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. 2020 Jun;127:104370.
doi: 10.1016/j.jcv.2020.104370. Epub 2020 Apr 14.

Prognostic Value of interleukin-6, C-reactive Protein, and Procalcitonin in Patients With COVID-19

Free PMC article

Prognostic Value of interleukin-6, C-reactive Protein, and Procalcitonin in Patients With COVID-19

Fang Liu et al. J Clin Virol. .
Free PMC article


Background: The inflammatory response plays a critical role in coronavirus disease 2019 (COVID-19), and inflammatory cytokine storm increases the severity of COVID-19.

Objective: To investigate the ability of interleukin-6 (IL-6), C-reactive protein (CRP), and procalcitonin (PCT) to predict mild and severe cases of COVID-19.

Study design: This retrospective cohort study included 140 patients diagnosed with COVID-19 from January 18, 2020, to March 12, 2020. The study population was divided into two groups according to disease severity: a mild group (MG) (n = 107) and a severe group (SG) (n = 33). Data on demographic characteristics, baseline clinical characteristics, and the levels of IL-6, CRP, and PCT on admission were collected.

Results: Among the 140 patients, the levels of IL-6, CRP, and PCT increased in 95 (67.9 %), 91 (65.0 %), and 8 (5.7 %) patients on admission, respectively. The proportion of patients with increased IL-6, CRP, and PCT levels was significantly higher in the SG than in the MG. Cox proportional hazard model showed that IL-6 and CRP could be used as independent factors to predict the severity of COVID-19. Furthermore, patients with IL-6 > 32.1 pg/mL or CRP > 41.8 mg/L were more likely to have severe complications.

Conclusion: The serum levels of IL-6 and CRP can effectively assess disease severity and predict outcome in patients with COVID-19.

Keywords: C-reactive protein; COVID-19; Interleukin-6; Procalcitonin; Prognosis.

Conflict of interest statement

Declaration of Competing Interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled, “Prognostic value of interleukin-6, C-reactive protein, and procalcitonin in patients with COVID-19”.


Fig. 1
Fig. 1
Serum levels of IL-6, CRP, and PCT in patients with COVID-2019 ***P<0.0001.
Fig. 2
Fig. 2
Receiver operating characteristic curve of interleukin-6 (IL-6), C-reactive protein (CRP), and procalcitonin (PCT) in patients with COVID-2019 on admission.
Fig. 3
Fig. 3
Survival according to the levels of interleukin-6 (IL-6),C-reactive protein (CRP), and procalcitonin (PCT).

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