Detection of lung and bone infection with antigranulocyte monoclonal antibody BW 250/183 radiolabelled with 99Tcm

Twenty-four patients with suspected infection (eight bone, 16 lung) were studied using monoclonal antibody BW250/183 which recognizes epitopes present on the surface of granulocytes. Bronchofibroscopic samples (microbiological studies and alveolar cell counts) were obtained from 14/16 patients with lung disease. Bronchofibroscopy isolated a micro-organism nine times. In two other cases, the diagnosis of infection was based on clinical course data. Infection was confirmed by surgical biopsy in the eight patients with bone pathology. Scans were performed 2 and 24 h after injection of 1 mg BW 250/183 labelled with 99Tcm. For lung disease, immunoscintigraphy was positive six times (five true positive, one false positive) and negative 10 times (six false negative, four true negative). Immunoscintigraphy was false negative when the lung infection was not systematized or no granulocytes were mobilized in the infectious site. Immunoscintigraphy was falsely positive when noninfectious lung disease mobilized granulocytes. It was positive in all patients with bone infection. Images recorded at 24 h had better sensitivity (five false negative) than those at 2 h (eight false negative).