Severity assessment in asthma: An evolving concept

Concordance of provider chart notation and guideline-based classification of asthma severity

OBJECTIVE

To evaluate concordance of asthma severity classification via physician chart notation compared with guideline-based criteria in adolescents with diagnosed asthma.

METHODS

Of 284 urban primary care and subspecialty clinic patients aged 13-18 years approached through convenience sampling, 203 surveys were completed (RR = 71.5%). We assessed concordance with sensitivity, specificity, and positive predictive values; overall agreement was evaluated with weighted kappa coefficients and McNemar's test.

RESULTS

When considering prescribed treatment according to NAEPP guidelines as a gold standard, the sensitivity for chart notation was very good for intermittent (95%) and less for non-intermittent severity ratings (51%, 58%, and 67% for moderate, severe, and mild persistent asthma, respectively). Overall agreement between chart notation and guideline-based asthma criteria ranged from fair-to-good for mild- (k = 0.36), moderate- (k = 0.44), and severe-persistent severity (k = 0.66). Although the agreement for intermittent severity was highest (k = 0.88), it did not significantly differ by between the two classifications (p ≥ 0.05).

CONCLUSIONS

Concordance for all non-intermittent asthma severity classifications varied between physician and medication-driven 2007 NAEPP guideline classifications in an ethnically diverse urban adolescent patient sample. Physicians should remain aware of the potential for this discordance and refer to the guidelines to classify and treat adolescents with asthma.

Discerning asthma endotypes through comorbidity mapping

Asthma is a heterogeneous, complex syndrome, and identifying asthma endotypes has been challenging. We hypothesize that distinct endotypes of asthma arise in disparate genetic variation and life-time environmental exposure backgrounds, and that disease comorbidity patterns serve as a surrogate for such genetic and exposure variations. Here, we computationally discover 22 distinct comorbid disease patterns among individuals with asthma (asthma comorbidity subgroups) using diagnosis records for >151 M US residents, and re-identify 11 of the 22 subgroups in the much smaller UK Biobank. GWASs to discern asthma risk loci for individuals within each subgroup and in all subgroups combined reveal 109 independent risk loci, of which 52 are replicated in multi-ancestry meta-analysis across different ethnicity subsamples in UK Biobank, US BioVU, and BioBank Japan. Fourteen loci confer asthma risk in multiple subgroups and in all subgroups combined. Importantly, another six loci confer asthma risk in only one subgroup. The strength of association between asthma and each of 44 health-related phenotypes also varies dramatically across subgroups. This work reveals subpopulations of asthma patients distinguished by comorbidity patterns, asthma risk loci, gene expression, and health-related phenotypes, and so reveals different asthma endotypes.

Quantitative CT Characteristics of Cluster Phenotypes in the Severe Asthma Research Program Cohorts

