99Tcm-HIG accumulates in the synovial tissue of rats with adjuvant arthritis by binding to extracellular matrix proteins.
Our objective was to investigate the mechanism of accumulation of 99Tcm-labelled non-specific polyclonal human immunoglobulin (99Tcm-HIG) in inflamed synovial tissue (ST) in an experimental animal model of arthritis. Following 99Tcm-HIG scintigraphy, the in vivo localization of 99Tcm-HIG in the ST of knee joints of rats with adjuvant arthritis was studied using immunohistochemical techniques. In addition, the in vitro binding of 99Tcm-HIG to extracellular matrix proteins was analysed by means of immunohistochemistry and enzyme-linked immunosorbent assay (ELISA). After 99Tcm-HIG scintigraphy, 99Tcm-HI was detected in the ST of rats with adjuvant arthritis. 99Tcm-HIG was diffusely distributed and not bound to cells. In vitro incubation of 99Tcm-HIG on the ST of rats with adjuvant arthritis revealed binding of 99Tcm-HIG to inflamed, but not to non-inflamed, ST. In addition, specific binding of 99Tcm-HIG to fibronectin, fibrin, collagen type I and III was demonstrated by ELISA. We conclude that the accumulation of 99Tcm-HIG in inflamed ST can be explained by the binding of 99Tcm-HIG to extracellular matrix proteins.
de Bois
M H
MH
Department of Rheumatology, University Hospital Leiden, The Netherlands.
Welling
M
M
Verwey
C L
CL
de Vries
E
E
Pauwels
E K
EK
Breedveld
F C
FC
Tak
P P
PP
D000818:Animals; D001169:Arthritis, Experimental / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D003094:Collagen / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005260:Female; D005337:Fibrin / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G; D007136:Immunoglobulins / Q000378:metabolism*; D011485:Protein Binding; D011877:Radionuclide Imaging; D051381:Rats; D011917:Rats, Inbred Lew; D012016:Reference Values; D012709:Serum Albumin / Q000378:metabolism; D013583:Synovial Membrane / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D013667:Technetium / Q000378:metabolism / Q000493:pharmacokinetics*
D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D007074:Immunoglobulin G; D007136:Immunoglobulins; D012709:Serum Albumin; C065376:technetium Tc 99m immunoglobulin; D013667:Technetium; D005337:Fibrin; D003094:Collagen