La rhinosinusite chronique (RSC) est une maladie inflammatoire des sinus suffisamment prévalente au Canada et pouvant avoir un impact significatif sur la qualité de vie des patients. Depuis plusieurs années, cette maladie complexe constitue un terrain fertile pour la recherche scientifique. Bien qu’elle soit bien comprise au niveau syndromique, plusieurs mystères persistent quant aux mécanismes physiopathologiques sous-jacents. Ces questionnements pourraient potentiellement expliquer les différences cliniques observées, particulièrement dans les réponses thérapeutiques. Considérant les lacunes persistantes dans la compréhension entière de la maladie, le présent mémoire tente de faire le point sur les endotypes épithéliaux ainsi que sur le pathobiome de la RSC. Dans un premier temps, l’analyse transcriptomique de cellules épithéliales cultivées en laboratoire de patients avec RSC a permis d’identifier deux groupes distincts en termes de marqueurs inflammatoires et de signature épithéliale. Ceci laisse supposer que ces mécanismes physiopathologiques seraient grandement impliqués dans la maladie. Dans un deuxième temps, et dans un objectif exploratoire et de faisabilité, le séquençage d’échantillons de RSC a permis de détecter la présence de virus, laissant présager que ceux-ci pourraient avoir un rôle dans la physiopathologie de la maladie et combler les mystères résiduels dans sa compréhension globale. En conclusion, les endotypes déterminés par le profil d’expression génique permettraient une meilleure classification de la RSC et une meilleure personnalisation des thérapies. De plus, la présence tangible de virus dans la RSC est certainement prometteuse et ouvre une grande porte de recherche. Toutefois, d’autres études seront nécessaires pour mieux caractériser leur nature et leur rôle. / Chronic rhinosinusitis (CRS) is a complex inflammatory disease of the sinuses that is prevalent in Canada and that can significantly affect patients’ quality of life. For several years now, this heterogenous disease have been in the scope of many scientific research. While CRS is clinically well understood, much remains unknown concerning the underlying pathophysiological mechanisms. This could potentially explain the notable clinical differences observed between patients, especially in terms of therapeutic responses. In hope of bridging the gaps in understanding CRS, the present thesis aims to discuss epithelial endotypes as well as the feasibility and potential role of viruses in CRS. Firstly, gene expression profiling revealed two distinct clusters of CRS patients: a group with severe non-Type 2 inflammation and epithelial dysfunction, and a group characterised by moderate non-Type 2 inflammation and epithelial dysfunction. This highlights that these two different mechanisms are involved in the development of CRS. Secondly, and with an exploratory intent, next-generation sequencing and transcriptomic assembly of CRS samples have confirmed the presence of viruses, suggesting that viruses are present in CRS and could possibly play a role in the pathogenesis of this disease, potentially addressing the shortcomings in CRS. To summarize, epithelial endotypes identified by gene expression profiling could aid in better classifying CRS to provide a tailored therapeutic option. The presence of viruses in CRS samples unfolds an interesting chapter in this field. However, larger populations will be required to better characterize the nature of these viruses and to assess their intrinsic role in CRS.