Background Clustering key clinical characteristics of participants in the Severe Asthma Research Program (SARP), a large, multicenter prospective observational study of patients with asthma and healthy controls, has led to the identification of novel asthma phenotypes. Purpose To determine whether quantitative CT (qCT) could help distinguish between clinical asthma phenotypes. Materials and Methods A retrospective cross-sectional analysis was conducted with the use of qCT images (maximal bronchodilation at total lung capacity [TLC], or inspiration, and functional residual capacity [FRC], or expiration) from the cluster phenotypes of SARP participants (cluster 1: minimal disease; cluster 2: mild, reversible; cluster 3: obese asthma; cluster 4: severe, reversible; cluster 5: severe, irreversible) enrolled between September 2001 and December 2015. Airway morphometry was performed along standard paths (RB1, RB4, RB10, LB1, and LB10). Corresponding voxels from TLC and FRC images were mapped with use of deformable image registration to characterize disease probability maps (DPMs) of functional small airway disease (fSAD), voxel-level volume changes (Jacobian), and isotropy (anisotropic deformation index [ADI]). The association between cluster assignment and qCT measures was evaluated using linear mixed models. Results A total of 455 participants were evaluated with cluster assignments and CT (mean age ± SD, 42.1 years ± 14.7; 270 women). Airway morphometry had limited ability to help discern between clusters. DPM fSAD was highest in cluster 5 (cluster 1 in SARP III: 19.0% ± 20.6; cluster 2: 18.9% ± 13.3; cluster 3: 24.9% ± 13.1; cluster 4: 24.1% ± 8.4; cluster 5: 38.8% ± 14.4; P < .001). Lower whole-lung Jacobian and ADI values were associated with greater cluster severity. Compared to cluster 1, cluster 5 lung expansion was 31% smaller (Jacobian in SARP III cohort: 2.31 ± 0.6 vs 1.61 ± 0.3, respectively, P < .001) and 34% more isotropic (ADI in SARP III cohort: 0.40 ± 0.1 vs 0.61 ± 0.2, P < .001). Within-lung Jacobian and ADI SDs decreased as severity worsened (Jacobian SD in SARP III cohort: 0.90 ± 0.4 for cluster 1; 0.79 ± 0.3 for cluster 2; 0.62 ± 0.2 for cluster 3; 0.63 ± 0.2 for cluster 4; and 0.41 ± 0.2 for cluster 5; P < .001). Conclusion Quantitative CT assessments of the degree and intraindividual regional variability of lung expansion distinguished between well-established clinical phenotypes among participants with asthma from the Severe Asthma Research Program study. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Verschakelen in this issue.

Elevated levels of interleukin-33 are associated with allergic and eosinophilic asthma

IL-33 is a recently discovered cytokine which plays an important role in asthma pathogenesis.

AIM

To evaluate serum IL-33 in patients with asthma and healthy controls, and to evaluate the association of IL-33 with different asthma phenotypes.

METHODS

Patients with asthma (n = 115) and healthy subjects (n = 85) were included in the study. Subjects with asthma were divided into groups according to their phenotype: allergic/non-allergic, eosinophilic/non-eosinophilic, obese/non-obese and severity according to GINA (mild, moderate and severe). The concentration of IL-33 in serum was measured by standardized enzyme-linked immunosorbent assay.

RESULTS

The level of IL-33 was significantly higher in patients with asthma when compared to healthy subjects (672.73 ± 104.47 pg/mL vs 268.52 ± 27.56 pg/mL, P < 0.05). IL-33 was also higher in the allergic asthma group patients when compared to non-allergic asthmatics (844.61 ± 152.08 pg/mL vs 369.56 ± 77.94 pg/mL, P < 0.05). There was a significantly higher serum IL-33 level in the eosinophilic asthma group when compared to the group of non-eosinophilic asthma patients (1001.10 ± 199.11 pg/mL vs 337.49 ± 72.68 pg/mL, P < 0.01). We did not find a significant difference in serum IL-33 level between different asthma severity groups, obese and non-obese asthmatics.

CONCLUSION

IL-33 is increased in asthma patients, particularly in some phenotypes: allergic asthma and eosinophilic asthma.

A Transcriptome-driven Analysis of Epithelial Brushings and Bronchial Biopsies to Define Asthma Phenotypes in U-BIOPRED

RATIONALE

Asthma is a heterogeneous disease driven by diverse immunologic and inflammatory mechanisms.

OBJECTIVES

Using transcriptomic profiling of airway tissues, we sought to define the molecular phenotypes of severe asthma.

METHODS

The transcriptome derived from bronchial biopsies and epithelial brushings of 107 subjects with moderate to severe asthma were annotated by gene set variation analysis using 42 gene signatures relevant to asthma, inflammation, and immune function. Topological data analysis of clinical and histologic data was performed to derive clusters, and the nearest shrunken centroid algorithm was used for signature refinement.

