Prognostic value of C-reactive protein in patients with COVID-19

Clin Infect Dis. 2020 May 23;ciaa641. doi: 10.1093/cid/ciaa641. Online ahead of print.


Background: Elevated serum C-reactive protein (CRP) level was observed in most patients with COVID-19.

Methods: Data of COVID-19 patients with clinical outcome in a designated hospital in Wuhan, China, were retrospectively collected and analyzed from Jan 30 to Feb 20, 2020. The prognostic value of admission CRP was evaluated in patients with COVID-19.

Results: Out of 298 patients enrolled, 84 died and 214 recovered. Most non-survivors tended to be males, old aged, or with chronic diseases. Compared to survivors, non-survivors showed significantly elevated white blood cell and neutrophil count, neutrophil to lymphocyte ratio (NLR), systemic immune-inflammation index (SII, defined by platelet count multiply by NLR), CRP, procalcitonin, and D-dimer, and decreased red blood cell, lymphocyte, and platelet count. Age, neutrophil count, platelet count, and CRP were identified as independent predictors of adverse outcome. The area under the receiver operating characteristic (ROC) curve (AUC) of CRP (0.896) was significantly higher than that of age (0.833), neutrophil count (0.820), and platelet count (0.678) in outcome prediction (all p<0.05). With a cut-off value of 41.4, CRP exhibited sensitivity 90.5%, specificity 77.6%, positive predictive value 61.3%, and negative predictive value 95.4%. Subgroup analysis revealed that CRP remained robust accuracy in adverse outcome prediction in patients with different disease severity (AUC 0.832, z=10.23, p<0.001; AUC 0.989, z=44.04, p<0.001). CRP was also an independent discriminator of severe/critical illness on admission (AUC 0.783, z=10.69, p<0.001).

Conclusions: In patients with COVID-19, admission CRP correlated with disease severity and tended to be a good predictor of adverse outcome.

Keywords: C-reactive protein; COVID-2019; SARS-CoV-2; prognosis.