Significance and Potential Role of Eosinophils in Non-Cystic Fibrosis Bronchiectasis.

Bronchiectasis is a complex and heterogeneous disease with a myriad of pulmonary and extrapulmonary etiologies. Bronchiectasis has a predominantly neutrophilic inflammatory profile. However, eosinophilic inflammation has also been documented in both the airways and the systemic circulation. Various diseases (eg, asthma, allergic bronchopulmonary aspergillosis, chronic rhinosinusitis with nasal polyps) characterized by heightened type 2 airway inflammatory responses, including blood or sputum eosinophilia, may coexist with bronchiectasis. Apart from those eosinophilic etiologies or comorbidities related to bronchiectasis, around 20% of patients with bronchiectasis have peripheral eosinophilia (at least 3% or 300 eosinophils/µL) with no identified concomitant disease (also termed "eosinophilic bronchiectasis"), whose roles have not been fully understood. The two key points regarding these observations are that eosinophils confer both bactericidal and antiviral properties against common pathogenic microorganisms that are usually detected in bronchiectasis, and that eosinophilic bronchiectasis has been associated with better therapeutic response to inhaled corticosteroids and other anti-TH2 profile treatments. In this review, we summarize the most significant evidence regarding the role of eosinophils in patients with bronchiectasis, including the association of bronchiectasis with eosinophilic diseases (as etiologies or comorbidities), and existing data on eosinophilic bronchiectasis not related to eosinophilic disorders.

[Budesonide attenuates airway remodeling and modules the expression of Janus protein tyrosine kinase 1, and signal transducers and activators of transcription 6 in asthma: an experiment with mice].

OBJECTIVE: To investigate the effects of budesonide (BUD) on the airway remodeling and the expression of Janus protein tyrosine kinases 1 (JAK1) and signal transducer and activator of transcription 6 (STAT6) in asthma. METHODS: Thirty female Balb/c mice were randomly divided into 3 equal groups: control group; asthma group, sensitized on day 1, 8, and 15 and challenged from day 21 to 52 with periodically repeated intranasal drip of ovalbumin (OVA); and BUD treated group, undergoing intranasal drip of OVA as mentioned above and intranasal administration of BUD 2 hours before each OVA challenge. 24 h after the final OVA inhalation an invasive single-chamber whole body plethysmograph was used to assess the airway responsiveness. Then bronchoalveolar lavage fluid (BALF) was obtained and ELISA was used to measure the contents of interleukin (IL)-4 and IL-13. The mice were killed and their lungs taken out. HE staining and periodic acid Schiff (PAS) staining were used to observe the airway score of goblet cells. Peribronchiolar collagen deposition was imaged in Masson-stained lung sections. Biochemical assay was used to determine the total lung tissue level of collagen. Potass hydrolyse method was used to examine the content of hydroxyproline in the lung tissue. Western blotting was used to detect the protein expression of alpha-smooth muscle actin (SMA), JAK1, and STAT6. RT-PCR was used to detect the mRNA expression of alpha-SMA. RESULTS: The value of LogPC100 of the asthma group was 1.88 +/- 0.34, significantly higher than those of the BUD and control groups (1.79 +/- 0.18 and 0.82 +/- 0.78 respectively, both P = 0.000). The airway score of goblet cells of the asthma group was 3.05 +/- 0.23, significantly higher than those of the BUD and control groups (1.35 +/- 0.26 and 0.40 +/- 0.13 respectively, both P < 0.01). The hydroxyproline content of the asthma group was (459 +/- 47) microg/100 mg tissue, significantly higher than those of the BUD and control groups [(284 +/- 16) and (181 +/- 22) microg/100 mg tissue respectively, both P < 0.01]. The level of IL-4 of the asthma group was (14.4 +/- 1.12) ng/L, significantly higher than those of the BUD and control groups [(7.3 +/- 0.6) and (5.6 +/- 0.8) ng/L respectively, both P < 0.01]. The IL-13 level of the asthma group was (16.8 +/- 0.9) ng/L, significantly higher than those of the BUD and control groups [(10.6 +/- 0.9) and (5.6 +/- 0.8) ng/L respectively, both P < 0.01]. Treatment of BUD attenuated the allergen-induced airway hyperresponsiveness (AHR) and structural changes in airway, and decreased the values of the airway scores of goblet cells, and levels of hydroxyproline, IL-4, and IL-13 in comparison with the asthma group (all P < 0.01). Repeated OVA challenge resulted in an upregulation of the expression levels of alpha-SMA, JAK1 and STAT6 protein and alpha-SMA mRNA, while use of BUD suppressed these changes. The changes of JAK1 and STAT6 expression were correlated significantly with the changes in the airway score of goblet cells, hydroxyproline content, expression level of alpha-SMA, and levels of IL-4 and IL-13 in BALF (all P < 0.05). CONCLUSION: BUD ameliorates the progression of airway remodeling following prolonged allergen challenge via regulation of JAK1/STAT6 signal pathway.

[Etiology and a diagnostic protocol for patients with chronic cough].

