Biological background subtraction improves immunoscintigraphy by subsequent injection of antigen.
We have developed an 111In-labeled antibody for in vivo use directed against tissue plasminogen activator demonstrating focal fibrinolytic activity. However, a major problem in immunoscintigraphy is the low signal-to-noise ratio due to circulating antibody. The hepatic clearance of t-PA is very rapid. The effect of a subsequent injection of a small amount of t-PA shortly after the antibody administration to increase the blood clearance rate of the formed antigen-antibody complexes was examined in six rabbits. More than 99% of the circulating antigen-antibody complexes were eliminated by the liver within 10 min. This technique could make immunoscintigraphy a first line diagnostic tool in acute medicine including imaging of thromboembolic lesions in organs with high blood volumes such as the lungs, the heart, and the brain.
Tromholt
N
N
Department of Clinical Physiology, Hillerød County Hospital, Bagsvaerd, Denmark.
Selmer
J
J
D000818:Animals; D006801:Humans; D007205:Indium Radioisotopes; D007275:Injections, Intravenous; D011817:Rabbits; D016719:Radioimmunodetection / Q000379:methods*; D013924:Thrombophlebitis / Q000000981:diagnostic imaging*; D014018:Tissue Distribution; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage* / Q000493:pharmacokinetics
D007205:Indium Radioisotopes; D010959:Tissue Plasminogen Activator