Th2 cytokine inhibition and cough in asthmatic and bronchitic patients.
ABSTRACT Activated T helper lymphocytes are present in the airway and their production of cytokines is important in the pathogenesis of asthma, however, the relationship between T helper lymphocyte-derived cytokines and airway cough reflex sensitivity remains unknown.
The effect of the orally active Th2 cytokine inhibitor suplatast tosilate on cough response to inhaled capsaicin was examined in eleven patients with stable atopic asthma and compared with patients having non-atopic asthma and chronic bronchitis (the latter of which is not related to Th2 cytokines). Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough reflex sensitivity. Concentration of serum total IgE level was also measured after treatment with suplatast tosilate.
The cough threshold after two weeks treatment with suplatast tosilate was significantly greater than the value with placebo accompanied by decrease of serum IgE level in atopic asthmatics. This significance was not observed in patients with non-atopic asthma or chronic bronchitis.
Th2 cytokines may be possible modulators augmenting airway cough reflex sensitivity in atopic asthmatic airways but not in non-atopic asthmatic or bronchitic airways.
Article: COX-2 inhibition attenuates cough reflex sensitivity to inhaled capsaicin in patients with asthma.[show abstract] [hide abstract]
ABSTRACT: Cyclooxygenase (COX) is an enzyme that converts arachidonic acid to prostanoids. There are two isoforms of COX, namely COX-1 and COX-2. COX-2 is highly inducible by several stimuli and is associated with inflammation. Recent studies have shown that COX-2 is upregulated in the airway epithelium of patients with asthma but little is known about the role it plays in cough, a common symptom of bronchial asthma. This study was designed to investigate the role of COX-2 in cough reflex sensitivity in patients with asthma. The effect of etodolac, a potent COX-2 inhibitor, on cough response to inhaled capsaicin was examined in 17 patients with stable asthma in a randomized, placebo-controlled crossover study. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting 5 or more coughs, was measured as an index of airway cough reflex sensitivity. The geometric mean (geometric SEM) cough threshold was significantly increased after a 2-week treatment program with oral etodolac (200 mg twice a day) compared with placebo (36.7 [1.2] vs 21.6 [1.2] gM, P<.02). These findings indicate that COX-2 may be a possible modulator augmenting airway cough reflex sensitivity in asthmatic airways.Journal of investigational allergology & clinical immunology: official organ of the International Association of Asthmology (INTERASMA) and Sociedad Latinoamericana de Alergia e Inmunología 01/2009; 19(5):370-4. · 2.27 Impact Factor