Abstract Body: Background: Cerebral amyloid angiopathy (CAA), in which amyloid-β (Aβ) is deposited in cerebral and meningeal blood vessels, is associated with not only stroke but also cognitive dysfunction. CAA is classified as type 1 with capillary amyloid β (Aβ) or type 2 without capillary Aβ. Although it is known that CAA activates inflammatory responses, acute phase protein orosomucoid (α-1-acid glycoprotein) expression is still unclear.
Methods: There were 26 autopsy brains, including 12 with CAA type1 and 10 with CAAtype2, 4 with other neurodegenerative diseases for control. We evaluated the extent of orosomucoid deposition in patients with CAA and control using pathological specimens, and also compared orosomucoid expression in type 1, type 2 CAA and control. Moreover, the relationships between orosomucoid and each clinical finding, such as history of hypertension, presence of lacunar infarct, cortical microinfarct, cortical superficial siderosis, and subcortical hemorrhage, were evaluated in CAA cases.
Results: Vascular immunostaining for orosomucoid was identified more in CAA brains than in controls (p < 0.001). In the comparison between the three groups, immunohistochemistry higher expression of orosomucoid in the arteries/ arterioles of CAA type1 than control group. Although there was no relationships between orosomucoid and hypertension, lacunar infarct, cortical superficial siderosis, and subcortical hemorrhage, CAA with cortical microinfarct cases showed higher number of orosomucoid positive vessels than cortical microinfarct negative cases.
Conclusion: Recently, we discovered that the levels of orosomucoid in the blood are elevated in patients with CAA. It was suggested that orosomucoid may be involved in the pathogenesis of CAA. Moreover, orosomucoid might be associated with type 1 CAA and cortical microinfact. As a limitation, the number of controls is small, so it is necessary to increase the number of cases.