Retrospektivna procjena učinka nintedaniba u mišjem modelu plućne fibroze

Pulmonary function tests (PFTs) routinely implemented in clinics are the first step in the diagnosis of idiopathic pulmonary fibrosis. Evaluation of PFTs in the mouse model of pulmonary fibrosis accompanied by histological readouts may improve the clinical predictability of new therapeutic candidates. Forced vital capacity (FVC) is considered the most predictive of restrictive pulmonary disorders. This study aimed to test the improvement of PFT in mice lung fibrosis induced by treatment with an approved substance nintedanib, considered the gold standard. The hypothesis that treatment in animal models will demonstrate similar effects as in humans in the most relevant clinical outcomes was tested. Two experimental designs were enrolled in this study, a preventive regimen, with treatment initiation from the day of the challenge; and a therapeutic regimen, starting on day 7 postchallenge when fibrotic changes are present in the lungs. Experiments were terminated at two different time points, at 14 and 21 days postchallenge. C57BL/6 mice were administered with bleomycin (BLM) intranasally and treated with nintedanib from day 0 to day 14 or from day 7 until day 21. Fourteen or 21 days after the BLM challenge, PFTs were assessed using the in vivo invasive lung function measurement system Buxco® Pulmonary Function Test (PFT) (DSI™, New Brighton, USA). Histological evaluation was performed as a modified Ashcroft score. The bleomycin challenge induced a significant decrease of FVC in both experiments. However, nintedanib treatment given in both regimens significantly improved lung functionality. These findings were confirmed with histological analysis of the Ashcroft scoring system, modified by Matsuse. In conclusion, a good correlation between functional test parameters and the clinical effect of nintedanib was shown in both experiments: the preventive regimen was sampled 14 days post-challenge and the therapeutic regimen 21 days post-challenge. Based on these findings, the implementation of PFTs could be a good platform to increase the translational value of the model and potential new treatments.