MEASUREMENTS AND MAIN RESULTS

Nine gene set variation analysis signatures expressed in bronchial biopsies and airway epithelial brushings distinguished two distinct asthma subtypes associated with high expression of T-helper cell type 2 cytokines and lack of corticosteroid response (group 1 and group 3). Group 1 had the highest submucosal eosinophils, as well as high fractional exhaled nitric oxide levels, exacerbation rates, and oral corticosteroid use, whereas group 3 patients showed the highest levels of sputum eosinophils and had a high body mass index. In contrast, group 2 and group 4 patients had an 86% and 64% probability, respectively, of having noneosinophilic inflammation. Using machine learning tools, we describe an inference scheme using the currently available inflammatory biomarkers sputum eosinophilia and fractional exhaled nitric oxide levels, along with oral corticosteroid use, that could predict the subtypes of gene expression within bronchial biopsies and epithelial cells with good sensitivity and specificity.

CONCLUSIONS

This analysis demonstrates the usefulness of a transcriptomics-driven approach to phenotyping that segments patients who may benefit the most from specific agents that target T-helper cell type 2-mediated inflammation and/or corticosteroid insensitivity.

Age of asthma onset and vulnerability to ambient air pollution: an observational population-based study of adults from Southern Taiwan

Background

Late-onset asthma (onset > 12 years) is pathologically distinct from early-onset asthma. The mechanism of air pollution is not a classic allergic inflammation and could have differential effect on late-onset and early-onset asthma. However, there is little known about the association of onset-age phenotype and air pollution. In this population-based study, we aimed to determine the association of asthma severity outcomes and air pollution regarding age at onset of asthma.

Methods

In 2004, we conducted a cross-sectional questionnaire survey about respiratory health among schoolchildren’s parents randomly selected from 94 of 816 elementary and middle schools in southern Taiwan. Participants ever having typical asthma symptoms were enrolled. We used kriging method to estimate individual exposure to ambient air pollution in the preceding year before the year of asthma severity survey. Ordered logistic regression was used to determine the association of exposure and asthma severity scores. Age at asthma onset of 12 years was used as a cut-off to define early- or late-onset asthma.

Results

The study surveyed 35,682 participants. Data from 23,551 participants remained satisfactory with a response rate of 66 %. Among 20,508 participants aged 26–50 years, 703 questionnaire-determined asthmatics were identified and included for analysis. Using the median of PM₁₀ (66 μg/m³) as a cut-off, those exposed to higher PM₁₀ were more likely to have higher severity scores (OR = 1.74; 95 % CI, 1.13 – 2.70) only for asthmatics with asthma onset at > 12 years.

Conclusions

In adulthood, exposure to PM₁₀ has a greater effect on late-onset asthma than early-onset asthma and deserves greater attention among ambient air pollutants.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0218-0) contains supplementary material, which is available to authorized users.

Different Severity and Severity Predictors in Early-Onset and Late-Onset Asthma: A Taiwanese Population-Based Study

BACKGROUND

Late-onset asthma has been shown to be more severe than early-onset asthma in clinic-based studies. However, population-based studies are scarce, and the predictors of severity have been less studied.

OBJECTIVES

To determine asthma severity and severity predictors regarding age at onset.

METHODS

A cross-sectional questionnaire survey was conducted among parents of children from 94 schools in Taiwan in 2004. Asthma severity was defined as short-acting β2-agonist (SABA), inhaled corticosteroid (ICS) and health care use in the last year. Information on age at onset, demographics, heredity and home exposure was collected. Ordered logistic or logistic regression was used for determining the associations between risk factors and severity.

RESULTS

Participants aged 26-50 years were included, resulting in 21,057 (67.8%) participants. Among them, 449 reported ever having had physician-diagnosed asthma, and 381 of those subjects answered the question on age at asthma onset. The risks of rescue SABA, ICS and health care use were generally higher among late-onset (13-50 years) than early-onset (0-12 years) asthmatics. Use of SABA and health care increased from childhood-onset, adolescent- or young adult-onset to adult-onset asthma. Allergic rhinitis was positively associated with SABA use (OR, 9.08; 95% CI, 1.06-77.99) and ICS use (OR, 5.08; 95% CI, 1.47-17.52) in early-onset asthma. Dehumidifier use was negatively associated with SABA use (OR, 0.50; 95% CI, 0.29-0.87) and ICS use (OR, 0.38; 95% CI, 0.19-0.78) in late-onset asthma.

