RESUMO Objetivo A escassez de pulmões viáveis ainda é um grande obstáculo para o transplante. As vítimas de trauma, que constituem potenciais doadores de pulmão, comumente apresentam choque hipovolêmico que acarreta inflamação e deterioração pulmonar e rejeição após o transplante. Buscando melhorar o enxerto pulmonar, testaram-se novas abordagens ao tratamento do doador. Este estudo foca o tratamento com células-tronco mesenquimais (CTMs) ou fatores solúveis produzidos pelas CTMs (FS-CTMs), usando um modelo com ratos para doadores de pulmão após choque hemorrágico. Métodos Quarenta e oito ratos foram divididos em quatro grupos: Controle (n=12), animais sem indução de choque hipovolêmico; Choque (n=12), animais submetidos a choque hipovolêmico (pressão arterial média de 40 mmHg); CTM (n=12), animais submetidos a choque hipovolêmico e tratados com CTMs; e FS (n=12), animais submetidos a choque hipovolêmico e tratados com FS-CTMs. Os animais foram submetidos a um procedimento de choque hipovolêmico (40 mmHg) com 50 minutos de duração. Os animais tratados foram monitorados por 115 minutos. Realizamos análise histopatológica do tecido pulmonar e quantificação dos marcadores inflamatórios (TNF-α, IL-1β, IL-6, IL-10, iCAM e vCAM) no tecido pulmonar e leucócitos no sangue periférico (LSPs). Resultados O choque hemorrágico resultou em taxas mais altas de LSPs e infiltrado de neutrófilos nos pulmões. Os animais do grupo FS apresentaram menor densidade de neutrófilos em comparação com os animais dos grupos Choque e CTM (p<0,001). Não foram observadas diferenças entre os grupos quanto aos níveis de citocinas no tecido pulmonar. Conclusão Os pulmões dos ratos submetidos a choque hemorrágico e tratados com FS-CTM apresentaram inflamação reduzida indicada por uma diminuição do infiltrado de neutrófilos nos pulmões.

ABSTRACT Objective The shortage of viable lungs is still a major obstacle for transplantation. Trauma victims who represent potential lung donors commonly present hypovolemic shock leading to pulmonary inflammation and deterioration and rejection after transplantation. Seeking to improve lung graft, new approaches to donor treatment have been tested. This study focuses on treatment with mesenchymal stem cells (MSCs) or soluble factors produced by MSCs (FS-MSC) using a rat model for lung donors after hemorrhagic shock. Methods Forty-eight rats were divided into four groups: Sham (n=12), animals without induction of hypovolemic shock; Shock (n=12), animals submitted to hypovolemic shock (mean arterial pressure 40 mmHg); MSC (n=12), animals submitted to hypovolemic shock and treated with MSCs, and FS (n=12), animals submitted to hypovolemic shock and treated with FS-MSC. The animals were subjected to a 50-minute hypovolemic shock (40 mmHg) procedure. The treated animals were monitored for 115 minutes. We performed histopathology of lung tissue and quantification of inflammatory markers (TNF-α, IL-1β, IL-6, IL-10, iCAM and vCAM) in lung tissue and peripheral blood leukocytes (PBLs). Results Hemorrhagic shock resulted in higher PBLs and neutrophil infiltrate in the lungs. FS animals had lower neutrophil density comparing with Shock and MSC animals (p<0.001). No differences in the cytokine levels in lung tissue were observed between the groups. Conclusions The lungs of rats submitted to hemorrhagic shock and treated with FS-MSC showed reduced inflammation indicated in a decrease in lung neutrophil infiltrate.

OBJECTIVES: To evaluate the impact of Burkholderia cepacia complex colonization in cystic fibrosis patients undergoing lung transplantation. METHODS: We prospectively analyzed clinical data and respiratory tract samples (sputum and bronchoalveolar lavage) collected from suppurative lung disease patients between January 2008 and November 2013. We also subtyped different Burkholderia cepacia complex genotypes via DNA sequencing using primers against the recA gene in samples collected between January 2012 and November 2013. RESULTS: From 2008 to 2013, 34 lung transplants were performed on cystic fibrosis patients at our center. Burkholderia cepacia complex was detected in 13 of the 34 (38.2%) patients. Seven of the 13 (53%) strains were subjected to genotype analysis, from which three strains of B. metallica and four strains of B. cenocepacia were identified. The mortality rate was 1/13 (7.6%), and this death was not related to B. cepacia infection. CONCLUSION: The results of our study suggest that colonization by B. cepacia complex and even B. cenocepacia in patients with cystic fibrosis should not be considered an absolute contraindication to lung transplantation in Brazilian centers.

Objetivo: Avaliar o emprego da técnica de perfusão pulmonar ex vivo (PPEV) clinicamente com a finalidade de transplante. Métodos: Estudo prospectivo envolvendo o recondicionamento de pulmões limítrofes, definidos por critérios específicos, tais como relação PaO2/FiO2 < 300 mmHg, com um sistema de PPEV. Entre fevereiro de 2013 e fevereiro de 2014, os pulmões de cinco doadores foram submetidos à PPEV por até 4 h. Durante a PPEV, a mecânica pulmonar foi avaliada continuamente. Amostras do perfusato foram colhidas a cada hora, assim como foi realizada a avaliação funcional dos órgãos. Resultados: A média de PaO2 dos pulmões captados foi de 262,9 ± 119,7 mmHg, sendo que, ao final da terceira hora de perfusão, essa foi de 357,0 ±108,5 mmHg. A capacidade de oxigenação dos pulmões apresentou discreta melhora durante a PPEV nas primeiras 3 h (246,1 ± 35,1; 257,9 ± 48,9; e 288,8 ± 120,5 mmHg, respectivamente), sem diferenças significativas entre os momentos (p = 0,508). As médias de complacência estática foram de, respectivamente, 63.0 ± 18,7; 75,6 ± 25,4; e 70,4 ± 28,0 mmHg após 1, 2 e 3 h, com melhora significativa entre a hora 1 e 2 (p = 0,029), mas não entre a hora 2 e 3 (p = 0,059). A resistência vascular pulmonar permaneceu estável durante a PPEV, sem diferenças entre os momentos (p = 0,284). Conclusões: Os pulmões avaliados permaneceram em condições fisiológicas de preservação; no entanto, o protocolo não foi efetivo para promover a melhora na função pulmonar, inviabilizando o transplante.

