Bronchoalveolar lavage fluid histamine levels in interstitial lung diseases.

We measured bronchoalveolar lavage (BAL) fluid histamine in 36 normal subjects, 32 patients with sarcoidosis, and 28 patients with idiopathic pulmonary fibrosis (IPF). Patients with sarcoidosis and IPF had significantly greater BAL histamine (59 +/- 21 and 203 +/- 42 pg/ml, respectively) than did normal subjects (18 +/- 8 pg/ml). Sarcoidosis patients with Stage 3 chest radiographs had significantly greater BAL histamine than did sarcoidosis patients with radiographic Stages 0, 1, or 2. Sarcoidosis patients with higher BAL lymphocytes also had higher levels of BAL histamine. Furthermore, among the sarcoidosis patients, we found a marked interactive effect between higher BAL lymphocytes and Stage 3 radiographs on BAL histamine. In IPF, subjects with increased BAL lymphocytes had significantly less BAL histamine than subjects with normal levels of lymphocytes. These studies suggest that BAL histamine may be a useful marker (of more active disease and/or poorer prognosis) to be evaluated in prospective studies in patients with sarcoidosis and IPF.