Monoclonal antibodies imaging applications

An allied application of radiolabelled anti-tumour monoclonal antibodies is that of diagnostic imaging (immunoscintigraphy). In this case, the radioisotope employed must be a y-emitter (such that the radioactivity can penetrate outward through the body for detection purposes). Although various radioisotopes of iodine have been evaluated, (technetium) is the one... 

The following discussion is focused on in vitro applications of monoclonal antibodies and nucleic acid probes as diagnostic reagents. The principles of production and characteristics of Mabs are described in Chapter 2. Their use as in vivo diagnostic imaging agents has been discussed in Chapter 3 in the context of therapeutic applications, and is not discussed further here. The principles of PCR and nucleic acid hybridization have been discussed in Chapter 2 and Chapter 4, respectively. 

The application of antibodies in cardiovascular targeting in vivo originated with the experimental demonstration of the feasibility of using radiolabeled antimyosin antibody for diagnosis of acute myocardial infarction in 1976. Since then, the use of antibodies in the cardiovascular system has encompassed imaging of myocarditis,heart transplant rejection, dilated cardiomyopathy, alcohol induced cardiomyopathy,adriamycin cardiotoxicity, various other cardiomyopathies, vascular clots, atherosclerotic lesions,and even certain cancers such as soft tissue sarcomas.f Yet the best characterized and studied antibody for cardiovascular diagnostic targeting is monoclonal antimyosin Fab for its exquisite specificity... 

The 30-year history of MAbs has been a rollercoaster ride to success. From hype to depression, and back to hype, is probably the shortest summary of what has happened. MAbs have been rapidly introduced into a number of applications within and outside the medical field (Table 1.2) [52-54]. Analytical in vitro methods such as enzyme-hnked immunosorbent assay (ELISA), radioimmunoassay (RIA), various blotting techniques, flow-cytometry, immunofluorescence, confocal imaging, and im-munohistochemistry are each dependent upon the use of polyclonal or monoclonal antibodies. 

Monoclonal antibodies exhibit a slow elimination from the blood, and accumulate in the liver. For these reasons, rapidly clearing antibody fragments are typically preferred for imaging applications in nuclear medicine. By contrast, intact immunoglobulins continue to represent the antibody format of choice for many therapeutic applications [15], which rely on the antibody s ability to interfere with signaling events, and to activate antibody-depen-... 

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