Antithrombin III as predictive indicator of survival in idiopathic pulmonary fibrosis (IPF) patients treated with nintedanib: a preliminary study.

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease often managed with nintedanib, a tyrosine kinase inhibitor targeting several profibrotic pathways. Although clotting processes are involved in wound healing and repair in the lung, there are no data on the role of antithrombin III (ATIII) in IPF patients treated with nintedanib. A previous proteomic analysis of serum of IPF patients before and after 1 year of nintedanib treatment showed differential protein expression of ATIII.

AIMS

Here we used quantitative methods to evaluate differential ATIII concentrations in IPF patients before and after 1 year of nintedanib treatment and to assess the potential of ATIII as a prognostic biomarker in IPF patients.

METHODS

Serum levels of ATIII were measured by enzyme-linked immunosorbent assay in 14 IPF patients before and after 1 year of nintedanib treatment.

RESULTS

A statistically significant inverse correlation was found between serum ATIII concentrations and pulmonary function test parameters in all patients at baseline and follow up. Baseline serum ATIII and bronchoalveolar lavage (BAL) neutrophils proved to be reliable predictors of poor prognosis. A baseline ATIII threshold of 126.5 μg/mL discriminated survivors from non-survivors.

CONCLUSIONS

After 12 months of antifibrotic treatment, IPF patients with high serum ATIII concentrations and high BAL neutrophil percentages had a poor prognosis and increased survival risk. The results of this preliminary study suggest that ATIII has potential as a biomarker of IPF severity and in predicting response to nintedanib therapy. As a marker, ATIII showed several advantages over BAL neutrophil percentage.