European Journal of Nuclear Medicine and Molecular Imaging

, Volume 33, Issue 2, pp 117–126

99mTc-interleukin-2 scintigraphy for the in vivo imaging of vulnerable atherosclerotic plaques

Authors

  • Alessio Annovazzi
    • Nuclear Medicine, 2nd Faculty of MedicineUniversity La Sapienza
  • Elena Bonanno
    • Department of Biopathology and Diagnostic ImagingUniversity Tor Vergata
  • Marcello Arca
    • Department of Clinical and Applied Medical Therapy, 1st Faculty of MedicineUniversity La Sapienza
  • Calogero D’Alessandria
    • Nuclear Medicine, 2nd Faculty of MedicineUniversity La Sapienza
  • Antonella Marcoccia
    • Medical Clinical Institute 1, 1st Faculty of MedicineUniversity La Sapienza
  • Luigi G. Spagnoli
    • Department of Biopathology and Diagnostic ImagingUniversity Tor Vergata
  • Francesco Violi
    • Medical Clinical Institute 1, 1st Faculty of MedicineUniversity La Sapienza
  • Francesco Scopinaro
    • Nuclear Medicine, 2nd Faculty of MedicineUniversity La Sapienza
  • Giorgio De Toma
    • Department of Surgery Pietro Valdoni, 1st Faculty of MedicineUniversity La Sapienza
    • Nuclear Medicine, 2nd Faculty of MedicineUniversity La Sapienza
    • Department of Nuclear MedicineUniversity of Groningen
    • Nuclear MedicineOspedale S. Andrea
Original Article

DOI: 10.1007/s00259-005-1899-4

Cite this article as:
Annovazzi, A., Bonanno, E., Arca, M. et al. Eur J Nucl Med Mol Imaging (2006) 33: 117. doi:10.1007/s00259-005-1899-4

Abstract

Purpose

Several histopathological studies have demonstrated that vulnerable plaques are enriched in inflammatory cells. The aims of this study were: (1a) to test the ability of 99mTc-labelled interleukin-2 (99mTc-IL2) to bind to IL2R-positive (IL2R+) cells in carotid plaques and (1b) to correlate the plaque uptake of 99mTc-IL2, measured in vivo, with the number of IL2R+ cells within the plaque, measured ex vivo by histology (transversal study, TS), and (2) to evaluate changes in 99mTc-IL2 uptake in plaques, before and after treatment with a statin or a hypocholesterolaemic diet (longitudinal study, LS).

Methods

Ultrasound scan was performed for plaque characterisation and localisation. Fourteen patients (16 plaques) eligible for endoarterectomy were recruited for the TS and underwent 99mTc-IL2 scintigraphy before surgery. Nine patients (13 plaques) were recruited for the LS; these patients received atorvastatin or a standard hypocholesterolaemic diet and 99mTc-IL2 scintigraphy was performed before and after 3 months of treatment.

Results

The degree of 99mTc-IL2 uptake was expressed as the plaque/background (T/B) ratio. In patients from TS, T/B ratios correlated with the percentage of IL2R+ cells at histology (r=0.707; p=0.002) and the number of IL2R+ cells at flow cytometry (r=0.711; p=0.006). No correlations were observed between ultrasound scores and either scintigraphic or histological findings. In patients from the LS, the mean 99mTc-IL2 uptake decreased in statin-treated patients (1.75±0.50 vs 2.16±0.44; p=0.012), while it was unchanged in the patients on the hypocholesterolaemic diet (2.33±0.45 vs 2.34±0.5).

Conclusion

99mTc-IL2 accumulates in vulnerable carotid plaques; this accumulation is correlated with the amount of IL2R+ cells and is influenced by lipid-lowering treatment with a statin.

Keywords

Carotid arteriesInflammationInterleukin-2Plaque

Copyright information

© Springer-Verlag 2005