Introdução: O estudo dos fatores clínicos associados ao prognóstico da rinossinusite crônica (rsc), seja associada à polipose nasossinusal (RSCcPN) ou não (RSCsPN), ainda é pouco abordado a longo prazo. Objetivo: Avaliar pacientes submetidos à ESS (cirurgia endoscópica nasal, do inglês endoscopic sinus surgery) para o tratamento de RSC no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, entre 1996 e 2006, e correlacionar a recidiva em longo prazo com parâmetros como a extensão da doença, atopia, tabagismo, asma, eosinofilia e doença respiratória exacerbada pela aspirina (DREA). Métodos: Duzentos e um pacientes foram seguidos por um período médio de 12 anos. Os dados clínicos foram levantados, assim como exames de endoscopia nasal, Tomografia Computadorizada (TC), exames séricos, prick test e prova de função pulmonar. O tempo de seguimento pós-operatório foi analisado, sendo considerado fator de mau prognóstico a indicação de novo procedimento cirúrgico. Foi realizada comparação entre os fatores pela curva de Kaplan-Meyer, e pós-teste de Log-rank. Resultados e Discussão: Pacientes com RSCcPN tiveram chance de nova cirurgia três vezes maior do que aqueles sem pólipos nasais, no período seguido. Entre os pacientes com RSCsPN, apenas a asma foi um fator de pior prognóstico significativo, levando à chance de cirurgia 5,5 vezes maior do que os não-asmáticos. Já entre os pacientes com RSCcPN, aqueles com recidiva apresentaram maior extensão da doença à TC antes da primeira cirurgia. Foram ainda considerados fatores significativamente de pior prognóstico nos pacientes com RSCcPN: asma (odds ratio [OR] de 3,2); atopia a fungos (OR de 1,9); eosinofilia periférica (considerada como >500/µL, levando a OR de 1,9); e intolerância ao Ácido Acetil Salicílico (AAS) (DREA, apresentando OR de 2,5). Conclusões: Concluiu-se que a presença de pólipos per se é fator de pior prognóstico, aumentando em três vezes a chance de recorrência cirúrgica. Entre os pacientes com RSCsPN, apenas a asma influenciou o prognóstico. Já naqueles com RSCcPN, a asma, eosinofilia periférica, atopia a fungos e DREA aumentaram significativamente a probabilidade de nova intervenção cirúrgica. / Introduction: The analysis of prognostic factors associated with the recurrence of chronic rhinosinusitis (CRS), either with nasal polyps (CRSwNP) or without (CRSsNP), is still poorly discussed in the literature. Objective: To evaluate the patients that underwent endoscopic sinus surgery (ESS) due to CRS in Clinics Hospital of Ribeirão Preto Medical School, University of São Paulo, between 1996 and 2006, and to correlate the long-term recurrence to clinical factors, such as extensiveness of the disease, atopy, smoking habits, eosinophilia, and Aspirinexacerbated respiratory disease (AERD). Methods: We collected data of 201 patients, who were followed during an average period of 12 years. Clinical data collected were: extensiveness of the disease at endoscopy and at CT scans, prick test, blood exams, and pulmonary function. The follow-up period after surgery was assessed, and the indication of a new surgical procedure was considered as a poor prognostic factor. Comparison between factors was performed by Kaplan-Meyer curve, with Log-rank post-test. Results and discussion: CRSwNP patients were 3 times more likely to need a revisional surgery than CRSsNP during the follow-up period. Only asthma was a significant prognostic factor in patients with CRSsNP, leading to 5.5 times higher chance of recurrence than non-asthmatic patients. Among patients with CRSwNP, patients with recurrence presented, prior to surgery, higher CT scan extension of the disease. Other factors that influenced the prognosis on CRSwNP were: asthma (odds ratio [OR]: 3.2); atopy for fungi (OR: 1.9); peripheral eosinophilia (considered as >500/?L, leading to an OR: 1.9); and ASA intolerance (AERD; OR: 2.5). Conclusions: The presence of polyps were related to poor prognosis per se, leading to a higher chance of surgical recurrence. Among patients with CRSsNP, only asthma influenced the prognosis. Among the patients with CRSwNP, asthma, peripheral eosinophilia, fungi atopy, and AERD significantly increased the likelihood of further surgical intervention.

