Clinical significance of serum HMGB1 in COPD and correlation with severity of airflow restriction and immune function

Abstract

Background: To explore the serum HMGB1 levels in patients with smoking-induced chronic obstructive pulmonary disease (COPD) and the correlations with airflow restriction and immune function. Methods: A total of 136 COPD patients were divided into mild, moderate and severe + extremely severe groups. Thirty-five healthy subjects were selected as control group. Serum HMGB1 levels were measured by ELISA, and the correlations with pulmonary and immune function indices were analyzed. Receiver operating characteristic (ROC) curve was plotted. Results: PaO2, eosinophil count, FEV1/FVC, FEV1% pred, and IgA, IgM, IgG levels of COPD patients were lower than those of control group, and decreased with airflow restriction aggravation. PaCO2, leukocyte count, neutrophil percentage, modified British Medical Research Council (mMRC) scale and COPD Assessment Test (CAT) scores, D-Dimer (D-D), PCT, CRP and HMGB1 levels, myeloid dendritic cell (mDC) and plasmacytoid dendritic cell (pDC) counts, and mDCs/pDCs of COPD patients exceeded those of control group, and increased with airflow restriction aggravation (P<0.05). HMGB1 levels of COPD patients were negatively correlated with FEV1/FVC, FEV1% pred, IgA, IgM and IgG levels and positively correlated with mDC count, pDC count and mDCs/pDCs (P<0.0001). The area under ROC curve was 0.883, the optimal cutoff value was 3.63 ng/mL, and sensitivity and specificity were 86.7% and 85.9%, respectively. Conclusions: Serum HMGB1 level in patients with smoking-induced COPD rises with airflow restriction aggravation and has significant correlations with the decline of pulmonary and immune functions, with high predictive value for COPD. HMGB1 is a potential biomarker for evaluating COPD progression.