Ms. Bajaj et al., Tissue factor pathway inhibitor expression by human pleural mesothelial and mesothelioma cells, EUR RESP J, 15(6), 2000, pp. 1069-1078
The mesothelial lining of the pleura and malignant mesothelioma promote fib
rin deposition in pleural injury or neoplasia via expression of tissue fact
or (TF). It was hypothesized that these cells might also regulate intrapleu
ral coagulation by elaborating TP pathway inhibitor (TFPI).
TFPI activity and antigen in pleural fluids were assayed from patients with
congestive heart failure (CHF), pneumonia, empyema, metastatic pleural can
cer and malignant mesothelioma, The authors also assessed expression of TF
and TFPI messenger ribonucleic acid (mRNA) as well as TFPI activity and ant
igen by human pleural mesothelial cells, malignant mesothelioma cells (MS-1
cell line) and human lung fibroblasts. Immunohistochemical analyses of nor
mal, fibrotic, and neoplastic pleura were performed to determine whether TF
PI antigen was expressed in vivo,
The study revealed that TFPI was present in transudates from patients with
CHF and exudative pleural effusions from patients with pneumonia, empyema o
r pleural carcinoma. TFPI mRNA, activity and antigen were expressed by pleu
ral mesothelial cells, MS-1 cells and lung fibroblasts, Cytokines and serum
stimulated a significant early increase in TP mRNA levels with minimal enh
ancement of TFPI mRNA, activity and antigen levels. TFPI antigen was found
in normal, fibrotic and neoplastic pleural tissues.
The current observations indicate that tissue factor pathway inhibitor is l
ocally expressed in pleural disease, but that it does not prevent the devel
opment of a prothrombotic environment favouring local fibrin deposition in
pleural inflammation or cancer.