As influências etárias do sistema imune de bezerros são descritas na primeira fase de vida desses animais e a hipótese de também ocorrerem ariações nos principais mecanismos de resposta inata do pulmão pode identificar períodos de maior suscetibilidade às principais doenças respiratórias que acometem os bezerros nesse período. Com a finalidade de minimizar os prejuízos econômicos associados às doenças respiratórias em bezerros, este estudo objetivou avaliar a dinâmica imunológica inata do sistema respiratório de bezerros sadios nos três primeiros meses de vida, no qual nove bezerros sadios foram acompanhados por três meses e submetidos a oito avaliações imunológicas. O material recuperado do lavado broncoalveolar colhido por broncoscopia foi submetido à avaliação funcional dos macrófagos alveolares utilizando as provas de fagocitose (SaPI e E.coli), burst oxidativo, quantificação de imunoglobulinas e expressão de CD14. Os dados foram avaliados pelo teste ANOVA oneway (unstacked) (paramétricos) e pelo teste Mann-Whitney (não paramétricos). Verificaramse alterações funcionais de fagócitos CD14+, que apesar de se manterem constantes em seus valores relativos durante todo o período, apresentou intensidade de fagocitose elevada pontual na terceira semana de vida e um aumento da fagocitose por mononucleares CD14+ aos 45 dias de idade com diminuição da intensidade da fagocitose por essas mesmas células a partir dessa idade. Conclui-se que a partir de 45 dias de vida os animais começam a montar uma resposta imune própria, porém pontual e que até os 90 dias não atingem a estabilidade necessária para atestar a conclusão do processo de maturação da resposta inata local. / The influences of age in calves\' immune system are described in their first phase of life. The hypothesis that variations occur in the main mechanisms of lung innate response can help to identify periods of greater susceptibility to the respiratory diseases that affect calves in the first stage of their life. With the purpose of minimizing the economic losses associated with respiratory disease in calves, this study aimed to evaluate the innate immune dynamics of the respiratory system of healthy calves in the first three months of life. Nine healthy calves were monitored for three months and eight immunologic evaluations were performed. Bronchoalveolar lavage samples were recovered by bronchoscopy. Then, the alveolar macrophages in samples were identified by protein expression of CD14 and undergone functional evaluation of phagocytosis (SAPI and E.coli) and oxidative burst. Immunoglobulin were also quantified in samples. Data was assessed by one-way ANOVA (unstacked) (parametric) and the Mann-Whitney test nonparametric). Functional alterations in phagocytes CD14 + were observed, and although their relative values were kept throughout the period, higher intensity of phagocytosis in the third week and increased phagocytosis by macrophages CD14 + at 45 days of life was observed. Decreased intensity of phagocytosis was observed after this age. It is concluded that from 45 days of life on, calves began to maintain their immune response, but until 90 days of life they did not achieve the stability to conclude the maturation of local innate response.

A Mannheimia haemolytica é uma importante bactéria relacionada ao Complexo Doença Respiratória dos Bovinos e a essa atribui-se uma evolução para uma forma grave de pneumonia fibrinonecrótica. É considerada um habitante comensal da nasofaringe que em situações de comprometimento da resposta imune adquire um perfil oportunista. O presente estudo buscou observar por meio de modelo de infecção experimental, as possíveis alterações locais e sistêmicas causadas pela M. haemolytica em bezerros experimentalmente inoculados. Dessa forma seria possível de maneira longitudinal, acompanhar a dinâmica dos principais aspectos de defesa das vias aéreas posteriores durante a infecção e após o tratamento com o antimicrobiano norfloxacina associado ou não à flunexina meglumina. Avaliou-se por exame físico acrescido de broncoscopia, alterações funcionais das células de defesa e mediadores inflamatórios, tanto séricos quanto locais e a atividade in vitro da norfloxacina sobre a função dos fagócitos sanguíneos e do lavado broncoalveolar (LBA). Para tal foram utilizados 12 bezerros sadios que foram experimentalmente infectados por M. haemolytica dos quais foram avaliadas as alterações clínicas e, quantitativamente e funcionalmente, as populações leucocitárias no sangue e no LBA, assim como o efeito da norfloxacina sobre a atividade funcional dos fagócitos no sangue e no LBA. Os resultados do presente estudo demonstraram o sucesso da infecção experimental por M. haemolytica pelos achados clínicos, broncoscópicos e citológicos. Ademais, a infecção experimental por M. haemolytica foi associada a alterações nas subpopulações de linfócitos T CD8+ e уδ, na produção intracelular de espécies reativas de oxigênio (ERO), fagocitose e viabilidade pelas células CD14+ sanguíneas e do LBA e granulócitos do sangue e, expressão de L-selectina pelos leucócitos polimorfonucleares do sangue. Nenhuma alteração evidente foi observada na expressão de citocinas IL-1β, IL-8 e TNF-α nas células sanguíneas e do LBA. O tratamento com antimicrobiano associado ou não ao anti-inflamatório foi capaz de curar a infecção e reestabelecer os parâmetros avaliados à sua condição basal. Portanto, não se observou benefícios com a utilização adicional do anti-inflamatório no reestabelecimento do quadro clínico e da resposta imune neste experimento. Contudo, apesar de algumas alterações na resposta sistêmica durante o quadro infeccioso, as alterações locais foram mais perceptíveis. Outro aspecto importante encontrado foi o efeito