Abstract Background: Adaptive immune cells, including CD4+CD69+ and CD4+CD25+FoxP3+ regulatory T (Treg) cells, are important for maintaining immunological tolerance. In human systemic lupus erythematosus (SLE), CD4+CD25+FoxP3+ Treg cells are reduced, whereas CD69 expression is increased, resulting in a homeostatic immune imbalance that may intensify autoreactive T cell activity. To analyze the mechanisms implicated in autotolerance failure, we evaluated CD4+CD69+ and CD4+CD25+FoxP3+ T cells and interleukin profiles in a pristane-induced SLE experimental model. Methods: For lupus induction, 26 female Balb/c mice received a single intraperitoneal 0.5 ml dose of pristane, and 16 mice received the same dose of saline. Blood and spleen samples were collected from euthanized mice 90 and 120 days after pristane or saline inoculation. Mononuclear cells from peripheral blood (PBMC), peritoneal lavage (PL) and splenocytes were obtained by erythrocyte lysis and cryopreserved for further evaluation by flow cytometry using the GuavaEasyCyte TM HT. After thawing, cells were washed and stained with monoclonal antibodies against CD3, CD4, CD8, CD25, CD28, CD69, FoxP3, CD14 and Ly6C (BD Pharmingen TM). Interleukins were quantified using Multiplex® MAP. The Mann-Whitney test and the Pearson coefficient were used for statistical analysis, and p < 0.05 considered significant. Results: Compared with the controls, SLE-induced animals presented increased numbers of CD4+CD69+ T cells in the blood on T90 and T120 (p = 0.022 and p = 0.008) and in the spleen on T120 (p = 0.049), but there were decreased numbers in the PL (p = 0.049) on T120. The percentage of Treg was lower in blood (p < 0.005 and p < 0.012) on T90 and T120, in spleen (p = 0.043) on T120 and in PL (p = 0.001) on T90. Increased numbers of CD4+ CD69+ T cells in the PL were positively associated with high IL-2 (p = 0.486) and IFN-γ (p = 0.017) levels, whereas reduced Treg cells in the blood were negatively correlated with TNFα levels (p = 0.043) and positively correlated with TGFβ1 (p = 0.038). Conclusion: Increased numbers of CD4+CD69+ T cells and reduced numbers of CD4+CD25+FoxP3+ Treg cells with an altered interleukin profile suggests loss of autotolerance in pristane-induced lupus mice, which is similar to human lupus. Therefore, this model is useful in evaluating mechanisms of cellular activation, peripheral tolerance and homeostatic immune imbalance involved in human SLE.

OBJECTIVES: The vulva is the primary site affected in lichen sclerosus, a chronic dermatosis in women that is histologically characterized by a zone of collagen remodeling in the superior dermis. The normal physiological properties of the vulva depend on the assembly of collagen types I (COLI), III (COLIII) and V (COLV), which form heterotypic fibers, and extracellular matrix protein interactions. COLV regulates the heterotypic fiber diameter, and the preservation of its properties is important for maintaining normal tissue architecture and function. In the current work, we analyzed the expression of COLV and its relationship with COLI, COLIII, elastic fibers and extracellular matrix protein 1 in vulvar biopsies from patients with lichen sclerosus. METHODS: Skin biopsies from 21 patients with lichen sclerosus, classified according to Hewitt histological criteria, were studied and compared to clinically normal vulvar tissue (N=21). Morphology, immunohistochemistry, immunofluorescence, 3D reconstruction and morphometric analysis of COLI, COLIII, COLV deposition, elastic fibers and extracellular matrix 1 expression in a zone of collagen remodeling in the superior dermis were performed. RESULTS: A significant decrease of elastic fibers and extracellular matrix 1 protein was present in the hyalinization zone of lichen sclerosus compared to healthy controls. The non-homogeneous distribution of collagen fibers visualized under immunofluorescence in the hyalinization zone of lichen sclerosus and control skin was confirmed by histomorphometry. Lichen sclerosus dermis shows a significant increase of COLI, COLIII and COLV expression compared to the healthy controls. Significant inverse associations were found between elastic fibers and COLV and between COLV and extracellular matrix 1 expression. A direct association was found between elastic fiber content and extracellular matrix 1 expression. Tridimensional reconstruction of the heterotypic fibers of the lichen sclerosus zone of collagen remodeling confirmed the presence of densely clustered COLV. CONCLUSIONS: Increased deposition of abnormal COLV and its correlation with extracellular matrix 1 and elastic fibers suggest that COLV may be a trigger in the pathogenesis of lichen sclerosus.

