Serum NGAL is elevated in patients with asthma and persistent airflow obstruction

Abstract

Background: Neutrophilic airway inflammation is one of the features of severe asthma. Neutrophil gelatinase-associated lipocalin (NGAL), or lipocalin-2, is a glycoprotein associated with neutrophilic inflammation and can be detected in blood. Recently, blood NGAL levels have been reported to be elevated in chronic obstructive pulmonary disease. However, the clinical significance of serum NGAL levels in patients with asthma has not been elucidated. The aim of this study was to explore the association between serum NGAL level and clinical parameters in patients with asthma.Methods: Sixty-one non-smoking people with stable asthma were enrolled in this study. All patients underwent blood collection and pulmonary function tests. The associations between serum NGAL levels and clinical parameters were analyzed retrospectively. Results: Serum NGAL levels in patients with asthma and obstructive ventilatory disorder were higher than those in patients with asthma without obstructive ventilatory disorder (76.4 ± 51.4 ng/mL vs 39.3 ± 27.4 ng/mL, p=0.0019). Serum NGAL levels were correlated with forced expired flow at 50% of vital capacity %predicted and forced expired flow at 25% of vital capacity %predicted (r=-0.3373, p=0.0089 and r=-0.2900, p=0.0234, respectively). Results of a multiple regression analysis demonstrated that serum NGAL level was independently associated with obstructive ventilatory disorder.Conclusion: Serum NGAL levels were elevated in patients with asthma and obstructive ventilatory disorder. NGAL may be involved in airway remodeling possibly mediated by neutrophilic inflammation in asthma.