in vitro da norfloxacina na produção intracelular de ERO, fagocitose bacteriana pelas células CD14+ sanguíneas e do LBA e em leucócitos polimorfonucleares no sangue. Conclui-se que as alterações funcionais dos fagócitos apresentaram papel importante na patogenia da mannheimiose, que foram condizentes com os achados clínicos da mannheimiose e da evolução do tratamento quando realizado no início do processo nosológico. / Mannheimia haemolytica is an important bacterial pathogen associated with Bovine Respiratory Disease Complex (BRDC) and it is believed to be the predominant cause of the disease’s evolution into a fibrinonecrotic pneumonia. A commensal inhabitant of the nasopharynx, M. haemolytica acts as an opportunist when host defenses are compromised. This study used an experimental infection model to investigate the possible local and systemic changes caused by M. haemolytica in inoculated calves. It sought to linearly follow the dynamics of the lower respiratory tract defense mechanisms, during the course of infection and after treatment with the antibacterial norfloxacin, which was administrated both with and without the anti-inflammatory flunixin meglumine. With clinical examination followed by bronchoscopy, this study evaluated the physiological modifications in defense cells and mediators of inflammation, and the in vitro influence of norfloxacin on phagocytes from the peripheral blood and Bronchoalveolar Lavage Fluid (BLF). Twelve (12) healthy calves were infected with M. haemolytica and posteriorly physically examined, and had samples of white cells from the peripheral blood and BLF analyzed for changes in count and physiology, further, the norfloxacin effect on phagocytes from the peripheral blood and BLF was also studied. The experimental infection proved itself to be successful based on clinical, bronchoscopic and cytological findings. Furthermore, the M. haemolytica experimental infection was associated with modifications in the subpopulations of lymphocytes CD8+ and уδ T cells, in intracellular production of Reactive Oxygen Species (ROS), viability and phagocytosis activity of CD14+ cells from the peripheral blood and BLF and granulocytes from the peripheral blood. No obvious change was observed in the expression of cytokines IL-1β, IL-8 e TNF-α by cells from the peripheral blood or BLF. The treatment with the antibacterial agent, with or without the anti-inflammatory, was proved to be successful in curing the disease, thus, the addition of an anti-inflammatory was considered unnecessary to revert the clinical infection and in the immune response. Although there was a systemic response during the course of infection, the local response was more noticeable. Another key finding of the present study was the in vitro effect of norfloxacin on the intracellular production of ROS and on phagocytosis activity of CD14+ cells from the peripheral blood and BLF and granulocytes from the peripheral blood. In conclusion, the functional changes in phagocytes play an important role in the pathogenesis of pulmonary infection caused by M. haemolytica, as they were consistent with the clinical findings of mannheimiosis and with the treatment when it was administrated in the beginning of the infection.

Doctor of Philosophy / Department of Anatomy and Physiology / David C. Poole / Exercise-induced pulmonary hemorrhage (EIPH) or epistaxis has been recognized in racehorses since the 16th century. Since this time, great strides have been made in terms of identifying the lungs as the source of the hemorrhage via the endoscope, utilization of bronchoalveolar lavage to quantify the hemorrhage, and the discovery of successful treatments such as furosemide and the nasal strip that ameliorate, but do not abolish EIPH. It has been determined that, in addition to extremely high pulmonary arterial pressures and the negative intrapleural pressures being the major physiologic forces causing pulmonary capillary stress failure, other factors have the potential for influencing the severity of EIPH including locomotory impact trauma, inflammatory airway disease (IAD), upper airway obstruction, coagulation anomalies, and high blood viscosity. It has been hypothesized that EIPH is detrimental to performance and this was recently confirmed by Hinchcliff et al. in 2004. EIPH is a complex multi-factorial condition with much still unknown about the etiology, best method for diagnosis, and most effective form of treatment. Chapter one of this dissertation determined the effectiveness of a novel treatment, concentrated equine serum, in ameliorating EIPH via reduction of IAD. Chapter two refuted the hypothesis that herbal formulations commonly used in the field with anecdotal success would decrease EIPH by correcting coagulation deficits during exercise, as scientific efficacy was not evident, at least at the dose and duration used in our investigation. Chapter three addressed the dogma that EIPH only occurs during maximal intensity exercise, and in demonstrating significant EIPH during sub-maximal exercise, emphasized the role that the airways play in contributing to the initiation and severity of EIPH. Chapter four examined the occurrence and severity of EIPH in the horse’s canine counterpart, the racing Greyhound. The demonstrated presence of mild EIPH in the Greyhound, a physiologically similar yet different athlete in comparison to the horse sheds new light on the etiology of this condition in both species. The results of these investigations have advanced the frontiers of our knowledge concerning EIPH. Specifically, they have generated novel information on the mechanistic bases of EIPH and have provided evidence supporting additional treatment options for reducing the severity of EIPH in horses.

