Journal Article

Usefulness of KL-6 for Predicting Clinical Outcomes in Hospitalized COVID-19 Patients

Mina Hur, Jong Ho Lee, Mikyoung Park, Chae Hoon Lee, Hanah Kim, Minjeong Nam

2022

Overview

Background: Krebs von den Lungen 6 (KL-6) is a novel biomarker for interstitial lung disease, and it reflects acute lung injury. We explored the usefulness of KL-6 to predict clinical outcomes in hospitalized coronavirus disease 2019 (COVID-19) patients. Methods: In a total of 48 hospitalized COVID-19 patients, KL-6 levels were measured using the HISCL KL-6 assay (Sysmex, Kobe, Japan) with the HISCL 5000 automated analyzer (Sysmex). Clinical outcomes (intensive care unit [ICU] admission, ventilator use, extracorporeal membrane oxygenation [ECMO] use, and 30-day mortality) were analyzed according to KL-6 percentiles. Age, initial KL-6 level, Charlson comorbidity index (CCI), and critical disease were compared using the receiver operating characteristic (ROC) curve and Kaplan-Meier methods for clinical outcomes. Results: KL-6 quartiles were associated with ICU admission, ventilator use, and ECMO use (all p < 0.05), except 30-day mortality (p = 0.187). On ROC curve analysis, initial KL-6 level predicted ICU admission, ventilator use, and ECMO use significantly better than age, CCI, and critical disease (all p < 0.05); age, initial KL-6 level, CCI, and critical disease predicted 30-day mortality comparably. On Kaplan–Meier survival analysis, hazard ratios (95% confidence interval) were 4.8 (1.2–19.3) for age, 4.7 (1.1–21.6) for initial KL-6 level, 3.9 (0.9–16.2) for CCI, and 2.1 (0.5–10.3) for critical disease. Conclusions: This study demonstrated that KL-6 could be a useful biomarker to predict clinical outcomes in hospitalized COVID-19 patients. KL-6 may contribute to identifying COVID-19 patients requiring critical care, including ICU admission and ventilator and/or ECMO use.

• Publisher: MDPI AG,MDPI
• Subject: Age / Analysis / biomarker / Biomarkers / Care and treatment / Chi-square test / Child, Preschool / clinical outcome / Clinical outcomes / Comorbidity / Coronaviruses / COVID-19 / COVID-19 - therapy / Diagnosis / Disease / Enzymes / Extracorporeal membrane oxygenation / Hospital patients / Hospitalization / Humans / Japan / Japan - epidemiology / KL-6 / KL-6; prediction; clinical outcome; COVID-19; biomarker / Laboratories / Lung Diseases, Interstitial / Medical prognosis / Medicine (General) / Mortality / Patients / Population / prediction / R5-920 / ROC Curve / Sepsis / Severe acute respiratory syndrome coronavirus 2 / Software / Statistical analysis / Survival analysis / Tumor necrosis factor / Tumor necrosis factor-TNF / Ventilators