[Study of the mechanisms of histamine release from human leukocytes by challenge of mycoplasma].

The percentage of histamine release from human leukocytes by challenge of Mycoplasma antigens and the level of Mycoplasma pneumoniae-specific IgE antibody in serum were examined to elucidate the mechanisms of Mycoplasma induced histamine release from human leukocytes. The following results were obtained. 1) In either normal persons (non-asthmatic group) or patients with bronchial asthma with and without increased titers of antibodies to M. pneumoniae IHA-positivity (IHA greater than or equal to 1:80) or negativity (IHA less than 1:80), histamine release from human leukocytes was found after challenge of Mycoplasma antigen. 2) In the non-asthmatic group, there was no significant difference in the histamine release rate among IHA-positive persons compared with that among IHA-negative persons. 3) In the asthmatic group too, IHA-positive and negative patients showed no significant difference in the histamine release rate. 4) The histamine release rate after challenge of M. pneumoniae increased in proportion to the concentration of the antigen added. 5) In all cases, the M. pneumoniae-specific IgE antibody (RAST) in serum was negative. These results suggest that histamine release from human leukocytes after challenge of Mycoplasma antigens occurs through non-immunological mechanisms that are not mediated by IgE antibody.