Immune response of healthy and leukemic cats to the feline oncornavirus-associated cell membrane antigen.

Feline leukemia is an infectious disease caused by a horizontally transmitted virus. Infection of animals or cultured cells with feline oncornaviruses results in the expression of a specific cell membrane antigen, feline oncornavirus-associated cell membrane antigen (FOCMA). The humoral antibody response to FOCMA is directly correlated with tumor progression. The measurement of this antibody is a useful tool for determining virus exposure. Using this procedure it was determined that cats living in leukemia "cluster" households as well as cats used as contact controls in virus injection experiments have a risk of infection of 90% or higher.