Factors influencing the responsiveness to inhaled glucocorticoids of patients with moderate-to-severe asthma

Obesity affects pulmonary function in Japanese adult patients with asthma, but not those without asthma

Obesity is associated with the severity of asthma, which is characterized by airway obstruction. Pulmonary function testing is one of the important examinations for evaluating airway obstruction. However, the impact of obesity on pulmonary function in patients with asthma is not fully understood. A total of 193 patients with asthma and 2159 patients without asthma who visited Saga University Hospital were investigated retrospectively. Obesity was defined as a body mass index (BMI) greater than 25 kg/m². Pulmonary functions including forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁) were compared between patients with and without asthma, focusing especially on obesity. FVC percent predicted and FEV₁ percent predicted were significantly lower in patients with asthma than in those without asthma (p = 0.03, < 0.01 respectively). In patients with asthma, FVC percent predicted and FEV₁ percent predicted were significantly lower in patients with obesity than in those without obesity (all p < 0.01). In addition, BMI was negatively correlated with FEV₁ (r =- 0.21, p = 0.003) and FVC (r = - 0.15, p = 0.04), along with the percent predicted. On multivariate analysis in patients with asthma, FVC (β [95% confidence interval] 0.12 [0.02-0.22], p = 0.02) and FEV₁ (0.13 [0.05-0.22], p < 0.01) were still significantly different between patients with and without obesity. However, these obesity-associated differences were not observed in patients without asthma. Obesity reduces pulmonary function, including FVC and FEV₁, in patients with asthma, but not in those without asthma.

May a different kinetic mode explain the high efficacy/safety profile of inhaled budesonide?

The claimed functional basis for ICSs in asthma and COPD is airway selectivity, attained by inhaling a potent, lipophilic compound with long local dissolution/absorption time. The development has been empirically based, resulting in five widely used ICSs. Among them, budesonide (BUD) deviates by being less lipophilic, leading to a more rapid systemic uptake with plasma peaks with some systemic anti-inflammatory activity. By this, BUD fits less well into the current pharmacological dogma of optimal ICS profile. In this review we compared the physicochemical, pharmacological and clinical properties of BUD, fluticasone propionate (FP) and fluticasone furoate (FF), representing different levels of lipophilicity, airway and systemic kinetics, focusing on their long-acting β2-agonist (LABA) combinations, in line with current GINA and GOLD recommendations. We are aware of the differences between formoterol (FORM) and the not rapid acting LABAs such as e.g. salmeterol and vilanterol but our comparisons are based on currently available combination products. A beclomethasone dipropionate (BDP)/FORM combination is also commented upon. Based on clinical comparisons in asthma and COPD, we conclude that the BUD/formoterol (BUD/FORM) combination is as effective and safe as the FP and FF combinations, and is in some cases even better as it can be used as "maintenance plus reliever therapy" (MART) in asthma and as maintenance in COPD. This is difficult to explain by current views of required ICS's/LABAs pharmacokinetic profiles. We propose that BUD achieves its efficacy by a combination of airway and systemic activity. The airway activity is dominating. The systemic activity contributes by plasma peaks, which are high enough for supportive anti-inflammatory actions at the blood and bone marrow levels but not sufficiently long to trigger a similar level of systemic adverse effects. This may be due to BUD's capacity to exploit a systemic differentiation mechanism as programmed for cortisol's various actions. This differentiation prospect can be reached only for an ICS with short plasma half-life. Here we present an alternative mode for an ICS to reach combined efficacy and safety, based on a poorly investigated and exploited physiological mechanism. A preference of this mode is broader versatility, due to that its straighter dose-response should allow a better adaptation to disease fluctuations, and that its rapid activity enables use as "anti-inflammatory reliever".

Quantitative comparison of dose-effect and time-course of fluticasone furoate and fluticasone propionate in adult and adolescent patients with persistent asthma: A systematic review and meta-analysis

This study aimed to quantitatively compare the efficacy of fluticasone furoate (FF) and fluticasone propionate (FP) in adolescents and adults with asthma. We searched the PubMed and EMBASE databases for placebo-controlled trials that met the inclusion criteria. Pharmacodynamic models were established to describe the time-course of the primary outcome (trough forced expiratory volume in the first second [FEV₁ ]). Secondary outcomes (asthma symptoms, quality of life and exacerbations) were also compared via a meta-analysis. A total of 14 articles were included in the analysis, involving 6640 subjects. The efficacy plateau of the two drugs could be reached in 2 weeks. The changes from the baseline in trough FEV₁ (95% CI) at week 2 of FF at 200 and 100 μg/day were 0.168 L (0.064-0.199) and 0.127 L (0.048-0.163), respectively. The changes from the baseline in trough FEV₁ (95% CI) at week 2 of FP at 1000, 500, 250 and 100 μg/day were 0.133 L (0.049-0.171), 0.127 L (0.043-0.163), 0.117 L (0.039-0.150) and 0.093 L (0.032-0.129), respectively. The efficacy of FP had reached a plateau at the maximum evaluated dose (1000 μg/day), while a plateau effect was not seen at the maximum evaluated dose of FF (200 μg/day). In terms of secondary outcomes, the relative effects of the two drugs relative to the placebo were similar and did not show obvious dose-effect relationships. In this study, the time-course and dose-effect characteristics of FP, FF and placebo were quantitatively evaluated, providing necessary quantitative information for asthma-related guidelines.

