Loeffler D A, Brickman C M, Juneau P L, Perry M F, Pomara N, Lewitt P A
Clinical Neuroscience Program, Sinai Hospital, Detroit, MI 48235, USA.
Neurobiol Aging. 1997 Sep-Oct;18(5):555-7. doi: 10.1016/s0197-4580(97)00110-3.
Complement activation is present in the brain in Alzheimer's disease (AD), and C1q concentrations are decreased in AD cerebrospinal fluid (CSF). To determine whether concentrations of other complement proteins are also altered in AD CSF, we measured concentrations of C3a and SC5b-9 in CSF from patients with probable AD (n = 19), normal aged controls (n = 11), and normal younger controls (n = 15). C3a concentrations were similar between AD and aged controls, but threefold higher than in younger controls (p < 0.05 vs. both groups). A similar pattern was found with SC5b-9, though the increase was only twofold and statistically significant only for AD vs. younger controls. These results suggest that an increased generation of complement proteins in localized areas of the AD brain does not result in elevated concentrations of these proteins in CSF, compared with age-matched controls. Increased C3a (and, to a lesser extent, SC5b-9) in aged controls may be due to increased complement activation, increased central nervous system production, and/or blood-brain barrier leakage of these proteins.
补体激活存在于阿尔茨海默病（AD）患者的大脑中，且AD患者脑脊液（CSF）中的C1q浓度降低。为了确定其他补体蛋白的浓度在AD患者脑脊液中是否也发生改变，我们检测了可能患有AD的患者（n = 19）、正常老年对照者（n = 11）和正常年轻对照者（n = 15）脑脊液中C3a和SC5b-9的浓度。AD患者和老年对照者之间的C3a浓度相似，但比年轻对照者高两倍（与两组相比，p < 0.05）。SC5b-9也呈现类似模式，尽管其升高仅两倍，且仅在AD患者与年轻对照者相比时有统计学意义。这些结果表明，与年龄匹配的对照者相比，AD大脑局部区域补体蛋白生成增加并未导致脑脊液中这些蛋白浓度升高。老年对照者中C3a（以及程度较轻的SC5b-9）增加可能是由于补体激活增加、中枢神经系统生成增加和/或这些蛋白的血脑屏障渗漏。
