with laryngeal squamous cell carcinoma (LSCC). Laryngeal tissue specimens from patients developing LSCC were subjected to TLR2, TLR4, and TLR9 immunohistochemistry. Nine patients with RRP without malignant transformation and 19 patients with LSCC without a pre-existing LP served as controls.

RESULTS

Nine of 324 patients (2.8%) with RRP developed LSCC. The intensity of nuclear staining of TLR4 was significantly lower in LPs transforming into LSCC than in LPs without malignant transformation. The expression of cytoplasmic TLR4 in LSCC correlated with tumor grade and T stage. Cytoplasmic TLR9 expression was significantly lower in LPs than in LSCC.

CONCLUSION

The expression of TLR4 may serve as a predictive marker of malignant transformation in LPs. High immunoexpression of cytoplasmic TLR4 in LSCC was associated with a more aggressive disease.

Xenograft model for therapeutic drug testing in recurrent respiratory papillomatosis

OBJECTIVE

Identifying effective treatment for papillomatosis is limited by a lack of animal models, and there is currently no preclinical model for testing potential therapeutic agents. We hypothesized that xenografting of papilloma may facilitate in vivo drug testing to identify novel treatment options.

METHODS

A biopsy of fresh tracheal papilloma was xenografted into a NOD-scid-IL2Rgamma(null) (NSG) mouse.

RESULTS

The xenograft began growing after 5 weeks and was serially passaged over multiple generations. Each generation showed a consistent log-growth pattern, and in all xenografts, the presence of the human papillomavirus (HPV) genome was confirmed by polymerase chain reaction (PCR). Histopathologic analysis demonstrated that the squamous architecture of the original papilloma was maintained in each generation. In vivo drug testing with bevacizumab (5 mg/kg i.p. twice weekly for 3 weeks) showed a dramatic therapeutic response compared to saline control.

CONCLUSION

We report here the first successful case of serial xenografting of a tracheal papilloma in vivo with a therapeutic response observed with drug testing. In severely immunocompromised mice, the HPV genome and squamous differentiation of the papilloma can be maintained for multiple generations. This is a feasible approach to identify therapeutic agents in the treatment of recurrent respiratory papillomatosis.

Genetic dysregulation in recurrent respiratory papillomatosis

OBJECTIVES/HYPOTHESIS

Recurrent respiratory papillomatosis (RRP) is a devastating disease, caused by infection of the upper aerodigestive tract with human papillomavirus types 6 and 11. There is no cure for RRP, and surgical removal is the mainstay of treatment. The purpose of this project was to compare genes of cell cycle, apoptosis, and inflammatory cytokines in laryngeal papilloma versus normal tissue for a better understanding of the molecular mechanisms of the disease to discover novel therapies.

STUDY DESIGN

Basic science research study.

METHODS

Papilloma tissue was obtained from patients requiring surgical debridement. For comparison, normal mucosa was obtained from the excised uvula of patients undergoing uvulopalatopharyngoplasty. Total RNA was extracted from both groups and then probed using customized reverse transcriptase real time polymerase chain reaction gene arrays.

RESULTS

The custom arrays examine expression of 84 separate genes within the cell cycle, apoptosis, and inflammatory cytokine pathways. Our findings based on 11 papilloma samples run in comparison to normal mucosa shows that the MCL-1 gene of the apoptosis pathway is significantly downregulated. cytokine genes IL1-A, IL-8, IL-18, and IL-31 are also significantly dysregulated.

CONCLUSIONS

Genes of cell cycle and apoptosis are generally upregulated and downregulated, respectively, as expected in papilloma tissue, with MCL-1 achieving significance when compared to normal tissue. The finding of particular interest is that inflammatory cytokine genes were significantly downregulated, including IL1-A, IL-18, and IL-31. This finding may explain why patients infected with the virus are unable to mediate a T-cell immune clearance of their disease.

In situ hybridization signal patterns in recurrent laryngeal squamous papillomas indicate that HPV integration occurs at an early stage

Laryngeal papillomas are benign tumors that frequently recur and can compromise airways. We investigated HPV genotype, physical status, and protein expression in juveniles versus adults. Thirty-five laryngeal papilloma specimens were obtained from ten juveniles (1-16 years) and eleven adults (24-67 years). In cases of recurrent papillomatosis (7 juveniles, 7 adults), the first and last papillomas were assayed. HPV type was determined by GP5+/6+ PCR and dot blot hybridization. In situ hybridization (ISH) was performed on 34 specimens; the data were recorded in terms of diffuse (episomal HPV) and punctate (integrated HPV) signal patterns. Immunohistochemistry for the HPV L1 capsid protein, a marker of HPV productive status, was performed on 32 samples. All samples tested HPV positive: HPV 11 in 2/10 (20.0%) juveniles and 5/11 (45.5%) adults; HPV 6 in 7/10 (70%) juveniles and 5/11 (45.5%) adults; and HPV 6/11 double infection was noted in one juvenile and one adult. ISH signals (punctate ± diffuse) were detected among 7/10 (70.0%) juveniles and 7/11 (63.6%) adults. L1 staining was detected in 1/9 (11.1%) juveniles and 6/10 (60.0%) adults (P = 0.06). These data support the idea that integration of low-risk HPV types into the cell genome is an early and common event in the etiology of juvenile and adult recurrent laryngeal papillomas. Productive HPV infections may be more common in adults; accordingly, constant laryngeal re-infection by HPV shed from a productive lesion may contribute to adult recurrent lesions, whereas the mechanism of papilloma recurrence in juveniles may be more attributable to HPV integration.