PROTHROMBOTIC ACTIVATION OF PULMONARY ARTERIAL ENDOTHELIAL-CELLS IN APATIENT WITH TUBERCULOSIS

Activation of endothelial cells occurs in response to numerous physiol ogical stimuli and results in the concerted expression of endothelial cell proteins that change the nonthrombogenic intimal surface of a ves sel into a thrombogenic surface, with the subsequent develop ment of l ocal thrombosis. For example, both type 1 plasminogen activator inhibi tor and tissue factor expression are mediated by endothelial cell stim ulation in vitro; however, in contrast to type 1 plasminogen activator inhibitor, it has been difficult to detect tissue factor associated w ith endothelial cells in vivo. This case study describes the presence of both type 1 plasminogen activator inhibitor and tissue factor antig en associated with pulmonary arterial endothelial cells of a patient e xhibiting a mycobacterial infection. The disease was associated with c hronic hemoptysis and characterized by extensive tissue destruction an d local thrombosis within the pulmonary artery. The data show that con ditions occur in vivo in which local thrombosis is associated with inc reased levels of type 1 plasminogen activator inhibitor and tissue fac tor. (C) 1996 by W.B. Saunders Company