RADIOLABELED ANTIBODY FRAGMENTS FOR ABSCESS IMAGING

A METHOD TO DISCOVER HIGH CONCENTRATIONS OF WHITE BLOOD CELLS IN THE HUMAN BODY IS ESSENTIAL TO DETERMINE THE LOCATION OF INFECTIONS OF UNKNOWN ORIGIN (OCCULT ABSCESSES) AND FOR OTHER CONDITIONS. PRESENT METHODS ARE EXPENSIVE, TIME-CONSUMING, AND REQUIRE SIGNIFICANT TECHNICAL EXPERTISE.THIS PROJECT WILL INVOLVE PREPARATION OF A RADIOPHARMACEUTICAL FOR USE IN DETECTING OCCULT ABSCESSES AND OTHER CONDITIONS IN WHICH THERE IS A HIGH LOCAL CONCENTRATION OF WHITE BLOOD CELLS. FRAGMENTS OF MONOCLONALANTIBODIES THAT BIND TO HUMAN LEUKOCYTES OR LEUKOCYTE SUBSETS WILL BE PREPARED IN A KIT TO FACILITATE THEIR RAPID RADIOLABELING WITH SODIUM PERTECHNETATE TC-99M. THE RADIOLABELED ANTIBODY FRAGMENTS WILL THEN BE USED FOR THE IN-VIVO TAGGING OF WHITE BLOOD CELLS. MONOCLONAL ANTIBODY 80 H.3, WHICH REACTS WITH THE FC RECEPTOR OF HUMAN GRANULOCYTES, WILL BE EVALUATED FOR THIS USE ALONG WITH SEVERAL OTHER COMMERCIALLY AVAILABLE MONOCLONAL ANTIBODIES. OTHER MONOCLONAL ANTIBODIES WILL BE USED AS THE NONSPECIFIC CONTROL IN EXPERIMENTS THAT TEST THE BINDING OF CANDIDATE ANTIBODIES. THE INITIAL EVALUATION WILL MEASURE THE EX-VIVO BINDING TO A SERIES OF SAMPLES USING SMALL ALIQUOTS OF CELLS THAT ARE OTHERWISE BEING LABELED FOR CLINICAL USE BY THE PRESENT METHOD OF IN-111 LABELING OF WHOLE WHITE BLOOD CELLS.