Leukotrienes and 8-isoprostane in exhaled breath condensate in bronchoprovocation tests with occupational allergens

Exhaled breath condensate (EBC) contains many substances, which could help in diagnosis of occupational asthma. The aim of the study is to monitor leukotrienes (LT) and 8-isoprostane from EBC in bronchoprovocation tests with allergens in 47 patients with suspected occupational asthma. Forty-one patients were tested negative. In negative bronchoprovocation tests, no significant differences (P<0.05) were seen between the five measurements during and after the test. In control measurements (without provocation), significant differences were found among four measurements done within 24 h for 8-isoprostane (P=0.0138). The relationship between the log transformed ratios of the EBC parameters and FEV1 was never significant at the 5% level in control measurements, while in negative tests, statistical significance was recorded for LTB4 (P=0.0299) before and 5 h after the test. Six of 47 patients were tested positive. Such a small number of patients did not allow proper statistical analysis and therefore, the results are described separately for each patient.