Its typical clinical manifestations are rapidly progressive glomerulonephritis and alveolar hemorrhage.

The first patient developed a nonfatal diffuse alveolar hemorrhage 2 days after study-drug completion.

Reduced TF-dependent activation of coagulation leads to alveolar hemorrhage.

Conclusion Our study indicates that TF-dependent activation of coagulation is required to limit alveolar hemorrhage and death after IAV infection.

An autopsy was performed and diffuse alveolar hemorrhage in all parts of the lungs were seen, which was confirmed by microscopic examination.

Results IAV infection of wild-type mice increased lung TF expression, activation of coagulation and inflammation in BALF, but also led to alveolar hemorrhage.

In contrast, deletion of TF in either myeloid cells or endothelial cells and hematopoietic cells did not increase alveolar hemorrhage or death after IAV infection.