RATIONALE Biomarker research for Alzheimer's disease (AD) has grown rapidly in recent years, ensuing the integration of the AD fluid biomarker profile: Aβ1-42, t-tau, and p-tau181, into clinical and research criteria. However, current insights of AD arise almost exclusively from studies on white individuals. Some studies have revealed that epidemiology, clinical features, and genetics of AD show variations between individuals from black and white backgrounds, conveying the importance of ethnoracial differences, and the possibility of such differences also influencing AD biomarker levels. This systematic review explored whether AD fluid biomarker levels differ between African American (AA) or Black African and white groups. AIM To compare AD fluid biomarkers (Aβ1-42, p-tau181, and t-tau) levels between AA or Black Africans and white individuals. METHOD PubMed, Scopus, and other sources were explored for studies that quantified AD biomarkers in biological fluid from whites and AA or Black African groups. Meta-analyses were performed to find the standardized mean difference for biomarkers that were quantified in ≥3 studies. RESULTS Five studies were included; studies on Black Africans were not found. The meta-analyses found CSF t-tau and p-tau181 were consistently lower in AA than white individuals, in samples with normal cognition or with mild cognitive impairment/dementia. CONCLUSIONS The meta-analyses found significant differences for CSF tau between AA and white individuals with normal cognition and within the dementia spectrum, expressing the importance of taking into account ethnoracial factors when interpreting CSF AD biomarkers levels. However, the generalisability of these differences is restricted by small samples' size, lack of unified methodologies and recruitment's biases within studies; further large multicentre studies with harmonized protocols and sufficient power are imperative to investigate the extent of ethnoracial differences across the spectrum of cognitive decline, with vaster efforts necessary to diversify recruitment.

中文翻译：

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比较非洲裔美国人或非洲黑人和白人群体之间阿尔茨海默病的液体生物标志物：系统评价和荟萃分析

基本原理 近年来，阿尔茨海默病 (AD) 的生物标志物研究发展迅速，随后将 AD 流体生物标志物谱：Aβ1-42、t-tau 和 p-tau181 整合到临床和研究标准中。然而，目前对 AD 的见解几乎完全来自对白人个体的研究。一些研究表明，AD 的流行病学、临床特征和遗传学显示出来自黑人和白人背景的个体之间的差异，传达了种族差异的重要性，并且这种差异也可能影响 AD 生物标志物水平。本系统评价探讨了 AD 液体生物标志物水平在非洲裔美国人 (AA) 或非洲黑人和白人群体之间是否存在差异。目的 比较 AA 或非洲黑人与白人个体之间的 AD 体液生物标志物（Aβ1-42、p-tau181 和 t-tau）水平。方法 探索了 PubMed、Scopus 和其他来源的研究，以量化白人和 AA 或非洲黑人群体生物体液中的 AD 生物标志物。进行荟萃分析以找到在≥3 项研究中量化的生物标志物的标准化平均差异。结果 包括五项研究；没有发现对非洲黑人的研究。荟萃分析发现，在认知正常或轻度认知障碍/痴呆的样本中，AA 中的 CSF t-tau 和 p-tau181 始终低于白人个体。结论 荟萃分析发现 AA 与认知正常且在痴呆范围内的白人个体之间的 CSF tau 存在显着差异，这表明在解释 CSF AD 生物标志物水平时考虑种族因素的重要性。然而，这些差异的普遍性受到样本量小、缺乏统一的方法和研究中招募的偏见的限制；进一步的大型多中心研究具有协调的协议和足够的权力，对于调查认知衰退范围内的种族差异的程度是必要的，并且需要做出更大的努力来使招募多样化。