Há diversas evidências epidemiológicas de correlações positivas entre indicadores de morbidade e mortalidade pulmonar e cardiovascular e aumentos na concentração atmosférica de MP2,5 (material particulado fino). O objetivo deste trabalho foi avaliar os efeitos da exposição subcrônica de MP2,5 sobre o tônus cardíaco autonômico, a inflamação pulmonar e sistêmica; o estresse oxidativo e a homeostase sanguínea, após oito semanas de repetidas instilações nasais de suspensão aquosa de MP2,5 da cidade de São Paulo em concentração ambiental. Dividiram-se os animais em dois grupos: salina e MP2,5 e avaliaram-se os seguintes parâmetros: frequência cardíaca (FC), variabilidade da frequência cardíaca (VFC), pressão arterial sistólica (PA), hemograma, contagem de plaquetas e reticulócitos, fibrinogênio plasmático, tempo de protrombina (TP), tempo de tromboplastina parcialmente ativada (TTPA), mielograma, citologia do lavado broncoalveolar (LBA), análise histopatológica e imuno-histoquímica (15-F2tisoprostano e -actina) de pequenas arteríolas pulmonares e coronarianas. Não houve alterações na FC e na PA (p > 0,05). Houve interação estatisticamente significante entre grupos e semanas em relação à VFC. O SDNN (desvio padrão dos intervalos R-R normais), a r-MSSD (raiz quadrada da média dos quadrados das diferenças sucessivas entre intervalos R-R normais adjacentes) e a AF (alta frequência) do grupo MP2,5 aumentaram significativamente na 7ª semana em comparação à 1ª semana (p < 0,05), enquanto a BF (baixa frequência) não se alterou (p > 0,05). A porcentagem de macrófagos no LBA do MP2,5 diminuiu significativamente (p < 0,05). Não se observaram alterações no sangue, mielograma e análise histopatólogica e imuno-histoquímica dos vasos (p > 0,05). Concluiu-se que a exposição subcrônica pela instilação nasal de suspensão aquosa de MP2,5 em concentração ambiental causou inflamação pulmonar tênue e alterou o equilíbrio cardíaco autonômico / There are several epidemiological evidences of positive correlation between indicators of pulmonary and cardiovascular morbidity and mortality and increases of PM2.5 (fine particulate matter) air concentration. The aim of this experiment was to evaluate the effects of subchronic exposure of PM2.5 on cardiac autonomic tone, pulmonary and systemic inflammation, oxidative strees and blood homeotasis of healthy rats after eight weeks of repeated nasal instillations of suspended PM2.5 from Sao Paulo city in environmental concentration. Rats were divided in two groups: saline and PM2.5. The following parameters were evaluated: heart rate (HR), heart rate variability (HRV), systolic blood pressure (BP), hemogram, platelets and reticulocytes count, plasmatic fibrinogen, prothrombin time (PT), activated partial thromboplastin time (APTT), bone marrow cells, bronchoalveolar lavage cells (BAL), histopathological and immunohistochemical analysis (15-F2tisoprostane and -actin) of pulmonary and coronary small arterioles. No changes were detected in HR and BP (p > 0.05). There were a statistically significant interaction between groups and weeks in relation to HRV. SDNN (standard deviation of normal RR intervals), r-MSSD (square root of the mean of the squared differences between adjacent normal RR intervals) and HF (high frequency) of PM2.5 group significantly increased on 7th week compaired to 1st week (p < 0.05), while LF (low frequency) did not alter (p > 0.05). BAL macrophages porcentage of PM2.5 group significantly decreased (p < 0.05). No alterations were observed in blood, bone marrow cells, histopathological and immunohistochemical analysis of vessels (p > 0.05). We concluded that subchronic exposure by nasal instillation of aquous suspension of PM2.5 in environmental concentration caused tenuous pulmonary inflammation and altered cardiac autonomic balance

Nós investigamos o perfil inflamatório do lavado broncoalveolar (LBA) em crianças portadoras de asma de difícil controle apesar do tratamento com corticóide oral e sua relação com parâmetros clínicos e funcionais. O LBA foi realizado em 24 crianças com asma de difícil controle (13M/11F; idade média de 13 anos) e 5 controles. Houve aumento do número de neutrófilos em 15 das 24 crianças (60%) portadoras de asma de difícil controle (mediana 15%, 5-43%) e aumento de eosinófilos em 5 pacientes (mediana 9%, 6.5%-18.5%). Observou-se uma correlação entre a necessidade de corticóide oral e o número de internações e o percentual de eosinófilos no LBA. Ocorreu uma tendência de maiores números de neutrófilos no lavado e uma pior função pulmonar. Nós identificamos dois subgrupos de crianças portadoras de asma de difícil controle com características clínicas e funcionais distintas. Pacientes com aumento do percentual de neutrófilos tendem a apresentar uma pior função pulmonar. Um pequeno número de pacientes apresentou um padrão eosinofílico no lavado broncoalveolar com função pulmonar normal, porém sinais de instabilidade clínica. / Therapy resistant asthma is a major clinical problem in childhood. We investigated the inflammatory cell profile in the airways of children with severe asthma despite systemic steroid treatment and the relationship with clinical and functional severity. Bronchoalveolar lavage (BAL) was performed in 24 children with severe asthma (13M/11F; mean age 12.5 yrs, range 5-l4 yrs), and 5 controls. All received prednisolone prior to BAL. Neutrophils were the predominant inflammatory cell type in BAL in 15/24 (60%) children with asthma (median 15%, 5-43%).and only 5 patients had increases in eosinophils (median 9%, 6.5%-18,5%). There was a correlation between higher BAL eosinophils and more admissions Patients with higher BAL neutrophils showed a trend for lower pre-BAL lung function. We identified subgroups of children with severe asthma presenting different clinical and functional characteristics. Patients with increased percentages in BAL neutrophils showed a trend for lower lung function. A small number of patients presented eosinophilic airway inflammation in BAL with virtually normal lung function but showing signs of clinical instability.

