TY - JOUR T1 - Imaging Cell Death with Radiolabeled Annexin V in an Experimental Model of Rheumatoid Arthritis JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1359 LP - 1365 VL - 43 IS - 10 AU - Anneke M. Post AU - Peter D. Katsikis AU - Jonathan F. Tait AU - Sharon M. Geaghan AU - H. William Strauss AU - Francis G. Blankenberg Y1 - 2002/10/01 UR - http://jnm.snmjournals.org/content/43/10/1359.abstract N2 - Rheumatoid arthritis is associated with chronic synovial inflammation due to the abnormal accumulation of macrophages and autoreactive T lymphocytes in joints. The autoreactive cells cause an inflammatory proapoptotic response to self-antigens resulting in eventual bone, cartilage, and soft-tissue loss and destruction. The goal of our study was to determine the timing and intensity of apoptosis in joints using 99mTc-labeled annexin V, an in vivo marker of apoptosis, in a murine model of immune arthritis. Methods: We used 99mTc-annexin V and autoradiography to study the extent and severity of apoptosis in the front and rear paws of DBA/1 mice with type II collagen-induced rheumatoid arthritis. Results: Compared with control values (n = 10), there was a significant (P < 0.002) nearly 3-fold increase in uptake of 99mTc-annexin V in the front foot pads, rear toes, rear foot pads, and heels at the time of maximal extremity swelling as determined by serial caliper measurements at 4 wk after inoculation with type II bovine collagen (n = 9). The front toes had a 5- to 6-fold increase in uptake compared with control values (P < 0.001). Histologic analysis revealed only scattered rare lymphocytes in the periarticular soft tissues, without joint destruction. Dual autoradiography with 125I-bovine serum albumin as a control showed that 99mTc-annexin V localization was specific. Treatment with methylprednisolone for 1 wk (n = 8) at 4 wk after immunization with type II collagen decreased 99mTc-annexin V uptake by 3- to 6-fold compared with control values (P < 0.002). Conclusion: 99mTc-annexin V can detect collagen-induced immune arthritis and its response to steroid therapy before joint destruction. ER -