Association between TAAR6 polymorphisms and airway responsiveness to inhaled corticosteroids in asthmatic patients

BACKGROUND

Genetic polymorphisms may be responsible for the wide variation in response to inhaled corticosteroids in asthmatic patients. We had previously reported that one polymorphism rs7772821, located on the 3'-UTR of trace amine-associated receptor 6 (TAAR6), is significantly associated with percentile changes in the forced expiratory volume in 1 s (%ΔFEV1) after inhaled corticosteroid treatment in asthmatics using a genome-wide association study. The aim of the present study was to validate the association between 15 single-nucleotide polymorphisms (SNPs) on the TAAR6 and airway responsiveness to inhaled corticosteroids in the asthmatics.

METHODS

The %ΔFEV1 induced by 4 weeks' treatment with inhaled fluticasone propionate (1000 μg daily) was measured in 246 asthmatics. The 15 SNPs of TAAR6 were genotyped using a TaqMan assay. An association analysis between %ΔFEV1 and TAAR6 polymorphisms was carried out using a linear regression model controlling for age, sex, smoking status, presence of atopy, and baseline FEV1 as covariates.

RESULTS

Among the 15 SNPs and seven haplotypes of TAAR6, rs7772821 (T>G) on the 3'-UTR showed the strongest correlation with inhaled corticosteroid-induced %ΔFEV1 (Pcorr=0.002 in the codominant model, Pcorr=0.03 in the dominant model, Pcorr=0.01 in the recessive model). The %ΔFEV1 of the rs7772821T>G minor homozygotes (60.77%) was higher than that of patients harboring either the rs7772821 T/G or T/T genotypes (21.32 and 31.60%, respectively).

CONCLUSION

The TAAR6 rs7772821 polymorphism may be one of the important genetic factors for predicting the response to treatment with inhaled corticosteroids in asthmatics.

A Case of Sevoflurane Use during Pregnancy in the Management of Persistent Status Asthmaticus

Background

Sevoflurane is rarely used for the treatment of status asthmaticus. We report a case of sevoflurane hepatotoxicity in pregnancy with presentation similar to HELLP syndrome.

Case

A G2P1001 at 23 weeks in status asthmaticus presented with pCO2 > 130 and pH < 7. She was nonresponsive to traditional therapy. Sevoflurane was added for a 24 hr period. Respiratory status improved. Extubation occurred on day 12. Workup for preeclampsia spectrum disorders occurred due to maternal hypertension. Given the atypical presentation and hepatotoxicity, a liver biopsy was performed. Histologic features suggested drug induced hepatic injury. Liver function subsequently normalized. She delivered a term neonate without short-term complications.

Conclusion

The use of sevoflurane is a treatment option of status asthmaticus during pregnancy. Providers should be aware of the potential for hepatotoxicity.

Identification of airway mucosal type 2 inflammation by using clinical biomarkers in asthmatic patients

BACKGROUND

The Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study profiled patients with mild, moderate, and severe asthma and nonatopic healthy control subjects.

OBJECTIVE

We explored this data set to define type 2 inflammation based on airway mucosal IL-13-driven gene expression and how this related to clinically accessible biomarkers.

METHODS

IL-13-driven gene expression was evaluated in several human cell lines. We then defined type 2 status in 25 healthy subjects, 28 patients with mild asthma, 29 patients with moderate asthma, and 26 patients with severe asthma based on airway mucosal expression of (1) CCL26 (the most differentially expressed gene), (2) periostin, or (3) a multigene IL-13 in vitro signature (IVS). Clinically accessible biomarkers included fraction of exhaled nitric oxide (Feno) values, blood eosinophil (bEOS) counts, serum CCL26 expression, and serum CCL17 expression.

RESULTS

Expression of airway mucosal CCL26, periostin, and IL-13-IVS all facilitated segregation of subjects into type 2-high and type 2-low asthmatic groups, but in the ADEPT study population CCL26 expression was optimal. All subjects with high airway mucosal CCL26 expression and moderate-to-severe asthma had Feno values (≥35 ppb) and/or high bEOS counts (≥300 cells/mm³) compared with a minority (36%) of subjects with low airway mucosal CCL26 expression. A combination of Feno values, bEOS counts, and serum CCL17 and CCL26 expression had 100% positive predictive value and 87% negative predictive value for airway mucosal CCL26-high status. Clinical variables did not differ between subjects with type 2-high and type 2-low status. Eosinophilic inflammation was associated with but not limited to airway mucosal type 2 gene expression.