Introdução: Vários modelos experimentais para o estudo da síndrome do desconforto respiratório do tipo agudo (SDRA) foram desenvolvidos, sendo o modelo de lavagem pulmonar o mais utilizado. No entanto, a técnica originalmente descrita foi modificada por outros autores, tornando difícil a reprodutibilidade deste modelo experimental. Objetivos: Avaliar os efeitos do recrutamento pulmonar, do uso de volumecorrente fixo e do uso de diferentes volumes de lavagem na instalação do modelo experimental de SDRA, em relação ao número de lavagens necessárias para a obtenção do modelo experimental, a mortalidade e a estabilidade hemodinâmica durante o procedimento. Metodologia: Coelhos adultos da raça New-Zealand-White, foram divididos em 5 grupos de estudo, de acordo com a técnica utilizada para a lavagem pulmonar: 1- Volume-corrente (Vt) fixo de 10 ml/kg, volume de lavagem de 30 ml/kg, sem recrutamento pulmonar; 2- Pressão inspiratória (Pinsp) fixa, com um volume de lavagem de 30 ml/kg, sem recrutamento pulmonar; 3- Vt fixo, com um volume de lavagem de 25 ml/kg sem recrutamento pulmonar; 4- Pinsp fixa, com volume de lavagem de 25 ml/kg sem recrutamento pulmonar; 5- Vt fixo, com volume de lavagem de 30 ml/kg, com recrutamento pulmonar antes da primeira lavagem. Os animais foram submetidos a repetidas lavagens pulmonares com soro fisiológico aquecido em intervalos de 5 minutos, até se atingir o critério de definição de SDRA, estabelecido como uma relação PaO2/FiO2 <= 100. Resultados: Não foram encontradas diferenças entre os grupos em relação ao número de lavagens necessárias para a instalação do modelo experimental. O uso de recrutamento alveolar prévio e a utilização de pressão inspiratória fixa com volume de lavagem de 25 ml/kg foi associado a uma tendência à maior mortalidade. Embora não se tenha observado diferenças na estabilidade hemodinâmica entre os grupos de estudo, os animais ventilados com Pinsp fixa apresentaram uma pior ventilação alveolar com valores mais baixos de pH em relação aos animais ventilados com Vt fixo. Conclusões: A utilização de manobra de recrutamento alveolar, a uso de um volume-corrente fixo ou pressão inspiratória fixa entre as lavagens, e a utilização de diferentes volumes de lavagem (25 e 30 ml/kg) não modificaram o número de lavagens necessárias para a obtenção do modelo experimental de SDRA, assim como não modificaram a estabilidade hemodinâmica dos animais durante a realização do procedimento. Foi observada uma tendência à maior mortalidade com a realização da manobra de recrutamento alveolar e com o uso de pressão inspiratória fixa associado ao volume de lavagem de 25 ml/kg. / Background: Many experimental models were developed for the study of the acute respiratory distress syndrome (ARDS), and the lung lavage model is the more frequently used. The original technique was modified by many authors, resulting in difficulties for this experimental model reproducibility. Objectives: To evaluate the effects of the pulmonary recruitment, the use of fixed tidal-volume and different lavage volumes at the experimental ARDS model installation, regarding to the number of lung lavages necessary to obtain the experimental model, the mortality and the hemodynamic stability during the procedure. Methods: New-Zealand-White adult rabbits were divided into 5 study groups, according to the technique used: 1- Fixed tidal-volume (Vt) of 10 ml/kg, lavage volume of 30 ml/kg, no pulmonary recruitment; 2- Fixed inspiratory pressure (IP), lavage volume of 30 ml/kg, no pulmonary recruitment; 3- Fixed Vt, lavage volume of 25 ml/kg, no pulmonary recruitment; 4- Fixed IP, lavage volume of 25 ml/kg, no pulmonary recruitment; 5- Fixed Vt, lavage volume of 30 ml/kg, using pulmonary recruitment. The animals were submitted to repeated lung lavages with warm saline at 5 min interval until the ARDS definition(PaO2/FiO2 <= 100) be reached. Results: There was no differences among the study groups regarding the number of lung lavages necessary to obtain the experimental model. The use of alveolar recruitment before the first lavage and the use of fixed ventilatory pressure with 25 ml/kg lavage volume were associated with trend to a higher mortality rate. Although there were no differences regarding the hemodynamic stability among the study groups, animals ventilated with fixed inspiratory pressure had worse alveolar ventilation with higher levels of PaCO2 and lower pH. Conclusions: The use of alveolar recruitment maneuvers, the use of a fixed tidal-volume or inspiratory pressure between the lung lavages and the utilization of different lavage volumes did not change the number of lung lavages necessary to obtain the experimental model of ARDS or the hemodynamic stability of the animals during the procedure. It was observed a trend to an increased mortality rate with the recruitment maneuver and with the use of a fixed inspiratory pressure associated to the lavage volume of 25 ml/kg.

