Comparison of 123I monoclonal granulocyte antibody and 99Tcm-HMPAO-labelled leucocytes in the detection of inflammation.

Thirteen patients with a suspicion of bacterial infection or inflammatory disease were studied with 99Tcm-HMPAO-labelled leucocytes (99Tcm-WBC) and 123I-labelled monoclonal antibodies against granulocytes (123I-MoAb-gc) within 5 days of the first study. Images were obtained at 30-40 min, 3-5 and 20-24 h. The quality of 99Tcm-WBC images was superior to that of the 123I-MoAb-gc. Eight cases were negative with both agents. Six inflammatory or infectious sites in five patients were clearly positive with 99Tcm-WBC even at 30 min, becoming moderately or strongly positive at 3-5 h but only three of them were weakly positive with 123I-MoAb-gc. One cause of the poor result with 123I-MoAb-gc may be the quite low activity in granulocytes and high plasma activity. We cannot recommend 123I-MoAb-gc as a primary imaging agent for inflammatory or infectious diseases for which 99Tcm-WBC seems very useful.