Journal Article

Prognostic role of blood KL-6 in rheumatoid arthritis–associated interstitial lung disease

Choi, Kwang Hun, Jacob, Joseph, Kim, Ho Cheol, Song, Jin Woo

2020

Overview

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) has a variable clinical course for which predicting prognosis is difficult. However, the role of blood biomarkers in RA-ILD is ill-defined. The aim of this study was to investigate the prognostic value of Krebs von den Lungen-6 (KL-6) levels in RA-ILD patients. The medical records of 84 patients with RA-ILD were retrospectively reviewed. Plasma KL-6 levels were measured by Nanopia KL-6 assay (SEKISUI MEDICAL, Tokyo), using latex-enhanced immunoturbidimetric assay. The median follow-up period was 61 months. Mean age was 61.4 years, 45.2% were men, 44.0% were ever-smokers, and 35.7% showed a usual interstitial pneumonia (UIP) pattern on high-resolution computed tomography. The median KL-6 level at baseline was 741.2 U/mL (interquartile range, 439.7-1308.9 U/mL). On multivariate logistic regression analysis, a high KL-6 level (≥ 640 U/mL) was an independently associated with a UIP pattern (odds ratio [OR], 5.173; P = 0.005) with old age (OR, 1.104, P = 0.005). On multivariate Cox analysis, a high KL-6 level (≥ 685 U/mL) was an independent prognostic factor for the mortality (hazard ratio [HR], 2.984; P = 0.016) with a older age (HR, 1.061; P = 0.030), male sex (HR, 3.610; P = 0.001), lower forced vital capacity (HR, 0.957; P = 0.002), and a UIP pattern (HR, 4.034; P = 0.002). Our results suggest that high KL-6 levels might be useful as a biomarker for the presence of a UIP pattern and prognosis in patients with RA-ILD.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Age / Age Factors / Aged / Analysis / Arthritis / Arthritis, Rheumatoid - complications / Arthritis, Rheumatoid - pathology / Autoimmune diseases / Biological markers / Biology and Life Sciences / Biomarkers / Biomarkers - blood / Biopsy / Blood / Carbon monoxide / CAT scans / Computed tomography / Critical care / Development and progression / Diseases / Female / Humans / Idiopathic Pulmonary Fibrosis - complications / Idiopathic Pulmonary Fibrosis - pathology / Latex / Levels / Logistic Models / Lung - physiology / Lung diseases / Lung Diseases, Interstitial - etiology / Lung Diseases, Interstitial - mortality / Lung Diseases, Interstitial - pathology / Lung volume measurement / Male / Male identity / Medical prognosis / Medical records / Medicine / Medicine and Health Sciences / Men / Middle Aged / Mortality / Mucin-1 - blood / Multivariate analysis / Odds Ratio / Patients / Physical Sciences / Pneumonia / Prognosis / Proportional Hazards Models / Pulmonary fibrosis / Regression analysis / Respiratory tract diseases / Retrospective Studies / Rheumatoid arthritis / Rheumatoid factor / Smokers / Smoking / Studies / Survival analysis / Survival Rate / Tomography / Tomography, X-Ray Computed / Variables / Vital Capacity