New approaches to targeting arthritis with radiopharmaceuticals

Though emission imaging techniques have been a major clinical tool for imaging osteoblastic activity and tumor involvement of the bony skeleton for over 20 years, radiolabelled probes specific for pathophysiology of synovium and articular cartilage are just beginning to be explored. Recent success with 99mTc labelled IgG, 18F-fluorodeoxyglucose, and antibodies to E-secretin encourage development of specific probes. The technology for radiolabelling peptide probes such as Mab and Fab with both positron emitters and conventional single photon emitters, the most recent concepts of labelling ssDNA aptamers specific for targeted proteins associated with diseases of the synovium and cartilage, and the availability of probes for substance P and porphyrin avid tissues has opened new horizons for studying the early onset of arthritis and therapeutic response to new forms of therapy.