Imaging of human infection with I-131-labeled recombinant human interleukin-8

The chemotactic cytokine interleukin-8 (IL-8) plays an important role in at traction and activation of polymorphonuclear leukocytes in infection and in flammation. A pilot study was conducted to determine if radiolabeled IL-8 w ould depict infection in humans. Methods: Human recombinant IL-8 (rhIL-8) l abeled with I-131 (specific activity, 0.4-0.7 MBq [11-18 mu Ci] I-131/mug I L-8) was injected intravenously into 8 diabetic patients with active foot i nfections and evidence of osteomyelitis, 2 patients with successfully treat ed osteomyelitis, and 1 patient with cellulitis of the thumb. Results: Foca l accumulation of I-131-rhIL-8 was seen in 8 of 8 patients with active foot infection and diffuse uptake was seen in the thumb of the 1 patient with c ellulitis. In the 2 patients with successfully treated bone infection, mult iphase Tc-99m-hydroxyethylene diphosphonate bone scans were negative early, but late-phase (>3 h) uptake depicted degenerative lesions that did not im age with I-131-rhIL-8. Conclusion: I-131-rhIL-8 accumulates rapidly within infected foci in osteomyelitis and cellulitis but not in successfully treat ed infections or degenerative joint disease.