Alzheimer Center, VU University Medical Center, Amsterdam, the Netherlands.
Neurobiol Aging. 2012 May;33(5):1011.e1-9. doi: 10.1016/j.neurobiolaging.2011.10.026. Epub 2011 Nov 26.
Cerebral microbleeds (MBs) may relate to amyloid in dementia. We selected 26 probable Alzheimer's disease (AD) patients with MBs, 26 age- and sex-matched AD patients without MBs, 11 vascular dementia (VaD) patients, and 22 patients with subjective complaints. We measured amyloid beta 1-42 (Aβ42) and 1-40 (Aβ40) in cerebrospinal fluid (CSF) and plasma, and blood-brain barrier (BBB) function using albumin ratios. CSF Aβ42 was lowest in AD with MBs, whereas Aβ40 was selectively decreased in VaD. In plasma, amyloid-beta was nonsignificantly elevated in VaD compared with controls. Higher albumin ratios in VaD suggested blood-brain barrier dysfunction. A MB pattern suggestive of cerebral amyloid angiopathy (CAA) related to lower CSF Aβ42, while a non-cerebral amyloid angiopathy specific MB distribution related to higher plasma Aβ40. Amyloid-beta is differentially implicated in AD with MBs and VaD. MB distribution related to different amyloid profiles, supporting distinct etiologies. Our results suggest that Aβ42 is retained in cerebrovasculature of AD patients with MBs, while in contrast, VaD patients may possibly drain amyloid.
脑微出血 (MBs) 可能与痴呆症中的淀粉样蛋白有关。我们选择了 26 例有 MBs 的可能阿尔茨海默病 (AD) 患者、26 例年龄和性别匹配的无 MBs 的 AD 患者、11 例血管性痴呆 (VaD) 患者和 22 例有主观抱怨的患者。我们测量了脑脊液 (CSF) 和血浆中的淀粉样蛋白 beta 1-42 (Aβ42) 和 1-40 (Aβ40)，并使用白蛋白比值测量了血脑屏障 (BBB) 功能。CSF Aβ42 在有 MBs 的 AD 中最低，而 VaD 中 Aβ40 选择性降低。在血浆中，与对照组相比，VaD 中的淀粉样蛋白-β略有升高。VaD 中的白蛋白比值较高表明血脑屏障功能障碍。MB 模式提示与脑淀粉样血管病 (CAA) 相关，与 CSF Aβ42 降低有关，而非 CAA 特异性 MB 分布与血浆 Aβ40 升高有关。淀粉样蛋白-β在 AD 伴 MBs 和 VaD 中的作用不同。MB 分布与不同的淀粉样蛋白谱相关，支持不同的病因。我们的结果表明，AD 伴 MBs 的患者中 Aβ42 保留在脑血管中，而相反，VaD 患者可能会排出淀粉样蛋白。
