99mTc-interleukin-2 scintigraphy in normal subjects and in patients with autoimmune thyroid diseases: a feasibility study.

Abstract

PURPOSE:

Radiolabelled interleukin-2 is a radiopharmaceutical used for the study of chronic inflammatory processes. (123)I-labelled interleukin-2 has successfully been used in a large number of patients affected by several immune-mediated diseases. (123)I, however, is expensive and not readily available. We have, therefore, developed a method for labelling interleukin-2 with (99m)Tc to high specific activity based on the use of an N(3)S bifunctional chelating agent. In this paper, we describe the results obtained with (99m)Tc-interleukin-2 in a series of eight normal subjects and of 12 patients with autoimmune thyroid diseases.

METHODS:

Biodistribution, pharmacokinetics, haematological and systemic toxicity, radiation absorbed dose and in vivo targeting were studied.

RESULTS:

Results showed rapid plasma clearance of (99m)Tc-interleukin-2 with retention mainly in the kidneys. Biodistribution and kinetics were similar to that observed for (123)I-interleukin-2. No acute systemic toxicity was found; a small decrease in peripheral blood lymphocytes was observed in the first hours only in patients, but it was mild and transient. (99m)Tc-interleukin-2 accumulated, to varying extents, in the thyroid of all patients affected by autoimmune thyroid diseases but not in the thyroid of normal subjects. The effective dose equivalent of a diagnostic activity of (99m)Tc-interleukin-2 (185 MBq) was 1.35 mSv. No correlation was observed between thyroid autoantibodies and uptake of (99m)Tc-interleukin-2.

CONCLUSIONS:

The use of (99m)Tc-interleukin-2 is safe and simple; the favourable dosimetry and biodistribution and the rapid clearance make it potentially useful for the study of chronic inflammatory diseases such as autoimmune thyroid disease.

• Authors: M Chianelli, S J Mather, A Grossman, R Sobnak, A Fritzberg, K E Britton, A Signore
• Journal: European journal of nuclear medicine and molecular imaging (Eur J Nucl Med Mol Imaging) Vol. 35 Issue 12 Pg. 2286-93 (Dec 2008) ISSN: 1619-7089 [Electronic] Germany
• PMID: 18542959 (Publication Type: Clinical Trial, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Interleukin-2
• Organotechnetium Compounds
• technetium Tc 99m interleukin 2

Topics

• Adult
• Autoimmune Diseases (diagnostic imaging)
• Case-Control Studies
• Feasibility Studies
• Female
• Granulocytes (drug effects, metabolism)
• Humans
• Interleukin-2 (pharmacokinetics, toxicity)
• Kinetics
• Lymphocytes (drug effects, metabolism)
• Male
• Metabolic Clearance Rate
• Organotechnetium Compounds (pharmacokinetics, toxicity)
• Radiation Dosage
• Radionuclide Imaging
• Thyroid Diseases (diagnostic imaging)
• Tissue Distribution