Cell-free DNA as a potential biomarker in stroke: a comprehensive review of observational studies

Stroke is an abrupt loss of brain function, which is caused by the interruption of blood flow to the brain. Several blood biomarkers have been evaluated for the assessment of stroke severity and outcome. However, their roles remain limited in clinical practice. Circulating cell-free deoxyribonucleic acid (DNA) has emerged as a potential biomarker of stroke, as reported from several animal and human studies. In this study, we aim to review the prognostic values of cell-free DNA in stroke from all relevant cohort studies. The PubMed database was searched using keywords, "cell-free DNA" and "stroke" for relevant articles. Twelve studies (n = 946 patients) are included in the final analysis. While the prognostic values of cell-free DNA in predicting functional outcomes and hospital mortality after different types of stroke were highlighted in many studies, the inconsistency in methods hinders comparability between studies. Overall, the knowledge about the potential prognostic ability of cell-free DNA in stroke remains limited and conflicting. More robust studies with consistent methods are needed