Frontiers in Medicine (Aug 2022)

Krebs von den Lungen-6 glycoprotein circulating levels are not useful as prognostic marker in COVID-19 pneumonia: A large prospective cohort study

  • Ivan Castellví,
  • Diego Castillo,
  • Hèctor Corominas,
  • Anaís Mariscal,
  • Sandra Orozco,
  • Natividad Benito,
  • Virginia Pomar,
  • Andrés Baucells,
  • Isabel Mur,
  • David de la Rosa-Carrillo,
  • David Lobo,
  • Ana Milena Millan,
  • Nerea Hernández de Sosa,
  • David Filella,
  • Laia Matas,
  • Laura Martínez-Martínez,
  • Cándido Juarez,
  • Jordi Casademont,
  • Pere Domingo

DOI
https://doi.org/10.3389/fmed.2022.973918
Journal volume & issue
Vol. 9

Abstract

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Coronavirus disease 2019 (COVID-19) has rapidly expanded worldwide. Currently, there are no biomarkers to predict respiratory worsening in patients with mild to moderate COVID-19 pneumonia. Small studies explored the use of Krebs von de Lungen-6 circulating serum levels (sKL-6) as a prognostic biomarker of the worsening of COVID-19 pneumonia. We aimed at a large study to determine the prognostic value of sKL-6 in predicting evolving trends in COVID-19. We prospectively analyzed the characteristics of 836 patients with COVID-19 with mild lung disease on admission. sKL-6 was obtained in all patients at least at baseline and compared among patients with or without respiratory worsening. The receiver operating characteristic curve was used to find the optimal cutoff level. A total of 159 (19%) patients developed respiratory worsening during hospitalization. Baseline sKL-6 levels were not higher in patients who had respiratory worsening (median {IQR} 315.5 {209–469} vs. 306 {214–423} U/ml p = 0.38). The last sKL-6 and the change between baseline and last sKL-6 were higher in the respiratory worsening group (p = 0.02 and p < 0.0001, respectively). The best sKL-6 cutoff point for respiratory worsening was 497 U/ml (area under the curve 0.52; 23% sensitivity and 85% specificity). sKL-6 was not found to be an independent predictor of respiratory worsening. A conditional inference tree (CTREE) was not useful to discriminate patients at risk of worsening. We found that sKL-6 had a low sensibility to predict respiratory worsening in patients with mild-moderate COVID-19 pneumonia and may not be of use to assess the risk of present respiratory worsening in inpatients with COVID-19 pneumonia.

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