Kinetics of 99mTc-labelled antibodies against CD4 (T-helper) lymphocytes in man.
The availability of radiolabeled anti-CD4 antibodies permitted the study of their kinetic behaviour. Four patients suffering from rheumatoid arthritis were investigated prospectively. Three of them received 250 micrograms of 99mTc-labelled anti-CD4 antibody (MAX.16H5). One patient received in vitro 99mTc-antibody-labelled lymphocytes. 4% of the activity was excreted by the kidneys. From 4 to 24 h the splenic uptake decreased from 7.5 to 4%, the liver uptake increased from 25 to 30% the bone marrow uptake remained about the same 50% and the uptake of a single diseased joint (2%) increased slightly to 2.5%. 15 to 30 min after injection of the antibody a redistribution of labelled cells or antibody from liver and spleen to the circulating blood seemed to occur. The recovery rate (0-1 h) of in vivo labelled cells amounted to 30%, that of in vitro labelled cells to 19%. One patient was examined with in vitro labelled CD4-expressing lymphocytes. There was no difference in the antibody kinetics between in vitro and in vivo labelled cells. The authors suggest that circulating CD4-lymphocytes can be labelled with monoclonal antibodies. The kinetics of these in vitro labelled cells and the injected labelled antibody itself resembles that of recirculating lymphocytes.
Becker
W
W
Department of Nuclear Medicine, University of Erlangen-Nürnberg, FRG.
Horneff
G
G
Emmrich
F
F
Burmester
G
G
Kalden
J
J
Wolf
F
F
D000911:Antibodies, Monoclonal; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000276:immunology*; D015704:CD4 Antigens / Q000276:immunology*; D006801:Humans; D007700:Kinetics; D011446:Prospective Studies; D011877:Radionuclide Imaging; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D013667:Technetium
D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D013667:Technetium