Abstract
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.
Keywords: COVID-19; KL-6; biomarker; clinical outcome; prediction.
【저자키워드】 COVID-19, Biomarker, KL-6, Clinical outcome, prediction., 【초록키워드】 coronavirus disease, Critical care, Hospitalized, intensive care, Comorbidity, Interstitial lung disease, outcome, clinical outcomes, acute lung injury, extracorporeal membrane oxygenation, ROC, clinical, ICU admission, Japan, ECMO, age, automated, characteristic, Admission, patients, predict, Critical disease, 30-Day mortality, Analysis, COVID-19 patient, ROC Curve, ventilator, hospitalized COVID-19 patients, 95% confidence interval, hazard ratio, Kaplan-Meier method, quartile, Kobe, Kaplan-Meier survival analysis, initial, Result, predicted, analyzed, significantly, contribute, demonstrated, reflect, were measured, CCI, 【제목키워드】 clinical,