Human epididymis protein 4 is a new biomarker to predict the prognosis of progressive fibrosing interstitial lung disease

Abstract

BACKGROUND The clinical course and prognosis of progressive fibrosing interstitial lung diseases ( PF-ILDs) vary from individual to individual. Predictive serum biomarkers for the management of the disease are needed. Serum human epididymis protein 4 (HE4) has been reported to be elevated in patients with IPF, yet its clinical utility has not been elucidated. We evaluated whether serum HE4 could be a biomarker for patients with PF-ILD. METHODS Serum HE4 was measured in a retrospective study that consisted of 34 patients with PF-ILD and 40 healthy volunteers. The relationship between serum HE4 levels and clinical parameters or prognosis was investigated. To validate the significance of the results, a prospective observational study that consisted of 37 patients with PF-ILD and 40 control patients without PF-ILD was performed.RESULTS Serum HE4 was higher in patients with PF-ILD than in health volunteers ( P < 0.01). A correlation of the serum HE4 levels with the extent of honeycombing on chest high-resolution computed tomography was identified (r = 0.41, P = 0.015). In multivariate analysis by the Cox proportional hazard model, higher HE4 levels (> 238 pmol/l) were associated with elevated mortality risk (HR 7.27, 95% CI 1.56-34.0, P = 0.01 in the derivation cohort; HR 44.3, 95% CI 4.19-468, P < 0.01 in validation cohort). CONCLUSIONS Serum HE4 levels may serve as a new diagnostic and prognostic biomarker for patients with PF-ILD.