Objective: To analyze the correlated clinical significance by testing the serum monocyte chemoattractant protein-1 (MCP-1) levels of patients with polymyositis/dermatomyositis (PM/DM).
Methods: The sera from 100 adult PM/DM patients, 20 patients with pulmonary infection and 42 healthy controls were selected. The serum MCP-1 concentrations were detected by enzyme-linked immunosorbent assay (ELISA). The correlations between serum MCP-1 levels and clinical features or laboratory examinations of PM/DM patients were investigated.
Results: The serum levels of MCP-1 were (1 869 ±1 590) ng/L, (1 349±1 303) ng/L, (493±255) ng/L and (256±144) ng/L in PM/DM patients with interstitial lung disease (ILD) and without ILD, patients with infectious lung disease and healthy controls, respectively. Serum MCP-1 levels in the PM/DM patients with ILD were significantly higher than those of the PM/DM patients without ILD, patients with infectious lung disease and healthy controls (all P values<0.01). Significant correlations were found between the elevated levels of serum MCP-1 and the presence of ILD in the patients with PM/DM (χ2=9.6, P<0.01). The sensitivity and specificity of serum abnormal MCP-1 levels for ILD in the patients with PM/DM were 60.7% and 68.2%, respectively. The incidence of fever, arthritis, decreased %DL(CO) , erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and serum ferritin were significantly higher in the MCP-1 raised group than in the MCP-1 normal group (all P values<0.005). Additionally, Spearman rank correlation analysis showed that serum MCP-1 levels were positively correlated with serum ferritin in peripheral blood in the patients with PM/DM.
Conclusion: The levels of serum MCP-1 are significantly elevated in PM/DM and it is significantly associated with ILD complication, and may contribute to the early differentiation of ILD from lung infectious disease.