Objective: To evaluate the clinical utility of a novel radiotracer, Tc-glucosamine, in assessing disease activity of both rheumatoid arthritis (RA) and ankylosing spondylitis (AS).Material and Methods: Twenty-five patients with RA (nine males and 16 females) and 12 patients with AS (all male) at various stages of disease were recruited for the study. A clinical history and examination was performed, followed by the measurement of hematological, biochemical, and autoimmune serological parameters to assess disease activity. Tc-glucosamine was intravenously administered and scans were compared with other imaging modalities, including plain X-ray, magnetic resonance imaging (MRI), and bone scans.
Results: In patients with AS, 99mTc-glucosamine scans were more capable of identifying active disease and differentiating between inflammatory and non-inflammatory causes. In patients with RA, 99m Tc-glucosamine accumulated at all known sites of disease involvement. Uptake was most pronounced in patients with active untreated disease. The relative tracer activity in the involved joints increased with time compared with that in the adjoining soft tissue, liver, and cardiac blood pool. Using Spearman's correlation coefficient, there was a positive correlation among glucosamine scan scores, C-reactive protein (p=0.048), and clinical assessment (p=0.003), which was not noted with bone scans.
Conclusion:The radiotracer was well tolerated by all patients, with no adverse reactions. Tc-labeled methylene diphosphonate nuclear bone scans for imaging inflamed joints and had the added advantage of demonstrating a significant clinical correlation between disease activity and scan findings.Keywords: Glucosamine, rheumatoid arthritis, ankylosing spondylitis, nuclear scan ments of cells at these sites. Tc-glucosamine can be locally produced by a nuclear scientist in a major nuclear medicine department and administered to a patient, as one would for a bone scan, and it is easy to produce, cheap to administer, and accessible. Other similar analogs of glucosamine, such as N-[2,4,5-trihydroxy-6-(hydroxymethyl) tetrahydro-2H-pyran-3-yl] acrylamide, have been demonstrated to have anti-arthritic and immunomodulatory effects in adjuvant-induced arthritis but are yet to be tested in humans as imaging agents (9).In this study, we extended our prior pilot investigations and evaluated 99m Tc-glucosamine imaging modality for its clinical utility, limitations, and applications, particularly in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Tc-glucosamine joint uptake was correlated with MRI, bone scans, and in three cases, the effect of anti-tumor necrosis factor (anti-TNF) treatment on scanning before and after therapy.
Material and MethodsEthics approval All patients provided their written informed consent. The Western Sydney Local Health District Human Research Ethics Committee granted ethics approval for this study.
Study populationPatients fulfilling the American College of Rheumatology revised criteria for...