New targets for modifying mast cell activation in asthma

Cysteinyl leukotriene 1 receptor expression associated with bronchial inflammation in severe exacerbations of COPD

BACKGROUND

Cysteinyl leukotriene 1 (CysLT1) receptor expression is known to be increased in the airway mucosa of patients with asthma, especially during exacerbations; however, nothing is known of its expression in COPD.

METHODS

We applied immunohistochemistry and in situ hybridization to endobronchial biopsies to determine inflammatory cell CysLT1 receptor protein and mRNA expression in the following: (1) 15 nonsmoker control subjects (NSC), (2) 16 smokers with moderate to severe COPD in its stable phase (S-COPD), and (3) 15 smokers with COPD hospitalized for a severe exacerbation (SE-COPD).

RESULTS

The total number of bronchial mucosal inflammatory cells (CD45+) and those expressing CysLT1 receptor protein were significantly greater in SE-COPD (CysLT1 receptor protein: median [range] = 139 [31-634]) as compared with S-COPD (32 [6-114]) or NSC (16 [4-66]) (P < .001 for both). CysLT1 receptor gene expression showed similar differences. A greater proportion of CD451 cells expressed CysLT1 receptor protein in SE-COPD (median [range] = 22% [8-81]) compared with S-COPD (10% [4-32]) (P < .03) or NSC (7% [1-19]) (P < .002). In SE-COPD, the relative frequencies of CysLT1 receptor-expressing cells were as follows: tryptase1 mast cells > CD681 monocytes/macrophage > neutrophils > CD201 B lymphocytes = EG21 eosinophils. Moreover, there were positive correlations between the numbers of cells expressing CysLT1 receptor protein and the numbers of CD451 cells (r = 0.78; P < .003) and tryptase1 mast cells (r = 0.62; P < .02).

CONCLUSIONS

Bronchial mucosal CysLT1 receptor-positive inflammatory cells are present in the bronchial mucosa in COPD in greatest number in those experiencing a severe exacerbation.

A systematic review of statin efficacy in asthma

BACKGROUND

Statins are known for their lipid-lowering effects and role in the treatment of atherosclerotic disease. They also have anti-inflammatory and immunomodulatory properties which could benefit asthma patients. We aimed to review the evidence on the efficacy and safety of statins in asthma-related outcomes.

METHODS

A systematic review of the literature on the effects of statins on asthma-related outcomes was performed following a search of the National Guideline Clearinghouse, Cochrane, Scopus, and Pubmed Medline databases in January 2012. Randomized controlled trials (RCTs) and observational studies (cohort/case-control design) assessing the effect of statins were included. The Grading of Recommendations Assessment Development and Evaluation (GRADE) system was used to rate the levels of evidence and grade of recommendation.

RESULTS

Twenty-four of the 379 articles retrieved electronically and one article identified by hand search were selected for full-text scrutiny by two independent reviewers. Eight studies were included: six RCTs and two observational studies. Statin use was not associated with consistent, statistical significant improvements in patient outcomes (asthma control, quality of life, steroid-sparing effects) or disease outcomes (lung function, airway responsiveness), and all the studies analyzed had low or very low quality of evidence. Inflammatory outcome improvements were observed in mild allergic asthma.

CONCLUSION

Statins do not seem to have any additional benefit in asthma control or steroid-sparing effect in asthma treatment. Considering the prevalence of both statin use and asthma, more, better designed studies are needed to determine whether a specific phenotype of asthma exists that could benefit from statin treatment.

Evaluation of atorvastatin for the treatment of patients with asthma: a double-blind randomized clinical trial

Purpose

Statins are known as cholesterol-lowering agents, but have been suggested for the treatment of asthma because of their anti-inflammatory effects. In this study, the potential therapeutic effects of atorvastatin were investigated in asthmatic patients.

Methods

A total of 62 patients with persistent mild to moderate asthma who presented at asthma clinics of Arak University of Medical Sciences were recruited in a double-blind randomized clinical trial. The asthma clinical control score was assessed based on the standardized Asthma Control Test. Lung volume, i.e., percentage of forced expiratory volume in one second (FEV1%) and percentage of forced vital capacity (FVC%), and peripheral blood eosinophils were also measured. The intervention group was treated with atorvastatin 40 mg per day for 8 weeks, while the control group received a placebo. Asthma controller treatments were not changed. At the beginning and end of the study, serum cholesterol and triglyceride levels were measured to evaluate adherence of the patients to the treatment.

Results

The asthma control score did not significantly differ between the intervention and control groups (P=0.06). Difference in FEV1%, FVC%, and blood eosinophil count between the intervention and control groups were not statistically significant (P>0.05). The differences in post-treatment cholesterol and low-density lipoprotein cholesterol levels were significant (P<0.05).

Conclusions

Our study shows that atorvastatin is not effective in the treatment of persistent mild to moderate asthma.