C-reactive protein and clinical outcome in COVID-19 patients: the importance of harmonized measurements

Area of Science:

• Biochemistry
• Immunology
• Infectious Disease

Background:

• C-reactive protein (CRP) is an acute phase reactant involved in inflammation and infection.
• Elevated CRP levels in coronavirus disease 2019 (COVID-19) correlate with increased disease severity and mortality.
• CRP has been proposed as a prognostic marker for classifying COVID-19 patient outcomes.

Purpose of the Study:

• To address confounding information regarding the interpretation of CRP levels in COVID-19.
• To highlight the need for standardized interpretative criteria, including assay quality and cut-off definitions.
• To emphasize the importance of result harmonization and measurement uncertainty control for global clinical application.

Main Methods:

• Review of available publications on CRP in COVID-19.
• Analysis of factors influencing CRP interpretation, such as assay performance.
• Discussion on the necessity of defining optimal cut-off values for prognostic classification.

Main Results:

• Frequent detection of elevated CRP in COVID-19 patients.
• Significant association between high CRP levels and poor outcomes (severity, ICU admission, death).
• Inconsistent methodologies and criteria for CRP interpretation across studies were identified.

Conclusions:

• Standardized CRP testing and interpretation are essential for reliable COVID-19 prognosis.
• Harmonization of results and control of measurement uncertainty are critical for global clinical use.
• Accurate CRP thresholds are necessary to prevent misclassification of COVID-19 patients.