Subthreshold and suboptimal desensitization of human basophils. II. Nonspecificity and irreversibility of desensitization.

Desensitization in human basophils was induced by suboptimal levels of antihuman IgE or antigen under normal calcium buffer conditions. Low doses of anti-IgE triggered only 0-12% histamine release during a 3-hour preincubation, yet initiated up to 100% desensitization upon rechallenge. After 24-27 h preincubation with allergen a, the cells did not regain releasability when rechallenged with either allergen a, allergen b or anti-IgE. Low dose, IgE-mediated desensitization in human basophils may lead to an irreversible and nonspecific inhibition of degranulation.