Galactin-1, 3 and 9: Potential biomarkers in idiopathic pulmonary fibrosis and other interstitial lung diseases

Introduction: Galectins are proteins that bind β-galactosides such as N-acetylactosamine present in N-linked and O-linked glycoproteins and that seem to be implicated fibrotic mechanisms. Here we aimed to define the role of serum galectins in idiopathic pulmonary fibrosis and idiopathic non-specific interstitial pneumonia (NSIP) by comparison with other chronic interstitial lung diseases (ILDs) and healthy subjects. Methods: Forty-one fibrotic ILD patients (median age (IQR), 65 years (20); 50 % male) were enrolled in the study. Peripheral blood concentrations of galectins-1, 3 and 9 were determined with commercial ELISA kits. Results: Galectin-1 and 9 concentrations were higher in the ILD group than in healthy controls (p = 0.0318 and p < 0.0001, respectively). Galectin-3 was also higher in ILD patients (borderline significant p = 0.0617). In particular, significantly higher Gal-1 concentrations were found in sarcoidosis and NSIP patients (p = 0.0418 and p = 0.0015, respectively), while Gal-9 concentrations were significantly higher in all ILD subgroups. Specific cut-offs for all galectins were calculated by receiver operating curve (ROC) analysis. Several correlations with lung function parameters were found. Discussion: Galectins 1, 3 and 9 concentrations were found altered in serum of ILD patients suggesting their potential utility as clinical, diagnostic and prognostic biomarkers. Inhibition of galectins may be useful in the therapeutic management of pulmonary fibrosis. Further studies on larger case series would be worthwhile.