阿尔茨海默病β淀粉样蛋白水平监测:11C-PIB PET/CT显像沉积量与血浆水平的相关性研究

Correlation between β-amyloid deposition on 11C-PIB PET/CT and plasma level in patients with Alzheimer′s disease

摘要:

目的 探讨血浆β淀粉样蛋白(Aβ)水平与¹¹C-PIB PET/CT显示的淀粉样蛋白沉积的相关性。方法 选择在沈阳军区总医院接受治疗的阿尔茨海默病(AD)患者、轻度认知障碍(MCI)患者和无痴呆健康正常对照(NC)老年人共计69例,各组均行¹¹C-PIB PET/CT显像和血浆Aβ42和Aβ40检测,勾画额叶、外侧颞叶、顶叶皮层、楔前叶/后扣带回和前扣带回5个感兴趣的区域,测量全脑和各个感兴趣区域的Aβ标准化摄取值(SUV),分析其与血浆Aβ42和Aβ40水平的相关性。采用SPSS 18.0 软件进行数据分析。结果 NC、MCI和AD组Aβ42/Aβ40标准化摄取值比(SUVR)逐渐下降,¹¹C-PIB SUVR值逐渐上升,差异均有统计学意义(P＜0.05)。血浆Aβ42水平、Aβ42/Aβ40与¹¹C-PIB PET显像SUVR值呈负相关(rAβ42=-0.461,rAβ42/Aβ40=-0.633),血浆Aβ40与¹¹C-PIB PET显像SUVR值呈正相关(r=0.430),差异均有统计学意义(P＜0.05)。3组相比,各脑区¹¹C-PIB SUVR值逐渐升高,回归分析表明,额叶、外侧颞叶和楔前叶/后扣带回¹¹C-PIB SUVR可由血浆Aβ42/Aβ40比值预测,差异具有统计学意义(P＜0.05),而顶叶和后扣带回的PIB结合与Aβ42/Aβ40比值关系不具有统计学意义(P＞0.05)。结论 血浆Aβ42/40比值可预测脑淀粉样蛋白沉积水平。¹¹C-PIB PET Aβ沉积量与血浆Aβ42/Aβ40 比值作为生物标志物具有潜在临床意义。

Abstract:

Objective To investigate the correlation between plasma β-amyloid protein (Aβ) and its deposition on ¹¹C-PiB PET/CT.Methods A total of 69 elderly individuals were enrolled in the study from General Hospital of Shenyang Military Command, either with Alzheimer′s disease (AD) or with mild cognitive impairment (MCI) or with no dementia (normal controls,NC). All subjects underwent amyloid imaging with ¹¹C-PIB PET/CT and measurement of plasma Aβ42 and Aβ40. Five regions of interest (frontal, lateral temporal, parietal cortex, posterior cingulate/precuneus and anterior cingulate) were identified. The maximum standardized uptake value (SUVmax) was measured for the whole brain and each region of interest, and their correlations with plasma Aβ42 and Aβ40 were analyzed. SPSS statistics 18.0 was used for data analysis. Results Standardized uptake value ratio (SUVR) of Aβ42/Aβ40 decreased gradually in NC, MCI and AD groups, and ¹¹C-PIB SUVR increased gradually, with significant differences(P＜0.05). ¹¹C-PIB SUVR correlated negatively with plasma Aβ42 (r=-0.461) and Aβ42/Aβ40 (r=-0.633) ratio and positively with plasma Aβ40 (r=0.430), the difference being statistically significant (P<0.05). ¹¹C-PIB SUVR of brain regions increased gradually in three groups. Regression analysis showed that ¹¹C-PIB SUVR of frontal lobe, temporal lobe and precuneus could be predicted by plasma Aβ42/Aβ40 ratio with statistically significant difference (P<0.05), but ¹¹C-PIB SUVR and plasma Aβ42/Aβ40 ratio were of no statistical significance in the parietal lobe and posterior cingulate (P＞0.05). Conclusion The plasma Aβ42/Aβ40 ratio is able to predict brain amyloid deposition, and amyloid deposition on ¹¹C-PiB PET and plasma Aβ42/Aβ40 ratios have significant clinical potential as biomarkers.