High-dose, unlabeled, nonspecific antibody pretreatment: influence on specific antibody localization to XXXX @entity320 xenografts.

@entity1 @entity320 @entity5 @entity19 @entity6527 @entity9749
Nonspecific uptake of radiolabeled monoclonal antibodies in normal tissues is a significant problem for @entity5 imaging. A potential means of decreasing nonspecific antibody binding is to "blockade" nonspecific antibody binding sites by predosing with cold, nonspecific isotype-matched antibody, before injecting specific antibody. Nontumor-specific murine monoclonal antibody LK2H10 ( @entity6527 ) or Ab-1 ( @entity9749 ) was given i.v. at doses of 0 to 3.5 mg to @entity19 with xenografts of @entity1 @entity320 . These @entity19 were then given i.v. 4 micrograms of 131I anti-high molecular weight antigen of @entity320 (HMWMAA) monoclonal antibody 763.24T ( @entity6527 ) or 225.28S ( @entity9749 ), respectively. These @entity19 were also given a tracer dose of 125I LK2H10 or Ab-1, respectively. Specific @entity5 uptake of anti-HMWMAA antibodies was see in all cases. No drop in @entity5 or nontumor uptake was demonstrated for either of the @entity5 -specific or nonspecific monoclonal antibodies due to nonspecific monoclonal antibody pretreatment. These data suggest that high doses of isotype-matched unlabeled nonspecific monoclonal antibody given before 131I @entity5 -specific monoclonal antibody, will not enhance @entity5 imaging.
