The association of fever and antibody response in rabbits immunized with human serum albumin.

Abstract

Rabbits immunized with human serum albumin will respond with fever upon challenge with the antigen. The presence or absence of pyrogenic responsiveness was correlated with circulating antibody measured by 2 different techniques. A quantitative relationship existed, over a narrow range, between dose of antigenic challenge and fever. The febrile response was usually mono-phasic followed a long latent period, was occasionally accompanied by initial hypothermia, and was not affected by prior induction of endo-toxin tolerance. Febrile tolerance to human serum albumin was induced by daily repetition of the challenge dose, was not affected Dy reticulo-endothelial system blockade, could not be passively transferred by serum, and did not protect rabbits from anaphylaxis when given a tenfold increase in challenge dose. The ability of certain immunized rabbits to respond to challenge with fever could be passively transferred to normal rabbits by whole serum only if antibody was detectable; it could also be transferred by Sephadex serum Fraction ii, which contained 7 S gamma-globulin. These studies indicate the association between febrile reactivity and the presence of circulating antibody in rabbits immunized with human serum albumin. In contrast to previous reports utilizing bovine serum albumin as the antigen, these studies point out certain differences between the fever elicited by bacterial endotoxin and the pyrogenic responses after the administration of human serum albumin to rabbits immunized with human serum albumin.