Effects of warfarin administration on the immune response of mice.

Administration of warfarin to mice is shown to have little effect on the humoral immune response of these animals to sheep red blood cells (a thymus dependent antigen) or the trinitrophenyl hapten coupled to E. coli lipopolysaccharide (a thymus independent antigen). The ability of low doses of sheep red blood cells to prime T-cells in vivo for helper activity in the in vitro antibody-forming response to trinitrophenyl coupled to sheep red blood cells is also apparently unaffected. By contrast, delayed hypersensitivity responses, measured by foot pad swelling, are significantly stimulated by administration of the drug.