Regional MMP-9 plasma concentrations, neutrophil MMP-9 expression, and MMP activity with plasma concentrations stratified by type of intracranial bleeding and functional outcome category. Semi-log plots of MMP-9 plasma concentrations (a, d, and e), fluorescence intensity of neutrophils stained for MMP-9 (b; presented with examples at single-cell level, scale bar in white = 10 μm), and gelatine zymography experiments (c) in arterial non-occlusive control samples at cervical level of the internal carotid artery (systemic) vs samples from centrally within the cerebral collateral circulation (ischaemic) in human large-vessel ischaemic stroke. Zymography bands (c) were obtained from n = 10 pooled plasma samples. Zymographic intensity of 86 kDa MMP-9 and 72 kDa MMP-2, respectively. Intracranial bleedings (d) were anatomically categorized according to the Heidelberg Bleeding Classification (HBC: 1a, haemorrhagic infarction (HI1)—scattered small petechiae; 1b, HI2—confluent petechiae; 1c, parenchymal haematoma (PH1)—haematoma within infarcted tissue, occupying <30%; 2, PH2—haematoma occupying ≥30% of the infarcted tissue; 3a—PH remote from infarcted brain tissue; 3b—intraventricular haemorrhage; 3c—subarachnoid haemorrhage; 3d—subdural haemorrhage) and grouped with respect to the type of bleeding (HBC classes 1a + b, minor [petechial] intracerebral haemorrhage; HBC classes 1c–3a, major intracerebral haemorrhage [parenchymal haematoma]; HBC classes 3b–d, intracranial-extracerebral haemorrhage). Functional outcome (e) was assessed by the modified Rankin Scale (mRS: mRS≥5, severe disability or death at hospital discharge). The long horizontal bar shows the median value, and the short error bar shows the interquartile range. Data were analysed using Wilcoxon matched-pairs signed rank test (a, b, d, and e), Kruskal–Wallis test with Benjamini, Krieger and Yekutieli post hoc analysis (d), and Mann–Whitney test (e). Individual p values are given for p < 0.05. CTCF, corrected total cellular fluorescence; HBC, Heidelberg Bleeding Classification; kDa, kilo Dalton; MMP-9/-2, Matrix Metalloproteinase-9/2; mRS, modified Rankin Scale; ng/ml, nanograms per millilitre; ns, not significant.