COVID-19 (coronavirus disease 2019), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a disease that originated from Wuhan, China that can be spread via droplet and airborne transmission, and direct contact. In its diagnosis, RT-PCR analysis of nasopharyngeal swabs and viral sequencing of respiratory or blood samples are utilized. However, due to the gaps in the pathophysiology of the disease, early detection and monitoring of COVID-19 remain insufficient. Thus, the researchers sought to further understand the importance of D-dimer, a by-product of fibrin breakdown, as a potential biomarker for COVID-19 disease severity and mortality, as well as establish its relationship with pre-existing COVID-19-related illnesses. Moreover, a systematic review was performed in order to collate existing evidence and fulfill the research objectives. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) was utilized to ensure the quality of the data retrieval and to serve as a guide for gathering and screening relevant research articles. The studies used were those that were translated or were written in English and published between January 1, 2020 and January 31, 2021. Furthermore, six (6) screening stages were conducted to ensure that the studies used for data analysis were unbiased and explicit in terms of inclusion and exclusion criteria. The mined D-dimer concentrations above the normal value (? 0.50 ?g/mL)showed that an increase in D-dimer levels is associated with increasing COVID-19 severity and mortality. Mild to moderate patients had a median value of 0.505 ?g/mL, whereas severe and critical cases had median values of 0.80 ?g/mL and 3.86 ?g/mL, respectively. In terms of mortality, D-dimer concentrations were similarly shown to be significantly higher in non-survivors of COVID-19, with a median value of 6.34 ?g/mL, as compared to 0.94 ?g/mL for survivors. It was found that D-dimer is a nonspecific biomarker for the severity and mortality of COVID-19 since some comorbidities could potentially contribute to the rise in D-dimer levels. D-dimer levels were significantly higher in severe to critical cases than in mild to moderate states. Non-survivors also had remarkably higher D-dimers than survivors. Further research is needed to establish the reliability of D-dimer as a COVID-19 diagnostic marker. Patients with elevated D-dimers are encouraged to be constantly monitored to avoid clinical deterioration.

COVID-19

Coronavirus

Disease severity

D-dimer

SARS-CoV-2

mortality

severe acute respiratory syndrome 2