Imaging infection with LeuTech.

LeuTech® is a 99 Tc m labelled, anti-CD15, IgM, murine monoclonal antibody shown to have high affinity (K d =10 -11 M) for CD15 receptors (5.1 x 105/cell) expressed on human neutrophils. LeuTech® was injected directly, intravenously, and its efficacy in imaging infection in 46 consecutive patients was determined. Human anti-mouse antibody (HAMA) response was examined in 30 normal volunteers using a standard LeuTech® dose reconstituted with decayed 99 Tc m solution. There were 38 true positive, six true negative, and two false negative scans. Of the 38 positive images, 33 (92%) were positive within 10 min after injection of LeuTech®. LeuTech® accuracy in this group of patients was 96%, sensitivity 95%, specificity 100%, positive predictive value (PPV) 100%, and negative predictive value (NPV) 75%. No elevation of the HAMA titre was observed in any of the 30 normal volunteers and no adverse reaction was noted in any patient. LeuTech® is a highly promising agent for rapid imaging of infectious foci.