CONCLUSION

A panel of clinical biomarkers accurately classified type 2 status based on airway mucosal CCL26, periostin, or IL-13-IVS gene expression. Use of Feno values, bEOS counts, and serum marker levels (eg, CCL26 and CCL17) in combination might allow patient selection for novel type 2 therapeutics.

Monoclonal antibody therapy for the treatment of asthma and chronic obstructive pulmonary disease with eosinophilic inflammation

Eosinophils have been linked with asthma for more than a century, but their role has been unclear. This review discusses the roles of eosinophils in asthma and chronic obstructive pulmonary disease (COPD) and describes therapeutic antibodies that affect eosinophilia. The aims of pharmacologic treatments for pulmonary conditions are to reduce symptoms, slow decline or improve lung function, and reduce the frequency and severity of exacerbations. Inhaled corticosteroids (ICS) are important in managing symptoms and exacerbations in asthma and COPD. However, control with these agents is often suboptimal, especially for patients with severe disease. Recently, new biologics that target eosinophilic inflammation, used as adjunctive therapy to corticosteroids, have proven beneficial and support a pivotal role for eosinophils in the pathology of asthma. Nucala® (mepolizumab; anti-interleukin [IL]-5) and Cinquair® (reslizumab; anti-IL-5), the second and third biologics approved, respectively, for the treatment of asthma, exemplifies these new treatment options. Emerging evidence suggests that eosinophils may contribute to exacerbations and possibly to lung function decline for a subset of patients with COPD. Here we describe the pharmacology of therapeutic antibodies inhibiting IL-5 or targeting the IL-5 receptor, as well as other cytokines contributing to eosinophilic inflammation. We discuss their roles as adjuncts to conventional therapeutic approaches, especially ICS therapy, when disease is suboptimally controlled. These agents have achieved a place in the therapeutic armamentarium for asthma and COPD and will deepen our understanding of the pathogenic role of eosinophils.

GLCCI1 Variation Is Associated with Asthma Susceptibility and Inhaled Corticosteroid Response in a Chinese Han Population

BACKGROUND AND AIMS

GLCCI1 variations are found to be associated with response to glucocorticoid therapy in non-Hispanic white subjects with asthma. However, there are also other relevant studies that were not consistent with this finding. In this study we aimed to evaluate the association of GLCCI1 variations with asthma susceptibility and inhaled corticosteroid (ICS) response in a Chinese adult Han population.

METHODS

We genotyped 24 single nucleotide polymorphisms of GLCCI1 in 182 asthmatic patients and 180 healthy controls. Furthermore, we analyzed the association of GLCCI1 variations with ICS response in 30 mild-to-moderate asthmatics.

RESULTS

rs11976862 homozygote mutant genotype GG was nominally associated with increased asthma risk (OR = 2.435, 95% CI: 1.221-4.854, p = 0.01148, p(corr) = 0.0127). Recessive model of rs37972, rs37973 and rs11976862 showed that the rare alleles were correlated with less improvement in FEV1 after fluticasone treatment for 12 weeks (p = 0.004, p = 0.009 and p = 0.039, respectively). The GLCCI1 mRNA expression level decreased obviously in asthmatics than in healthy controls (0.037663 ± 0.0216833 vs. 0.046352 ± 0.0235812, p = 0.000). For asthmatics, GLCCI1 mRNA expression level significantly increased after fluticasone treatment for 12 weeks (0.067641 ± 0.031547 vs. 0.030048 ± 0.014613, p = 0.000). Moreover, changes of GLCCI1 mRNA expression were significantly related with rs37973 and rs11976862 in a recessive model (p = 0.014 and p = 0.033, respectively).

CONCLUSIONS

GLCCI1 variations are associated with asthma susceptibility and ICS response in a Chinese Han adult population. GLCCI1 variations may affect ICS response by modulating GLCCI1 expression.

Corticosteroid insensitivity in smokers with asthma : clinical evidence, mechanisms, and management

Corticosteroids are the most effective treatment for asthma, but the therapeutic response varies considerably between individuals. Several clinical studies have found that smokers with asthma are insensitive to the beneficial effects of short- to medium-term inhaled corticosteroid treatment compared with non-smokers with asthma. It is estimated that 25% of adults in most industrialized countries smoke cigarettes, and similar surveys amongst asthmatic individuals suggest that the prevalence of smoking in this grouping mirrors that found in the general population. Therefore, cigarette smoking is probably the most common cause of corticosteroid insensitivity in asthma. Cigarette smoking and asthma are also associated with poor symptom control and an accelerated rate of decline in lung function. The mechanism of corticosteroid insensitivity in smokers with asthma is currently unexplained but could be due to alterations in airway inflammatory cell phenotypes, changes in glucocorticoid receptor alpha/beta ratio, and/or reduced histone deacetylase activity. Smoking cessation should be encouraged in all smokers with asthma. Short-term benefits include improvements in lung function and asthma control. However, the numbers of sustained quitters is disappointingly small. Additional or alternative drugs need to be identified to treat those individuals who are unable to stop smoking or who have persistent symptoms following smoking cessation.

