Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Apr;93(4):2505-2512.
doi: 10.1002/jmv.26793. Epub 2021 Jan 22.

Prognostic roles of KL-6 in disease severity and lung injury in COVID-19 patients: A longitudinal retrospective analysis

Kai Deng  1 , Qinghong Fan  1 , Yanhong Yang  1 , Xizi Deng  1 , Ruiying He  1 , Yizhou Tan  1 , Yun Lan  1 , Xilong Deng  1 , Yuejun Pan  1 , Yaping Wang  1 , Yujuan Guan  1 , Huiyuan Liu  1 , Fengjuan Chen  1 , Xiaoneng Mo  1 , Xinghua Tan  1 , Chun Luo  1 , Xueliang Wen  1 , Ying Liu  1 , Jinxin Liu  1 , Lieguang Zhang  1 , Xiaoping Tang  1 , Fengyu Hu  1 , Feng Li  1
Affiliations

Prognostic roles of KL-6 in disease severity and lung injury in COVID-19 patients: A longitudinal retrospective analysis

Kai Deng et al. J Med Virol. 2021 Apr.

Abstract

To investigate the dynamic changes of Krebs von den Lungen-6 (KL-6) among patients with coronavirus disease 2019 (COVID-19) and the role of KL-6 as a noninvasive biomarker for predicting long-term lung injury, the clinical information and laboratory tests of 166 COVID-19 patients were collected, and a correlation analysis between KL-6 and other parameters was conducted. There were 17 (10.2%, 17/166) severe/critical and 149 (89.8%, 149/166) mild COVID-19 patients in our cohort. Serum KL-6 was significantly higher in severe/critical COVID-19 patients than in mild patients (median 898.0 vs. 451.2 U/ml, p < .001). KL-6 was next confirmed to be a sensitive and specific biomarker for distinguishing mild and severe/critical patients and correlate to computed tomography lung lesions areas. Serum KL-6 concentration during the follow-up period (>100 days postonset) was well correlated to those concentrations within 10 days postonset (Pearson r = .867, p < .001), indicating the prognostic value of KL-6 levels in predicting lung injury after discharge. Finally, elevated KL-6 was found to be significantly correlated to coagulation disorders, and T cells subsets dysfunctions. In summary, serum KL-6 is a biomarker for assessing COVID-19 severity and predicting the prognosis of lung injury of discharged patients.

Keywords: COVID-19; KL-6; lung injury; prognosis.

PubMed Disclaimer

Conflict of interest statement

The authors declare that there are no conflict of interests.

Figures

Figure 1
Figure 1
Serum Krebs von den Lungen‐6 (KL‐6) levels of healthy control (n = 59), mild (n = 149), and severe/critical coronavirus disease 2019 patients (n = 17). ***p < .001
Figure 2
Figure 2
Linear regression models predict Krebs von den Lungen‐6 (KL‐6) at >100 days postonset among all coronavirus disease 2019 (COVID‐19) cases (left panel, n = 81) and COVID‐19 cases with KL‐6 ≥300 U/ml during hospitalization (right panel, n = 60)
Figure 3
Figure 3
Linear correlations between computed tomography (CT) lung lesions areas and the Krebs von den Lungen‐6 (KL‐6) values within the previous week (A) (n = 73) and within the next week (B) (n = 80)
Figure 4
Figure 4
Dynamic profile of the coagulation indexes of a severe/critical patient. LDH is also shown as a biomarker for COVID‐19 severity. A dotted line in red or green represents the upper or lower normal limit of each index (right Y‐axis), respectively. APTT, activated partial thromboplastin time; COVID‐19, coronavirus disease 2019; FDP, fibrin degradation product; Fib, fibrinogen; INR, international normalized ratio; KL‐6, Krebs von den Lungen‐6; LDH, lactate dehydrogenase; PT, prothrombin time; PTA, prothrombin time activity; TT, thrombin time
See this image and copyright information in PMC

References

    1. https://www.who.int/emergencies/diseases/novel-coronavirus-2019/situatio.... Accessed October 30, 2020.
    1. Ziegler CGK, Allon SJ, Nyquist SK, et al. SARS‐CoV‐2 receptor ACE2 is an interferon‐stimulated gene in human airway epithelial cells and is detected in specific cell subsets across tissues. Cell. 2020;181(5):1016‐1035. - PMC - PubMed
    1. Yao XH, He ZC, Li TY, et al. Pathological evidence for residual SARS‐CoV‐2 in pulmonary tissues of a ready‐for‐discharge patient. Cell Res. 2020;30(6):541‐543. - PMC - PubMed
    1. Li H, Liu L, Zhang D, et al. SARS‐CoV‐2 and viral sepsis: observations and hypotheses. Lancet. 2020;395(10235):1517‐1520. - PMC - PubMed
    1. Qian Z, Travanty EA, Oko L, et al. Innate immune response of human alveolar type II cells infected with severe acute respiratory syndrome‐coronavirus. Am J Respir Cell Mol Biol. 2013;48(6):742‐748. - PMC - PubMed

Publication types