OBJECTIVE: To validate the importance of the angiotensin II receptor isotypes and the lymphatic vessels in systemic sclerosis and idiopathic pulmonary fibrosis. METHODS: We examined angiotensin II type 1 and 2 receptors and lymphatic vessels in the pulmonary tissues obtained from open lung biopsies of 30 patients with systemic sclerosis and 28 patients with idiopathic pulmonary fibrosis. Their histologic patterns included cellular and fibrotic non-specific interstitial pneumonia for systemic sclerosis and usual interstitial pneumonia for idiopathic pulmonary fibrosis. We used immunohistochemistry and histomorphometry to evaluate the number of cells in the alveolar septae and the vessels stained by these markers. Survival curves were also used. RESULTS: We found a significantly increased percentage of septal and vessel cells immunostained for the angiotensin type 1 and 2 receptors in the systemic sclerosis and idiopathic pulmonary fibrosis patients compared with the controls. A similar percentage of angiotensin 2 receptor positive vessel cells was observed in fibrotic non-specific interstitial pneumonia and usual interstitial pneumonia. A significantly increased percentage of lymphatic vessels was present in the usual interstitial pneumonia group compared with the non-specific interstitial pneumonia and control groups. A Cox regression analysis showed a high risk of death for the patients with usual interstitial pneumonia and a high percentage of vessel cells immunostained for the angiotensin 2 receptor in the lymphatic vessels. CONCLUSION: We concluded that angiotensin II receptor expression in the lung parenchyma can potentially control organ remodeling and fibrosis, which suggests that strategies aimed at preventing high angiotensin 2 receptor expression may be used as potential therapeutic target in patients with pulmonary systemic sclerosis and idiopathic pulmonary fibrosis.

OBJETIVO: Estudar a expressão de COX-1 e COX-2 em áreas pulmonares remodeladas em pacientes com esclerose sistêmica (ES) ou fibrose pulmonar idiopática (FPI) e correlacioná-la com a sobrevida desses pacientes.MÉTODOS: Examinamos espécimes de biópsia pulmonar a céu aberto de 24 pacientes com ES e de 30 pacientes com FPI, utilizando-se tecido pulmonar normal como controle. Os padrões histológicos incluíram pneumonia intersticial não específica (PINE) fibrótica em pacientes com ES e pneumonia intersticial usual (PIU) nos pacientes com FPI. Imuno-histoquímica e histomorfometria foram usadas para avaliar a expressão celular de COX-1 e COX-2 em septos alveolares, vasos e bronquíolos, sua correlação com provas de função pulmonar e seu impacto na sobrevida.RESULTADOS: A expressão de COX-1 e COX-2 em septos alveolares foi significativamente maior em FPI-PIU e ES-PINE do que no tecido controle. Não houve diferença entre FPI-PIU e ES-PINE quanto à expressão de COX-1 e COX-2. A análise multivariada baseada no modelo de regressão de Cox mostrou que os fatores associados a baixo risco de morte foram ter idade menor, valores elevados de DLCO/volume alveolar, FPI, e alta expressão de COX-1 em septos alveolares, ao passo que os fatores associados a alto risco de morte foram ter idade maior, valores baixos de DLCO/volume alveolar, ES (com PINE) e baixa expressão de COX-1 em septos alveolares.CONCLUSÕES: Nossos resultados sugerem que estratégias de prevenção de baixa síntese de COX-1 terão maior impacto sobre a ES, ao passo que as de prevenção de alta síntese de COX-2 terão maior impacto sobre a FPI. Porém, são necessários ensaios clínicos randomizados prospectivos para confirmar essa hipótese.

OBJECTIVE: To study the expression of COX-1 and COX-2 in the remodeled lung in systemic sclerosis (SSc) and idiopathic pulmonary fibrosis (IPF) patients, correlating that expression with patient survival.METHODS: We examined open lung biopsy specimens from 24 SSc patients and 30 IPF patients, using normal lung tissue as a control. The histological patterns included fibrotic nonspecific interstitial pneumonia (NSIP) in SSc patients and usual interstitial pneumonia (UIP) in IPF patients. We used immunohistochemistry and histomorphometry to evaluate the expression of COX-1 and COX-2 in alveolar septa, vessels, and bronchioles. We then correlated that expression with pulmonary function test results and evaluated its impact on patient survival.RESULTS: The expression of COX-1 and COX-2 in alveolar septa was significantly higher in IPF-UIP and SSc-NSIP lung tissue than in the control tissue. No difference was found between IPF-UIP and SSc-NSIP tissue regarding COX-1 and COX-2 expression. Multivariate analysis based on the Cox regression model showed that the factors associated with a low risk of death were younger age, high DLCO/alveolar volume, IPF, and high COX-1 expression in alveolar septa, whereas those associated with a high risk of death were advanced age, low DLCO/alveolar volume, SSc (with NSIP), and low COX-1 expression in alveolar septa.CONCLUSIONS: Our findings suggest that strategies aimed at preventing low COX-1 synthesis will have a greater impact on SSc, whereas those aimed at preventing high COX-2 synthesis will have a greater impact on IPF. However, prospective randomized clinical trials are needed in order to confirm that.