Nós investigamos o perfil inflamatório do lavado broncoalveolar (LBA) em crianças portadoras de asma de difícil controle apesar do tratamento com corticóide oral e sua relação com parâmetros clínicos e funcionais. O LBA foi realizado em 24 crianças com asma de difícil controle (13M/11F; idade média de 13 anos) e 5 controles. Houve aumento do número de neutrófilos em 15 das 24 crianças (60%) portadoras de asma de difícil controle (mediana 15%, 5-43%) e aumento de eosinófilos em 5 pacientes (mediana 9%, 6.5%-18.5%). Observou-se uma correlação entre a necessidade de corticóide oral e o número de internações e o percentual de eosinófilos no LBA. Ocorreu uma tendência de maiores números de neutrófilos no lavado e uma pior função pulmonar. Nós identificamos dois subgrupos de crianças portadoras de asma de difícil controle com características clínicas e funcionais distintas. Pacientes com aumento do percentual de neutrófilos tendem a apresentar uma pior função pulmonar. Um pequeno número de pacientes apresentou um padrão eosinofílico no lavado broncoalveolar com função pulmonar normal, porém sinais de instabilidade clínica. / Therapy resistant asthma is a major clinical problem in childhood. We investigated the inflammatory cell profile in the airways of children with severe asthma despite systemic steroid treatment and the relationship with clinical and functional severity. Bronchoalveolar lavage (BAL) was performed in 24 children with severe asthma (13M/11F; mean age 12.5 yrs, range 5-l4 yrs), and 5 controls. All received prednisolone prior to BAL. Neutrophils were the predominant inflammatory cell type in BAL in 15/24 (60%) children with asthma (median 15%, 5-43%).and only 5 patients had increases in eosinophils (median 9%, 6.5%-18,5%). There was a correlation between higher BAL eosinophils and more admissions Patients with higher BAL neutrophils showed a trend for lower pre-BAL lung function. We identified subgroups of children with severe asthma presenting different clinical and functional characteristics. Patients with increased percentages in BAL neutrophils showed a trend for lower lung function. A small number of patients presented eosinophilic airway inflammation in BAL with virtually normal lung function but showing signs of clinical instability.