OBJECTIVE: The spectrum and frequency of causes and the diagnostic protocol for chronic cough were explored. METHODS: A total of 194 patients with at least 3 weeks of chronic cough and normal chest radiographs were recruited from the outpatient clinic of Guangzhou Institute of Respiratory Diseases between July 2003 to June 2004. The causes were investigated using a well-established protocol. The diagnostic protocol included history inquiring and physical examination, pulmonary function tests, induced sputum cell differentials, 24 h esophageal pH monitoring, CT of the paranasal sinuses or chest, fiberoptic rhinoscopy or bronchoscopy. The final diagnosis was made based on clinical manifestation, examination findings and a positive response to therapy. RESULTS: The cause of chronic cough was defined in 95.4% of the patients, with a single cause found in 153 patients (82.7%), and multiple causes in 32 patients (17.3%). The five most important causes of cough were: eosinophilic bronchitis (n = 51, 22.4%), rhinitis and/or paranasal sinusitis (PNDs, n = 39, 17.1%), cough-variant asthma (n = 31, 13.6%), atopic cough (n = 28, 12.3%), and gastroesophageal reflux (n = 27, 11.8%). CONCLUSIONS: The spectrum and frequency of causes of chronic cough in our study is different from the previous reports in western countries. Eosinophilic bronchitis and atopic cough are important causes of chronic cough. A modified diagnostic protocol was established accordingly.

[Characteristics of airway inflammatory cells and mediators in eosinophilic bronchitis patients].

OBJECTIVE: To investigate the features of airway inflammation in patients with eosinophilic bronchitis (EB) by analyzing the inflammatory cells and mediators in induced sputum and bronchoalveolar lavage fluid (BALF). METHODS: Sputum induced by hypertonic saline aerosol inhalation was collected in 43 patients with EB (EB group), 20 patients with cough variant asthma (CVA, CVA group), 16 patients with bronchial asthma (asthma group) and 21 healthy controls (healthy group). Bronchoalveolar lavage was also performed in 11 patients with EB and 10 patients with CVA. Differential cell count was carried out in sputum and BALF. Levels of eosinophilic cationic protein (ECP), leukotriene C(4) (LTC(4)) and histamine in sputum and BALF were measured. RESULTS: The percentage of sputum eosinophils (EOS) showed significant difference among the four groups; healthy group 0.0020 +/- 0.0050, EB group 0.1130 +/- 0.1470, CVA group 0.1900 +/- 0.1800, asthma group 0.3860 +/- 0.2670 (P < 0.01). The difference between asthma group and CVA group, and the difference between CVA group and EB group were significant (P < 0.05). The percentage of EOS in BALF was (0.011 +/- 0.016) in EB group, (0.053 +/- 0.040) in CVA group, the difference being significant (P < 0.05). The concentration of sputum ECP was (0.62 +/- 0.66) mg/L in EB group, (1.27 +/- 1.74) mg/L in CVA group, (0.07 +/- 0.10) mg/L in healthy group, the difference among the three groups being significant (P < 0.01). The difference of LTC(4) level was also significant when CVA group (0.65 +/- 0.62) microg/L was compared with EB group (0.39 +/- 0.61) microg/L (P < 0.05) and healthy group (0.15 +/- 0.11) microg/L (P < 0.01). The difference of histamine level in the supernatant of BALF was significant between CVA group (3.4 +/- 1.4) microg/L and EB group (1.6 +/- 1.5) microg/L (P < 0.05). CONCLUSIONS: EOS infiltration is mainly localized to the central airway in EB, with lower airway levels of LTC(4) and histamine as compared to CVA. These inflammatory features may partly explain the absence of non-specific airway hyperresponsiveness in patients with EB.

[The clinical features and the diagnosis of gastro-esophageal reflux induced cough].

OBJECTIVE: Gastro-esophageal reflux (GER) is an important etiological factor inducing chronic cough. This study aims to identify the clinical features for the diagnosis of GER induced cough (GERC). METHODS: A modified Irwin's diagnostic protocol and continuous 24-hour esophageal pH monitoring were performed in 50 patients with chronic cough. Twenty patients were diagnosed as having GERC. The clinical features were compared with those of non-GER (NGER) induced cough. RESULTS: One hundred and ninety-two patients met the chronic cough criteria and were fully evaluated. The x +/- s of age was (40.6 +/- 12.1) years (range, 10 - 69 years) and 101 were males and 91 were females, with a cough history of 25 months (range, 2 - 487 months). GER accounted for 10.4% (n = 20) of the causes and was the fourth common cause of chronic cough. The mean +/- SD of age was (37.7 +/- 13.9) years (range, 10 - 60 years) in the GERC group, with a cough history of 61 months (range, 3 - 360 months). Cough associated with having meals (occurring while eating or anytime during the subsequent 2 h) was present in 13 out of the 20 patients in GERC, significantly higher than that in NGER (2 out of 23 patients) (chi2= 14.29, P < 0.01). The specificity, the positive predictive value and the sensitivity of cough associated with meals for GERC were 91.3%, 86.7% and 65.0%, respectively. Regurgitation associated symptom was present in 11 out of the 20 patients in the GERC group, not significantly different from that in the NGER group (8 out of 23 patients). Continuous 24 hour ambulatory esophageal pH measurement showed that reflux events were more common in upright [8.9 (range, 1.9 - 71.9)%] than in supine position [1.4 (range, 0 - 41.2)%] as well as at post-meal [20.2 (range, 2.1 - 84.2)%] than during meal period [1.95 (range, 0 - 51.6)%] (P < 0.01 and P < 0.05). CONCLUSION: Cough associated with having meals is of diagnostic value for GERC. The reflux events are more frequent when patients are awake, with upright position and after meals.