OBJECTIVE: This study sought to identify the relationship between fibroblast telomerase expression, myofibroblasts, and telomerase-mediated regulatory signals in idiopathic pulmonary fibrosis. METHODS: Thirty-four surgical lung biopsies, which had been obtained from patients with idiopathic pulmonary fibrosis and histologically classified as usual interstitial pneumonia, were examined. Immunohistochemistry was used to evaluate fibroblast telomerase expression, myofibroblast α-smooth muscle actin expression and the tissue expression of inter leu kin-4, transforming growth factor-β, and basic fibroblast growth factor. The point-counting technique was used to quantify the expression of these markers in unaffected, collapsed, mural fibrosis, and honeycombing areas. The results were correlated to patient survival. RESULTS: Fibroblast telomerase expression and basic fibroblast growth factor tissue expression were higher in collapsed areas, whereas myofibroblast expression and interleukine-4 tissue expression were higher in areas of mural fibrosis. Transforming growth factor-β expression was higher in collapsed, mural fibrosis and honeycombing areas in comparison to unaffected areas. Positive correlations were found between basic fibroblast growth factor tissue expression and fibroblast telomerase expression and between interleukin-4 tissue expression and myofibroblast α-smooth muscle actin expression. Negative correlations were observed between interleukin-4 expression and basic fibroblast growth factor tissue expression in areas of mural fibrosis. Myofibroblast α-smooth muscle actin expression and interleukin-4 tissue expression in areas of mural fibrosis were negatively associated with patient survival. CONCLUSION: Fibroblast telomerase expression is higher in areas of early remodeling in lung tissues demonstrating typical interstitial pneumonia, whereas myofibroblast α-smooth muscle actin expression predominates in areas of late remodeling. These events seem to be regulated by basic fibroblast growth factor and interleukin-4 tissue expression, respectively.

OBJETIVO: Investigar o significado de marcadores de imunidade celular e de componentes elásticos/colágeno da matriz extracelular em estruturas granulomatosas em biópsias de pacientes com sarcoidose pulmonar ou extrapulmonar. MÉTODOS: Determinações qualitativas e quantitativas de células inflamatórias, de fibras de colágeno e de fibras elásticas em estruturas granulomatosas em biópsias cirúrgicas de 40 pacientes com sarcoidose pulmonar e extrapulmonar foram realizadas por histomorfometria, imuno-histoquímica, e técnicas de coloração com picrosirius e resorcina-fucsina de Weigert. RESULTADOS: A densidade de linfócitos, macrófagos e neutrófilos nas biópsias extrapulmonares foi significativamente maior do que nas biópsias pulmonares. Os granulomas pulmonares apresentaram uma quantidade significativamente maior de fibras de colágeno e menor densidade de fibras elásticas que os granulomas extrapulmonares. A quantidade de macrófagos nos granulomas pulmonares correlacionou-se com CVF (p < 0,05), ao passo que as quantidades de linfócitos CD3+, CD4+ e CD8+ correlacionaram-se com a relação VEF1/CVF e com CV. Houve correlações negativas entre CPT e contagem de células CD1a+ (p < 0,05) e entre DLCO e densidade de fibras colágenas/elásticas (r = -0,90; p = 0,04). CONCLUSÕES: A imunofenotipagem e o remodelamento apresentaram características diferentes nas biópsias dos pacientes com sarcoidose pulmonar e extrapulmonar. Essas diferenças correlacionaram-se com os dados clínicos e espirométricos dos pacientes, sugerindo que há duas vias envolvidas no mecanismo de depuração de antígenos, que foi mais eficaz nos pulmões e linfonodos.

OBJECTIVE: To investigate the significance of cellular immune markers, as well as that of collagen and elastic components of the extracellular matrix, within granulomatous structures in biopsies of patients with pulmonary or extrapulmonary sarcoidosis. METHODS: We carried out qualitative and quantitative evaluations of inflammatory cells, collagen fibers, and elastic fibers in granulomatous structures in surgical biopsies of 40 patients with pulmonary and extrapulmonary sarcoidosis using histomorphometry, immunohistochemistry, picrosirius red staining, and Weigert's resorcin-fuchsin staining. RESULTS: The extrapulmonary tissue biopsies presented significantly higher densities of lymphocytes, macrophages, and neutrophils than did the lung tissue biopsies. Pulmonary granulomas showed a significantly higher number of collagen fibers and a lower density of elastic fibers than did extrapulmonary granulomas. The amount of macrophages in the lung samples correlated with FVC (p < 0.05), whereas the amount of CD3+, CD4+, and CD8+ lymphocytes correlated with the FEV1/FVC ratio and VC. There were inverse correlations between TLC and the CD1a+ cell count (p < 0.05), as well as between DLCO and collagen/elastic fiber density (r = -0.90; p = 0.04). CONCLUSIONS: Immunophenotyping and remodeling both showed differences between pulmonary and extrapulmonary sarcoidosis in terms of the characteristics of the biopsy samples. These differences correlated with the clinical and spirometric data obtained for the patients, suggesting that two different pathways are involved in the mechanism of antigen clearance, which was more effective in the lungs and lymph nodes.

