Use of a radiolabeled monoclonal antibody against E-selectin for imaging of endothelial activation in rheumatoid arthritis.
OBJECTIVE
To determine the potential of 111In-labeled anti-E-selectin monoclonal antibody (MAb) to image localized endothelial activation in rheumatoid arthritis (RA).


METHODS
Fourteen patients with RA were studied after intravenous administration of 111In-labeled F(ab')2 fragments of MAb against the cytokine-inducible endothelial cell activation antigen E-selectin (MAb 1.2B6). To compare uptake of 1.2B6 with that of nonspecific immunoglobulin, 111In-labeled polyclonal human immunoglobulin (HIG) was separately administered to 6 of these patients and the relative uptake of each tracer was determined.


RESULTS
Prominent and discrete uptake of the radiolabeled MAb 1.2B6 was clearly visible in inflamed joints of all patients. Compared with 111In-HIG, 111In-1.2B6 provided superior images in terms of sensitivity and image intensity. Furthermore, the distribution of uptake in inflamed joints was different for the 2 tracers, with 1.2B6 showing a more focal localization in synovium.


CONCLUSIONS
This study demonstrates that it is possible to objectively assess E-selectin expression on activated endothelium in vivo in patients with RA, using a radiolabeled MAb. This technique has considerable potential for monitoring disease activity and response to therapy in inflammatory diseases.
Chapman
P T
PT
Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
Jamar
F
F
Keelan
E T
ET
Peters
A M
AM
Haskard
D O
DO
D000368:Aged; D000911:Antibodies, Monoclonal / Q000493:pharmacokinetics; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000276:immunology; D019040:E-Selectin / Q000032:analysis / Q000276:immunology*; D004727:Endothelium / Q000737:chemistry / Q000276:immunology; D005260:Female; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007136:Immunoglobulins / Q000378:metabolism; D007205:Indium Radioisotopes / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013585:Synovitis / Q000000981:diagnostic imaging
D000911:Antibodies, Monoclonal; D019040:E-Selectin; D007140:Immunoglobulin Fab Fragments; D007136:Immunoglobulins; D007205:Indium Radioisotopes