Association of serum monomeric periostin level with outcomes of acute exacerbation of idiopathic pulmonary fibrosis and fibrosing nonspecific interstitial pneumonia

Background: The associations of serum monomeric periostin (M-PN) level and serial change in M-PN with acute exacerbation of chronic fibrosing interstitial pneumonia (AE-FIP) are unclear. Methods: We prospectively measured serum M-PN level from onset of AE to day 14 in 37 patients with AE-FIP and evaluated its association with outcome. To determine localization of periostin expression, immunohistochemical staining of pathological lung tissue from autopsy cases of AE-IPF was evaluated. Results: Data from 37 AE-FIP patients (28 men; age 73.9 +/- 7.8 years) were analyzed. With healthy controls as reference, serum M-PN level was significantly higher in patients with AE-FIP (P=0.02) but not in those with stable idiopathic pulmonary fibrosis (P=1.00). M-PN was significantly lower on day 7 than at AE-FIP onset in survivors [14.6 +/- 5.8 vs. 9.3 +/- 2.8 ng/mL (onset to day 7: P<0.001)] but not in non-survivors [14.6 +/- 5.1 vs. 13.2 +/- 5.1 ng/mL (onset to day 7: P=0.07)]. In analysis using a cut-off value for serial change in M-PN (Delta M-PN), 3-month survival was 92.3% in the Delta M-PN decrease group and 36% in the Delta M-PN increase group (P=0.002). In multivariate analysis, 3-month survival tended to be associated with high Delta M-PN (OR: 12.4, 95% CI: 0.82-187.9, P=0.069). Conclusions: Serial change in serum M-PN level may be a prognostic indicator of AE-FIP.