FUNDAMENTO: A sobrecarga ventricular direita aguda está associada a situações clínicas de elevada morbimortalidade, tais como: ressecções pulmonares extensas, tromboembolismo pulmonar, transplante pulmonar e edema pulmonar das altitudes. Alguns pontos de sua fisiopatologia permanecem obscuros. OBJETIVO: Avaliar os efeitos hemodinâmicos da sobrecarga ventricular direita aguda experimental em suínos. MÉTODOS: A sobrecarga ventricular direita foi induzida pela oclusão das artérias pulmonares através de ligaduras. Vinte porcos foram utilizados no estudo, sendo alocados em 04 grupos: um controle, não submetido à oclusão vascular pulmonar, e três de sobrecarga ventricular direita submetidos à oclusão das seguintes artérias pulmonares: SVD1 (artéria pulmonar esquerda); SVD2 (artéria pulmonar esquerda e do lobo inferior direito) e SVD3 (artéria pulmonar esquerda, do lobo inferior direito e do lobo mediastinal), obstruindo a vasculatura pulmonar em 42, 76 e 82,0% respectivamente. Variáveis de hemodinâmica foram medidas a cada 15 minutos durante a uma hora do estudo. Na análise estatística, foram utilizados ajustes de modelos lineares mistos com estrutura de variâncias e covariâncias. RESULTADOS: Nas comparações intergrupais, houve aumento significativo da frequência cardíaca (p = 0,004), pressão arterial pulmonar média (p = 0,001) e pressão capilar pulmonar (p < 0,0001). Houve redução significativa da pressão arterial média (p = 0,01) e do índice sistólico (p = 0,002). Não houve diferença significativa no índice cardíaco (p = 0,94). CONCLUSÃO: Apesar da intensa sobrecarga ventricular direita promovida pela obstrução de 82,0% da vasculatura pulmonar e pelo aumento significativo da pressão arterial pulmonar não houve disfunção cardiovascular severa e/ou choque circulatório no período estudado.

BACKGROUND: Acute right ventricular overload is associated with high morbidity and mortality clinical situations such as: extensive lung resection, pulmonary thromboembolism, lung transplantation and high altitude pulmonary edema. Some points of its pathophysiology remain unclear. OBJECTIVE: To assess the hemodynamic effects of experimental acute right ventricular overload in pigs. METHODS: Right ventricular overload was induced through the occlusion of the pulmonary arteries using ligationss. Twenty pigs were used in the study, divided into 04 groups: one control group not subject to pulmonary vascular occlusion, and three right ventricular overload groups subject to occlusion of the following pulmonary arteries: SVD1 (left pulmonary artery); SVD2 (left pulmonary artery and right lower lobe) and SVD3 (left pulmonary artery, right lower lobe and mediastinal lobe), obstructing the pulmonary vasculature in 42, 76 and 82.0% respectively. Hemodynamic variables were measured every 15 minutes during one hour of study. The statistical analysis employed mixed linear models with variance and covariance structures. RESULTS: Group comparisons revealed significant increases in heart rate (p = 0.004), mean pulmonary artery pressure (p = 0.001) and pulmonary capillary wedge pressure (p < 0.0001). There was no significant difference in cardiac index (p = 0.94). CONCLUSION: Despite the severe right ventricular overload promoted by 82.0% obstruction of the pulmonary vasculature and the significant increase in pulmonary arterial pressure, there was no severe cardiovascular dysfunction and/or circulatory shock during the study period.

FUNDAMENTO: La sobrecarga ventricular derecha aguda está asociada a situaciones clínicas de elevada morbimortalidad, tales como: resecciones pulmonares extensas, tromboembolismo pulmonar, transplante pulmonar y edema pulmonar de las alturas. Algunos puntos de su fisiopatología permanecen obscuros. OBJETIVO:Evaluar los efectos hemodinámicos de la sobrecarga ventricular derecha aguda experimental en porcinos. MÉTODOS:La sobrecarga ventricular derecha fue inducida por la oclusión de las arterias pulmonares a través de ligaduras. Veinte cerdos fueron utilizados en el estudio, siendo divididos en 4 grupos: uno control, no sometido a la oclusión vascular pulmonar, y tres de sobrecarga ventricular derecha sometidos a la oclusión de las siguientes arterias pulmonares: SVD1 (arteria pulmonar izquierda); SVD2 (arteria pulmonar izquierda y del lóbulo inferior derecho) y SVD3 (arteria pulmonar izquierda, del lóbulo inferior derecho y del lóbulo mediastinal), obstruyendo la vasculatura pulmonar en 42, 76 y 82,0% respectivamente. Variables de hemodinámica fueron medidas cada 15 minutos durante una hora del estudio. En el análisis estadístico, fueron utilizados ajustes de modelos lineares mixtos con estructura de variancias y covariancias. RESULTADOS:En las comparaciones intergrupales, hubo aumento significativo de la frecuencia cardíaca (p = 0,004), presión arterial pulmonar media (p = 0,001) y presión capilar pulmonar (p < 0,0001). Hubo reducción significativa de la presión arterial media (p = 0,01) y del índice sistólico (p = 0,002). No hubo diferencia significativa en el índice cardíaco (p = 0,94). CONCLUSIÓN:A pesar de la intensa sobrecarga ventricular derecha promovida por la obstrucción de 82,0% de la vasculatura pulmonar y por el aumento significativo de la presión arterial pulmonar no hubo disfunción cardiovascular severa y/o shock circulatorio en el período estudiado.

