Histamine and leukotriene C₄ levels in bronchoalveolar lavage (BAL) fluid in patients with bronchial asthma

The levels of histamine and leukotriene C₄(LTC₄) in bronchoalveolar lavage (BAL) fluid and the release of these mediators from BAL cells stimulated by Ca ionophore A 23187 were examined in 22 athmatic subjects. In BAL fluid, histamine was detectable in 9 (40.9%) and LTC₄ was detectable in 10 (45.5%) of the 22 asthma patients. BAL cells from patients with detectable histamine (DH), many of whom were evaluated as atopic, released more histamine and less LTC₄ than those of patients without DH. In contrast, BAL cells from patients with detectable LTC, (DL), many of whom were assessed as nonatopic, released more LTC₄ and less histamine than those of patients without DL. These results suggest that histamine and LTC₄ levels differ in relation to the IgE-mediated allergic reaction.