Introdução: Vários modelos experimentais para o estudo da síndrome do desconforto respiratório do tipo agudo (SDRA) foram desenvolvidos, sendo o modelo de lavagem pulmonar o mais utilizado. No entanto, a técnica originalmente descrita foi modificada por outros autores, tornando difícil a reprodutibilidade deste modelo experimental. Objetivos: Avaliar os efeitos do recrutamento pulmonar, do uso de volumecorrente fixo e do uso de diferentes volumes de lavagem na instalação do modelo experimental de SDRA, em relação ao número de lavagens necessárias para a obtenção do modelo experimental, a mortalidade e a estabilidade hemodinâmica durante o procedimento. Metodologia: Coelhos adultos da raça New-Zealand-White, foram divididos em 5 grupos de estudo, de acordo com a técnica utilizada para a lavagem pulmonar: 1- Volume-corrente (Vt) fixo de 10 ml/kg, volume de lavagem de 30 ml/kg, sem recrutamento pulmonar; 2- Pressão inspiratória (Pinsp) fixa, com um volume de lavagem de 30 ml/kg, sem recrutamento pulmonar; 3- Vt fixo, com um volume de lavagem de 25 ml/kg sem recrutamento pulmonar; 4- Pinsp fixa, com volume de lavagem de 25 ml/kg sem recrutamento pulmonar; 5- Vt fixo, com volume de lavagem de 30 ml/kg, com recrutamento pulmonar antes da primeira lavagem. Os animais foram submetidos a repetidas lavagens pulmonares com soro fisiológico aquecido em intervalos de 5 minutos, até se atingir o critério de definição de SDRA, estabelecido como uma relação PaO2/FiO2 <= 100. Resultados: Não foram encontradas diferenças entre os grupos em relação ao número de lavagens necessárias para a instalação do modelo experimental. O uso de recrutamento alveolar prévio e a utilização de pressão inspiratória fixa com volume de lavagem de 25 ml/kg foi associado a uma tendência à maior mortalidade. Embora não se tenha observado diferenças na estabilidade hemodinâmica entre os grupos de estudo, os animais ventilados com Pinsp fixa apresentaram uma pior ventilação alveolar com valores mais baixos de pH em relação aos animais ventilados com Vt fixo. Conclusões: A utilização de manobra de recrutamento alveolar, a uso de um volume-corrente fixo ou pressão inspiratória fixa entre as lavagens, e a utilização de diferentes volumes de lavagem (25 e 30 ml/kg) não modificaram o número de lavagens necessárias para a obtenção do modelo experimental de SDRA, assim como não modificaram a estabilidade hemodinâmica dos animais durante a realização do procedimento. Foi observada uma tendência à maior mortalidade com a realização da manobra de recrutamento alveolar e com o uso de pressão inspiratória fixa associado ao volume de lavagem de 25 ml/kg. / Background: Many experimental models were developed for the study of the acute respiratory distress syndrome (ARDS), and the lung lavage model is the more frequently used. The original technique was modified by many authors, resulting in difficulties for this experimental model reproducibility. Objectives: To evaluate the effects of the pulmonary recruitment, the use of fixed tidal-volume and different lavage volumes at the experimental ARDS model installation, regarding to the number of lung lavages necessary to obtain the experimental model, the mortality and the hemodynamic stability during the procedure. Methods: New-Zealand-White adult rabbits were divided into 5 study groups, according to the technique used: 1- Fixed tidal-volume (Vt) of 10 ml/kg, lavage volume of 30 ml/kg, no pulmonary recruitment; 2- Fixed inspiratory pressure (IP), lavage volume of 30 ml/kg, no pulmonary recruitment; 3- Fixed Vt, lavage volume of 25 ml/kg, no pulmonary recruitment; 4- Fixed IP, lavage volume of 25 ml/kg, no pulmonary recruitment; 5- Fixed Vt, lavage volume of 30 ml/kg, using pulmonary recruitment. The animals were submitted to repeated lung lavages with warm saline at 5 min interval until the ARDS definition(PaO2/FiO2 <= 100) be reached. Results: There was no differences among the study groups regarding the number of lung lavages necessary to obtain the experimental model. The use of alveolar recruitment before the first lavage and the use of fixed ventilatory pressure with 25 ml/kg lavage volume were associated with trend to a higher mortality rate. Although there were no differences regarding the hemodynamic stability among the study groups, animals ventilated with fixed inspiratory pressure had worse alveolar ventilation with higher levels of PaCO2 and lower pH. Conclusions: The use of alveolar recruitment maneuvers, the use of a fixed tidal-volume or inspiratory pressure between the lung lavages and the utilization of different lavage volumes did not change the number of lung lavages necessary to obtain the experimental model of ARDS or the hemodynamic stability of the animals during the procedure. It was observed a trend to an increased mortality rate with the recruitment maneuver and with the use of a fixed inspiratory pressure associated to the lavage volume of 25 ml/kg.

