C-Reactive Protein and Covid-19 Severity: A Systematic Review.

Background: COVID-19 clinical course has been quite unpredictable and efforts have been made to identify reliable markers that will help in early disease progression, prognosis and severity detection. Objective: This study thus aimed to provide evidence that will guide clinical management by reviewing studies that assessed CRP concentration and COVID-19 severity/outcome.

Methods: Three electronic databases, PubMed/Medline, Google Scholar, and JSTOR were searched to identify studies available online as at 1st September 2020 which assessed COVID-19 clinical outcome and CRP concentration. The search strategy involved words combination like "C-reactive protein" OR "inflammatory markers" OR "acute phase reactants" and "coronavirus 2019" OR ''COVID-19" OR "2019-nCoV" OR "SARS-CoV-2".

Results: Sixty-one articles were systematically reviewed out of 812 studies identified after duplicates were removed. The 61 studies comprised 13,891 COVID-19 patients made of 7,840 (56.4%) males and 6,051 (43.6%) females. All the papers revised were observational studies except one case-control and they cut across fifteen countries. The result of the review demonstrated that the severe cases had higher levels of C - reactive protein when compared to the mild cases in all the studies (100%). The increase in C-reactive protein was statistically significant in 78.7% of the cases.

Conclusion: High levels of CRP are associated with COVID-19 severity.

Highlights: Severe cases of COVID-19 is characterized with higher CRP levels. COVID-19 cases should be screened regularly for CRP to monitor severity.