CONCLUSIONS

In adults, late-onset asthma was more severe than early-onset asthma. Severity, as indicated by SABA and ICS use, was positively associated with allergic rhinitis in early-onset asthma and negatively associated with dehumidifier use in late-onset asthma.

Childhood asthma clusters and response to therapy in clinical trials

BACKGROUND

Childhood asthma clusters, or subclasses, have been developed by computational methods without evaluation of clinical utility.

OBJECTIVE

To replicate and determine whether childhood asthma clusters previously identified computationally in the Severe Asthma Research Program (SARP) are associated with treatment responses in Childhood Asthma Research and Education (CARE) Network clinical trials.

METHODS

A cluster assignment model was determined by using SARP participant data. A total of 611 participants 6 to 18 years old from 3 CARE trials were assigned to SARP pediatric clusters. Primary and secondary outcomes were analyzed by cluster in each trial.

RESULTS

CARE participants were assigned to SARP clusters with high accuracy. Baseline characteristics were similar between SARP and CARE children of the same cluster. Treatment response in CARE trials was generally similar across clusters. However, with the caveat of a smaller sample size, children in the early-onset/severe-lung function cluster had best response with fluticasone/salmeterol (64% vs 23% 2.5× fluticasone and 13% fluticasone/montelukast in the Best ADd-on Therapy Giving Effective Responses trial; P = .011) and children in the early-onset/comorbidity cluster had the least clinical efficacy to treatments (eg, -0.076% change in FEV1 in the Characterizing Response to Leukotriene Receptor Antagonist and Inhaled Corticosteroid trial).

CONCLUSIONS

In this study, we replicated SARP pediatric asthma clusters by using a separate, large clinical trials network. Early-onset/severe-lung function and early-onset/comorbidity clusters were associated with differential and limited response to therapy, respectively. Further prospective study of therapeutic response by cluster could provide new insights into childhood asthma treatment.

Mesenchymal stromal cells mediate Aspergillus hyphal extract-induced allergic airway inflammation by inhibition of the Th17 signaling pathway

Systemic administration of mesenchymal stromal cells (MSCs) suppresses airway inflammation and methacholine-induced airway hyper-responsiveness (AHR) in mouse models of T helper cell (Th) type 2-mediated eosinophilic allergic airway inflammation (AAI); however, the efficacy of MSCs in mouse models of severe Th17-mediated neutrophilic AAI has not yet been demonstrated. We assessed MSC effects in a mouse model of mixed Th2/Th17 AAI produced by mucosal exposure to Aspergillus fumigatus hyphal extract (AHE). Following sensitization produced by oropharyngeal AHE administration, systemic (tail vein) administration of syngeneic MSCs on the first day of challenge significantly reduced acute AHR predominantly through reduction of Th17-mediated airway inflammation. In parallel experiments, MSCs also mitigated AHR when administered during recurrent challenge 10 weeks after initial sensitization and challenge through reduction in systemic Th17-mediated inflammation. Investigation into potential mechanistic actions of MSCs in this model demonstrated that although T regulatory cells were increased in all AHE-treated mice, MSC administration did not alter T regulatory cell numbers in either the acute or recurrent model. Differential induction of interleukin-17a secretion was observed in ex vivo restimulation of mediastinal lymph node mixed-cell cytokine analyses. Although the mechanisms by which MSCs act to decrease inflammation and AHR in this model are not yet fully elucidated, decrease in Th17-mediated airway inflammation appears to play a significant role. These results provide a basis for further investigations of MSC administration as a potential therapeutic approach for severe refractory neutrophilic asthma.