Introdução: O tratamento da Rinossinusite Crônica (RSC) tem sofrido poucos avanços nas últimas décadas. Uma das barreiras na aquisição de novas terapias é a falta de conhecimento pleno sobre sua fisiopatogenia. A carência de avanço decorre principalmente da complexa e provável multifatorialidade da RSC, associada à inexistência de um bom modelo animal que possa mimetizar os fenômenos biológicos que ocorrem em humanos. A maioria dos modelos animais de RSC descrita na literatura mimetiza uma infecção aguda ou promove bloqueio das vias de drenagem que, na maioria das vezes, não corresponde aos mecanismos encontrados nas RSC em humanos. Por outro lado, diversas evidências indicam que as bactérias exercem importante papel na fisiopatogenia da RSC, possivelmente pela presença de biofilmes ou indução de inflamação crônica promovida por endo e exotoxinas. Objetivo: Neste estudo avaliou-se a viabilidade de um modelo experimental de RSC em coelhos, utilizando-se a exposição crônica de toxinas bacterianas em animais previamente sensibilizados à ovalbumina (OVA), analisando seus efeitos histopatológicos sobre a mucosa nasossinusal. Material e Métodos: Após indução de sensibilização com injeção subcutânea de OVA 2,5% e 0,4% de hidróxido de alumínio por duas semanas, os coelhos foram submetidos à implantação de cateter de longa duração em seio maxilar direito. Após, foram submetidos à irrigação nasossinusal com OVA 2,5% três vezes por semana, por duas semanas, e em seguida, irrigação de soluções contendo diferentes toxinas bacterianas (enterotoxina estaflocócica B (SEB) 1 ?g/mL, lipopolissacáride (LPS) 100 ng/mL e ácido lipotecóico (LTA) 100 ng/mL) por quatro semanas. Os animais foram sacrificados 24 horas após a última irrigação e a mucosa do seio maxilar direito (teste) e esquerdo (controle interno) foi coletada para avaliação histopatológica. Resultados: A exposição nasossinusal ao SEB causou espessamento epitelial, infiltração celular, eosinofilia e neutrofilia tecidual, além de redução do epitélio ciliado. A exposição ao LPS causou espessamento epitelial e subepitelial, infiltração celular, eosinofilia epitelial e subepitelial e aumento da fibrose subepitelial. O LTA causou espessamento epitelial e subepitelial, infiltração celular e eosinofílica subepitelial e aumento da fibrose subepitelial. Conclusão: A exposição crônica de toxinas bacterianas na mucosa nasossinusal promoveu alterações histológicas, como espessamento da mucosa e infiltração celular, semelhantes às encontradas em pacientes com RSC. O presente estudo demonstrou que este é um modelo animal viável de RSC. Mais estudos serão necessários para elucidar se os mecanismos patogênicos deste modelo são semelhantes aos observados em humanos. / Background: The treatment of chronic rhinosinusitis (CRS) has had little evolvement in the last decades. One of the barriers to the development of new therapies is the lack of knowledge about CRS pathophysiology. The complexity and multifactoriality of this disease, together with the inexistence of a proper animal model of CRS, are probably the causes for the few advances in CRS therapy. Most of the animal models of CRS resemble acute infection or promote sinonasal obstructions, which are not a very common etiologies in CRS patients. However, there has been a lot of evidence that bacteria play an important role in the pathophysiology of CRS, probably due to the presence of biofilms, or the chronic inflammation induced by endo e exotoxins. Objective: This study aims to evaluate the viability of an experimental model of CRS in rabbits through the use of bacterial toxins in previously sensitized animals with ovalbumin, analyzing its histopathological effects onto the sinonasal mucosa. Materials and Methods: After inducing ovalbumin (OVA) sensitization by intradermic injection of OVA 2,5% and 0,4% aluminum hydroxide for 2 weeks, rabbits underwent maxillary sinus instillation of OVA 2,5% three times a week for 2 weeks followed by sinus lavage with either one bacterial toxin (Staphylococcus aureus enterotoxin B (SEB) 1 ?g/mL, lipopolysaccharide (LPS) 100 ng/mL, lipoteichoic acid (LTA), 100 ng/mL) for 4 weeks. Rabbits were euthanised 24 hours after the last sinus lavage and the mucosa of right maxillary sinus (tested side) and left side (control) were collected for histopathological evaluation. Results: The sinonasal exposure to SEB resulted in epithelial thickening, inflammatory cells infiltration (tissue eosinophilia and neutrophilia) and reduction of ciliated cells. The exposure to LPS resulted in epithelial and subepithelial thickening, inflammatory cells infiltration, epithelial and subepithelial eosinophilia and increased subepithelial fibrosis. The exposure to LTA resulted in epithelial and subepithelial thickening, subepithelial inflammatory cells infiltration and eosinophilia and increased subepithelial fibrosis. Conclusion: This study reported the effects of bacterial toxins on the the sinonasal mucosa of ovalbumin-sensitized rabbits, demonstrating similar changes that are observed in CRS patients. Our results show that this is a viable animal model of CRS. Further studies are need to elucidate whether the pathomechanisms in this model are similar to what are observed in humans.

