Positron Emission Tomography with11C-D-deprenyl in Patients with Rheumatoid Arthritis

Abstract
Seven patients with arthritic disease and with clinical signs of inflammation of the knee joint, were investigated with positron emission tomography (PET) after injection of [N-methyl-11C]-D-deprenyl. Two healthy volunteers were included as controls. In five patients the investigation was repeated after an intra-articular injection of glucocorticoids. All patients showed very high uptake of the tracer in the paraarticular structures of the joint. After treatment there was approximately a 50% reduction of the uptake in the treated knees, both in the high uptake regions and in the surrounding soft tissues. No change was observed in the non-treated knees. In the healthy volunteers, only soft tissue surrounding the joint showed an uptake of the tracer, but at a magnitude which was 6–8 times lower than the high uptake regions in the arthritis patients. Although the mechanisms for the high uptake of 11C-D-deprenyl in affected joints of patients with arthritis is not clear, the present work points to a potential of PET for the assessment of disease intensity and monitoring of treatment.