Early rheumatoid-like joint lesions in rabbits injected with foreign serum. IV. Influence of delayed-type...

Intradermal injection of rabbits with lipid-coupled bovine serum proteins or bovine serum itself prior to a regimen of intravenous injections of bovine serum enhanced the incidence of joint lesions over that seen in animals receiving the intravenous regimen only. This increased of synovial lesions appeared, however, to be unrelated, either to the state of delayed hypersensitivity or to the concentration of passive haemagglutinating antibodies to bovine serum proteins in these animals. Lipid-coupled bovine serum, given as a first course in a regimen of intravenous injections, was no more arthritogenic than the native proteins and, as a second course series of intravenous injections, was definitely less arthritogenic.