Extravascular coagulation and fibrinolysis in murine lung inflammation induced by the mycobacterial cord factor trehalose-6,6'-dimycolate.

Diffuse pulmonary inflammation in interstitial lung diseases is associated with increased coagulation in the extravascular spaces of the lung. We hypothesized that conditions favoring coagulation over fibrinolysis in the lung are related to inflammation. Pulmonary coagulation and fibrinolysis were studied in two strains of mice susceptible or resistant to the development of lung inflammation in response to the mycobacterial cell wall glycolipid trehalose-6,6'-dimycolate (TDM). Susceptible animals treated with TDM intravenously develop well-organized collections of mononuclear cells in the lung parenchyma referred to as granulomas in this report. More granulomas were found in the susceptible ICR mice than in the resistant A/J mice after intravenous administration of TDM (7 +/- 1 granulomas/mm2 versus 1 +/- 0.3 granulomas/mm2, p = 0.005). Granuloma formation was associated with increased lung procoagulant activity (PCA) measured in bronchoalveolar lavage (BAL) cell lysates from susceptible mice. In contrast, TDM-resistant A/J mice challenged with TDM did not have a significant BAL cell PCA response, but expressed several-fold greater levels of lung BAL fluid plasminogen activator activity (PAA) than ICR mice. To examine the role of coagulation in the TDM pulmonary inflammatory response, susceptible C57Bl/10SnJ mice were anticoagulated by oral administration of warfarin prior to challenge of TDM; these mice developed fewer pulmonary granulomas than TDM-treated mice without warfarin treatment (2.6 +/- 0.5 granulomas/mm2 versus 6.5 +/- 0.8 granulomas/mm2, p < 0.001) but had similar BAL cell PCA and lung inflammatory changes as measured by lung weights and BAL cellularity.(ABSTRACT TRUNCATED AT 250 WORDS)