Image-Guided Cancer Therapy: A Multidisciplinary Approach

Abstract

1214 Objectives To evaluate the potential role of CXCL10 imaging in detection of early and ongoing acute rejection with allograft skin model. Methods Anti-CXCL10 mAb was radioiodinated with 131I; the labeled rate, radiochemical purity and stability were investigated. Allografted BALB/c mice underwent 131I-CXCL10 mAb imaging at the eighth day. The ex vivo biodistribution at 1, 12, 24, 48, 72h after injection of 131I-anti-CXCL10 mAb was carried out after autoradiography at each time point. T/NT ratio was obtained from grafted skin’s ID%/g with the opposite normal skin’s ID%/g. Graft skins at 72h were used for immunohistochemistry of CXCL10 expression. The specificity was proved with Anti-CXCL10 mAb injection in blocking experiment. BALB/c mice underwent isografted was used as control group in all experiments above. Results The labeled rate of 131I-CXCL10 mAb is 96.8%, and radiochemical purity is 98.3%. The radiochemical purity is still above 95% in both serum and NS after 96h.The ex vivo biodistribution showed as Table 1. The tracer was mainly metabolized through liver and kidney, quickly localized within allografts. The T/NT ratio is 3.99±0.36 at 72h,while control group is 1.60±0.16. Phosphor-Autoradiography showed clear graft imaging at 6h after tracer injection, and keep clear at 48h(Fig1).The immunohistochemistry staining showed stronger CXCL10 expression in allografted area. Conclusions These data demonstrated that CXCL10 is a promising candidate target for acute rejection detection which may be very helpful for early detection of allorejection in clinic.