To determine the pathogenetic role of leukotrienes in chronic airway diseases, sputum samples from patients with bronchial asthma (BA), diffuse panbronchiolitis (DPB), sinobronchial syndrome (SBS), and bronchiectasis (BE) were examined for the presence of leukotrienes (LT) C4, D4, E4, B4, all apparently derived from airway inflammatory cells. Sputum samples from 21 patients, including 10 with BA attack (5 atopic type, 5 non-atopic type) and 11 with chronic obstructive airway diseases (3 DPB, 6 SBS, and BE), were studied. Patients expectorated sputum directly into test-tubes containing 80% ethanol. Following ethanol extraction and partial purification by a C18 SEP-PAK column, LTs were further purified by high performance liquid chromatography (HPLC). Fractions from HPLC with elution times corresponding to synthetic LTC4, D4, E4, and B4 were used to quantify LTs by radioimmunoassay. Eosinophils and neutrophils in the sputum (0.5 ml) were counted following Papanicolaou staining. Percentages of eosinophils in sputum were higher in BA, while those of neutrophils were higher in DPB. Sputum levels of LTC4 were 1.2 +/- 1.6 in BA, 0.12 +/- 0.11 in SBS, and 0.42 +/- 0.14 ng/ml in DPB. Those of LTD4 were 0.21 +/- 0.27 in BA, 0.9 +/- 0.13 in DPB, and 0.10 +/- 0.07 in SBS. LTE4 levels were 5.06 +/- 3.83 in DPB and 2.66 +/- 4.32 in BA. Levels of LTB4 were 1.36 +/- 1.19 in DPB, 0.28 +/- 0.27 in BA, 0.12 +/- 0.07 in SBS, and 0.04 +/- 0.04 in BE. In asthmatics, peptide leukotriene content in sputum was higher than that in chronic airway disease patients.(ABSTRACT TRUNCATED AT 250 WORDS)