Table 1

Summary of the study

Species	Experiment	Result
Human	Lung biopsy	Total mast cell number was increased in IPF lung.
	Lung biopsy	The number of tryptase and chymase-double-positive mast cells was increased and correlated with the disease severity as measured by FVC.
	Plasma	Plasma tryptase, but not chymase levels were markedly increased in patients with severe IPF and negatively correlated with FVC.
Rat	Ex vivo	Mast cells reseeded on fibrotic lung matrix released more active and total TGF-β1 in the culture medium compared with mast cells reseeded on non-fibrotic lung matrix.
	Ex vivo	Mechanical stretch-induced mast cell degranulation, TGF-β1 release and its signalling pathway activation in fibrotic lung. Mast cell stabilisers attenuated it.
	In vivo	Mast cell was increased at well after the fibrogenic process was established, but not at earlier time points.
		At day 14, chymase and tryptase-double-positive mast cells are few at parenchymal area, however, a small number of chymase-single-positive mast cells accumulated around the bronchial area. By day 21, a significant amount of chymase and tryptase-double-positive mast cells was present in the lung parenchyma.
		Cromoglycate attenuated the development of TGF-β1-induced pulmonary fibrosis.