Clinical significance of asthma clusters by longitudinal analysis in Korean asthma cohort

Background

We have previously identified four distinct groups of asthma patients in Korean cohorts using cluster analysis: (A) smoking asthma, (B) severe obstructive asthma, (C) early-onset atopic asthma, and (D) late-onset mild asthma.

Methods and Results

A longitudinal analysis of each cluster in a Korean adult asthma cohort was performed to investigate the clinical significance of asthma clusters over 12 months.

Cluster A showed relatively high asthma control test (ACT) scores but relatively low FEV₁ scores, despite a high percentage of systemic corticosteroid use. Cluster B had the lowest mean FEV₁, ACT, and the quality of life questionnaire for adult Korean asthmatics (QLQAKA) scores throughout the year, even though the percentage of systemic corticosteroid use was the highest among the four clusters. Cluster C was ranked second in terms of FEV₁, with the second lowest percentage of systemic corticosteroid use, and showed a marked improvement in subjective symptoms over time. Cluster D consistently showed the highest FEV₁, the lowest systemic corticosteroid use, and had high ACT and QLQAKA scores.

Conclusion

Our asthma clusters had clinical significance with consistency among clusters over 12 months. These distinctive phenotypes may be useful in classifying asthma in real practice.

Three phenotypes of adult-onset asthma

RATIONALE

Adult-onset asthma differs from childhood-onset asthma in many respects. It is more heterogeneous, often severe and frequently associated with loss of lung function. To identify underlying mechanisms of adult-onset asthma and to capture predictors of disease progression, detailed characterization and phenotyping is necessary.

OBJECTIVES

To characterize adult-onset asthma and identify subphenotypes of adult-onset asthma.

METHODS

A cohort of 200 patients with adult-onset (>18 year) asthma (age 54 (26-75) year) was recruited from one academic and three nonacademic pulmonary outpatient clinics in Amsterdam, the Netherlands. These patients were fully characterized with respect to clinical, functional and inflammatory markers. After data reduction, K-means nonhierarchical cluster analysis was performed to identify clusters of adult-onset asthma.

MEASUREMENTS AND MAIN RESULTS

Patients with adult-onset asthma were predominately female (61%) and nonatopic (55%). Within this group of patients were identified three clusters of adult-onset asthma. Cluster 1 (n = 69) consisted of patients with severe eosinophilic inflammation-predominant asthma and persistent airflow limitation despite high-intensity anti-inflammatory treatment, with relatively low symptom scores. The second cluster was characterized by obese women with frequent symptoms, high healthcare utilization and low sputum eosinophils. The third cluster consisted of patients with mild-to-moderate, well-controlled asthma with normal lung function and low inflammatory markers. Repeatability accuracy was 98.2%.

CONCLUSIONS

Amongst patients with adult-onset asthma, three subphenotypes can be identified with distinct clinical and inflammatory characteristics. These subphenotypes help to understand the underlying pathobiology and provide clinicians with directions for personalized management.

Effects of omalizumab in non-atopic asthma: results from a Spanish multicenter registry

Aim. To evaluate the effectiveness of omalizumab in non-atopic asthma. Methods. Using data from a multicenter registry of severe asthma, we evaluated and compared the clinical outcome of 29 omalizumab-treated severe non-atopic asthmatics with 266 omalizumab-treated severe allergic asthmatics. Effectiveness was assessed by considering severe exacerbations, pulmonary function, the Global Evaluation of Treatment Effectiveness (GETE) scale, and Asthma Control Test (ACT). Results. Omalizumab demonstrated significant improvement in the clinical status of non-atopic asthmatics as measured by GETE, which rose from 1.6 ± 1.1 to 2.8 ± 0.9 [corrected] at 4 months (p = .0215) to 2.9 ± 0.9 at 1 year (p = .0093) and to 3.4 ± 0.6 at 2 years (p = .0078), and by the ACT, which increased from 13.3 ± 5.5 [corrected] to 17.5 ± 5.4 at 4 months (p = .0236) to 17.9 ± 4.8 at 1 year (p = .0136) and to 20.6 ± 3.9 at 2 years (p = .0024). Forced expiratory volume in 1 second (FEV1) improved from 61.0 ± 19.4% to 65.1 ± 17.2 at 4 months to 64.1 ± 24.7 at 1 year and to 67.3 ± 23.0% [corrected] at 2 years, but without significant differences between initial and follow-up measurements (p = .52, .91, and .45, respectively) and exacerbations decreased from 3.1 ± 3.5 to 1.9 ± 2.8 at 1 year (p = .1709) to 1.8 ± 4.4 at 2 years (p = .2344). The results were not significantly different from those obtained in atopic asthmatics. Conclusion. Anti-IgE therapy can be effective in non-atopic severe asthma.