Asthma characteristics and biomarkers from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) longitudinal profiling study

BACKGROUND

Asthma is a heterogeneous disease and development of novel therapeutics requires an understanding of pathophysiologic phenotypes. The purpose of the ADEPT study was to correlate clinical features and biomarkers with molecular characteristics, by profiling asthma (NCT01274507). This report presents for the first time the study design, and characteristics of the recruited subjects.

METHODS

Patients with a range of asthma severity and healthy non-atopic controls were enrolled. The asthmatic subjects were followed for 12 months. Assessments included history, patient questionnaires, spirometry, airway hyper-responsiveness to methacholine, fractional exhaled nitric oxide (FENO), and biomarkers measured in induced sputum, blood, and bronchoscopy samples. All subjects underwent sputum induction and 30 subjects/cohort had bronchoscopy.

RESULTS

Mild (n = 52), moderate (n = 55), severe (n = 51) asthma cohorts and 30 healthy controls were enrolled from North America and Western Europe. Airflow obstruction, bronchodilator response and airways hyperresponsiveness increased with asthma severity, and severe asthma subjects had reduced forced vital capacity. Asthma control questionnaire-7 (ACQ7) scores worsened with asthma severity. In the asthmatics, mean values for all clinical and biomarker characteristics were stable over 12 months although individual variability was evident. FENO and blood eosinophils did not differ by asthma severity. Induced sputum eosinophils but not neutrophils were lower in mild compared to the moderate and severe asthma cohorts.

CONCLUSIONS

The ADEPT study successfully enrolled asthmatics across a spectrum of severity and non-atopic controls. Clinical characteristics were related to asthma severity and in general asthma characteristics e.g. lung function, were stable over 12 months. Use of the ADEPT data should prove useful in defining biological phenotypes to facilitate personalized therapeutic approaches.

Serum periostin: a novel biomarker for asthma management

Chronic airway inflammation and remodeling are fundamental features of asthma. Even with adequate inhaled corticosteroid (ICS) treatment, there are still patients who exhibit Th2/eosinophilic inflammation and develop airflow limitation, a functional consequence of airway remodeling. There are few biomarkers that are applicable in the clinical setting that reflect refractory Th2/eosinophilic inflammation and remodeling of the asthmatic airways. Therefore, establishing such biomarkers is essential for managing patients who suffer from these conditions. This review addresses the importance of serum periostin measurements by describing observations made in a KiHAC multicenter cohort with periostin used as a marker of pulmonary function decline and refractory Th2/eosinophilic inflammation in patients with asthma receiving long-term ICS treatment. Furthermore, serum periostin could be a companion diagnostic for targeted therapy against refractory Th2/eosinophilic inflammation. Finally, the distinct characteristics of serum periostin as compared to conventional biomarkers are addressed.

Genome-wide association study identifies ALLC polymorphisms correlated with FEV₁ change by corticosteroid

OBJECTIVES

Asthma can be suppressed by inhaled corticosteroids (ICS). However, response to ICS shows marked inter-individual variability. This study is aimed to identify the genetic variants associated with the change in the percentage of forced expiratory volume in 1second (%ΔFEV1) following ICS treatment.

METHODS

A genome-wide association study was performed in a Korean asthmatic cohort. To further investigate these genetic associations, 11 additional single-nucleotide polymorphisms (SNPs) on the allantoicase (ALLC) gene were selected from the HapMap database and genotyped in the same asthmatic patients in the follow-up study.

RESULTS

In a genome-wide study, we identified the lowest P-value in ALLC, but none of the SNPs met the genome-wide association criteria (P<1.0×10(-8)). However, among 25 SNPs on ALLC in the follow-up study, 6 variants showed significant associations with the mean %ΔFEV1 in the study subjects (P<3.73×10(-6)).

CONCLUSIONS

Although the associated signals could not overcome the genome-wide multiple correction due to small sample size (n=189), our results suggest that associated SNPs of ALLC might be genetic predictors of response to ICS, at least with respect to ΔFEV1 in Korean asthmatics.

Association of eosinophilic inflammation with FKBP51 expression in sputum cells in asthma

BACKGROUND

Airway eosinophilia is a predictor of steroid responsiveness in steroid-naïve asthma. However, the relationship between airway eosinophilia and the expression of FK506-binding protein 51 (FKBP51), a glucocorticoid receptor co-chaperone that plays a role in steroid insensitivity in asthma, remains unknown.

