CRP, ferritin, IL-6 and D-dimer: how significant they are in prediction of disease severity in COVID-19 - A retrospective study

Abstract

<b>Introduction:</b> The evaluation of inflammatory response degree can be used in predicting disease severity in COVID-19. <b>Aims and objectives:</b> We aimed to examine the significance of C-reactive protein, ferritin, IL-6 and D-dimer levels as predictors of disease severity in COVID-19 patients. <b>Methods:</b> The study included 100 hospitalized patients (58 males, 42 females) divided into two groups: presenting with moderate (53) and severe disease (47). The C-reactive protein, ferritin, and D-dimer levels were retrospectively evaluated on day one, seven and fourteen, and IL-6 levels on day one of hospitalization. Data were statistically processed and the null hypothesis was tested with a significance threshold of p&lt;0.05. <b>Results:</b> The mean age of patients is 62.03±13.72 years (30-96 years). CRP levels decrease statistically significantly during the follow-up period (p&lt;0.001). D-dimer levels change statistically significantly over a period of 14 days (p=0.003), decreasing after the seventh day (p=0.006). Ferritin and D-dimer levels after day seven are statistically significantly higher in patients with severe disease (p=0.004 and p=0.001, respectively) and could be considered predictors of disease severity (OR 1.001; p=0.007 and p=0.005, respectively). Initial IL-6 levels are statistically significantly higher in patients with severe disease (p=0.014) so that values above 40.75 pg/ml predict severe disease with sensitivity of 61.8% and specificity of 50% (OR 1.010, p=0.024). <b>Conclusions:</b> Ferritin and D-dimer levels&nbsp;in the second week of hospitalization and initial IL-6 above 40.75 pg/ml could be used as predictors of disease severity in COVID-19 patients.