Abstract
1067
Objectives The islet and AD β-amyloid share similar secondary structures. Recent study indicates that there is a significant increased risk for type II diabetic patients to develop AD. With the aim to unveil the interrelationship of these two age-related diseases, we investigated the feasibility of the AD β-amyloid targeting tracer [18F]FDDNP for imaging pancreatic islet amyloid.
Methods Paraffin fixed human pancreas tissue from a T2DM patient was cut into a series of continuous section slides. The sections were stained by H&E, anti-amylin antibody , Congo Red, PAS, and FDDNP reference compound respectively. The tissue sections from the same pancreas specimen were incubated in[18F]FDDNP PBS buffer solution with and without its reference compound for radioautography. Subsequently, we carried out a pilot study of [18F]FDDNP pancreatic PET imaging in 3 control human subjects without T2DM. The mean SUVs of uptake in the pancreatic head, neck, body and tail, blood pool, liver, and vertebral bone at different time points from 5 to 120 min post injection were determined.
Results A large number of islet amyloid was observed in the H&E, anti-amylin antibody, Congo Red, and PAS stained human pancreas tissue sections. Similar islet amyloid distribution and phenotypes were clearly observed in the FDDNP reference compound stained continuous pancreas tissue sections. Furthermore, an radioautographic image of [18F]FDDNP showed the intensive accumulation of radioactivity in the same pancreatic tissue. The islet amyloid specific uptake was blocked by the FDDNP reference compound. The mean SUVs from all parts of pancreas were fall to the same level of the blood pool after the first15 min. The pancreas images can be clearly distinguished from the liver and other metabolism organs at all-time points.
Conclusions The in vitro and in vivo data suggested that [18F]FDDNP is a potential tracer for pancreatic islet amyloid PET imaging.