OBJECTIVE

To evaluate the relationship between eosinophilic inflammation and FKBP51 expression in sputum cells in asthma.

METHODS

The FKBP51 mRNA levels in sputum cells from steroid-naïve patients with asthma (n = 31) and stable asthmatic patients on inhaled corticosteroid (ICS) (n = 28) were cross-sectionally examined using real-time PCR. Associations between FKBP51 levels and clinical indices were analyzed.

RESULTS

In steroid-naïve patients, the FKBP51 levels were negatively correlated with eosinophil proportions in blood (r = -0.52) and sputum (r = -0.57), and exhaled nitric oxide levels (r = -0.42) (all p<0.05). No such associations were observed in patients on ICS. In steroid-naïve patients, improvement in forced expiratory volume in one second after ICS initiation was correlated with baseline eosinophil proportions in blood (r = 0.74) and sputum (r = 0.76) and negatively correlated with FKBP51 levels (r = -0.73) (all p<0.0001) (n = 20). Lastly, the FKBP51 levels were the lowest in steroid-naïve asthmatic patients, followed by mild to moderate persistent asthmatic patients on ICS, and the highest in severe persistent asthmatic patients on ICS (p<0.0001).

CONCLUSIONS

Lower FKBP51 expression in sputum cells may reflect eosinophilic inflammation and glucocorticoid responsiveness in steroid-naïve asthmatic patients.

Association between WDR21A polymorphisms and airway responsiveness to inhaled corticosteroids in asthmatic patients

OBJECTIVE

Genetic polymorphism is partially responsible for the wide variation in the response of moderate-to-severe asthmatic patients to inhaled corticosteroids. The goal of the study was to examine polymorphisms in WDR21A, which encodes a putative glucocorticoid receptor (GR)-interacting protein, for their possible association with corticosteroid responsiveness.

METHODS

The change in forced expiratory volume in 1 s [FEV(1) (ΔFEV(1))] induced by 4 weeks of inhaled treatment with fluticasone propionate (1000 µg daily) was measured in 230 asthmatic patients. Fifteen single nucleotide polymorphisms (SNPs) of WDR21A were genotyped using a TaqMan assay, and 11 SNPs were used for further analysis. WDR21A transcripts were analyzed for variant splicing using reverse transcriptase-PCR. The WDR21A protein structure was predicted using a template-based modeling method and docked to a GR using Zdock.

RESULTS

Of the 11 SNPs and three haplotypes of WDR21A analyzed, only the intronic SNP -10073G>C appeared to affect ΔFEV(1). The ΔFEV(1) of the -10073C/C homozygous genotype was twice that of the -10073G/G and -10073C/G genotypes (P(corr)=0.04 in recessive model). No splicing variant of WDR21A was observed, regardless of genotype. The predicted WDR21A protein structure was similar to the Gβ(1) protein structure (template modeling-score=0.93).

CONCLUSION

The minor allele -10073C of WDR21A may induce a good response to inhaled corticosteroids possibly through competition with the Gβ(1) proteins for binding to GRs.

Steroid response in refractory asthmatics

Inhaled glucocorticosteroids are currently the most effective anti-inflammatory controller medications for treating persistent asthma. The efficacies of glucocorticoids include reducing asthma symptoms, reducing exacerbation frequency, improving quality of life, improving lung function, decreasing airway hyperresponsiveness, controlling airway inflammation, and reducing mortality. However, the treatment response to glucocorticosteroids in asthmatics varies, and certain subtypes of asthma, such as refractory asthma, respond poorly to high-dose inhaled glucocorticoid and systemic steroids. The medical costs of treating refractory asthmatics represent about 50% of the total healthcare cost for asthma. A thorough understanding of the mechanisms of glucocorticoid action, patient responses to glucocorticoids, and steroid resistance observed in refractory asthmatics is necessary for the targeted development of therapeutic drugs. This review discusses the characteristics of severe refractory asthmatics and the mechanisms of steroid response and resistance in asthma treatment.

Application of proteomics in asthma research

Bronchial asthma is caused by allergic airway inflammation, resulting in reversible airway obstruction, characterized by airway hyper-responsiveness, bronchoconstriction, increased mucus secretion and an increase in lung vessel permeability. The pathophysiological changes in asthma have been attributed to the altered expression of biologically plausible proteins associated with transcriptional pathways, inflammatory mediators, chemokines, cytokines, apoptosis and cell proliferation. Such multifactorial diseases characteristically involve an interplay of many genetic variations of molecular and biochemical pathways and their interactions with environmental factors. The complex nature of the asthma phenotype, together with genetic heterogeneity and environmental influences, has made it difficult to uncover the aspects that underlie this common disease. Recently, genomic and proteomic technologies have been developed to identify associations between genes, proteins and disease. This approach, called 'omics biology', aims to recognize early onset of disease, institute preventive treatment and identify new molecular targets for novel drugs in multifactorial diseases. This article reviews examples of how proteomic technology can be used to find asthma marker proteins (from the cell model to clinical samples). Identification of protein changes in different stages of asthma could provide further insights into the complex molecular mechanisms involved in this disease. These studies provide new insights for finding novel pathological mediators and biomarkers of asthma.

