Role of carbohydrate antigens sialyl Lewis (a) (CA19-9) in bronchoalveolarlavage in patients with pulmonary fibrosis

Background: It has been reported that carbohydrate antigen sialyl Lewis (a) (CA19-9) levels are elevated in serum as well as in bronchoalveolar lavage fluid (BALF) of patients with pulmonary fibrosis. However, the biological significance of CA19-9 is unclear. Objective: The purpose of the present st udy was to evaluate correlations between CA19-9 levels in BALF and several biochemical as well as clinical parameters in patients with pulmonary fibro sis. In addition, biological functions of CA19-9 were also examined. Method s: We studied 24 patients with a diagnosis of pulmonary fibrosis: 16 with i diopathic pulmonary fibrosis (IPF) and 8 with pulmonary fibrosis associated with a collagen vascular disorder (PF-CVD). In BALF, carbohydrate antigens sialyl Lewis (a) (CA19-9), elastase: alpha(1)-proteinase inhibitor complex (E-PI), hepatocyte growth factor (HGF), LDH, IgG, IgA, albumin, and cell d ifferentiation were measured. We also evaluated the effects of CA19-9 on ne utrophil functions. Results: CA19-9/albumin levels in BALF significantly co rrelated with HGF/albumin, elastase/albumin, LDH/albumin, total number of a lveolar macrophages, and total number of neutrophils. Purified CA19-9 had a chemotactic activity for neutrophils. In addition, neutrophil chemotactic activity to C5a, fMLP, and interleukin 8 was significantly stimulated after incubation with purified CA19-9. Furthermore, CA19-9 increased the express ion of CD15s on neutrophils. Conclusions: Our data demonstrated (i) CA19-9 in BALF correlated with other markers of inflammation in pulmonary fibrosis , and (ii) CA19-9 can modify neutrophil functions. These results suggest th at CA19-9 may play a role in the process of lung injury in patients with pu lmonary fibrosis.