Affiliations: [a] Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, China
| [b] Shigatse Branch, Xinqiao Hospital, Third Military Medical University, Shigatse, China
| [c] Key Laboratory of Ageing and Brain Diseases, Chongqing, China
| [d] Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
Correspondence:
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Correspondence to: Yu-Hui Liu, MD, PhD, and Yan-Jiang Wang, MD, PhD, Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing 400000, China. E-mails: [email protected] (Wang)
Abstract: Background:The G protein-coupled receptor P2RY2 protein of the purinergic receptor family is involved in the pathogenesis of Alzheimer’s disease (AD). Naturally occurring antibodies against P2RY2 (NAbs-P2RY2) are present in human plasma, with their clinical relevance in AD unknown. Objective:To explore the alteration of NAbs-P2RY2 in AD patients and its associations with biomarkers and cognition of AD patients. Methods:The levels of naturally occurring antibodies against the four extracellular domains of P2RY2 (NAbs-P2RY2-1, NAbs-P2RY2-2, NAbs-P2RY2-3, and NAbs-P2RY2-4) were measured in the plasma of 55 AD patients, 28 non-AD dementia patients, and 70 cognitively normal participants. The correlations of autoantibody levels with cognitive scale scores, AD plasma biomarkers, and brain amyloid burden were examined. Results:NAbs-P2RY2-1, NAbs-P2RY2-3, and NAbs-P2RY2-4 were reduced in AD patients. Plasma levels of NAbs-P2RY2-2 and NAbs-P2RY2-3 levels were positively associated with cognitive and functional performances. Among these antibodies, plasma NAbs-P2RY2-2 levels were positively associated with plasma amyloid-β 42 levels. While plasma NAbs-P2RY2-3 levels were negatively associated with brain amyloid burden in AD patients. Conclusion:These findings indicate an alteration of humoral immunity against P2RY2 in AD patients. Further mechanistical investigations are needed to reveal the role of NAbs-P2RY2 in the pathogenesis of AD.
