Radiolabelled leucocytes: a new diagnostic tool in occult infection/inflammation

Autologous white blood cells were labelled with Indium 111 (111In wbc) and reinjected into 18 children with suspected infection and 10 children with suspected inflammatory bowel disease aged 5 weeks to 15 years. In addition two immunosuppressed children with suspected infection received donor 111In wbc. Gamma camera images were obtained between one and four hours and 20 and 24 hours. Other appropriate investigations were also undertaken in these children. Of 18 positive 111In wbc scans 17 were true positive. There were 12 negative scans of which 9 were true negative and three were false negative. The overall results showed a sensitivity of 85%, a specificity of 90%, and an accuracy of 86%. Used appropriately this technique forms a valuable back up investigation.