Serum high‐mobility group box 1 is associated with the onset and severity of acute exacerbation of idiopathic pulmonary fibrosis

ABSTRACT Background and objective High‐mobility group box 1 (HMGB1) is a known mediator of acute lung injury through the acceleration of pro‐inflammatory –signalling. Previous studies showed that HMGB1 is increased in the lung and circulation of patients with acute exacerbation of idiopathic pulmonary fibrosis (AE‐IPF). This study investigated the predictive value of circulatory HMGB1 for disease progression and prognosis of IPF in the stable phase and AE phase. Methods In total, 76 patients with stable IPF, 17 patients with AE‐IPF, 37 patients with chronic obstructive pulmonary disease (COPD) and 74 healthy controls were included. Serum HMGB1 levels were compared among the four groups and the associations of HMGB1 levels with the onset of AE and prognosis were evaluated in patients with stable IPF. The prognostic value of HMGB1 was determined in AE‐IPF. Results Serum HMGB1 levels in patients with stable IPF were significantly higher than those in healthy controls, and in patients with AE‐IPF they were even higher than the levels in either of these groups (6.26 ± 5.27, 3.42 ± 2.69 and 19.20 ± 16.76 ng/mL, respectively). There was no significant difference in serum HMGB1 levels between stable IPF patients and COPD patients. Higher levels of HMGB1 were associated with earlier onset of AE in stable IPF patients and with shorter survival in AE‐IPF patients ( P = 0.030 and 0.001, respectively). Conclusion Higher levels of serum HMGB1 predict earlier onset of AE in stable IPF patients and shorter survival in AE‐IPF patients, indicating that HMGB1 is associated with acute deterioration of the disease.