CysLT1-R expression following allergen provocation in asthma and allergic rhinitis

The relationship between inflammatory markers and spirometric parameters in ACOS, Asthma, and COPD

Objective: The inflammatory mechanisms underpinning asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) have not been fully elucidated. Here, we examined the levels of cysteinyl leukotrienes (cys-LTs), prostaglandin D2 (PG-D2), prostaglandin E2 (PG-E2), interleukin 5 (IL-5), and a disintegrin and metalloprotease domain (ADAM 33) in ACOS patients to determine the relationship between levels of these inflammatory markers and pulmonary functions.Methods: Blood samples were obtained from asthma, COPD, and ACOS patients who received combined therapy and were stable for the last month to measure cys-LTs, PG-D2, PG-E2, IL-5, and ADAM33 levels. Differences between groups and their correlations with pulmonary function tests were evaluated.Results: In total, 24 ACOS, 27 asthma, and 35 COPD patients were included. . PG-D2 levels were higher in ACOS (120.9 ± 117.2 ng/L) and asthma (119.6 ± 111.7 ng/L) patients than in COPD (82.6 ± 46.7 ng/L) patients (p = 0.036 and p = 0.038, respectively). In ACOS patients, PG-D2, cys-LTs, and ADAM33 levels were negatively correlated with FEV1/FVC% values (p = 0.021, p = 0.008, and p = 0.028, respectively). In COPD patients, a negative correlation was detected between PG-E2 and FEV1/FVC% (p = 0.007), whereas positive correlations were detected between IL-5 and pulmonary function tests, including FVC, FVC%, FEV1, FEV1%, FEF25-75, and FEF25-75% (p = 0.047, p = 0.005, p = 0.002, p = 0.002, p = 0.010, and p = 0.005, respectively). In asthma patients, cys-LTs levels were negatively correlated with FEV1 and FEF25-75 values (p = 0.045 and p = 0.037, respectively).Conclusions: PG-D2 levels may be a valuable biomarker to differentiate COPD in asthma and ACOS patients.

Effects of leukotriene D4 nasal challenge on bronchial responsiveness and inflammation in asthmatic patients with allergic rhinitis

BACKGROUND

In asthmatic patients with allergic rhinitis (AR), increased cysteinyl leukotrienes (CysLTs) production in the secretion of nasal mucosa has been associated with greater bronchial hyperresponsiveness (BHR) after nasal allergen challenge. However, the role of CysLTs in eliciting BHR after nasal allergen challenge has not been evaluated. The aim of this study is to evaluate the effect of LTD₄ nasal challenge on BHR and inflammation in asthmatic patients with AR.

METHODS

In this self-controlled study, fifteen eligible consecutively recruited subjects underwent methacholine (Mch) bronchial provocation test before and 30 minutes after LTD₄ nasal provocation test. The cumulative concentration of LTD₄ inducing a 60% increase in nasal airway resistance (PC₆₀NAR) was calculated. The mean values of cumulative doses inducing a 20% decrease in forced expiratory flow in one second (PD₂₀FEV₁) for Mch before and after nasal challenge were compared. Fractional exhaled nitric oxide (FeNO), differential inflammatory cell counts in nasal lavage and induced sputum before and after nasal challenge were compared.

RESULTS

House dust mites were the major allergens accounting for 10/15 (66.7%) of asthmatic patients with AR. The PC₆₀NAR for LT was (8.39±3.48)×10^-3 mg·mL^-1. The PD₂₀FEV₁ before and after nasal challenge was 3.05±3.81 and 2.70±3.81 µmol, respectively (P=0.45). The percentages of eosinophils were (38.36±23.14)% and (45.70±24.86)% in nasal lavage, and (17.51±11.05)% and (24.29±16.52)% in induced sputum before and 24 hours after nasal challenge. The neutrophil counts were (60.64±23.14)% and (53.30±24.46)% in nasal lavage, and (53.83±23.27)% and (56.19±22.28)% in induced sputum before and 24 hours after nasal challenge. The values of FeNO were 40 [35] and 43 [30] ppb before and 24 hours after nasal challenge. No severe adverse effects were reported during the tests.

CONCLUSIONS

Although most asthmatic patients with AR were sensitive to LTD₄ nasal challenge, LTD₄ nasal provocation tests do not confer any major effect on BHR. LTD₄ might not play a vital role in eliciting bronchial responsiveness induced by nasal allergen challenge.