Clinical trial of specific imaging of infections

Objective For several decades Ga-67 citrate, technetium-99m (Tc-99m) or 111 In-labelled leukocytes have been used for imaging the inflammatory process. Unfortunately, these radiopharmaceuticals are not infection-specific markers. In preclinical settings, radiolabelled antimicrobial peptides (AMPs), such as UBI 29-41 seem to be highly infection-specific and even high doses of these peptides have shown neither toxicity nor side effects in animals. Methods In this study we present data of a recent clinical trial carried out with the Tc-99m labelled antimicrobial peptide UBI 29-41 (Tc-99m-UBI 29-41) regarding its sensitivity, specificity, and accuracy in detecting various types of infections in 148 patients. The outcome of the trial with Tc-99m-UBI 29-41 is compared with that of five other trials. Results Preparation of Tc-99m-UBI 29-41 as a kit formulation is an easy, rapid, and reproducible process, and the tracer is very well tolerated by patients. The radiopharmaceutical has proven to be very stable and after injection into patients the biodistribution (renal clearance) and dosimetry seem to be favourable over other infection imaging radiopharmaceuticals. In this preliminary human study, patients with fever of unknown origin, osteomyelitis, diabetic foot, prosthesis infection, septic arthritis, or bacteraemia were successfully imaged with Tc-99m-UBI 29-41 scintigraphy. Conclusion Tc-99m-UBI 29-41 is a promising agent for the specific detection of infections in humans because of its high sensitivity (96.3%), specificity (94.1%), and accuracy (95.3%) with high positive predictive (95.1%) and negative predictive values (95.5%). Nucl Med Commun 31: 726-733 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.