Background: Hemorrhagic and ischemic magnetic resonance imaging lesions as well as the more recently described decrease in vasomotor reactivity have been suggested as possible biomarkers for... Show moreBackground: Hemorrhagic and ischemic magnetic resonance imaging lesions as well as the more recently described decrease in vasomotor reactivity have been suggested as possible biomarkers for cerebral amyloid angiopathy (CAA). Analyses of these markers have been primarily cross-sectional during the symptomatic phase of the disease, with little data on their longitudinal progression, particularly in the presymptomatic phase of the disease when it may be most responsive to treatment. We used the unique opportunity provided by studying Dutch-type hereditary cerebral amyloid angiopathy (D-CAA) to determine longitudinal progression of CAA biomarkers during the presymptomatic as well as the symptomatic phase of the disease. Methods: In this longitudinal case-control study, magnetic resonance imaging markers and cognitive performance were assessed at baseline and after approximate to 4 years in 10 presymptomatic and 6 symptomatic D-CAA mutation carriers and 20 control subjects. These magnetic resonance imaging markers included hemorrhagic and ischemic manifestations, measurements of cerebral blood flow, and vasomotor reactivity to visual stimulation. Results: In presymptomatic D-CAA mutations carriers, vasomotor reactivity showed a decline over time for blood-oxygen-level-dependent amplitude (P=0.011) and prolongation of time to peak (P<0.001). In contrast, no significant changes in hemorrhagic markers, ischemic markers, cerebral blood flow, and cognition were found. In symptomatic D-CAA mutation carriers, the number of intracerebral hemorrhages increased over the 4-year period (P=0.007). Conclusions: Our findings indicate that in the presymptomatic phase of D-CAA, cerebrovascular reactivity measured by the blood-oxygen-level-dependent amplitude and time to peak to visual stimulation progressively worsens and can thus be regarded as a disease progression marker. In the symptomatic phase, the most salient marker of progression appears to be recurrent intracerebral hemorrhage. Show less
Aims: The aim of this work is to study the association of urokinase plasminogen activator (uPA) with development and progression of cerebral amyloid angiopathy (CAA). Materials and methods: We... Show moreAims: The aim of this work is to study the association of urokinase plasminogen activator (uPA) with development and progression of cerebral amyloid angiopathy (CAA). Materials and methods: We studied the expression of uPA mRNA by quantitative polymerase chain reaction (qPCR) and co-localisation of uPA with amyloid-beta (A beta) using immunohistochemistry in the cerebral vasculature of rTg-DI rats compared with wild-type (WT) rats and in a sporadic CAA (sCAA) patient and control subject using immunohistochemistry. Cerebrospinal fluid (CSF) uPA levels were measured in rTg-DI and WT rats and in two separate cohorts of sCAA and Dutch-type hereditary CAA (D-CAA) patients and controls, using enzyme-linked immunosorbent assays (ELISA). Results: The presence of uPA was clearly detected in the cerebral vasculature of rTg-DI rats and an sCAA patient but not in WT rats or a non-CAA human control. uPA expression was highly co-localised with microvascular A beta deposits. In rTg-DI rats, uPA mRNA expression was highly elevated at 3 months of age (coinciding with the emergence of microvascular A beta deposition) and sustained up to 12 months of age (with severe microvascular CAA deposition) compared with WT rats. CSF uPA levels were elevated in rTg-DI rats compared with WT rats (p = 0.03), and in sCAA patients compared with controls (after adjustment for age of subjects, p = 0.05 and p = 0.03). No differences in CSF uPA levels were found between asymptomatic and symptomatic D-CAA patients and their respective controls (after age-adjustment, p = 0.09 and p = 0.44). Increased cerebrovascular expression of uPA in CAA correlates with increased quantities of CSF uPA in rTg-DI rats and human CAA patients, suggesting that uPA could serve as a biomarker for CAA. Show less