Background Idiopathic pulmonary fibrosis (IPF) is a devastating form of chronic lung injury of unknown aetiology characterised by progressive lung scarring. A diagnosis of definite IPF requires High Resolution Computed Tomography (HRCT) appearances indicative of usual interstitial pneumonia (UIP), or in patients with 'possible UIP' CT appearances, histological confirmation of UIP. However the proportion of such patients that undergo SLB varies, perhaps due to a perception of risk of biopsy and additive diagnostic value of biopsy in individual patients. We hypothesised that an underlying UIP pathological pattern may result in increased risk of death and aimed to explore this by comparing the risk of SLB in suspected idiopathic interstitial pneumonia, stratified according to HRCT appearance. Additionally we sought to determine the positive-predictive value of biopsy to diagnose IPF in patients with 'possible UIP HRCT' in our population. In patients with possible UIP who are not biopsied, the clinical value of bronchoalveolar lavage (BAL) is uncertain. We aimed to prospectively study the diagnostic and prognostic value of BAL differential cell count (DCC) in suspected IPF and determine the feasibility of repeat BAL and the relationship between DCC and disease progression in two successive BALs. We hypothesised that BAL DCC between definite and possible IPF was different and that baseline DCC and change in BAL DCC predicted disease progression. Alveolar macrophages (AMs) are an integral part of the lung's reparative mechanism following injury, however in IPF they contribute to pathogenesis by releasing pro-fibrotic mediators promoting fibroblast proliferation and collagen deposition. Expansion of novel subpopulations of pulmonary monocyte-like cells (PMLCs) has been reported in inflammatory lung disease. We hypothesised that a distinct AM polarisation phenotype would be associated with disease progression. We aimed to perform detailed phenotyping of AM and PMLCs in BAL in IPF patients. Several prognostic scoring systems and biomarkers have been described to predict disease progression in IPF but most were derived from clinical trial patients or tertiary referral centres and none have been validated in separate cohorts. We aimed to identify a predictive tool for disease progression utilising physiological, HRCT and serum biomarkers in a unique population of incident treatment naïve IPF patients. Methods Between 01/01/07 and 31/12/13, 611 consecutive incident patients with suspected idiopathic interstitial pneumonia (IIP) presented to the Edinburgh lung fibrosis clinic. Of these patients 222 underwent video-assisted thoracoscopic lung biopsy and histological pattern was determined according to ATS/ERS criteria. Post-operative mortality and complication rates were examined. Fewer than 2% received IPF-directed therapy and less than 1% of the cohort were lost to follow-up. Disease progression was defined as death or ≥10% decline in VC within 12 months of BAL. Cells were obtained by BAL and a panel of monoclonal antibodies; CD14, CD16, CD206, CD71, CD163, CD3, CD4, CD8 and HLA-DR were used to quantify and selectively characterise AMs, resident PMLCs, inducible PMLCs, neutrophils and CD4+/CD8+ T-cells using flow cytometry. Classical, intermediate and non-classical monocyte subsets were also quantified in peripheral blood. Potential biomarkers (n=16) were pre-selected from either previously published studies of IPF biomarkers or our hypothesis-driven profiling. Linear logistic regression was used on each predictor separately to assess its importance in terms of p-value of the associated weight, and the top two variables were used to learn a decision tree. Results Based on the 2011 ATS/ERS criteria, 87 patients were categorised as 'definite UIP', of whom 3 underwent SLB for clinical indications. IPF was confirmed in all 3 patients based on 2013 ATS/ERS/JRS/ALAT diagnostic criteria. 222 patients were diagnosed with 'possible UIP'; 55 underwent SLB, IPF was subsequently diagnosed in 37 patients, 4 were diagnosed with 'probable IPF' and 14 were considered 'not IPF'. In this group, 30 patients were aged 65 years or over and 25/30 (83%) had UIP on biopsy. 306 patients had HRCTs deemed 'inconsistent with UIP', SLB was performed in 168 patients. Post6 operative 30-day mortality was 2.2% overall, and 7.3% in the 'possible UIP' HRCT group. Patients with 'definite IPF' based on HRCT and SLB appearances had significantly better outcomes than patients with 'definite UIP' on HRCT alone (P=0.008, HR 0.44 (95% CI 0.240 to 0.812)). BAL DCC was not different between definite and possible UIP groups, but there were significant differences with the inconsistent with UIP group. In the 12 months following BAL, 33.3% (n=7/21) of patients in the definite UIP group and 29.5% (n=18/61) in the possible UIP group had progressed. There were no significant differences in BAL DCC between progressor and non-progressor groups. Mortality in patients with suspected IPF and a BAL DCC consistent with IPF was no different to those with a DCC inconsistent with IPF (P=0.425, HR 1.590 (95% CI 0.502 to 4.967)). There was no difference in disease progression in either group (P=0.885, HR 1.081 (95% CI 0.376 to 3.106)). There was no statistically significant difference in BAL DCC at 0 and 12 months in either group. There was no significant change in DCC between 0 and 12 month BALs between progressors and non-progressors. Repeat BAL was well tolerated in almost all patients. There was 1 death within 1 month of a first BAL and 1 death within 1 month of a second BAL; both were considered 'probably procedure-related'. AM CD163 and CD71 (transferrin receptor) expression were significantly different between groups (P < 0.0001), with significant increases in the IPF group vs non fibrotic ILD (P < 0.0001) and controls (P < 0.0001 and P < 0.001 respectively). CD71 expression was also significantly increased in the IPF progressor vs non-progressor group (P < 0.0001) and patients with high CD71 expression had significantly poorer survival than the CD71low group (P=0.040, median survival 40.5 and 75.6 months respectively). CD206 (mannose receptor) expression was also significantly