Blood–Brain Barrier Disruption in Humans Is Independently Associated With Increased Matrix Metalloproteinase-9

Background and Purpose—Matrix metalloproteinases (MMP) may play a role in blood–brain barrier (BBB) disruption after ischemic stroke. We hypothesized that plasma concentrations of MMP-9 are associated with a marker of BBB disruption in patients evaluated for acute stroke. Methods—Patients underwent MRI on presentation and 24 hours later. The MRI marker, termed hyperintense acute reperfusion injury marker (HARM), is gadolinium enhancement of cerebrospinal fluid on fluid-attenuated inversion recovery MRI. Plasma MMP-9 and tissue inhibitor of matrix metalloproteinase-1 were measured by enzyme-linked immunosorbent assay. Logistic regression models tested for predictors of HARM on 24-hour follow-up scans separatel