Plasma D-dimer : a promising indicator of COVID-19 infection severity or only an acute phase reactant.

OBJECTIVE: Serum D-dimer levels, as well as other biomarkers related to coagulation, are significantly elevated during severe community acquired pneumonia. The aim of this study is to investigate the utility of plasma D-dimer levels determining the severity of inflammation and prognosis in pediatric patients with COVID-19 infection. METHODS: We retrospectively chart reviewed medical records of pediatric patients (< 18 years of age) admitted to Istanbul Fcaulty of Medicine, Department of Pediatrics Infectious Disease Service between March 11, and June 30, 2020. We collected demographic, clinical, biochemical and radiographic data. RESULTS: A hundred and seventy-one pediatric patients (1 - 216 months of age) admitted to pediatric infecitous disease service included in this study. Patients were classified into 4 categories; 1) COVID-19 infection confirmed by PCR, 2) Suspected COVID-19 infection due to close exposure history and radiographic findings, 3) Lower respiratory tract infection other than COVID-19 confirmed with multiplex respiratory viral panel, and 4) Systemic infections other than lower respiratory tract infection. Lymphopenia was observed significantly higher in patients with COVID-19 infection compared to patients with other respiratory viral infections (p=0.06). In patients with radiographic findings concerning for COVID-19 infection, elevated serum D-dimer levels were detected significantly higher than lymphopenia (p=0.07). CONCLUSIONS: Elevated serum D-dimer levels at baseline are associated with inflammation especially in patients with COVID-19 infection with radipgraphic findings. Monitoring serum D-dimer levels may be used for early identification of severe cases in children.