Asthma symptom utility index: reliability, validity, responsiveness, and the minimal important difference in adult asthmatic patients

BACKGROUND

The evaluation of asthma symptoms is a core outcome measure in asthma clinical research. The Asthma Symptom Utility Index (ASUI) was developed to assess the frequency and severity of asthma symptoms. The psychometric properties of the ASUI are not well characterized, and a minimal important difference (MID) is not established.

OBJECTIVES

We assessed the reliability, validity, and responsiveness to change of the ASUI in a population of adult asthmatic patients. We also sought to determine the MID for the ASUI.

METHODS

Adult asthmatic patients (n = 1648) from 2 previously completed multicenter randomized trials were included. Demographic information, spirometric results, ASUI scores, and other asthma questionnaire scores were obtained at baseline and during follow-up visits. Participants also kept a daily asthma diary.

RESULTS

The internal consistency reliability of the ASUI was 0.74 (Cronbach α). Test-retest reliability was 0.76 (intraclass correlation). Construct validity was demonstrated by significant correlations between ASUI scores and Asthma Control Questionnaire scores (Spearman correlation r = -0.79; 95% CI, -0.85 to -0.75; P < .001) and Mini Asthma Quality of Life Questionnaire scores (r = 0.59; 95% CI, 0.51-0.61; P < .001). Responsiveness to change was demonstrated, with significant differences between mean changes in ASUI scores across groups of participants differing by 10% in percent predicted FEV(1) (P < .001) and by 0.5 points in Asthma Control Questionnaire scores (P < .001). Anchor-based and statistical methods support an MID for the ASUI of 0.09 points.

CONCLUSIONS

The ASUI is reliable, valid, and responsive to changes in asthma control over time. The MID of the ASUI (range of scores, 0-1) is 0.09.

Longitudinal changes in asthma control with omalizumab: 2-year interim data from the EXCELS Study

BACKGROUND

Asthma guidelines emphasize the importance of achieving and maintaining asthma control; however, many patients with moderate to severe asthma fail to achieve adequate control.

OBJECTIVE

This 2-year interim analysis evaluated the longitudinal effects of omalizumab on asthma control in patients treated in real-world clinical practice settings.

METHODS

EXCELS is an ongoing observational cohort study of approximately 5000 omalizumab-treated and 2500 non-omalizumab-treated patients aged ≥12 years with moderate to severe asthma. Asthma control was measured using the Asthma Control Test (ACT) every 6 months.

RESULTS

Subgroups of the omalizumab cohort included those who initiated omalizumab at baseline (new starts, n = 549) and those treated with omalizumab >7 days before baseline (established users, n = 4421). For reference, data are also presented for patients who were not receiving omalizumab prior to or at the time of enrolment (non-omalizumab, n = 2867). Over half of the new starts (54%) achieved improvement in ACT consistent with the minimally important difference (MID, defined as ≥3-point improvement) by Month 6 and this proportion increased throughout the follow-up period, reaching 62% at Month 24. Similar results were observed in patients stratified by moderate and severe asthma. Established users of omalizumab maintained asthma control throughout the observation period.