OBJECTIVE: The importance of type V collagen and its relationships with other types of collagen and with vascular and epithelial apoptosis were studied in a model of chemical carcinogenesis in the mouse lung. METHODS: Two groups of male Balb/c mice were studied: a) animals that received two intraperitoneal doses of 3 g/kg urethane carcinogen (urethane group = 24); and b) animals submitted to a sham procedure, comparable to the test group (control group = 7). Both groups were sacrificed after 120 days. In situ detection of apoptosis, immunohistochemistry, immunofluorescence and histomorphometry were used to evaluate the fraction occupied by the tumor, vascular and epithelial apoptosis, and type V, III and I collagen fibers in the lung parenchyma from both groups. RESULTS: The lung parenchyma from the urethane group showed low fractions of vascular and epithelial apoptosis as well as reduced type V collagen fibers when compared to the control group. A significant direct association was found between type V and III collagen fibers and epithelial apoptosis, type V collagen fibers and vascular apoptosis, and type V and type I collagen fibers. CONCLUSION: The results show that a direct link between low amounts of type V collagen and decreased cell apoptosis may favor cancer cell growth in the mouse lung after chemical carcinogenesis, suggesting that strategies aimed at preventing decreased type V collagen synthesis or local responses to reduced apoptosis may have a greater impact in lung cancer control.

BACKGROUND: Cases of H1N1 and other pulmonary infections evolve to acute respiratory failure and death when co-infections or lung injury predominate over the immune response, thus requiring early diagnosis to improve treatment. OBJECTIVE: To perform a detailed histopathological analysis of the open lung biopsy specimens from five patients with ARDS with confirmed H1N1. METHODS: Lung specimens underwent microbiologic analysis, and examination by optical and electron microscopy. Immunophenotyping was used to characterize macrophages, natural killer, T and B cells, and expression of cytokines and iNOS. RESULTS: The pathological features observed were necrotizing bronchiolitis, diffuse alveolar damage, alveolar hemorrhage and abnormal immune response. Ultrastructural analysis showed viral-like particles in all cases. CONCLUSIONS: Viral-like particles can be successfully demonstrated in lung tissue by ultrastructural examination, without confirmation of the virus by RT-PCR on nasopharyngeal aspirates. Bronchioles and epithelium, rather than endothelium, are probably the primary target of infection, and diffuse alveolar damage the consequence of the effect of airways obliteration and dysfunction on innate immunity, suggesting that treatment should be focused on epithelial repair.

OBJETIVO: O objetivo deste trabalho foi examinar o processo de remodelamento no parênquima e na matriz extracelular em dois padrões histológicos-pneumonia intersticial não-específica (PINE) e pneumonia intersticial usual (PIU)-em casos associados à esclerose idiopática/esclerose sistêmica (ES). MÉTODOS: Investigamos 15 casos de PINE idiopática, 10 casos de PIU idiopática, 5 casos de PIU associada à ES (PIU-ES) e 9 de PINE associada à ES (PINE-ES). No parênquima pulmonar, as células epiteliais, células endoteliais e miofibroblastos foram avaliados através de coloração imuno-histoquímica, ao passo que a coloração histoquímica foi utilizada para avaliar as fibras elásticas e de colágeno na matriz extracelular. RESULTADOS: A porcentagem de células epiteliais positivas para proteína A do surfactante foi significativamente maior nos casos de PINE idiopática do que nos de PINE-ES, assim como nos casos de PIU idiopática do que nos de PIU-ES. A PINE e a PIU idiopáticas apresentaram valores significativamente maiores de imunoexpressão de alfa actina de músculo liso nos miofibroblastos do que a PINE-ES e a PIU-ES. A porcentagem de células endoteliais CD34 na microvasculatura pulmonar foi significativamente menor na PIU idiopática do que na PIU-ES. A densidade de fibras do colágeno foi significativamente maior em ambas as formas idiopáticas de PINE e PIU do que na PINE-ES e PIU-ES. Em contraste, a densidade de fibras elásticas foi significativamente menor na PIU idiopática do que na PIU-ES. CONCLUSÕES: A síntese aumentada de colágeno, a destruição de fibras elásticas, a alta proliferação miofibroblástica e a microvascularização diminuída podem representar um processo de remodelamento encontrado na pneumonia intersticial idiopática, enquanto o reverso pode representar mais um processo de reparo na pneumonia intersticial associada à ES.

