Abstract
1219
Objectives To quantitatively evaluate osteoarthritis (OA) relevant inflammatory process with a novel PET method
Methods The right knees of healthy Sprague-Dawley rats were given an intra-articular injection of monoiodoacetate (MIA) to induce OA. Five days later, the animals were administered intravenous injections of cFLFLF-PEG-64Cu (~7400 KBq KBq/rat) and microPET/CT images were acquired at 3 hrs post injection. The synovial membranes and knee joints were harvested for histological analyses.
Results MIA induced infiltration of OA attracted activated leukocytes into the synovial membrane of the injured knee joints. The infiltrated leukocytes expressed FPR receptor, and images with cFLFLF-PEG-64Cu tracer showed enhanced PET signals in the MIA-treated knees. The SUVmax for right (inflamed) /left (control) legs were 17.96 ± 5.45 and 3.00 ± 1.40, respectively, with student t-test p value < 0.05. The FPR expression on the cells in the injured synovial membrane was corroborated by immunohistological analysis on ex vivo tissue.
Conclusions Inflammation associated with OA can be monitored using leukocyte specific cFLFLF-PEG-64Cu/PET imaging. This novel approach offers great potential for early detection of OA and can be used for monitoring the progress of OA.