Demonstration of feline leukemia virus antibody in cats by passive hemagglutination (38583).

Two FeLV fractions from Sephadex G-150 gel filtration were used to sensitize RBC for the PHA test. When the cells were coated with the fraction from the second peak consisting mostly of a mojor gs antigen of FeLV, no antibodies could be detected either in hyperimmunized cat sera or sera from leukemic cats, whereas antibodies were readily detectable in immunized rabbits. Using cells coated with the first peak eluants or Tween-ether disrupted FeLV, PHA antibodies were detected in cat sera. There existed, however, one significant exception that a cat with the diagnosis of mast cell leukemia showed antibody against the second peak fraction. Little or no antibodies could be detected in cat sera by CF or gel-diffusion. There was some correlation between hemagglutinating antibodies and conglutinating complement absorbing antibodies, but these antibodies did seem to differ from neutralizing antibody.