OBJECTIVE: The aim of this study was to examine the parenchymal and extracellular matrix remodeling process in two histologic patterns-nonspecific interstitial pneumonia (NSIP) and usual interstitial pneumonia (UIP)-in cases of idiopathic and sclerosis/systemic sclerosis (SSc)-associated interstitial pneumonia. METHODS: We examined 15 cases of idiopathic NSIP, 10 cases of idiopathic UIP, 5 cases of SSc-UIP and 9 cases of SSc-NSIP. In the lung parenchyma, epithelial cells, endothelial cells and myofibroblasts were evaluated by immunohistochemical staining, whereas histochemical staining was used in order to evaluate collagen/elastic fibers in the extracellular matrix. RESULTS: The percentage of surfactant protein A-positive epithelial cells was significantly greater in idiopathic NSIP than in SSc-NSIP, as well as being greater in idiopathic UIP than in SSc-UIP. Idiopathic NSIP and idiopathic UIP presented significantly higher immunoexpression of alpha smooth muscle actin in myofibroblasts than did SSc-NSIP and SSc-UIP. The percentage of CD34 endothelial cells in the pulmonary microvasculature was significant lower in idiopathic UIP than in SSc-UIP. The density of collagen fibers was significantly greater in idiopathic NSIP and idiopathic UIP than in SSc-NSIP and UIP. In contrast, the elastic fiber density was significantly lower in idiopathic UIP than in SSc-UIP. CONCLUSIONS: Increased collagen synthesis, destruction of elastic fibers, high myofibroblast proliferation and poor microvascularization might represent a remodeling process found in idiopathic interstitial pneumonia, whereas the reverse might represent a repair process in SSc-associated interstitial pneumonia.

INTRODUCTION/OBJECTIVES: Systemic sclerosis, or scleroderma, is a rheumatic disease characterized by autoimmunity, vasculopathy, and fibrosis of the skin and several internal organs. In the present study, our aim was to assess the skin alterations in animals with scleroderma during the first stages of disease induction. METHODS: To induce scleroderma, female New Zealand rabbits (n = 12) were subcutaneously immunized with 1 mg/ml of collagen V (Col V) in complete Freund's adjuvant, twice with a thirty-day interval. Fifteen days later, the animals received an intramuscular booster with type V collagen in incomplete Freund's adjuvant, twice with a fifteen-day interval. The control group was inoculated with 1 ml of 10 mM acetic acid solution diluted with an equal amount of Freund's adjuvant. Serial dorsal skin biopsies were performed at 7, 15, and 30 days and stained with H&E, Masson's trichrome and Picrosírius for morphological and morphometric analyses. RESULTS: Immunized rabbits presented a significant increase in collagen in skin collected seven days after the first immunization (p=0.05). CONCLUSION: The results from this experimental model may be very important to a better understanding of the pathogenic mechanisms involved in the beginning of human SSc. Therapeutic protocols to avoid early remodeling of the skin may lead to promising treatments for SSc in the future.

OBJETIVO: Estabelecer, com ajuda do microscópio eletrônico, critérios que possibilitem uma diferenciação mais exata entre os quatro tipos maiores de tumores neuroendócrinos pulmonares: tumor carcinóide típico e atípico, carcinoma de grandes células neuroendócrino e carcinoma de pequenas células. MÉTODOS: Todos os tumores foram avaliados morfometricamente e 16 variáveis foram relacionadas com diferenciação das células tumorais; estas variáveis foram analisadas sob microscopia eletrônica com ajuda de um analisador de imagem digital em 27 tumores. A avaliação através da microscopia eletrônica revelou que todos os tumors investigados podiam ser classificados a um dos quarto tipos listados acima. A análise das variáveis morfométricas foi usada para agrupar os tumores em três grandes grupos, os quais foram relacionados à sobrevivência pelas curvas de Kaplan Meier. RESULTADOS: Os três grupos de carcinoma neuroendócrino associaram-se às curvas da sobrevivência, as quais mostraram características ultrastruturais na microscopia eletrônica de significância prognóstica distinta. Os tumores foram contidos em três grupos bem definidos, que representam o espectro da diferenciação neuroendócrina: tumor carcinóide (grupo 1); tumor carcinóide atípico e carcinoma de grandes células neuroendócrino (grupo 2); e carcinoma de pequenas células (grupo 3). O grupo 2 representa um espectro intermediário na carcinogênese neuroendócrina, entre o carcinóide típico e o carcinoma de pequenas células. CONCLUSÕES: Nossos achados confirmam que a microscopia eletrônica é uma ferramenta útil no diagnóstico e prognóstico dos casos de tumores pulmonares.