higher in the IPF progressor vs non-progressor group (P=0.034). There were no differences in baseline BAL neutrophil, eosinophil or lymphocyte percentages between IPF progressor or non-progressor groups. The percentage of rPMLCs was significantly increased in BAL fluid cells of IPF patients compared to those with non-fibrotic ILD (P < 0.0001) and healthy controls (P < 0.05). Baseline rPMLC percentage was significantly higher in IPF progressors vs IPF non-progressors (P=0.011). Baseline BAL iPMLC:rPMLC ratio was also significantly different between IPF progressor and non-progressor groups (P=0.011). Disease progression was confidently predicted by a combination of clinical and serological variables. In our cohort we identified a predictive tool based on two key parameters, one a measure of lung function and one a single serum biomarker. Both parameters were entered into a decision tree, and when applied to our cohort yielded a sensitivity of 86.4%, specificity of 92.3%, positive predictive value of 90.5% and negative predictive value of 88.9%. We also applied previously reported predictive tools such as the GAP Index, du Bois score and CPI Index to the Edinburgh IPF cohort. Conclusions SLB can be of value in the diagnosis of ILD, however perhaps due to the perceived risks associated with the procedure, only a small percentage of patients undergo SLB despite recommendations that patients have histological confirmation of the diagnosis. Advanced age is a strong predictor for IPF, and in our cohort 83% of patients aged over 65 years with 'possible UIP' HRCT appearances, had UIP on biopsy. BAL and repeat BAL in IPF is feasible and safe (< 1.5% mortality). Of those that underwent repeat BAL, disease progression was not associated with a change in DCC. However, 22% of lavaged patients died or were deemed too frail to undergo a second procedure at 12 months. These data emphasise the importance of BAL in identifying a novel human AM polarisation phenotype in IPF. Our data suggests there is a distinct relationship between AM subtypes, cell-surface expression markers, PMLC subpopulations and disease progression in IPF. This may be utilised to investigate new targets for future therapeutic strategies. / Disease progression in IPF can be predicted by a combination of clinical variables and serum biomarker profiling. We have identified a unique prediction model, when applied to our locally referred, incident, treatment naïve cohort can confidently predict disease progression in IPF. IPF is a heterogeneous disease and there is a definite clinical need to identify 'personalised' prognostic biomarkers which may in turn lead to novel targets and the advent of personalised medicines.

Background: Tobacco smoking is the main cause of chronic obstructive pulmonary disease, COPD, but the mechanisms by which cigarette smoke induces COPD are still elusive. T lymphocytes have been implicated in the pathogenesis of the disease, but their role in the airway inflammation in COPD is not fully understood. The aim of this thesis was therefore to address T lymphocyte subsets and their activation in the airways of subjects with COPD, in comparison to smokers with normal lung function (S) and never smokers (NS). Methods: Subjects with moderate to severe COPD were recruited along with controls. They were all non-atopic and clinically stable, without any exacerbation during at least three months prior to inclusion. Only medication with short-acting β2-agonists and/or anti-cholinergic drugs was permitted. All subjects underwent bronchoscopy with endobronchial mucosal biopsy sampling as well as bronchial wash, BW, and bronchoalveolar lavage, BAL, collection. Biopsies were immunohistochemically stained for inflammatory cells and markers. BW and BAL fluids were prepared for differential cell counts. Soluble markers were measured in BW and lymphocyte subsets were determined in BAL using flow cytometry. Results: In biopsies, an increase in epithelial CD3+ and CD8+ cells was found in COPD, compared to NS. In BAL fluid, CD8+ cells were enhanced, whereas CD4+ cells were reduced in subjects with COPD and S, compared to NS. Furthermore, CD4+ and CD8+ cells were more activated both in COPD and S, in terms of increased expression of CD25, CD69 and HLA-DR. NKG2D-expressing CD8+ T cells in BAL fluid were enhanced in both COPD and S. CD4+CD25bright cells were upregulated in COPD and S, suggesting the presence of regulatory T cells. Further analyses of T cell subsets with the more specific markers for regulatory T cells, FoxP3 and CD127, indicated a smoking-induced expansion of non-regulatory T cells, which tended to normalize after smoking cessation in COPD. Currently smoking subjects with COPD still expressed high proportions of activated non-regulatory CD4+ T cells. The data on FoxP3 expression further indicated that the increase in CD25 expression in COPD and S was not only associated with the expansion of regulatory T cells. As CD127 expression is reported to be inversely associated with FoxP3, the data indicate the expansion of a non-regulatory CD25+ population in smokers and patients with stable COPD. The immunohistochemical staining for the NKG2D ligands MICA and MICB on epithelial cells was unchanged. Conclusion: The results of this thesis suggest a role for CD4+ and CD8+ T-cells in clinically stable COPD, indicating that T-cells are of importance in the long-term inflammatory response in COPD. Regardless of current smoking habits, activated CD8+ T lymphocytes were found to be increased in BAL fluid from subjects with COPD, suggesting that changes in CD8+ T cells are associated with a persistent immune response and, thus, of importance in COPD pathogenesis. In contrast, the expansion of non-regulatory CD25+CD4+ cells in BAL fluid seemed to be preferentially smoke-related. In summary, the data indicate that, among airway T cells, changes in CD8+ cells seem to be highly associated with COPD pathogenesis, whereas changes in CD4+ cells appear to be related to cigarette smoke-induced responses. Further, a non regulatory population of helper T cells was identified in BAL fluid of COPD patients, which may contribute to the persistent cytotoxic T cell responses.