Pharmacogenetic study of the effects of NK2R G231E G>A and TBX21 H33Q C>G polymorphisms on asthma control with inhaled corticosteroid treatment

BACKGROUND AND OBJECTIVE

Inhaled corticosteroids (ICS) are widely used as maintenance regimens for asthma patients. However, response to ICS shows marked inter-individual variability. Genetic factors have been shown to be potential predictors of responsiveness to ICS. We aimed to evaluate those pharmacogenetic effects on asthma control in further detail.

METHODS

Fifty-three mild-to-moderate asthmatics were genotyped for four genetic polymorphisms of four genes: beta2-adrenergic receptor (ADRB2), adenylate cyclase 9 (ADCY9), neurokinin receptor 2 (NK2R) and T-box 21 (TBX21). The principal clinical outcome was the achievement of asthma control, as assessed using the Global Initiative for Asthma (GINA) guidelines. During treatment with ICS, the forced expiratory volume in 1 second (FEV(1)), maximal mid-expiratory flow (MMEF) and peak expiratory flow rate (PEFR) were monitored every 4 weeks and twice daily.

RESULTS

Forty-eight of the 53 patients with asthma were in a controlled or partly controlled state after 12 weeks of treatment with ICS, whereas five asthmatics were in an uncontrolled state even after active treatment. Of the four genetic polymorphisms examined, NK2R G231E G>A and TBX21 H33Q C>G were significantly associated with asthma control status (P = 0.041 and P = 0.006). The subjects with wild-type alleles at each polymorphism showed a significant association with the well-controlled or partly controlled state, as compared to those with mutant alleles. At 5-12 weeks after ICS treatment, the NK2R G231E G>A was associated with therapeutic response to ICS, as reflected by improvement in predicted FEV(1)%.

CONCLUSION

Our results suggest that NK2R G231E G>A and TBX21 H33Q C>G are genetic predictors of response to ICS, at least with respect to asthma control status and changes in FEV(1)%, in Korean patients with asthma. Further prospective validation of those associations is necessary.

Asthmatics without rhinitis have more fixed airway obstruction than those with concurrent rhinitis

PURPOSE

Rhinitis and asthma usually occur together. There are increasing evidences that allergic rhinitis (AR) may influence the clinical course of asthma. The aim of this study is to evaluate clinical parameters and therapeutic response in patients with between asthma and asthma with AR.

METHODS

Four-hundred eighty-five patients with asthma and 428 asthmatics with AR, who had lesser than 50 years old and smoked less than 10 pack-years were recruited. We compared FEV1 and FEV1/FVC following bronchodilator, atopy, IgE, emphysema on HRCT, and aspirin intolerance between two groups. Also we compared physiologic fixed airway obstruction defined using FEV1/FVC and FEV1 less than 75% following anti-asthmatic drug for 1 year.

RESULTS

46.8% (428/913) asthmatics suffered from AR. There were no differences of total IgE, body mass index, PC20, sputum eosinophils and emphysema on HRCT between two groups. The age in asthmatics was higher than that in those with AR. FEV1/FVC was lower in asthmatics than in those with AR. The prevalence of atopy was higher in asthmatics with AR than in asthmatics. Aspirin intolerance was higher in asthmatics with AR than in asthmatics (42/218 vs 13/109, P=0.001). Fixed airway obstruction were more observed in asthmatics than in those with AR (39/319 vs 28/355, P=0.001) after anti-asthmatic drug for 1 year.

CONCLUSIONS

Asthmatics with AR had more atopy and aspirin intolerance than asthmatics, and asthmatics had poor response to anti-inflammatory drugs than those with concurrent rhinitis, indicating that asthmatics have more fixed airway obstruction than those with concurrent rhinitis.

Effects of glucocorticoids on the neutrophil count: a cohort study among hospitalized patients

BACKGROUND

Systemic glucocorticoids are often used in clinical practice for a large variety of indications. Clinical observations have shown that patients using glucocorticoids often have higher neutrophil counts. Debate remains whether this observed neutrophilia is associated with glucocorticoid use or that other factors, like disease and severity of disease, should be considered. The objective of this study was to investigate the effect of systemic glucocorticoids on the absolute neutrophil count in hospitalized patients.