OBJECTIVE: To establish reproducible electron microscopic criteria for identifying the four major types of neuroendocrine tumors of the lung: carcinoid; atypical carcinoid; large cell neuroendocrine carcinoma; and small cell carcinoma. METHODS: Measurements were made on electron micrographs using a digital image analyzer. Sixteen morphometric variables related to tumor cell differentiation were assessed in 27 tumors. The examination under electron microscopy revealed that all of the tumors could be classified as belonging to one of the four categories listed above. Cluster analysis of the morphometry variables was used to group the tumors into three clusters, and Kaplan-Meier survival function curves were employed in order to draw correlations between each cluster and survival. RESULTS: All three clusters of neuroendocrine carcinomas were found to be associated with survival curves, demonstrating the prognostic significance of electron microscopic features. The tumors fell into three well-defined clusters, which represent the spectrum of neuroendocrine differentiation: typical carcinoid (cluster 1); atypical carcinoid and large cell neuroendocrine carcinoma (cluster 2); and small cell carcinoma (cluster 3). Cluster 2 represents an intermediate step in neuroendocrine carcinogenesis, between typical carcinoid tumors and small cell carcinomas. CONCLUSIONS: Our findings confirm that electron microscopy is useful in making the diagnosis and prognosis in cases of lung tumor.

OBJETIVO: Apresentar um método alternativo para detectar micrometástases em linfonodos previamente negativos para câncer de pulmão não-pequenas células (CPNPC) pela coloração de rotina com hematoxilina-eosina. MÉTODOS: Setenta e sete linfonodos hilares e mediastinais ressecados de 18 pacientes portadores de CPNPC foram investigados para a presença de micrometástases associando-se análise em microsséries e imunoistoquímica. RESULTADOS: Micrometástases foram detectadas após a identificação de células neoplásicas citoqueratina e cromogranina positivas em microsséries de linfonodos. Dos 18 pacientes inicialmente estadiados como pN0 pela coloração de rotina com hematoxilina-eosina, 9 (50%) foram reestadiados como N1, e o prognóstico foi reavaliado em função de parâmetros histológicos e clínicos. A comparação das curvas de sobrevida mostrou que os pacientes sem micrometástases tiveram maior sobrevida do que os portadores de micrometástases. Além disso, após a análise multivariada controlada para idade, sexo, tipo histológico e reestadiamento, a presença de micrometástases mostrou-se como um fator independente na sobrevida. Entre os pacientes que haviam sido previamente estadiados como pN0, o risco de morte mostrou-se 7 vezes maior para os que foram posteriormente diagnosticados com micrometástases do que para aqueles nos quais não foram identificadas micrometástases. CONCLUSÃO: A combinação da análise em microsséries com a imunoistoquímica pode representar um método alternativo de baixo custo e menos demorado para identificar metástases ocultas e prever o prognóstico em pacientes portadores de CPNPC pN0 cujos tumores foram cirurgicamente ressecados. São necessários estudos prospectivos randomizados com casuísticas maiores para determinar a acurácia desse método alternativo.

OBJECTIVE: To present an alternative method of detecting micrometastases in lymph nodes previously testing negative for non-small cell lung cancer (NSCLC) by routine hematoxylin-eosin staining. METHODS: A total of 77 hilar and mediastinal lymph nodes resected from 18 patients with NSCLC were investigated for the presence of micrometastases using a combination of microarray analysis and immunohistochemistry. RESULTS: Micrometastases were detected by identifying cytokeratin- and chromogranin-positive cells in lymph node microarrays. Of the 18 patients initially staged as pN0 through routine hematoxylin-eosin staining, 9 (50%) were restaged as N1, and the prognoses were re-evaluated in terms of histological and clinical parameters. The comparison of the survival curves revealed that survival was higher in the patients without micrometastases than in those with micrometastases. In addition, in the multivariate analysis adjusted for age, gender, histological type, and restaging, the presence of micrometastases proved to be an independent predictor of survival. Among patients who had been previously staged as pN0, the risk of death was found to be 7-times greater for those later diagnosed with micrometastases than for those in whom no micrometastases were identified. CONCLUSION: The combination of microarray analysis and immunohistochemistry might represent a low-cost and less time-consuming alternative for identifying occult micrometastases and predicting prognoses in surgically resected patients with pN0 NSCLC. Larger randomized, prospective studies are needed in order to determine the accuracy of this method.