Objective: To evaluate the use of ex vivo lung perfusion (EVLP) clinically to prepare donor lungs for transplantation. Methods: A prospective study involving EVLP for the reconditioning of extended-criteria donor lungs, the criteria for which include aspects such as a PaO2/FiO2 ratio < 300 mmHg. Between February of 2013 and February of 2014, the lungs of five donors were submitted to EVLP for up to 4 h each. During EVLP, respiratory mechanics were continuously evaluated. Once every hour during the procedure, samples of the perfusate were collected and the function of the lungs was evaluated. Results: The mean PaO2 of the recovered lungs was 262.9 ± 119.7 mmHg at baseline, compared with 357.0 ± 108.5 mmHg after 3 h of EVLP. The mean oxygenation capacity of the lungs improved slightly over the first 3 h of EVLP-246.1 ± 35.1, 257.9 ± 48.9, and 288.8 ± 120.5 mmHg after 1, 2, and 3 h, respectively-without significant differences among the time points (p = 0.508). The mean static compliance was 63.0 ± 18.7 mmHg, 75.6 ± 25.4 mmHg, and 70.4 ± 28.0 mmHg after 1, 2, and 3 h, respectively, with a significant improvement from hour 1 to hour 2 (p = 0.029) but not from hour 2 to hour 3 (p = 0.059). Pulmonary vascular resistance remained stable during EVLP, with no differences among time points (p = 0.284). Conclusions: Although the lungs evaluated remained under physiological conditions, the EVLP protocol did not effectively improve lung function, thus precluding transplantation.

OBJECTIVE: This study evaluated the performance of lungs that were preserved with different solutions (Celsior, Perfadex or saline) in an ex vivo rat lung perfusion system. METHODS: Sixty Wistar rats were anesthetized, anticoagulated and randomized into three groups (n = 20). The rats were subjected to antegrade perfusion via the pulmonary artery with Perfadex, Celsior, or saline, followed by 6 or 12 hours of ischemia (4ºC, n = 10 in each group). Respiratory mechanics, gas exchange and hemodynamics were measured at 10-minute intervals during the reperfusion of heart-lung blocks in an ex vivo system (IL2-Isolated Perfused Rat or Guinea Pig Lung System, Harvard Apparatus, Holliston, Massachusetts, USA; Hugo Sachs Elektronik, Germany) for 60 minutes. The lungs were prepared for histopathology and evaluated for edema following reperfusion. Group comparisons were performed using ANOVA and the Kruskal-Wallis test with a 5% level of significance. RESULTS: Gas exchange was not significantly different between lungs perfused with either Perfadex or Celsior at the same ischemic times, but it was very low in lungs that were preserved with saline. Airway resistance was greater in the lungs that were preserved for 12 hours. Celsior lungs that were preserved for 6 and 12 hours exhibited lower airway resistance (p = 0.01) compared to Perfadex lungs. Pulmonary artery pressure was not different between the groups, and no significant differences in histopathology and apoptosis were observed between the groups. CONCLUSIONS: Lungs that were preserved with Celsior or Perfadex exhibited similar gas exchange and histopathological findings. Airway resistance was slightly lower in the Celsior-preserved lungs compared with the Perfadex-preserved lungs.

OBJECTIVE: Infections have been and remain the major cause of morbidity and mortality after lung transplantation. Because mucociliary clearance plays an important role in human defense mechanisms, the influence of drugs on the mucociliary epithelium of patients undergoing lung transplantation must be examined. Prednisone is the most important corticosteroid used after lung transplantation. The aim of this study was to evaluate the effects of bronchial transection and prednisone therapy on mucociliary clearance. METHODS: A total of 120 rats were assigned to 4 groups according to surgical procedure or drug therapy: prednisone therapy (1.25 mg/kg/day); bronchial section and anastomosis + prednisone therapy (1.25 mg/kg/day); bronchial section + saline solution (2 ml/day); and saline solution (2 ml/day). After 7, 15, or 30 days, the animals were sacrificed, and the lungs were removed from the thoracic cavity. The in situ mucociliary transport velocity, ciliary beat frequency and in vitro mucus transportability were evaluated. RESULTS: Animals undergoing bronchial section surgery and anastomosis had a significant decrease in the ciliary beat frequency and mucociliary transport velocity 7 and 15 days after surgery (p<0.001). These parameters were normalized 30 days after the surgical procedure. Prednisone improved mucous transportability in the animals undergoing bronchial section and anastomosis at 15 and 30 days (p<0.05). CONCLUSION: Bronchial section and anastomosis decrease mucociliary clearance in the early postoperative period. Prednisone therapy improves mucus transportability in animals undergoing bronchial section and anastomosis.