Specific targeting of infectious foci with radioiodinated human recombinant interleukin-1 in an experimental model.
In the present study, radioiodinated human recombinant interleukin-1 (IL-1) was investigated for its potential to image infectious foci in vivo in an animal model of infection. Twenty-four hours after induction of a Staphylococcus aureus abscess in the left calf muscle, mice were i.v. injected with both iodine-125 labelled IL-1 and iodine-131 labelled myoglobin, a size-matched control agent. The animals were killed for tissue biodistribution studies at 2, 6, 12, 24 and 48 h p.i. Gamma camera images were obtained at 6, 24 and 48 h after injecting mice with 123I-IL-1. Radioiodinated IL-1 rapidly cleared from the body; after 12 h the abscess was the organ with the highest activity. The absolute abscess uptake of 125I-IL-1 remained high compared to 131I-myoglobin, resulting in significantly higher abscess-to-muscle ratios of 125I-IL-1 compared to 131I-myoglobin. The ratios of 125I-IL-1 reached the ultimate value of 44.4+/-10.8 at 48 h p.i., whereas the ratios of 131I-myoglobin did not exceed 5.9+/-0.7. Gamma camera imaging revealed clearly visible abscesses. In conclusion, our results demonstrate specific retention of radioiodinated IL-1 in the abscess, presumably by interaction of IL-1 with its receptor on the inflammatory cells. The high target-to-background ratios that were obtained over the course of time indicate that the IL-1 receptor may be a valuable target for the imaging of infectious foci.
van der Laken
C J
CJ
Department of Nuclear Medicine, University Hospital Nijmegen, Nijmegen, The Netherlands.
Boerman
O C
OC
Oyen
W J
WJ
van de Ven
M T
MT
Claessens
R A
RA
van der Meer
J W
JW
Corstens
F H
FH
D000038:Abscess / Q000000981:diagnostic imaging*; D000818:Animals; D002460:Cell Line; D005260:Female; D006614:Hindlimb; D006801:Humans; D007375:Interleukin-1 / Q000493:pharmacokinetics; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D051379:Mice; D009211:Myoglobin / Q000493:pharmacokinetics; D011869:Radioligand Assay; D011877:Radionuclide Imaging; D011994:Recombinant Proteins; D013203:Staphylococcal Infections / Q000000981:diagnostic imaging*; D014018:Tissue Distribution
D007375:Interleukin-1; D007457:Iodine Radioisotopes; D009211:Myoglobin; D011994:Recombinant Proteins