OBJETIVOS: Apresentar alterações histopatológicas pulmonares encontradas em autopsias de pacientes falecidos por insuficiência respiratória aguda (IRA) e verificar se doenças de base e específicos fatores de risco associados aumentam a incidência dessas alterações. MÉTODOS: Foram revisados laudos finais de autopsias e selecionadas 3.030 autopsias de pacientes > 1 ano de idade, com infiltrado pulmonar radiológico, portadores de doença de base e fatores de risco associados, que morreram por alterações pulmonares decorrentes de IRA. RESULTADOS: As principais alterações histopatológicas pulmonares causadoras de morte imediata foram: dano alveolar difuso (DAD); edema pulmonar; pneumonia intersticial linfocítica (PIL) e hemorragia alveolar. As principais doenças de base encontradas foram: AIDS; broncopneumonia; sepse; cirrose hepática; tromboembolismo pulmonar; infarto agudo do miocárdio (IAM); acidente vascular cerebral; tuberculose; câncer; insuficiência renal crônica e leucemia. Os principais fatores de risco associados foram: idade > 50 anos; hipertensão arterial; insuficiência cardíaca congestiva; doença pulmonar obstrutiva crônica e diabetes mellitus. Pacientes com esses fatores de risco e AIDS apresentaram alta probabilidade de desenvolver PIL; pacientes com esses mesmos fatores, de desenvolver DAD, se portadores de sepse ou cirrose hepática; pacientes com tromboembolismo e os mesmos fatores de risco, de desenvolver hemorragia alveolar; pacientes com esses fatores de risco e IAM, de desenvolver edema pulmonar. CONCLUSÕES: Os achados pulmonares em pacientes com óbito por IRA apresentaram quatro padrões histopatológicos: DAD, edema pulmonar, PIL e hemorragia alveolar. Doenças de base e específicos fatores de risco associados correlacionaram-se positivamente com determinados padrões histopatológicos detectados à autópsia.

OBJECTIVE: To present the pulmonary histopathological alterations found in the autopsies of patients with acute respiratory failure (ARF) and determine whether underlying diseases and certain associated risk factors increase the incidence of these histopathological patterns. METHODS: Final autopsy reports were reviewed, and 3030 autopsies of patients > 1 year of age with an underlying disease and associated risk factors were selected. All had developed diffuse infiltrates and died of ARF-related pulmonary alterations. RESULTS: The principal pulmonary histopathological alterations resulting in immediate death were diffuse alveolar damage (DAD), pulmonary edema, lymphocytic interstitial pneumonia (LIP) and alveolar hemorrhage. The principal underlying diseases were AIDS, bronchopneumonia, sepsis, liver cirrhosis, pulmonary thromboembolism, acute myocardial infarction (AMI), cerebrovascular accident, tuberculosis, cancer, chronic kidney failure and leukemia. The principal associated risk factors were as follows: age > 50 years; arterial hypertension; congestive heart failure; chronic obstructive pulmonary disease; and diabetes mellitus. These risk factors and AIDS correlated with a high risk of developing LIP; these same risk factors, if concomitant with sepsis or liver cirrhosis, correlated with a risk of developing DAD; thromboembolism and these risk factors correlated with a risk of developing alveolar hemorrhage; these risk factors and AMI correlated with a risk of developing pulmonary edema. CONCLUSION: Pulmonary findings in patients who died of ARF presented four histopathological patterns: DAD, pulmonary edema, LIP and alveolar hemorrhage. Underlying diseases and certain associated risk factors correlated positively with specific histopathological findings on autopsy.

OBJECTIVES: Certain aspects of pulmonary pathology observed in autopsies of HIV/AIDS patients are still unknown. This study considers 250 autopsies of HIV/AIDS patients who died of acute respiratory failure and describes the demographic data, etiology, and histological pulmonary findings of the various pathologies. METHODS: The following data were obtained: age, sex, and major associated diseases (found at the autopsy). Pulmonary histopathology was categorized as: diffuse alveolar damage; pulmonary edema; alveolar hemorrhage; and acute interstitial pneumonia. Odds ratio of the HIV/AIDS-associated diseases developing a specific histopathological pattern was determined by logistic regression. RESULTS: A total of 197 men and 53 women were studied. The mean age was 36 years. Bacterial bronchopneumonia was present in 36% (91 cases) and Pneumocystis jiroveci pneumonia in 27% (68) of patients. Pulmonary histopathology showed acute interstitial pneumonia in 40% (99), diffuse alveolar damage in 36% (89), pulmonary edema in 13% (33), and alveolar hemorrhage in 12% (29) of patients. Multivariate analysis showed a significant and positive association between Pneumocystis jiroveci pneumonia and acute interstitial pneumonia (Odds ratio, 4.51; 95% CI, 2.46 - 8.24; p < 0.001), severe sepsis and/or septic shock and diffuse alveolar damage (Odds ratio, 3.60; 95% CI, 1.78 -7.27; p < 0.001), and cytomegalovirus and acute interstitial pneumonia (Odds ratio, 2.22; 95% CI, 1.01 - 4.93; p = 0.05). CONCLUSIONS: This report is the first autopsy study to include demographic data, etiologic diagnosis, and respective histopathological findings in patients with HIV/AIDS and acute respiratory failure. Further studies are necessary to elucidate the complete pulmonary physiopathological mechanism involved with each HIV/AIDS-associated disease.