Effect of autogenic bacterial antigens on the production of histamine releasing factor by mononuclear cells from intrinsic asthmatic patients.

The production of histamine releasing factor (HRF) by mononuclear cells (MNC) from intrinsic asthmatic patients has previously been reported. In this study, we investigated the effect of preincubation of lymphocytes with autogenic killed bacteria upon the production of HRF. Bacteria were isolated from the sputum, and nasopharyngeal swab obtained from patients and control subjects. MNC from intrinsic asthmatics and healthy controls were preincubated with killed bacteria for 4 h, then washed and cultured for 18 h. HRF activity of the cell-free supernatants was assayed in the histamine release test using basophils from normal subjects. We found that MNC from the patients spontaneously produce significant amounts of HRF. Preincubation of the cells with autogenic bacterial antigens enhanced HRF production in 12 of 25 patients and only in one of 15 control subjects. No specific bacterial strain was identified as having the sole stimulatory property for HRF production; rather, individual susceptibility predisposes to the ability to produce HRF in response to some common bacteria. When MNC from healthy subjects were preincubated with bacterial antigens isolated from the patients, no enhancement in HRF production was observed. We concluded that MNC from some intrinsic asthmatics are specifically sensitized to certain bacterial antigens and release HRF upon contact with these antigens.