Differential Dynamics of the Levels of Low Molecular Weight DNA Fragments in Plasma of Patients With Ischemic and Hemorrhaging Strokes

Objective: To evaluate low-molecular-weight (LMW) DNA as possible prognostic biomarker in acute ischemic and hemorrhagic stroke. Methods:  LMW DNA samples were isolated from plasma and cerebrospinal fluid by phenol deproteinization, analyzed by gradient polyacrylamide electrophoresis and quantified by spectrophotometry. Results: Two common types of the stroke, ischemic and hemorrhagic, differ by the temporal dynamics of cell-free DNA (cfDNA) accumulation. In hemorrhagic stroke, initial increase in LMW DNA levels, most likely reflects an extent of the tissue damage, while in ischemic patients, the LMW DNA levels increase in parallel with the damage caused by hypoxia and subsequent compensatory reperfusion. Conclusions: These time-course data specify optimal assessment windows with maximum differentiating power for stroke outcomes: 24-48 hours post-event for ischemic stroke, and as close as possible to the moment of hospital admission for hemorrhagic stroke. These data also indicate the role of apoptosis in the formation of ischemic focus.