BASOPHIL-BOUND IGE AND SERUM IGE DIRECTED AGAINST HAEMOPHILUS-INFLUENZAE AND STREPTOCOCCUS-PNEUMONIAE IN PATIENTS WITH CHRONIC-BRONCHITIS DURING ACUTE EXACERBATIONS

The investigation includes 12 patients hospitalized with acute exacerb ations of chronic bronchitis (CB) and infected in the lower respirator y tract with Haemophilus influenzae (HI) or Streptococcus pneumoniae ( SP). Eight patients were infected with HI, three with SP, and one pati ent with both species. Basophil-bound IgE and serum IgE directed again st these species were examined using the patients' own bacterial isola tes. All patients showed IgE-mediated histamine release when their per ipheral leukocytes were incubated in vitro with the infecting species, indicating basophil-bound IgE directed against their own bacterium. N o IgE-mediated response was obtained in the control group of 12 health y individuals. Bacteria-specific IgE in serum was demonstrated by immu nofluorescence assay and further verified by passive sensitization. Th ere was a positive serum titre in seven of nine patients housing HI an d in all SP-infected patients but not in the control group. No synchro nism was found between a positive response in the histamine release te st and the immunofluorescence assay by parallel testing during the tes t period. This may be due to a time delay between production of serum IgE and its fixation to the cell surface. The results indicate a poten tial for a bacteria-specific IgE-mediated immune response in CB. Thus, by triggering mediator release, bacteria may be involved in the patho genesis of exacerbations in CB.