CONCLUSION

Over a 2-year period, patients initiating omalizumab therapy experienced clinically relevant improvements in asthma control, which were maintained during 2 years of longitudinal follow-up. Established users of omalizumab maintained asthma control over the 2-year period with a small improvement similar to that seen in non-omalizumab users.

Severe chronic allergic (and related) diseases: a uniform approach--a MeDALL--GA2LEN--ARIA position paper

Concepts of disease severity, activity, control and responsiveness to treatment are linked but different. Severity refers to the loss of function of the organs induced by the disease process or to the occurrence of severe acute exacerbations. Severity may vary over time and needs regular follow-up. Control is the degree to which therapy goals are currently met. These concepts have evolved over time for asthma in guidelines, task forces or consensus meetings. The aim of this paper is to generalize the approach of the uniform definition of severe asthma presented to WHO for chronic allergic and associated diseases (rhinitis, chronic rhinosinusitis, chronic urticaria and atopic dermatitis) in order to have a uniform definition of severity, control and risk, usable in most situations. It is based on the appropriate diagnosis, availability and accessibility of treatments, treatment responsiveness and associated factors such as comorbidities and risk factors. This uniform definition will allow a better definition of the phenotypes of severe allergic (and related) diseases for clinical practice, research (including epidemiology), public health purposes, education and the discovery of novel therapies.

Key findings and clinical implications from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study

Patients with severe or difficult-to-treat asthma are an understudied population but account for considerable asthma morbidity, mortality, and costs. The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study was a large, 3-year, multicenter, observational cohort study of 4756 patients (n=3489 adults ≥ 18 years of age, n=497 adolescents 13-17 years of age, and n=770 children 6-12 years of age) with severe or difficult-to-treat asthma. TENOR's primary objective was to characterize the natural history of disease in this cohort. Data assessed semiannually and annually included demographics, medical history, comorbidities, asthma control, asthma-related health care use, medication use, lung function, IgE levels, self-reported asthma triggers, and asthma-related quality of life. We highlight the key findings and clinical implications from more than 25 peer-reviewed TENOR publications. Regardless of age, patients with severe or difficult-to-treat asthma demonstrated high rates of health care use and substantial asthma burden despite receiving multiple long-term controller medications. Recent exacerbation history was the strongest predictor of future asthma exacerbations. Uncontrolled asthma, as defined by the 2007 National Heart, Lung, and Blood Institute guidelines' impairment domain, was highly prevalent and predictive of future asthma exacerbations; this assessment can be used to identify high-risk patients. IgE and allergen sensitization played a role in the majority of severe or difficult-to-treat asthmatic patients.

L-carnitine improves the asthma control in children with moderate persistent asthma

The objective. was to investigate L-Carnitine level and the effects of its supplementation in children with moderate persistent Asthma. Methods. Free and total serum carnitine levels were measured in 50 children having moderate persistent asthma and 50 healthy control children. The patients group was randomly divided into two subgroups. Subgroup A was supplemented with L-carnitine for 6 months while subgroup B was used as a placebo controls. Both subgroups were assessed by pulmonary function tests (PFT) and childhood-asthma control test (C-ACT) before and 6 months after carnitine supplementation. Results. Total and free carnitine levels were significantly lower in patient group than in control group. PFT and C-ACT showed significant improvements in asthmatic children supplemented with L-carnitine than in those who were not supplemented. Conclusion. L-carnitine levels were initially lower in moderate persistent asthmatic children as compared to healthy control children. Asthmatic children who received L-carnitine supplementation showed statistically significant improvement of C-ACT and PFT.

L-carnitine improves the asthma control in children with moderate persistent asthma

The objective. was to investigate L-Carnitine level and the effects of its supplementation in children with moderate persistent Asthma. Methods. Free and total serum carnitine levels were measured in 50 children having moderate persistent asthma and 50 healthy control children. The patients group was randomly divided into two subgroups. Subgroup A was supplemented with L-carnitine for 6 months while subgroup B was used as a placebo controls. Both subgroups were assessed by pulmonary function tests (PFT) and childhood-asthma control test (C-ACT) before and 6 months after carnitine supplementation. Results. Total and free carnitine levels were significantly lower in patient group than in control group. PFT and C-ACT showed significant improvements in asthmatic children supplemented with L-carnitine than in those who were not supplemented. Conclusion. L-carnitine levels were initially lower in moderate persistent asthmatic children as compared to healthy control children. Asthmatic children who received L-carnitine supplementation showed statistically significant improvement of C-ACT and PFT.