METHODS

A cohort study was conducted using data from the Utrecht Patient Oriented Database which comprises clinical data of patients of the University Medical Center Utrecht. We identified all adult patients, hospitalized in 2005 with at least two blood samples for hematological testing during admission and compared in-hospital glucocorticoid use with non-use.

RESULTS

A total of 809 glucocorticoid users and 2658 non-users were included in the study with comparable neutrophil counts at admission (8.2.10(9)/l for glucocorticoid users and 8.0.10(9)/l for non-users). Overall analysis showed a slight association between glucocorticoid use and an increase in neutrophil count (RR 1.3; 95% CI 1.1-1.5). However, within diagnostic subgroups there was no increase in neutrophil count in glucocorticoid users. Furthermore, among all no dose response relationship, no effect of time between the two samples, and no effect of anti-inflammatory/sodium retaining potency was found.

CONCLUSION

Observed neutrophilia in users of systemic glucocorticoids is probably associated with underlying disease, rather than glucocorticoid use itself.

Asthma in smokers: challenges and opportunities

PURPOSE OF REVIEW

Cigarette smoking in asthma is associated with poor symptom control and reduced sensitivity to corticosteroids. We summarize recent evidence supporting the adverse effects of smoking in asthma and consider strategies to manage these patients.

RECENT FINDINGS

Smokers have more severe symptoms and are more likely to be admitted to hospital due to poorly controlled asthma compared with nonsmokers with asthma. Possible causes of reduced sensitivity to inhaled corticosteroids in smokers with asthma are noneosinophilic airway inflammation, impaired glucocorticoid receptor function, and/or reduced histone deacetylase activity. Smoking cessation improves asthma control, but quit rates are low. The optimal drug therapy for smokers with asthma is not established due, in part, to the small number of clinical trials performed in these patients. Preliminary data, however, suggest that leukotriene-receptor antagonists may have a beneficial effect in smokers with mild asthma.

SUMMARY

Cigarette smoking in asthma is a risk factor for poor asthma control and reduced sensitivity to corticosteroids. Every effort should be made to encourage individuals with asthma who smoke to quit. Clinical trials are required to identify therapies that restore corticosteroid sensitivity or directly improve symptom control in individuals with asthma who are unable to stop smoking.

Treating patients with respiratory disease who smoke

The high prevalence of cigarette smoking in patients with respiratory disease puts them at risk of developing clinically important drug interactions. Cigarette smoking reduces the therapeutic response to certain drugs such as theophyllines through the induction of hepatic cytochrome P450 isoenzymes. Smokers with asthma and patients with COPD have reduced sensitivity to corticosteroids, possibly due to non-eosinophilic airway inflammation, altered glucocorticoid receptor activity or reduced histone deacetylase activity. Although all smokers should be encouraged to stop smoking, there is limited information on the influence of smoking cessation on the therapeutic and anti-inflammatory effects of a number of the drugs used in the treatment of respiratory disease.

Correlation between the Korean version of Asthma Control Test and health-related quality of life in adult asthmatics

The Asthma Control Test (ACT) is a patient-completed questionnaire developed to assess asthma control. Health-related quality of life (HRQL) in asthmatics has shown relatively low correlations with parameters of asthma control and the relationship between the ACT and HRQL in asthmatics is yet unclear. Because revalidations of translated versions of questionnaires are critical for its utilization, we first sought to validate the Korean version of ACT and then to evaluate the relationship between the ACT and HRQL. Patients (n=117) completed the ACT and asthma-related quality of life questionnaire (AQLQ) at 3 physician visits. Pulmonary function was measured and an asthma specialist rated asthma control. The Korean version of ACT was found to be reliable, valid, and responsive to changes in asthma control over time up to three consecutive visits. ACT scores correlated significantly (p=0.001) with symptoms domain (r=0.72), activity domain (r=0.65), emotional domain (r=0.69), and environmental domain (r=0.67) of AQLQ. In conclusion, the Korean version of the ACT was found to be a reliable and valid tool for measuring asthma control, and to correlate well with AQLQ scores. Moreover, the ACT was responsive to changes in AQLQ scores over time.

Determinants of response to fluticasone propionate and salmeterol/fluticasone propionate combination in the Gaining Optimal Asthma controL study

BACKGROUND

During the Gaining Optimal Asthma controL study, 3416 patients with uncontrolled asthma were randomized to receive salmeterol/fluticasone propionate combination (SFC) or fluticasone propionate (FP) for 1 year. Approximately two thirds of patients achieved well-controlled (WC) asthma, and one third continued to have asthma that was not well controlled (NWC).

OBJECTIVE

This analysis aimed to (1) identify factors influencing treatment response and (2) assess the clinical benefits of SFC and FP in patients with NWC asthma.

