Exhaled leukotrienes and bronchial responsiveness to methacholine in patients with seasonal allergic rhinitis.

BACKGROUND

Allergic rhinitis and bronchial asthma can coexist and affect each other.

OBJECTIVE

To investigate the relationship between the postseasonal increase in the concentration of leukotriene (LT) B4 and LTE4 in exhaled breath condensate (EBC) and bronchial responsiveness to methacholine (BRM) in patients with seasonal allergic rhinitis (SAR).

METHODS

In 28 patients with SAR and 50 healthy study patients, the leukotrienes were measured in EBC during and after the pollen season by gas chromatography/mass spectrometry. The BRM was determined after the pollen season.

RESULTS

In 7 patients with SAR, significantly increased concentrations of both the leukotrienes were found in EBC during and 5 months after the pollen season. The following seasonal and postseasonal median values were measured in patients with SAR in comparison with control patients: LTB4: 131 and 90 pg/mL vs 80 and 79 pg/mL, P < .001 and P = .03, respectively; LTE4: 122 and 86 pg/mL vs 76 and 74 pg/mL, P < .001 and P = .02, respectively. Five months after the pollen season, the concentrations of LTB4 and LTE4 decreased with respect to their seasonal values (90 and 86 pg/mL, respectively, P < .001, for both leukotrienes). In 7 patients with SAR and leukotriene levels exceeding the reference limits, significantly increased BRM was also found (LTB4: P = .02; LTE4: P = .002).

CONCLUSIONS

The seasonal and postseasonal increases in LTB4 and LTE4 concentrations in EBC of the patients with SAR correlated significantly with the later increase in BMR. This relationship could provide a useful predictive parameter for early inflammatory processes in the lower airways of patients with allergic rhinitis.