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Doctoral Thesis
DOI
10.11606/T.5.2008.tde-25032009-131328
Document
Author
Full name
Julio Henrique Rosa Croda
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2008
Supervisor
Committee
Duarte, Maria Irma Seixas (President)
Capelozzi, Vera Luiza
Lancellotti, Carmen Lucia Penteado
Nicodemo, Antonio Carlos
Salomão, Reinaldo
Title in Portuguese
Patogênese da síndrome pulmonar hemorrágica na leptospirose humana
Keywords in Portuguese
Autopsia
Imunoglobina A
Insuficiência respiratória
Leptospirose/etiologia
Sindrome pulmonar por Hantavírus
Abstract in Portuguese
A leptospirose é uma zoonose de alta morbidade em humanos e um importante problema de saúde pública. Causada por bactérias do gênero Leptospira, a doença apresenta diversas formas clínicas e é especialmente importante em países em desenvolvimento. Síndrome pulmonar hemorrágica é a maior causa de óbito em pacientes com formas severas da doença. Os mecanismos patogênicos relacionados à síndrome pulmonar hemorrágica na leptospirose humana são desconhecidos. Com o objetivo de avaliar estes mecanismos patogênicos, 30 necrópsias (tecido pulmonar) de pacientes com síndrome pulmonar hemorrágica na leptospirose e 7 controles foram avaliados. Para determinar a participação os mecanismos patogênicos envolvidos, experimentos de histologia e imunohistoquímica (IgM, IgG, IgA, and C3) foram realizados em amostras de tecidos pulmonares, bem como dosagem sérica de auto-anticorpos específicos (anticardiolipina e anti-membrana basal) de amostras pareadas de soros de pacientes com leptospirose com e sem síndrome hemorrágica pulmonar e de indivíduos doadores de banco de sangue. Nos achados patológicos, os pacientes com síndrome hemorrágica pulmonar na leptospirose diferem dos controles com hemorragia pulmonar em alguns aspectos: moderada ou intensa presença de macrófagos na luz alveolar (97% versus 29%, respectivamente; p < 0.01); presença de membrana hialina na superficie alveolar (100% versus 0% respectivamente; p < 0.01); intensa necrose e regeneração de pneumócitos II (100% versus 0%, respectivamente; p < 0.01); e presença de plasmócitos no septo aveolar (80% versus 29%; p < 0.02). Nenhuma diferença estatisticamente significativa foi observada em relação ao número de outras células no septo alveolar. Leptospiras intactas foram raramente observadas. A detecção de antígeno de leptospira não foi correlacionada com a intensidade de hemorragia pulmonar. Em nenhum dos tecidos pulmonares estudados foi evidenciado alterações microscópicas sugestivas de coagulação intravascular disseminada. Deposição de imunoglobulina foi detectada na superfície alveolar de 18 de 30 pacientes com síndrome pulmonar hemorrágica na leptospirose. Três padrões de marcação de imunoglobulina e complemento foram observados em tecido pulmonar de pacientes com hemorragia pulmonar e leptospirose: (A) marcação linear delicada, como uma membrana, recobrindo a superfície luminal alveolar de pneumócitos I e II; (MF) marcação multifocal, aleatória ao longo do septo; e (I) marcação fraca granular, focal, intra-alveolar. Não houve diferenças significativas na concentração de auto-anticorpos contra membrana basal nos diferentes grupos estudados. Observamos diferenças significativas nos títulos de anticorpos IgM anticardiolipina entre a primeira e segunda amostra, nos pacientes com e sem hemorragia pulmonar (p<0.01 e p=0.04, respectivamente). Aumento significativo nos títulos de anticorpos anti-cardiolipina da classe IgG, bem como na relação IgG/IgM, foi observado apenas nos pacientes com hemorragia pulmonar (p=0.01 e p=0.01). Nós concluímos que o comprometimento pulmonar na leptospirose humana grave ocorre principalmente sob a forma de uma pneumopatia hemorrágica com características peculiares, cujo quadro morfológico difere de outras hemorragias pulmonares. Caracteriza-se pela deposição linear de imunoglobulina (IgM, IgG e IgA) e complemento(C3) na superfície luminal alveolar de pneumócitos I e II e multifocal nos septos alveolares. Associa-se à intensa necrose de pneumócitos I e II, regeneração de pneumócitos II, além de inflamação septal e alveolar
Title in English
Pathogenesis of leptospirosis pulmonary hemorrhage syndrome in human
Keywords in English
Autopsy
Hantavirus pulmonary syndrome
Leptospirosis/ethnology
Respiratory insufficiency
Abstract in English
Leptospirosis is a zoonotic disease that is a cause of high morbidity and mortality in humans and is an important public health problem. Caused by bacteria of Leptospira genus, this disease presents diverse clinical manifestations and is especially important in developing countries. Leptospirosis pulmonary hemorrhage syndrome is the major cause of death in patients with the severe form of leptospirosis. The pathogenic mechanisms of this syndrome are unknown. With the purpose of identifying these pathogenic mechanisms, 30 necropsies (pulmonary samples) from patients with leptospirosis pulmonary hemorrhage syndrome and seven controls were evaluated. . To determine whether the immune system is involved, histology and immunohistochemistry (IgM, IgG, IgA, and C3) experiments were performed on lung tissue samples, as well sera measurements of autoantibodies (against the basal membrane and anti-cardiolipin) were performed in leptospirosis patients with and without pulmonary hemorrhage syndrome (in paired samples) and in healthy donors from a blood bank. We found that patients with leptospirosis pulmonary hemorrhage syndrome differed from control pulmonary hemorrhage patients in several features: the presence of moderate to high levels of macrophages in the alveolar space (77% versus 29%, respectively; p = 0.02), the presence of the focal hyaline membrane on alveolar surface (100% versus 0%; p < 0.01), extensive necrosis and regeneration of pneumocyte II cells (100% versus 0%; p < 0.01) and the presence of plasma cells in the alveolar septum (77% versus 29%, respectively; p =0.02). No statistically significant differences were observed in the number of others cells in the alveolar septae. Intact leptospires were rarely detected. Leptospiral antigen was not correlated with the intensity of the lesions. None of the patients showed microscopic evidence for disseminated intravascular coagulation. Immunoglobulin deposits were detected on the alveolar surface of 18/30 leptospirosis patients with pulmonary hemorrhage. Three staining patterns were observed for the immunoglobulins and C3 in the lung tissues of leptospirosis patients with pulmonary hemorrhage syndrom: (A) delicate linear staining adjacent to the alveolar surface, like a membrane covering the luminal surface of type I and II pneumocyte cells; (MF) random, multifocal staining along the alveolar septum; and (I) weak, focal intra-alveolar granular staining.. We were not able to show any significant difference in autoantibodies concentration in the different groups. We found significant difference between the titles of anticardiolipin IgM antibodies in the first and second sera sample from leptospirosis patients with and without pulmonary hemorrhage (p<0.01 e p=0.04, respectively). The increased in the titles of anti-cardiolipin IgG antibodies, as well IgG/IgM ratio was observed only in patients with pulmonary hemorrhage(p=0.01 and p=0.01). We concluded that the pulmonary involvement on severe human leptospirosis have particular characteristics, which the morphologic aspect differ from the others causes of lung hemorrhage. It was distinguished by linear deposition of immunoglobulin and complement (C3C) on the luminal alveolar surface of pneumocyte I and II cells. This event was associated with pneumocyte I and II cells necrosis, pneumocyte II regeneration and septal and alveolar inflammation
 
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Publishing Date
2009-04-06
 
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