Serum Krebs von den Lungen-6 level predicts disease progression in interstitial lung disease.

Ui Won Ko,Eun Jung Cho,Hyun Jung Koo,Jin Woo Song,Kyung-Hyun Do,Heung-Bum Oh,Masataka Kuwana

doi:10.1371/journal.pone.0244114

Ui Won Ko, Eun Jung Cho + Show 5 more

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https://doi.org/10.1371/journal.pone.0244114

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Abstract

Disease progression (DP) in interstitial lung disease (ILD) is variable and difficult to predict. In previous reports, serum Krebs von den Lungen-6 (KL-6) was suggested to be useful in diagnosing and predicting survival in ILD. The aim of our study was to investigate the usefulness of serum KL-6 as a predictor of DP in ILD. Clinical data of 199 patients with ILD (idiopathic pulmonary fibrosis: 22.8%) were prospectively collected and serum KL-6 levels were measured. DP was defined as a relative decline in forced vital capacity (FVC) ≥ 10%, acute exacerbation, or death during follow-up. The median follow-up period was 11.1 months. The mean age of the subjects was 62.2 years, and 59.8% were male. DP occurred in 21.6% of patients. The progressed group showed lower FVC, lower diffusing capacity for carbon monoxide, lower the minimum oxygen saturation during the 6-minute walk test, higher fibrosis scores on high-resolution computed tomography, and higher KL-6 levels (826.3 vs. 629.0 U/mL; p < 0.001) than those of the non-progressed group. In receiver operating characteristic curve analysis, serum KL-6 levels were a significant predictor of DP in ILD (area under the curve = 0.629, p = 0.009, and the optimal cut-off level was 811 U/mL). In multivariable Cox analysis, high serum KL-6 levels (≥ 800 U/mL) were only independently associated with DP in ILD (HR 2.689, 95% CI 1.445–5.004, P = 0.002). Serum KL-6 levels might be useful to predict DP in patients with ILD.

Highlights

Interstitial lung disease (ILD) is defined as a group of lung diseases affecting the interstitium and includes more than 200 different types, including idiopathic pulmonary fibrosis (IPF) [1]
Previous studies reported that older age, male sex, lower lung function, a usual interstitial pneumonia pattern, and more extensive disease on highresolution computed tomography (HRCT) are associated with poor prognosis in ILD [3,4,5,6,7,8,9]
Diagnosis of IPF, idopathic non-specific interstitial pneumonia, cryptogenic organizing pneumonia (COP) and unclassifiable ILD was made according to the international guidelines [23, 24]

Summary

Introduction

Interstitial lung disease (ILD) is defined as a group of lung diseases affecting the interstitium and includes more than 200 different types, including idiopathic pulmonary fibrosis (IPF) [1]. The clinical course of ILD is highly variable and unpredictable; some patients appear stable or show a slow decline, whereas others show rapid deterioration or periods of relative stability interposed with periods of acute respiratory decline [2]. Predicting disease progression is difficult but important for the effective management of ILD. Previous studies reported that older age, male sex, lower lung function (forced vital capacity [FVC], diffusing capacity of the lung for carbon monoxide [DLCO]), a usual interstitial pneumonia pattern, and more extensive disease on highresolution computed tomography (HRCT) are associated with poor prognosis in ILD [3,4,5,6,7,8,9].

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