Background:Cerebrospinal fluid (CSF) or blood biomarkers like phosphorylated tau proteins (p-tau) are used to detect Alzheimer’s disease (AD) early. Increasing studies on cognitive function and blood or CSF p-tau levels are controversial. Objective:Our study examined the potential of p-tau as a biomarker of cognitive status in normal control (NC), mild cognitive impairment (MCI), and AD patients. Methods:We searched PubMed, Cochrane, Embase, and Web of Science for relevant material through 12 January 2023. 5,017 participants from 20 studies—1,033 AD, 2,077 MCI, and 1,907 NC—were evaluated. Quantitative analysis provided continuous outcomes as SMDs with 95% CIs. Begg tested publication bias. Results:MCI patients had lower CSF p-tau181 levels than AD patients (SMD =−0.60, 95% CI (−0.85, −0.36)) but higher than healthy controls (SMD = 0.67). AD/MCI patients had greater plasma p-tau181 levels than healthy people (SMD =−0.73, 95% CI (−1.04, −0.43)). MCI patients had significantly lower p-tau231 levels than AD patients in plasma and CSF (SMD =−0.90, 95% CI (−0.82, −0.45)). MCI patients showed greater CSF and plasma p-tau231 than healthy controls (SMD = 1.34, 95% CI (0.89, 1.79) and 0.43, (0.23, 0.64)). Plasma p-tau181/231 levels also distinguished the three categories. MCI patients had higher levels than healthy people, while AD patients had higher levels than MCI patients. Conclusions:CSF p-tau181 and p-tau231 biomarkers distinguished AD, MCI, and healthy populations. Plasma-based p-tau181 and p-tau231 biomarkers for AD and MCI need further study.

中文翻译：

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血浆和脑脊液中磷酸化 Tau 181 和 Tau 231 水平与阿尔茨海默病认知功能的关联：系统评价和荟萃分析

背景：脑脊液 (CSF) 或磷酸化 tau 蛋白 (p-tau) 等血液生物标志物可用于早期检测阿尔茨海默病 (AD)。越来越多的关于认知功能和血液或脑脊液 p-tau 水平的研究存在争议。目的：我们的研究探讨了 p-tau 作为正常对照 (NC)、轻度认知障碍 (MCI) 和 AD 患者认知状态生物标志物的潜力。方法：我们在 PubMed、Cochrane、Embase 和 Web of Science 中检索了截至 2023 年 1 月 12 日的相关材料。对来自 20 项研究的 5,017 名参与者（1,033 名 AD、2,077 名 MCI 和 1,907 名 NC）进行了评估。定量分析提供了 SMD 的连续结果，置信区间为 95%。贝格测试了发表偏倚。结果：MCI 患者的脑脊液 p-tau181 水平低于 AD 患者（SMD =−0.60，95% CI（−0.85，−0.36）），但高于健康对照（SMD = 0.67）。AD/MCI 患者的血浆 p-tau181 水平高于健康人（SMD =−0.73，95% CI（−1.04，−0.43））。MCI 患者血浆和脑脊液中的 p-tau231 水平显着低于 AD 患者（SMD =−0.90，95% CI（−0.82，−0.45））。MCI 患者的脑脊液和血浆 p-tau231 含量高于健康对照（SMD = 1.34，95% CI（0.89，1.79）和 0.43，（0.23，0.64））。血浆 p-tau181/231 水平也区分了这三类。MCI 患者的水平高于健康人，而 AD 患者的水平高于 MCI 患者。结论：脑脊液 p-tau181 和 p-tau231 生物标志物可区分 AD、MCI 和健康人群。基于血浆的 p-tau181 和 p-tau231 AD 和 MCI 生物标志物需要进一步研究。