Analysis of C-reactive Protein and Ferritin as Inflammatory Marker and their Association with the Severity of COVID-19: A Cross-sectional Study

Introduction: Virus-induced hyperinflammation can lead to mild symptoms or multiorgan dysfunction in severe Coronavirus Disease-2019 (COVID-19). In contrast to moderate conditions, severe COVID-19 exhibits higher levels of inflammatory markers, and tracking these markers may enable early disease detection and a good prognosis. The role of ferritin and C-reactive Protein (CRP) as inflammatory markers is evident in literature. However, it has not been proven whether this differs between patients who COVID-19 and non COVID-19 patients. Aim: To compare CRP and ferritin levels between COVID-19 positive patients and apparently normal Reverse Transcription-Polymerase Chain Reaction (RT-PCR) negative individuals, and to assess their association with COVID-19 severity. Materials and Methods: A cross-sectional study was conducted in isolation wards and Intensive Care Units (ICUs) at a Tertiary Care Hospital in Government Medical College Manjeri, Kerala, India. The study was conducted over six months, from August 2020 to January 2021. A total of 70 patients diagnosed with COVID-19 and 35 RT-PCR negative healthy subjects, aged between 18-75 years, were included. CRP and ferritin levels were measured and compared between COVID-19 patients and apparently normal RT-PCR negative individuals. The quantitative parameters were evaluated using the Mann-Whitney U test, and the categorical values were analysed using the Chi-square test. Statistical significance was defined as a p-value of ≤0.05. Results: All COVID-19 patients were between the ages of 18 and 75 years, with a mean age of 55.03±13.01 years in symptomatic COVID-19 positive (group A), 57.89±10.85 years in COVID-19 positive with pneumonia (group B), and 40.89±15.89 years in the control group (group C). In group A, there were 18 (51%) males and 17 (49%) females, while in group B, 23 (66%) were males and 12 (34%) were females. Out of the 35 control group participants, 17 (49%) were males and 18 (51%) were females. No significant differences were reported when comparing the genders of patients with healthy subjects. The results of the present study showed significantly higher median values of CRP (34.90) and ferritin (652.20) in COVID-19 patients compared to non-COVID-19 individuals, which were 4 and 116, respectively (p-value <0.001). Conclusion: Increased levels of CRP and ferritin in COVID-19 patients suggest that they can be used as inflammatory markers for the early detection of the disease. Moreover, higher levels in individuals with severe symptoms, as opposed to those with mild symptoms, define their involvement in illness severity.