Shin Jonghan, Lee Sang-Yoon, Kim So-Hee, Kim Young-Bo, Cho Seong-Jin
Neuroscience Research Institute, Gachon University of Medicine and Science, Namdong-Gu, Incheon, Republic of Korea.
Neuroimage. 2008 Nov 1;43(2):236-44. doi: 10.1016/j.neuroimage.2008.07.022. Epub 2008 Jul 23.
Recently developed positron emission tomography (PET) tracers, such as PIB and FDDNP, help to visualize amyloid plaques and neurofibrillary tangles in living subjects. FDDNP binds to both amyloid plaques and tangles, whereas PIB selectively labels amyloid plaques. Therefore, it will be interesting to see a direct comparison of the regional binding of the two radiotracers for plaques (PIB) and plaques and tangles (FDDNP) using multitracer PET imaging for both PIB and FDDNP in the same subjects with and without Alzheimer's disease. Here we report that multitracer PET images of PIB and FDDNP in the same Alzheimer subjects show negligible PIB but strong FDDNP binding in the medial temporal cortex (hippocampus, amygdala, and parahippocampal gyrus), whereas there are significant quantities of both PIB and FDDNP binding in neocortical areas. These results suggest that tangles rather than amyloid plaques are the dominant pathology in the medial temporal cortex of living Alzheimer patients. In nondemented elderly normal subjects, PIB binding shows a significant increase in the posterior cingulate cortex compared with other brain regions, whereas in the same normal subjects we found significant FDDNP binding in the medial temporal cortex. Interestingly, the medial temporal FDDNP uptake values in normal elderly subjects were inversely correlated with long delay recall scores in the California Verbal Learning Test, a measure of episodic memory performance. We conclude that multitracer PET imaging of amyloid plaques and tangles using FDDNP and PIB in both nondemented and demented subjects provides important insight into these complicated pathological processes in living subjects.
最近研发的正电子发射断层扫描（PET）示踪剂，如匹兹堡化合物B（PIB）和氟代二氢脱氧葡萄糖（FDDNP），有助于在活体受试者中可视化淀粉样斑块和神经原纤维缠结。FDDNP能与淀粉样斑块和缠结都结合，而PIB则选择性地标记淀粉样斑块。因此，利用多示踪剂PET成像，在患有和未患有阿尔茨海默病的同一受试者中，直接比较这两种放射性示踪剂对斑块（PIB）以及斑块和缠结（FDDNP）的区域结合情况将会很有意思。在此我们报告，在同一阿尔茨海默病受试者中，PIB和FDDNP的多示踪剂PET图像显示，内侧颞叶皮质（海马体、杏仁核和海马旁回）中PIB结合可忽略不计，但FDDNP结合很强，而在新皮质区域则有大量的PIB和FDDNP结合。这些结果表明，缠结而非淀粉样斑块是活体阿尔茨海默病患者内侧颞叶皮质中的主要病理特征。在未患痴呆症的老年正常受试者中，与其他脑区相比，PIB结合在后扣带回皮质中显著增加，而在同一正常受试者中，我们发现内侧颞叶皮质中有显著的FDDNP结合。有趣的是，正常老年受试者内侧颞叶的FDDNP摄取值与加利福尼亚言语学习测试中的长时延迟回忆分数呈负相关，该测试是情景记忆表现的一项指标。我们得出结论，在未患痴呆症和患痴呆症的受试者中，使用FDDNP和PIB对淀粉样斑块和缠结进行多示踪剂PET成像，为了解活体受试者中这些复杂的病理过程提供了重要见解。
