Fig. 1

Diagram illustrating the outline of the present research, consisting of Study 1 and Study 2. Study 1 was designed to identify unique lipid species and metabolic pathways in the peripheral blood of PF patients compared with HC subjects. Study 2 was designed to identify lipids related to the degree of absolute decline in %FVC at 6 M and 12 M after starting nintedanib. The PF patients enrolled in Study 2 were those enrolled in Study 1 who agreed to take anti-fibrotic medication. Patients were divided with an absolute decline in %FVC < 2.5% (less decline, 6 M responders) and those with a decrease in %FVC ≧ 2.5% (more decline, 6 M non-responders) 6 M after starting nintedanib, and absolute decline in %FVC < 5% (less decline, 12 M responders) and those with a decrease in %FVC ≧ 5% (more decline,12 M non-responders) 12 M after starting nintedanib. As an ancillary experiment, we investigated whether the lipids extracted in Study 1 and Study 2 contained candidates specifically related to endothelial cells or fibroblasts