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Published on: February 16, 2022
Serum KL-6 level is a useful biomarker for evaluating the severity of coronavirus disease 2019
Nobuyasu Awano1, Minoru Inomata1, Naoyuki Kuse1
1Department of Respiratory Medicine, Japanese Red Cross Medical Center, 4-1-22 Hiroo, Shibuya-ku, Tokyo, 150-8935, Japan.
Insights
Serum Krebs von den Lungen-6 (KL-6) levels are significantly higher in severe COVID-19 patients. Elevated KL-6 is a useful biomarker for assessing COVID-19 severity and patient prognosis.
Area of Science:
- Pulmonology
- Infectious Diseases
- Biomarker Discovery
Background:
- Coronavirus disease 2019 (COVID-19) is a global pandemic.
- Identifying reliable biomarkers for COVID-19 severity is crucial for patient management.
Purpose of the Study:
- To investigate the utility of serum Krebs von den Lungen-6 (KL-6) as a biomarker for COVID-19 severity.
- To compare KL-6 levels between non-severe and severe COVID-19 cases.
Main Methods:
- Retrospective study of 54 COVID-19 patients categorized as non-severe or severe.
- Analysis of patient characteristics and serum KL-6 levels at diagnosis and peak.
- Utilized receiver operating characteristic curves to determine optimal KL-6 cut-off values.
Main Results:
- Severe COVID-19 patients were older and had more comorbidities.
- Serum KL-6 levels were significantly higher in the severe group (median 338 U/mL at diagnosis, 781 U/mL at peak) compared to the non-severe group (p < 0.001).
- Peak KL-6 level of 371 U/mL demonstrated high sensitivity (85.7%) and specificity (96.6%) for identifying severe disease.
Conclusions:
- Serum KL-6 levels are significantly elevated in patients with severe COVID-19.
- KL-6 serves as a valuable and accurate biomarker for assessing COVID-19 severity.
Background:
Coronavirus disease 2019 (COVID-19) is currently spreading worldwide. This study examined whether serum Krebs von den Lungen-6 (KL-6) level is a useful biomarker for evaluating the severity of COVID-19.
Methods:
We retrospectively examined patients diagnosed with COVID-19 at the Japanese Red Cross Medical Center between February 1, 2020, and May 15, 2020. Patients were divided into four categories based on clinical and radiological findings: mild, moderate, severe, and critical. Patients who presented with a mild or moderate illness and patients who started with or worsened to a severe or critical illness were classified as the non-severe and severe groups, respectively. The two groups were compared for patient characteristics, including serum KL-6 levels. Receiver operating characteristic curves were used to define the optimum cut-off value of serum KL-6 level to evaluate COVID-19 severity.
Results:
A total of 54 patients were enrolled, including 33 in the non-severe group and 21 in the severe group, of which four died. Compared with those in the non-severe group, more patients in the severe group were significantly older and had comorbidities. Serum KL-6 levels were significantly higher in the severe group than in the non-severe group both at diagnosis (median, 338 U/mL) and at peak levels within one week after diagnosis (median, 781 U/mL) (both p < 0.001). Serum KL-6 value at peak level (371 U/mL) was used as the optimal cut-off to evaluate disease severity (sensitivity, 85.7%; specificity, 96.6%).
Conclusions:
Serum KL-6 levels were significantly elevated in severe COVID-19 and is useful for evaluating its severity.
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