Fig 1.
Characterization of the new periostin ELISA kit.
(A) Periostin in serum was immunoprecipitated by SS18A or SS19C and detected by SS19C in non-reduced (left panel) or reduced (right panel) conditions. (B) Periostin in serum was immunoprecipitated by SS18A, SS17B, SS20A, or SS19D, respectively, and detected by SS19C in non-reduced conditions. (C) Serial immunoprecipitation of periostin by SS20A followed by SS19D (left lane) or by SS18A followed by SS17B (right lane), respectively, in non-reducing conditions.
Fig 2.
Selection of patients with IPF or fNSIP.
The chart shows selection of patients with IPF or fNSIP. In the CoDD-PF study, 40 IPF patients and five fNSIP patients were selected from 107 enrolled patients. In the Kurume study, 20 IPF patients and two fNSIP patients were selected. In addition, 137 healthy donors were enrolled.
Fig 3.
Abilities of each biomarker to diagnose IPF.
(A) Serum levels of each biomarker in IPF patients, fNSIP patients, and healthy donors. Serum levels of monomeric periostin, total periostin, KL-6, SP-D, and LDH in IPF patients (n = 60), fNSIP patients (n = 7) and control donors (n = 137). (B) ROC curve analysis of each biomarker between IPF patients and healthy donors. Monomeric periostin (red), total periostin (orange), KL-6 (black), SP-D (green), and LDH (blue) between IPF patients (n = 60) and healthy donors (n = 137). ***: p<0.001, **: p<0.01.
Fig 4.
Ability of each biomarker to predict the short-term progression of IPF.
Correlations between monomeric periostin, total periostin, KL-6, SP-D or LDH and short-term change of %VC (A) or %DL, CO (B) in IPF patients (n = 44 for %VC and 39 for %DL, CO).
Fig 5.
Effects of clustering IPF patients into high and low groups for each biomarker to predict the short-term progression of IPF.
IPF patients were clustered into high and low groups by the cut-off values of monomeric periostin (15.0 ng/mL), total periostin (100 ng/mL), KL-6 (1,000 IU/mL), SP-D (220 ng/mL) or LDH (240 IU/L). Short-term change of %VC (A, n = 44) or %DL, CO (B, n = 39) (upper) and proportion (down) in each high or low group is depicted.
Fig 6.
Comparison of the ratios of monomeric periostin in IPF and other high-periostin diseases.
The comparison between monomeric periostin and total periostin in IPF patients (n = 60, open triangle) and AD (upper, n = 224, dot), SSc (lower left, n = 37, dot), or asthma (lower right, n = 143, dot) patients is shown. All patients or low-range patients in AD are shown in upper left and right panels, respectively. The regression lines are inserted.