Tc-99m-3PRGD2 SPECT Imaging of angiogenesis of rheumatoid arthritis in rats and humans

1078 Objectives To validate 99mTc-3PRGD2 SPECT on imaging synovial neoangiogenesis of rheumatoid arthritis (RA) in rats and the patient for early detection and anti-RA management. Methods Rheumatoid arthritis in Sprague Dawley rats were generated by Type II collagen immunization, rheumatoid arthritis patients were recruited from the clinic (IACUC and IRB were approved). αVβ3, CD31, CD34 immunohistochemical staining were performed in RA rat joint tissues and in normal rat; X-ray and 99mTc-3PRGD2 SPECT were performed. Results CD31, CD34 and αvβ3 expression was significantly higher in RA joints of rat than in normal ones. Significant high 99mTc-3PRGD2 accumulation was observed in the involved joints of disease rats and RA patients than normal subjects. In a serial SPECT studies from the same rats, increase in 99mTc-3PRGD2 uptake was paralleled to disease development was observed, abnormally increased tracer accumulation in the late conformed involved joints was observed as short as 2 weeks after type II collagen immunization while X-ray was normal at this time point. Avastin therapy significantly decreased 99mTc-3PRGD2 uptake in the RA joint of the rats, accompanied with improvement in symptom. Conclusions Our findings indicate that 99mTc-3PRGD2 targeted receptor imaging enable to de early detect synovial neoangiogenesis in RA in rodents and patients, can be used to monitor anti-RA effect. Research Support Natural Sicence Fundation of China (81260224) Inner Mongolia Science fundation 2012MS1153 Inner Mongolia Medical University Project 2012MS1153