On the relation between the formation of antihapten and anti-carrier protein antibodies in the immune response induced by conjugates of various haptens with homologous serum proteins.

Rabbits inoculated with conjugates of homologous serum with ortho-aminophenol (OAP), para-aminophenol (PAP), 3-hydroxy-sulfanilamide (3-HS), DOPA and alpha-methyldopa (alpha MD), 5-aminosalicylic acid (5-ASA) and 3-hydroxy-para-aminobenzoic acid (3-HPABA) give rise to both hapten specific and anti-carrier protein antibodies. By contrast, the conjugates of homologous serum with penicilloyl (P) hapten induced only antihapten antibodies. The conclusion is, therefore, drawn that the formation of anti-carrier antibodies upon inoculation with conjugates of various haptens appears to be dependent on the nature of hapten in the conjugate. The discrepancy between the behaviour of P conjugates, on the one hand, and the DOPA and alpha MD conjugates, on the other hand, is in agreement with the observation from the clinical immunology, which has signaled a high incidence of antibodies with autoantibody character in patients taking DOPA and alpha MD, but rarely, if ever, such antibodies have been found in patients treated with penicillin.