Introduction : La chronicité de la rhinosinusite, sa résistance aux antibiotiques, et ses exacerbations aiguës laissent croire que les biofilms sont impliqués dans la rhinosinusite chronique. Objectifs : Nous avons évalué la capacité des bactéries Pseudomonas aeruginosa, staphylocoques à coagulase négative et Staphylococcus aureus à former des biofilms par un essai in vitro, et si cette capacité de formation a un lien avec l’évolution de la maladie. Nous avons évalué in vitro l’effet de la moxifloxacine, un antibiotique utilisé dans le traitement de la rhinosinusite chronique sur des biofilms matures de Staphylococcus aureus. Méthodes : Trent et une souches bactériennes ont été isolées de 19 patients atteints de rhinosinusite chronique et qui ont subit au moins une chirurgie endoscopique des sinus. L’évolution de la maladie a été notée comme "bonne" ou "mauvaise" selon l’évaluation du clinicien. La production de biofilm a été évaluée grâce à la coloration au crystal violet. Nous avons évalué la viabilité du biofilm après traitement avec la moxifloxacine. Ces résultats ont été confirmés en microscopie confocale à balayage laser et par la coloration au LIVE/DEAD BacLight. Résultat et Conclusion : Vingt deux des 31 souches ont produit un biofilm. La production d’un biofilm plus importante chez Pseudomonas aeruginosa et Staphylococcus aureus était associée à une mauvaise évolution. Ceci suggère un rôle du biofilm dans la pathogenèse de la rhinosinusite chronique. Le traitement avec la moxifloxacine, à une concentration de 1000X la concentration minimale inhibitrice réduit le nombre des bactéries viables de 2 à 2.5 log. Ces concentrations (100 µg/ml - 200 µg/ml) sont faciles à atteindre dans des solutions topiques. Les résultats de notre étude suggèrent que l’utilisation de concentrations supérieure à la concentration minimale inhibitrice sous forme topique peut ouvrir des voies de recherche sur de nouveaux traitements qui peuvent être bénéfiques pour les patients atteints de forme sévère de rhinosinusite chronique surtout après une chirurgie endoscopique des sinus. / Introduction: The role of biofilms in chronic diseases is increasingly recognized. Chronic rhinosinusitis, with its chronic indolent course, resistance to antibiotics, and acute exacerbations, has an evolution that parallels that of other biofilm-related diseases. Objectives: 1-To develop an in vitro method to assess the biofilm formation capacity. 2- To determine whether biofilm-forming capacity of bacteria demonstrated in chronic rhinosinusitis has an impact on persistence of the disease following endoscopic sinus surgery. 3- To determine the in vitro activity of moxifloxacin against Staphyylococcus aureus in biofilm form. Method: Thirty-one bacterial strains recovered from 19 patients with chronic rhinosinusitis at least one year post-endoscopic sinus surgery. Evolution of disease was assessed by questionnaire and endoscopy as favorable or unfavorable. The bacteria were cultured on a 96-well culture plaque and a semi-quantitative method using crystal violet to quantify biofilm production was used. Confirmation of the effect of the antimicrobial agents on viability was performed with confocal laser microscopy, using a LIVE/DEAD BacLight staining. Results: Twenty-two of 31 samples produced a biofilm thicker or equal to the positive control. Biofilm formation was associated with a poor evolution for Pseudomonas aeruginosa and Staphylococcus aureus, but not for coagulase-negative staphylococci. Biofilm treated with moxifloxacin at 1000X (0.1mg/ml – 0.2 mg/ml) gave a 2 to 2.5 log reduction in number of viable bacteria. Conclusion: We have shown that Crystal violet method is able to detect biofilm formation. There is a correlation between in vitro biofilm production by Pseudomonas aeruginosa and Staphylococcus aureus and unfavorable evolution after endoscopic sinus surgery, suggesting a role for biofilm in chronic rhinosinusitis. Increased concentrations of moxifloxacin, easily attainable in topical solutions have a potential role in the management of biofilm infections.

