Fluorine-18-antimyosin monoclonal antibody fragments: preliminary investigations in a canine myocardial infarct model.

Abstract

The purpose of this study was to determine in a canine model whether selective myocardial infarct uptake of 18F-labeled antimyosin monoclonal antibody fragments could be achieved in a time frame compatible with the short half-life of this nuclide. Antimyosin monoclonal antibody fragments were labeled with 18F using a succinimidyl [18F]fluorobenzylamine ester acylation agent. Six dogs had myocardial infarction induced by coronary artery occlusion and were reperfused prior to the intravenous administration of 0.6-4.7 mCi of 18F-labeled F(ab')2 (two dogs) or Fab (four dogs). Analysis of tissues obtained 2-4 hr after antibody administration revealed infarct:normal myocardium uptake ratios as high as 14-21:1 for F(ab')2 and 9-12:1 for Fab. Even with Fab, however, prolonged 18F activity in the blood pool interfered with delineation of infarcts by PET imaging. In one dog, perfusion imaging with [13N]ammonia before antimyosin administration was performed, and regions of normal and ischemic myocardium were determined. With these regions of interest, infarct:normal myocardium uptake ratios calculated from the 18F-labeled Fab images increased from 1.5:1 at 1 hr to 4.0:1 at 5 hr. We conclude that 18F-labeled antimyosin fragments may be of value for hot-spot imaging of damaged myocardium with PET; however, blood-pool subtraction techniques will probably be required.

• Authors: M R Zalutsky, P K Garg, S H Johnson, H Utsunomiya, R E Coleman
• Journal: Journal of nuclear medicine : official publication, Society of Nuclear Medicine (J Nucl Med) Vol. 33 Issue 4 Pg. 575-80 (Apr 1992) ISSN: 0161-5505 [Print] United States
• PMID: 1552343 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Fluorine Radioisotopes
• Immunoglobulin Fab Fragments
• Myosins

Topics

• Animals
• Dogs
• Fluorine Radioisotopes
• Immunoglobulin Fab Fragments
• Myocardial Infarction (diagnostic imaging, metabolism)
• Myosins (immunology)
• Radioimmunodetection
• Tissue Distribution
• Tomography, Emission-Computed