The significance of peripheral immunity in the pathogenesis and progression of Alzheimer’s diseases (AD) has been recognized. Brain-infiltrated peripheral immune components transporting across the blood–brain barrier (BBB) may reshape the central immune environment. However, mechanisms of how these components open the BBB for AD occurrence and development and correlations between peripheral and central immunity have not been fully explored. Herein, we formulate a hypothesis whereby peripheral immunity as a critical factor allows AD to progress. Peripheral central immune cell crosstalk is associated with early AD pathology and related risk factors. The damaged BBB permits peripheral immune cells to enter the central immune system to deprive its immune privilege promoting the progression toward developing AD. This review summarizes the influences of risk factors on peripheral immunity, alongside their functions, highlighting the concept of peripheral and central immunity as an integrated system in AD pathogenesis, which has received scant attention before.

外周免疫在阿尔茨海默病（AD）发病机制和进展中的重要性已得到认识。穿过血脑屏障（BBB）传输的大脑浸润的外周免疫成分可能会重塑中枢免疫环境。然而，这些成分如何打开血脑屏障导致AD发生发展的机制以及外周免疫和中枢免疫之间的相关性尚未得到充分探索。在此，我们提出了一个假设，即外周免疫是导致 AD 进展的关键因素。外周中枢免疫细胞串扰与早期 AD 病理和相关危险因素有关。受损的血脑屏障允许外周免疫细胞进入中枢免疫系统，剥夺其免疫特权，从而促进 AD 的进展。本文总结了危险因素对外周免疫的影响及其功能，强调了外周免疫和中枢免疫作为 AD 发病机制中一个完整系统的概念，而这一概念此前很少受到关注。