Introduction : La chronicité de la rhinosinusite, sa résistance aux antibiotiques, et ses exacerbations aiguës laissent croire que les biofilms sont impliqués dans la rhinosinusite chronique. Objectifs : Nous avons évalué la capacité des bactéries Pseudomonas aeruginosa, staphylocoques à coagulase négative et Staphylococcus aureus à former des biofilms par un essai in vitro, et si cette capacité de formation a un lien avec l’évolution de la maladie. Nous avons évalué in vitro l’effet de la moxifloxacine, un antibiotique utilisé dans le traitement de la rhinosinusite chronique sur des biofilms matures de Staphylococcus aureus. Méthodes : Trent et une souches bactériennes ont été isolées de 19 patients atteints de rhinosinusite chronique et qui ont subit au moins une chirurgie endoscopique des sinus. L’évolution de la maladie a été notée comme "bonne" ou "mauvaise" selon l’évaluation du clinicien. La production de biofilm a été évaluée grâce à la coloration au crystal violet. Nous avons évalué la viabilité du biofilm après traitement avec la moxifloxacine. Ces résultats ont été confirmés en microscopie confocale à balayage laser et par la coloration au LIVE/DEAD BacLight. Résultat et Conclusion : Vingt deux des 31 souches ont produit un biofilm. La production d’un biofilm plus importante chez Pseudomonas aeruginosa et Staphylococcus aureus était associée à une mauvaise évolution. Ceci suggère un rôle du biofilm dans la pathogenèse de la rhinosinusite chronique. Le traitement avec la moxifloxacine, à une concentration de 1000X la concentration minimale inhibitrice réduit le nombre des bactéries viables de 2 à 2.5 log. Ces concentrations (100 µg/ml - 200 µg/ml) sont faciles à atteindre dans des solutions topiques. Les résultats de notre étude suggèrent que l’utilisation de concentrations supérieure à la concentration minimale inhibitrice sous forme topique peut ouvrir des voies de recherche sur de nouveaux traitements qui peuvent être bénéfiques pour les patients atteints de forme sévère de rhinosinusite chronique surtout après une chirurgie endoscopique des sinus. / Introduction: The role of biofilms in chronic diseases is increasingly recognized. Chronic rhinosinusitis, with its chronic indolent course, resistance to antibiotics, and acute exacerbations, has an evolution that parallels that of other biofilm-related diseases. Objectives: 1-To develop an in vitro method to assess the biofilm formation capacity. 2- To determine whether biofilm-forming capacity of bacteria demonstrated in chronic rhinosinusitis has an impact on persistence of the disease following endoscopic sinus surgery. 3- To determine the in vitro activity of moxifloxacin against Staphyylococcus aureus in biofilm form. Method: Thirty-one bacterial strains recovered from 19 patients with chronic rhinosinusitis at least one year post-endoscopic sinus surgery. Evolution of disease was assessed by questionnaire and endoscopy as favorable or unfavorable. The bacteria were cultured on a 96-well culture plaque and a semi-quantitative method using crystal violet to quantify biofilm production was used. Confirmation of the effect of the antimicrobial agents on viability was performed with confocal laser microscopy, using a LIVE/DEAD BacLight staining. Results: Twenty-two of 31 samples produced a biofilm thicker or equal to the positive control. Biofilm formation was associated with a poor evolution for Pseudomonas aeruginosa and Staphylococcus aureus, but not for coagulase-negative staphylococci. Biofilm treated with moxifloxacin at 1000X (0.1mg/ml – 0.2 mg/ml) gave a 2 to 2.5 log reduction in number of viable bacteria. Conclusion: We have shown that Crystal violet method is able to detect biofilm formation. There is a correlation between in vitro biofilm production by Pseudomonas aeruginosa and Staphylococcus aureus and unfavorable evolution after endoscopic sinus surgery, suggesting a role for biofilm in chronic rhinosinusitis. Increased concentrations of moxifloxacin, easily attainable in topical solutions have a potential role in the management of biofilm infections.

