Antibodies against nickel-albumin in rabbits and man.

Five albino rabbits were immunized every 2 weeks by intradermal injections of a nickel rabbit-albumin complex and during alternate weeks by occluded cutaneous applications of 5% nickel sulphate in petrolatum. After 6 weeks of immunization, passive immunodiffusion disclosed precipitating antibodies against the nickel-albumin complex in the serum of the rabbits. The specificity of these antibodies was substantiated by the precipitation of anti-albumin antibodies with rabbit albumin prior to immunodiffusion. Passive immunodiffusion was used to examine serum from 14 nickel-sensitive patients for precipitating antibodies against nickel human-albumin complex. Five of the patients had widespread erythematous, non-eczematous reactions following oral challenge with 2.5 mg nickel as nickel sulphate, while five others suffered an aggravation of their nickel dermatitis. Precipitating antibodies were found in three patients, all of whom had experienced rapid-onset erythema after oral challenge. A weak precipitate was seen in one of nine controls. The specificity of the precipitates was substantiated by reproducibility and by negative immunodiffusion after precipitation in the positive sera with the antigen.