Dynamic studies of lymphocytes labelled with indium-111 during and after treatment with monoclonal anti-idiotype antibody in advanced B cell lymphoma.

The migration pattern of lymphocytes labelled with indium-111 was followed in a patient with B cell non-Hodgkin's lymphoma treated with a murine monoclonal anti-idiotype antibody. During the early phase of continuous infusion of antibody rapid fluxes of labelled lymphocytes into and out of the blood were seen. Dynamic scanning showed immediate uptake in the lungs; thereafter activity decreased in the lungs and increased in the liver. Studies of labelled and unlabelled cells in the circulation showed that treatment resulted in the removal of lymphocytes from the blood which was repopulated from an extravascular compartment. Tumour cells were shown to be cleared from the blood by the reticuloendothelial system in the liver. Indium-111 should be used circumspectly because it may cause chromosomal damage in labelled cells, but it is clearly useful as a radiolabel for following the migration pathways of lymphocytes in vivo.