Increased Levels of VCAM-1 in Sera and VLA-4 Expression on Neutrophils in Dermatomyositis with Interstitial Lung Disease

Vascular cell adhesion molecule-1 (VCAM-1) and its ligand very late antigen (VLA-4) play important roles in many autoimmune diseases. Our study aimed to investigate the serum level of VCAM-1 and VLA-4 expression on peripheral blood neutrophil surface in patients with dermatomyositis (DM), especially focusing on patients with interstitial lung disease (ILD). Blood specimens of 42 patients with DM and 42 healthy controls matched for age and gender were recruited. Total serum VCAM-1 level was measured using commercial enzyme-linked immunosorbent assay (ELISA) and the percentages of VLA-4 expression on neutrophils were analyzed by flow cytometry. We divided patients into subgroups according to whether they had ILD and whether they exhibited diffuse alveolar damage (DAD) via high-resolution computed tomography (HRCT). sVCAM-1 was increased in classical DM (cDM) and clinical amyopathic dermatomyositis (CADM) compared with healthy controls (both p < .01). DM-ILD had higher sVCAM-1 levels than the none-ILD group (p < .01). sVCAM-1 was also significantly increased in the DAD group compared to the none-DAD group (p < .01). The percentages of VLA-4 expression on neutrophils in cDM and CADM patients were significantly elevated than that in healthy controls (both p < .01). The percentage of VLA-4 expression on neutrophils in DM patients with ILD was higher than none-ILD group (p < .01). In the patients with ILD, DAD group had a higher percentage of VLA-4 expression on neutrophils than none-DAD group (p < .01). Our findings indicated that serum VCAM-1 levels combined with VLA-4 expression on neutrophils might be useful for detecting the severity of lung disease in patients with DM.