PET imaging agent could provide early diagnosis of rheumatoid arthritis

May 3, 2018, Society of Nuclear Medicine and Molecular Imaging
(A) On day 23 and day 37, increased uptake is noted in the front and hind paws of this mouse with collagen-induced arthritis. (B) Predictive performance of day 23 18F-FEDAC uptake for the development of clinical arthritis. ROC = receiver operating characteristic; Sn = sensitivity; Sp = specificity. Credit: Seoul National University and Ewha Womans University, Seoul, South Korea

A novel PET tracer developed by Korean researchers can visualize joint inflammation and could provide early diagnosis of rheumatoid arthritis, a common autoimmune disease that causes chronic inflammation of joints and can lead to deformity and dysfunction. The study is reported in the featured basic science article in The Journal of Nuclear Medicine's May issue.

Activated , that helps protect the body from harmful bacteria and infected cells, are known to play a pivotal role in (RA) development. Focusing on the translocator protein (TSPO), which is abundant in activated macrophages, researchers developed fluorine-18 (18F)-FEDAC, a radiolabeled ligand that targets TSPO and binds to it.

"This study is novel because it showed the value of 18F-FEDAC PET as an inflammation biomarker for early detection of rheumatoid arthritis, even before onset of clinical symptoms of joints," explains Gi Jeong Cheon, MD, PhD, of Seoul National University College of Medicine in Seoul, Korea.

For the study, 18F-FEDAC was tested in a mouse model, using both 18F-FEDAC and 18F-FDG PET imaging. Microscopic examinations of tissue were performed to evaluate macrophages and TSPO expression.

Results showed increased TSPO mRNA and protein expression in activated macrophages, and uptake of 18F-FEDAC in activated macrophages was higher than it was in non-activated cells. In addition, 18F-FEDAC uptake by arthritic joints increased early on (day 23), whereas 18F-FDG uptake did not. However, 18F-FDG uptake by arthritic joints increased at later stages (day 37) to a higher level than 18F-FEDAC uptake.

This early study demonstrates that 18F-FEDAC makes it possible to see active inflammation sites in arthritic joints by targeting TSPO expression in activated macrophages, and it suggests imaging with 18F-FEDAC could be useful when RA is suspected.

Cheon points out, "Early treatment can reduce the progression of joint destruction and enhance the effect of disease-modifying antirheumatic drugs or target drugs, because the burden of inflammatory reaction is smaller in the very early phase of RA." He notes, "We observed that 18F-FEDAC uptake increased in paws of murine RA models in association with TSPO expression of activated macrophages, even before the onset of clinical symptoms of arthritis. 18F-FEDAC can help us to find which patients will actually progress to clinically significant rheumatoid arthritis and need treatment."

Reflecting on the comparison of 18F-FEDAC PET with 18F-FDG, Cheon states, "From our data, we found that each tracer may be useful for different information about arthritis—18F-FEDAC for early detection of subclinical arthritis and 18F-FDG for measuring disease activity of symptomatic . These findings are expected to contribute to the improvement of personalized therapeutic outcomes by expanding the scope of molecular imaging and ."

Explore further: Gene expression study may help guide Arthritis care

More information: Seock-Jin Chung et al, 18F-FEDAC as a Targeting Agent for Activated Macrophages in DBA/1 Mice with Collagen-Induced Arthritis: Comparison with18F-FDG, Journal of Nuclear Medicine (2018). DOI: 10.2967/jnumed.117.200667

Related Stories

Gene expression study may help guide Arthritis care

February 22, 2018
Researchers who analyzed gene expression in synovial tissue samples from rheumatoid arthritis patients' joints identified different patterns that may be clinically meaningful. The findings, which are published in Arthritis ...

Molecular imaging gets to the root of rheumatoid arthritis

June 9, 2014
Rheumatoid arthritis causes chronic pain for almost half of adults by the time they retire, but a new molecular imaging technique can visualize inflammation in the joints, giving doctors a clear read on chronic pain and possible ...

Rheumatoid arthritis meets precision medicine

March 19, 2018
Scientists are bringing precision medicine to rheumatoid arthritis for the first time by using genetic profiling of joint tissue to see which drugs will work for which patients, reports a new Northwestern Medicine multi-site ...

Brain is susceptible to acute MI, chronic heart failure

January 17, 2018
(HealthDay)—Acute myocardial infarction (MI) and chronic heart failure have effects on the brain, according to a study published in the Jan. 23 issue of the Journal of the American College of Cardiology.

Maintaining sufficient vitamin D levels may help to prevent rheumatoid arthritis

November 20, 2017
Maintaining sufficient vitamin D levels may help to prevent the onset of inflammatory diseases like rheumatoid arthritis, research led by the University of Birmingham has discovered.

Rheumatoid arthritis linked to an increased risk of COPD

October 19, 2017
New research suggests that rheumatoid arthritis may increase the risk of developing chronic obstructive pulmonary disease (COPD). The findings, which appear in Arthritis Care & Research, indicate that greater vigilance may ...

Recommended for you

Researchers watch the knee degenerate and understand how osteoarthritis may begin

December 12, 2018
For hockey great Bobby Orr, a torn knee ligament ended his career at age 30. Orr had more than 17 knee operations, at one point having his meniscus removed—the cartilaginous tissue that helps stabilize and lubricate the ...

3-D printing offers helping hand to people with arthritis

December 11, 2018
Adaptive aids are expensive. Additive manufacturing, using low-cost 3-D printers, can save upwards of 94 percent for simple household items.

Potential arthritis treatment prevents cartilage breakdown

November 28, 2018
Osteoarthritis, a disease that causes severe joint pain, affects more than 20 million people in the United States. Some drug treatments can help alleviate the pain, but there are no treatments that can reverse or slow the ...

Patchy distribution of joint inflammation resolved

November 16, 2018
Chronic inflammatory rheumatic diseases such as rheumatoid arthritis (RA) and spondylo-arthritis (SpA) are chronic, disabling diseases with a poor outcome for loco-motoric function if left untreated. RA and SpA each affect ...

Defense against joint degeneration

October 30, 2018
During cartilage development, chondrocytes secrete the extracellular matrix (ECM) and embed within the same environment. During progressive joint disease, such as osteoarthritis (OA), dysregulation of the process can lead ...

Becoming more sensitive to pain increases the risk of knee pain not going away

October 30, 2018
Becoming more sensitive to pain, or pain sensitization, is an important risk factor for developing persistent knee pain in osteoarthritis, according to a new study by researchers at Université de Montréal and its affiliated ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.