Exhaled Cys-LTs
At the initial visit, Cys-LTs were detected in 25 of 50 patients (14.6 ± 3.3 pg/mL; Fig 1, left, a). However, in all our normal subjects, the levels were undetectable. After treatment with montelukast, cys-LT levels fell to 8.5 ± 2.6 pg/mL after 2 weeks (p > 0.05) and to 3.9 ± 1.3 pg/mL after 4 weeks (p < 0.01). When we included into analysis only patients with detectable cys-LTs at the initial visit, the reduction in cys-LT levels became more significant (Fig 1, right, b).
Exhaled LTB4
At the initial visit, LTB4 levels were significantly higher compared to normal subjects (33.0 ± 3.9 pg/mL and 9.0 ± 2.1 pg/mL, respectively; p < 0.001). After treatment with montelukast, LTB4 fell to 20.4 ± 2.5 pg/mL after 2 weeks (p < 0.05) and to 17.0 ± 2.2 pg/mL after 4 weeks (p < 0.01; Fig 2, left, a). Only 27 patients attended a follow-up visit after discontinuation of treatment. In those patients, there was a slight but statistically insignificant increase in LTB4 (Fig 2, right, b).
AQL
There was a significant improvement of pooled AQL scores after 2 weeks and 4 weeks of treatment with montelukast (Fig 3, top, a). Thus, the mean score improved from 145.5 ± 5.8 to 172.7 ± 5.1 after 2 weeks (p < 0.005) and remained stable at 172.3 ± 6.1 after 4 weeks of treatment. The most responsive domain was “activity.” However, in 27 patients who were followed up for 2 weeks after discontinuation of treatment, there was a significant fall of pooled AQL scores (Fig 3, bottom, b). The most responsive domain was “symptoms.” There were no significant correlations between the changes in exhaled cys-LTs and changes of AQL scores, and also between changes in exhaled LTB4 and changes of AQL scores. You can read about the results of coronary artery spasm studies following the link.
Lung Function and Exhaled NO
After treatment with montelukast, no significant changes were found in FEV1, FVC, and exhaled NO. Initial FEV1 was 2.01 ± 0.11 L; after 2 weeks and 4 weeks of treatment with montelukast, FEV1 levels were 2.09 ± 0.11 L and 2.06 ± 0.11 L, respectively. Initial exhaled NO was 26.5 ± 4.6 ppm; after 2 weeks and after 4 weeks, exhaled NO levels were 24.2 ± 4.2 ppm and 24.5 ± 4.7 ppm, respectively.
You can find useful information on our website about occupational asthma and work-exacerbated asthma.
Figure 1. Left, a: concentrations of cys-LTs in EBC in 50 patients with asthma at the initial visit, at 2 weeks, and at 4 weeks of treatment with montelukast (**p < 0.01). Right, b: concentrations of cys-LTs in EBC in 25 patients at the initial visit, at 2 weeks, and at 4 weeks of treatment with montelukast (only patients with cys-LTs > 0 pg/mL at the initial visit were included; *p < 0.05; **p < 0.01).
Figure 2. Left, a: concentrations of LTB4 in EBC at the initial visit, at 2 weeks, and at 4 weeks of treatment with montelukast, 10 mg (*p < 0.05; **p < 0.01). Right, b: concentrations of LTB4 in 27 patients at the initial visit, at 2 weeks, and at 4 weeks of treatment with montelukast, and 2 weeks after discontinuation of treatment (only patients who attended four visits were included; *p < 0.05).
Figure 3. Top, a: mean AQL questionnaire score at the initial visit (white bars), at 2 weeks (gray bars), and at 4 weeks (black bars) of treatment with montelukast (*p < 0.01; **p < 0.005). Bottom, b: mean AQL questionnaire score at the initial visit (white bars), at 2 weeks (gray bars), and at 4 weeks (black bars) of treatment with montelukast, and 2 weeks after discontinuation of treatment (dark gray bars) [only 27 patients who attended four visits were included; *p < 0.05; **p < 0.01].