METHODS

Logistic regression analysis was used to investigate whether covariates influenced the achievement of at least WC asthma in the study population. In patients with NWC asthma, predefined criteria were used to assess improvements in 6 clinical outcomes.

RESULTS

Factors affecting the probability of having NWC asthma included smoking status (current vs never: odds ratio [OR], 2.757; 95% CI, 2.061-3.689; P < .0001; former vs never: OR, 1.274; 95% CI, 1.031-1.574; P = 0.0273), sex (women vs men: OR, 0.652; 95% CI, 0.527-0.806; P < .0001), history of inhaled corticosteroid use (no history vs history: OR, 0.546; 95% CI, 0.437-0.683; P < .0001), and treatment (FP vs SFC: OR, 1.972; 95% CI, 1.686-2.308; P < .0001). Of patients with NWC asthma, 86% to 96% showed improvements in 1 or more clinical outcomes.

CONCLUSION

It is imperative for good asthma control that patients stop smoking. Patients who did not have at least WC asthma demonstrated clinical improvements in individual asthma outcomes.

CLINICAL IMPLICATIONS

Although not all patients can achieve guideline-defined control, long-term treatment with SFC or FP is associated with clinical improvements in nearly all patients, regardless of smoking history or inhaled corticosteroid use.

Acute severe asthma: recent advances

PURPOSE OF REVIEW

Acute severe asthma is challenging to the clinician both in terms of recognition and appropriate treatment. About 30% of these episodes need admission to the medical intensive care unit with a mortality of 8%. Relapse rates vary from 7 to 15% depending on how well the patient is managed. The purpose of this review is to discuss recent advances in identification of risk factors, pathophysiology and management of acute severe asthma.

RECENT FINDINGS

Although the exact mechanism for acute severe asthma is unclear, some that are implicated include inflammation, airway remodeling and downregulation of beta-receptors. None of the environmental factors have been clearly related to the development of near fatal attacks. Genetic polymorphisms have been associated with severe asthma. Lack of steroid responsiveness has been linked to severe asthma attacks. Chemokines and basement membrane changes characteristic of severe asthma are reported in a few studies. Lack of symptom perception in a certain group of patients with acute severe asthma leads to delayed interventions. Specific treatment modalities and ventilator management is reviewed.

SUMMARY

Severe asthma is a phenotype of asthma with variable pathology and clinical presentation. Early recognition and timely intervention is needed to prevent significant mortality and morbidity.

The mechanisms, diagnosis, and management of severe asthma in adults

There has been a recent increase in the prevalence of asthma worldwide; however, the 5-10% of patients with severe disease account for a substantial proportion of the health costs. Although most asthma cases can be satisfactorily managed with a combination of anti-inflammatory drugs and bronchodilators, patients who remain symptomatic despite maximum combination treatment represent a heterogeneous group consisting of those who are under-treated or non-adherent with their prescribed medication. After excluding under-treatment and poor compliance, corticosteroid refractory asthma can be identified as a subphenotype characterised by a heightened neutrophilic airway inflammatory response in the presence or absence of eosinophils, with evidence of increased tissue injury and remodelling. Although a wide range of environmental factors such as allergens, smoking, air pollution, infection, hormones, and specific drugs can contribute to this phenotype, other features associated with changes in the airway inflammatory response should be taken into account. Aberrant communication between an injured airway epithelium and underlying mesenchyme contributes to disease chronicity and refractoriness to corticosteroids. The importance of identifying underlying causative factors and the recent introduction of novel therapeutic approaches, including the targeting of immunoglobulin E and tumour necrosis factor alpha with biological agents, emphasise the need for careful phenotyping of patients with severe disease to target improved management of the individual patient's needs.

What are the best estimates of pediatric asthma control?

PURPOSE OF REVIEW

To evaluate asthma outcome measures in the face of the variable nature of asthma. The outcome measures are divided into objective and subjective clinical measures, humanistic measures such as quality of life, and costs of asthma control.

RECENT FINDINGS

Objective measures of asthma include those traditionally used such as spirometry, peak expiratory flow rate, and airway hyperresponsiveness. Recently, more attention has been geared towards markers of inflammation including exhaled nitric oxide and sputum eosinophils. Subjective measures of asthma control include patient-derived parameters such as number of wheezing episodes, nocturnal symptoms, exercise-induced symptoms, short-acting beta-agonist use, steroid bursts, emergency-department visits, and hospitalizations. Asthma-related quality of life is related to asthma morbidity, and patients with better baseline quality of life have improved outcomes. Asthma-related costs include direct costs mostly comprised of hospitalizations and emergency-room visits, and indirect costs including school absenteeism.

SUMMARY

There is no ideal outcome measure for evaluating pediatric asthma control, but each of these outcome measures must be used together to evaluate a patient at each outpatient visit. Patient-centered measures of asthma control must also be further incorporated into office visits for improved asthma management.