Role of antibody in the elimination of trypanosomes after DL-alpha-difluoromethylornithine chemotherapy.

The drug DL-alpha-difluoromethylornithine (DFMO), a specific inhibitor of ornithine decarboxylase, was studied as an antitrypanosomal drug. We showed that an antibody response to the surface antigen of trypanosomes was necessary for rapid elimination of parasites after DFMO treatment, as effects of drug treatment were greatly reduced in immunosuppressed mice. Efficacy of the treatment also varied with the inherent ability of different mouse strains to mount antibody responses to trypanosomal surface antigen. Further, some trypanosomes were more resistant to the combined effects of drug and host immunity, as relapses occurred with certain parasite clones.