RESUMO
BACKGROUND & AIMS: The liver's response to injury is fibrosis, and when chronic, cirrhosis. Age is a critical factor impacting many immune-mediated processes, potentially including the liver's wounding response to injury. METHODS: The effects of age on acute and chronic liver injury were evaluated using a carbon tetrachloride model in mice. Lymphocyte and macrophage populations were assessed by flow cytometry and immunohistochemical analysis. RESULTS: Acute liver injury was greater in 18-month-old (old) mice than in 9-month-old (middle-aged) mice as judged by changes in aminotransferases. Similarly, livers of 18-month-old mice had a significantly greater fibrogenic response to injury than did livers of 9-month-old mice after chronic injury (assessed by col1α1 mRNA expression, morphometric analysis and hydroxyproline measurement). Interestingly, livers from young mice (6 weeks old) also exhibited an increase in fibrogenesis compared to 9-month-old mice, albeit not to the same degree as in old mice. Consistent with a role for macrophages in fibrogenesis, the number of liver macrophages in young and 9-month-old mice increased, while in chronically injured livers of 18-month-old mice, the number of macrophages was reduced, and was less than in the livers of young and 9-month-old injured livers. CONCLUSIONS: Our data indicate that the fibrogenic response to injury varies substantially with age, and moreover that macrophage recruitment and dynamics may be an important component in differential age-associated fibrotic disease.
Assuntos
Envelhecimento/imunologia , Doença Hepática Induzida por Substâncias e Drogas/imunologia , Cirrose Hepática Experimental/imunologia , Fígado/imunologia , Subpopulações de Linfócitos/imunologia , Macrófagos/imunologia , Fatores Etários , Envelhecimento/metabolismo , Envelhecimento/patologia , Alanina Transaminase/sangue , Animais , Tetracloreto de Carbono , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Cadeia alfa 1 do Colágeno Tipo I , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Fibronectinas/genética , Fibronectinas/metabolismo , Hidroxiprolina/metabolismo , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/metabolismo , Cirrose Hepática Experimental/patologia , Subpopulações de Linfócitos/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , RNA Mensageiro/metabolismoRESUMO
Although bovine thrombin is commonly used in the operating room, there is evidence that exposure to bovine thrombin can result in the development of autoimmune antibodies, usually against factor V, which can lead to a profound coagulopathy. It is thought that impurities in bovine thrombin preparations are responsible for the adverse reactions in patients. Here we describe a case in which exposure to a relatively pure bovine thrombin preparation resulted in the development of an antihuman factor V antibody-associated coagulopathy. This report calls into question the safety of even relatively pure bovine thrombin.