. 2021 Oct 11;9:20503121211050755. doi: 10.1177/20503121211050755

Table 3.

Summary of different studies showing levels of C-reactive protein (CRP) in patients with COVID-19, 2020.

Author	Country	Patient category	CRP value (mg/L)	comment
Li et al.	China	First test	52.9	In 85%–100% of dead patients, CRP was found increased before death indicating that there is a high inflammatory reaction in COVID-19 patients. CRP can be a good indicator of disease progression and the decline of lymphocytes counts
Li et al.	China	Last test	96.2
Han et al.	China	Mild	4.25	CRP level was increased among poor prognostic patients
Han et al.	China	Severe	33.4	CRP level was increased among poor prognostic patients
Wang et al.	China	Mild	12.1	Patients with severe disease had increased levels of CRP compared with non-severe patients. CRP was highly associated with the aggravation of non-severe COVID-19 patients, which is evidenced from regression analysis
Wang et al.	China	Severe	43.8
Wang		Mild	1.52	Increased CRP levels were correlated with severe COVID-19 presentation
Wang		Severe	105
Kermali et al.	United Kingdom	Mild	33.2	Among others, CRP showed higher levels in patients with severe COVID-19 patients compared to their non-severe counterparts
Kermali et al.	United Kingdom	Severe	57.9
Pan et al.	China	Discharge	53.5	CRP level was found significantly correlated with death than discharged improved patients.
Pan et al.	China	Death	85.8
Velavana et al.	Vietnam	All cases	Increased	Clinicians must consider the serum levels of CRP, which may be applicable in risk stratification to predict severe and fatal COVID-19 in admitted patients
Velavana et al.	Vietnam	Severe cases	Increased
Zhou et al.	China	Mild	0.46	CRP levels extremely varies between mild and severe COVID-19 patients
Zhou et al.	China	Severe	1.46
Luo et al.	China	Mild	9.65	Compared to survivors, non-survivors showed a significantly increased CRP level, and thereby identified as independent predictors of poor disease outcome.
Luo et al.	China	Severe	100
Chen et al.	China	Mild manifestation on CT scan	11.47	Among others, increased CRP levels were all associated with the development of ARDS
		Moderate manifestation on CT scan	22.94
		Severe manifestation on CT scan	34.8
Chen et al.	China	Mild	12.47	Higher level of plasma CRP was linearly correlated to the severity of COVID-19 disease.
Chen et al.	China	Severe	23
Potempa et al.	United States	Non-severe	28.7	CRP blood levels correspond with acute phase response activation, making them a straightforward, quick, and cost-effective tool to estimate the extent of tissue damage that is occurring in that patient
Potempa et al.	United States	Severe	47.6
Sadeghi-Haddad-Zavareh et al.	Iran	Non-severe	Slight increase	In severe cases, CRP levels were substantially higher than in non-severe cases. CRP could be utilized as an independent predictor in predicting the severity of COVID-19, according to an analysis of the ROC curve.
Sadeghi-Haddad-Zavareh et al.	Iran	Severe	Increased
Pepys	United Kingdom	–	–	CRP has not yet been identified in COVID-19 lesions, but given the significant cell damage and amount of circulating CRP, it must be there.
Ali et al.		Deceased (65%)	>100	They discovered that CRP levels in deceased individuals were significantly increased, indicating hepatic impairment.
Ali et al.		Recovered (6%)	>100
Acar et al.	Turkey	Non-survivor		They concluded that inflammatory parameters, such as CRP, among others were associated with disease severity and could be used as potentially important risk factors for COVID-19 progression.
Acar et al.	Turkey	Survivor
Stringer et al.	United Kingdom	Dead	115	The most accurate predictor of death was found to be IL-6, with CRP coming in second.
Stringer et al.	United Kingdom	Survived	69
Yauhen et al.	UAE	Admitted to ICU	High	Because CRP levels indicate the activity of an inflammatory process, they have a strong predictive value.
Yauhen et al.	UAE	Not admitted to ICU	Low
Cui et al.	United States	Participants with Corticosteroid, low risk of death	CRP responder	Inpatient mortality may be predicted by a reduction in CRP of 50% or more within 72 h after starting corticosteroid medication. This could be used as an early indicator for COVID-19 patients’ responsiveness to corticosteroid therapy.
Cui et al.	United States	Participants with Corticosteroid, high risk of death	CRP non-responder
Kazemi et al.	Iran	Dead	85.82	There’s an association between CRP and illness severity.
Kazemi et al.	Iran	Improved	32.99	There’s an association between CRP and illness severity.

CRP: C-reactive protein; CT: computed tomography; ARDS: acute respiratory distress syndrome; ROC: receiver operating characteristic; ICU: intensive care unit; UAE: United Arab Emirates.