RT Journal Article
SR Electronic
T1 PET and SPECT imaging of rheumatoid arthritis with radiolabeled anti-FAP antibody correlates with severity of arthritis
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 329
OP 329
VO 55
IS supplement 1
A1 Laverman, Peter
A1 Gerrits, Danny
A1 van der Geest, Tessa
A1 Koenders, Marije
A1 Nayak, Tapan
A1 Freimoser-Grundschober, Anne
A1 Klein, Christian
A1 Oyen, Wim
A1 Boerman, Otto
YR 2014
UL http://jnm.snmjournals.org/content/55/supplement_1/329.abstract
AB 329 Objectives Rheumatoid arthritis is an autoimmune disease that results in chronic synovial inflammation. Molecular imgaging techniques might aid in adjusting treatments, ultimately leading to improved therapeutic efficacy. Activated fibroblast-like synoviocytes play an important role in joint destruction. These cells abundantly express fibroblast activation protein (FAP). Here we used an anti-FAP antibody, labeled with 89Zr and 111In for specific imaging of FAP expression in an experimental model of RA. Methods Arthritis was induced with collagen in DBA/1J mice. The monoclonal anti-FAP antibody 28H1 with high bivalent affinity for murine FAP (< 1 pM) and human FAP (268 pM) was conjugated with desferoxamine and DTPA and labeled with 89Zr and 111In. Mice were scanned at 24 and 72 h pi. Mice were euthanized at 72 h pi and tissues of interest were dissected. A separate group was injected with FDG. Results Both 89Zr-28H1 and 111In-28H1 showed high uptake in inflamed joints, being 3-4 fold higher than that of the irrelevant isotype-matched control antibody DP47GS, strongly indicating specific accumulation of 28H1. Uptake of 111In-28H1 ranged from 3.3 %ID/g in non-inflamed joints to 27.4 %ID/g in severely inflamed joints. DP47GS accumulation ranged from 2.5 %ID/g in non-inflamed tissue to 11.7 %ID/g in severely inflamed joints. Uptake of 28H1 in inflamed joints correlated with arthritis score (r2=0.92) and increased with severity of inflammation. FDG only accumulated in severely inflamed joints. FDG uptake in the joints did not correlate with severity of inflammation (r2=0.36). Both PET/CT and SPECT/CT imaging with 89Zr-28H1 and 111In-28H1 antibody showed excellent delineation of the inflamed joints at both 24 and 72 h pi. Conclusions The anti-FAP antibody 28H1 labeled with 89Zr or 111In showed excellent characteristics for imaging inflamed synovial tissue, and uptake correlated with severity of the inflammation.