There has been intense interest in finding a biomarker that prognosticates the severity of disease in patients who get the Covid-19 infection. This is important, as it has relevance in allocating health care resources to individuals that need it most during the Pandemic.
I reviewed a study that was done by Mert Ozen and colleagues to determine the utility of D-dimer levels as a biomarker in determining disease severity and prognosis in COVID-19.
The study was done by researchers at Pamukkale University, Medical Faculty, Department of Emergency Medicine, 20070 Denizli, Turkey; Pamukkale University, Medical Faculty, Department of Diagnostic Radiology, Denizli, Turkey; Pamukkale University, Medical Faculty, Department of Biostatistics, 20070 Denizli, Turkey.
Study Methods:
Retrospective anaysis in 120 patients whose COVID-19 diagnosis was based on RT-PCR.
How was disease severity classified ?
Clinically, the severity of COVID-19 was classified as noncomplicated or mild or severe pneumonia. Radiologically, the area of affected lungs compatible with viral pneumonia in each patient's computed tomography was classified as either 0-30% or ≥ 31% of the total lung area.
Study Metrics:
The D-dimer values and laboratory data of patients with COVID-19 were compared with inpatient status, duration of hospitalization, and lung involvement during treatment and follow-up. To assess the predictive value of D-dimer, receiver operating characteristic (ROC) analysis was conducted.
What are the results of this study ?
1) D-dimer elevation (> 243 ng/ml) was detected in 63.3% (76/120) of the patients.
2) The mean D-dimer value was calculated as 3144.50 ± 1709.4 ng/ml (1643-8548) for inpatients with severe pneumonia in the intensive care unit.
3) D-Dimer values showed positive correlations with age, duration of stay, lung involvement, fibrinogen, neutrophil count, neutrophil lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR).
4) When the threshold D-dimer value was 370 ng/ml in the ROC analysis, this value was calculated to have 77% specificity and 74% sensitivity for lung involvement in patients with COVID-19.
What are the conclusions of this study ?
D-Dimer levels in patients with COVID-19 correlate with outcome, but further studies are needed to see how useful they are in determining prognosis.
Reference: Ozen M, Ylimaz A, Cakmak V, Oskay A, Seyit M and Senol H. D-dimer as a potential marker for disease severity in Covid-19. Am J Emerg Med 2021: 40: 55-59.