Decrease in antithrombin III and prothrombin serum levels contribute to coagulation disorders during leptospirosis

Autor(es)

Fernandes, Luis G. V. ; Filho, Antonio F. S. ; Souza, Gisele O. ; Vasconcellos, Silvio A. ; Romero, Eliete C. ; Nascimento, Ana L. T. O.

• Tipo de documento: Artigo Científico
• Fonte: MICROBIOLOGY-SGM; v. 162, n. 8, p. 1407-1421, AUG 2016.
• Citações Web of Science: 2

Resumo

Pathogenic bacteria of the genus Leptospira are the causative agent of leptospirosis, an emergent infectious disease that affects humans and animals worldwide. Severe forms of the disease in humans include jaundice, multiple organ failure and intense haemorrhage. Up to now, mechanisms associated with the haemorrhage foci are poorly understood. We report in this work that, despite the low levels of antithrombin III in convalescent human serum samples, virulent, culture-attenuated and saprophyte strains of Leptospira are unable to bind and/or degrade this thrombin inhibitor, suggesting an indirect mechanism of pathogenesis. Lower levels of prothrombin were found in serum samples at the onset and convalescent phase of the disease when compared to normal human sera. The concomitant decreased levels of antithrombin III and prothrombin suggest a process of stimulated coagulation, which is corroborated by the increase of prothrombin fragment F1+2 in the serum samples. Data obtained with hamsters experimentally infected with virulent Leptospira interrogans serovars Kennewicki and Canicola strongly point out that haemorrhage is correlated with decreased levels of thrombin inhibitors and prothrombin. Activated coagulation might lead to an overconsumption of coagulation factors ultimately leading to bleeding and organ failure. (AU)

• Processo FAPESP: 12/24164-0 - Caracterização da interação de Leptospira interrogans com o sistema protrombina/trombina e possíveis implicações na virulência
• Beneficiário: Luis Guilherme Virgílio Fernandes
• Linha de fomento: Bolsas no Brasil - Doutorado
• Processo FAPESP: 14/50981-0 - Busca de proteínas de superfície nas sequências do genoma da Leptospira interrogans: caracterização funcional e imunológica para o entendimento de mecanismos envolvidos na patogênese de bactéria
• Beneficiário: Ana Lucia Tabet Oller Do Nascimento
• Linha de fomento: Auxílio à Pesquisa - Temático
• Processo FAPESP: 12/23913-9 - Identificação e caracterização de proteínas de Leptospira interrogans envolvidas nas interações patógeno - hospedeiro
• Beneficiário: Ana Lucia Tabet Oller Do Nascimento
• Linha de fomento: Auxílio à Pesquisa - Regular