目的：探讨外周血淋巴细胞中G蛋白偶联受体激酶5（G protein-coupled receptor kinase-5,GRK5）水平与阿尔茨海默病（Alzheimer′s disease, AD）患者认知障碍间的相关性。方法：选择2015年1月至2017年12月期间我院住院和门诊的AD患者,根据简易智能精神状态量表（mini-mental state examination, MMSE）评分分为轻度AD（27例）和中-重度AD组（37例）,另选择30名健康体检者作为对照。应用酶联免疫吸附试验（enzyme linked immunosorbent assay, ELISA）检测所有研究对象外周血淋巴细胞中的GRK5蛋白表达情况,进行组间比较,并分析外周血GRK水平与患者疾病间的相关性。结果：轻度[（7.58±0.50） ng/mL]及中-重度AD组[（4.37±0.26） ng/mL]外周血淋巴细胞中GRK5水平与对照组[（15.65±0.74） ng/mL]相比,差异均有统计学意义（P<0.001）;轻度AD组与中-重度AD组相比,差异亦有统计学意义（P<0.001）;线性回归分析显示,外周血淋巴细胞中GRK5蛋白水平与MMSE评分呈显著正相关（R2=0.678 1）。结论：AD患者存在GRK5水平下降;外周血淋巴细胞GRK5可能作为早期诊断AD的一种新型生物标志物。
Objective: To investigate the correlation between G protein-coupled receptor kinase-5 (GRK5) level in peripheral lymphocytes and the degree of cognitive impairment in Alzheimer's disease(AD) patients. Methods: A total of 64 patients with AD during January 2015 to December 2017 were enrolled and divided into two groups, including 27 cases of mild dementia and 37 cases of moderate-to-severe dementia; 30 healthy subjects were served as controls. Enzyme-linked immunosorbent assay(ELISA) was used to detect the GRK5 level in peripheral lymphocytes of AD patients and controls. Results: The GRK5 level in mild and moderate-to-severe AD patients was significantly lower than that in controls (P<0.001). Moreover, the GRK5 level in moderate-to-severe AD patients was significantly lower than that in the mild AD patients (P<0.001). Linear regression analyses revealed a strong positive correlation between the GRK5 level and the Mini Mental State Examination (MMSE) score (P<0.001). Conclusions: Our data suggestes that low level of GRK5 is existed in AD patients and mirrored the impairment of cognitive state. GRK5 level of peripheral blood lymphocytes might be used as a novel biomarker for the early diagnosis of AD patients.
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