La rhinosinusite chronique (RSC) est une maladie avec une haute prévalence au Canada et des impacts économiques et individuels importants. Une des options thérapeutiques dans l’algorithme complexe de traitement est la chirurgie endoscopique des sinus (CES), qui est préconisée chez les patients qui ont une réponse insatisfaisante à la thérapie médicale. Le présent mémoire porte sur les critères minimaux nécessaires à l’atteinte du succès en matière de CES. Dans un premier temps, une consultation d’experts en RSC Canadiens provenant de 12 institutions nous a permis d’offrir des définitions du succès acceptable ainsi que du succès optimal du point de vue des prestataires de santé. Dans un deuxième temps, une étude auprès de 22 patients souffrant de RSC nous a permis d’identifier les thèmes importants qui doivent guider le processus décisionnel collaboratif. La première étude a permis de conclure qu’une définition du succès post-opératoire en CES se doit de comporter 2 composantes : un aspect objectif (endoscopie nasale) et un aspect subjectif (test d’issues mesurées par le patient ou questionnaire spécifique). Selon les experts, pour parler de succès optimal il faut une résolution complète des symptômes ainsi qu’un résultat endoscopique parfait. La deuxième étude a permis de démontrer que les patients accordent beaucoup plus d’importance à la résolution du symptôme cardinal qui les a amenés à consulter. Cette dernière étude a également permis une exploration plus large des objectifs et attentes, ainsi que de l’expérience patient en ce qui a trait à la RSC et à la CES. En conclusion, l’évaluation des aspects subjectifs devrait être l’aspect le plus important que les cliniciens évaluent pour parler de succès. Une évaluation de la cavité nasale et des sinus devrait complémenter cette évaluation environ 3 mois après la chirurgie. Ce mémoire inclus des algorithmes pour aider les cliniciens dans l’évaluation du succès opératoire après une CES. / Chronic rhinosinusitis (CRS) is a prevalent, complex disease with important economic and individual impacts. Functional endoscopic sinus surgery (FESS) is widely used treatment for CRS, which is considered in patients with an unsatisfactory response to maximal medical therapy. This thesis examines the different ways clinicians may obtain feedback with regards to post-operative success and aims to offer definitions of acceptable success and optimal success. First, a consultation of Canadian experts in CRS from 12 institutions permitted us to construct definitions of acceptable and optimal success from healthcare providers’ viewpoint. Second, a study in collaboration with 22 patients suffering from CRS allowed us to identify key themes which will facilitate the inclusion of primary stakeholders in shared decision-making. The first study allowed us to conclude that a definition of postoperative success must be based on 2 components: an objective aspect (nasal endoscopy) and a subjective aspect (patient-reported outcome measure or specific questionnaire). According to experts, optimal success requires a complete resolution of symptoms as well as a perfect endoscopic result. With the second study, we demonstrated that patients tend to focus on the resolution of their cardinal symptom. This last study also allowed us to widely explore patients’ objectives and expectations, as well as their experience with CRS and FESS. In conclusion, subjective aspects should be the most important determinants of success after FESS. In addition, an evaluation of the nasal cavity and sinuses should complement the subjective evaluation approximately 3 months after surgery. This thesis includes algorithms to aid clinicians in evaluating the outcome of FESS for patients with CRS.