CHELATE CONJUGATES OF MONOCLONAL-ANTIBODIES FOR IMAGING LYMPHOID STRUCTURES IN THE MOUSE

  • 1 January 1985
    • journal article
    • research article
    • Vol. 26  (5) , 493-502
Abstract
Radiolabeling of a mouse monoclonal antibody (MoAb) specific for the mouse histocompatibility alloantigen IAk expressed by the B lymphocytes of BALB/k and C3H mice but not BALB/c mice was performed by mixing the chelate-labeled anti (.alpha.) IAk MoAb with purified, no-carrier-added 111In citrate. Labeling efficiency was 85-95%, and the labeled .alpha.IAk MoAb retained its antigen binding properties in vitro and in vivo. The organ, spleen and lymph node distribution of i.v., and s.c. administered 111In.alpha.IAk MoAb was compared in mice, 2 IAk positive and 1 IAk negative strains, and to 125I.alpha.IAk MoAb in one IAk positive strain. The 111In.alpha.IAk MoAb was more stable in vivo compared to 125I.alpha.IAk MoAb, as shown by a much slower excretion and a higher absolute uptake in lymph nodes and spleen. Lymph node to blood ratio was increased 2-fold by i.v., anti-EDTA MoAb. S.c. injection permitted clear images of the tiny lymph nodes in the mouse. Potential clinical applications of 111In.alpha. lymphocyte MoAb include localization of normal lymph nodes and T and B cell leukemias and lymphomas, as well as detecting lymphatic metastases of other cancers. Therapy may also be possible using MoAb labeled with .beta.-emitting metal ions such as yttrium-90.