Asthma phenotypes in adults and clinical implications

It is becoming increasingly recognized that asthma is a heterogeneous disease, whether based on clinical factors, including the patient's age at diagnosis, symptom spectrum and treatment response, triggering factors, or the level and type of inflammation. Attempts to analyze the importance of these characteristics to the clinical presentation of asthma have led to the appreciation of numerous separate and overlapping asthma phenotypes. However, these approaches are 'biased' and based on the clinician/scientist's own experience. Recently, unbiased approaches have also been attempted using both molecular and statistical tools. Early results from these approaches have supported and expanded on the clinician's concepts. However, until specific biologic markers are identified for any of these proposed phenotypes, the definitive nature of any phenotype will remain speculative.

Importance of hedgehog interacting protein and other lung function genes in asthma

BACKGROUND

Two recent large meta-analyses of genome-wide association studies of lung function in general populations of European descent identified 11 candidate genes/regions. The importance of these genes in lung function in white and African American subjects with asthma is unknown.

OBJECTIVES

To determine whether genes that regulate lung function in general populations are associated with lung function abnormalities in subjects with asthma from different racial groups.

METHODS

Single nucleotide polymorphisms (SNPs) were tested in 5 asthma populations (N = 1441) for association with pulmonary function, and meta-analysis was performed across populations. The SNPs with the highest significance were then tested for association with bronchodilator reversibility and bronchial hyperresponsiveness to methacholine. A joint analysis of consistently replicated SNPs was performed to predict lung function in asthma.

RESULTS

Hedgehog interacting protein (HHIP) on chromosome 4q31 was associated with lung function in all 5 populations (rs1512288: P(meta) = 9.62E-05 and 3.23E-05 for percent predicted FEV(1) [ppFEV(1)] and percent predicted forced vital capacity [ppFVC], respectively). The SNPs in HHIP were also associated with reversibility (P < .05) but not bronchial hyperresponsiveness to methacholine. Because of differences in linkage disequilibrium in the African American subjects, the most relevant SNPs in HHIP were identified. A subset of normal lung function genes, including HHIP, family with sequence similarity 13, member A (FAM13A), and patched homolog 1 (PTCH1), together predict lung function abnormalities, a measure of severity in white and African American subjects with asthma.

CONCLUSION

A subset of the genes, including HHIP, that regulate lung function in general populations are associated with abnormal lung function in asthma in non-Hispanic white and African American subjects.

Clinical benefits of 7 years of treatment with omalizumab in severe uncontrolled asthmatics

RATIONALE

Severe asthma is characterized by inadequate symptom control and by high rate of inflammation despite high doses of steroids. Omalizumab, a recombinant humanized monoclonal anti-IgE, provides a new therapeutic strategy in severe allergic asthma.

AIMS

This study was aimed to assess whether long-term treatment with omalizumab improved clinical control in severe asthmatics.

METHODS

We investigated omalizumab effects on asthma outcomes evaluating seven severe allergic asthmatic patients who were treated for 7 years with add-on omalizumab. Number of exacerbations, use of antibiotics, additional asthma medications (systemic steroids, nebulized steroids and bronchodilators), and spirometry were analyzed before and after omalizumab treatment.

RESULTS

Omalizumab was well tolerated by all the studied patients. It improved FEV1 and FEV1/FVC ratio and reduced symptom score, asthma exacerbations, use of antibiotics, and use of nebulized steroids, bronchodilators, and oral corticosteroids. These effects were evident after 4 years of treatment and more pronounced after 7 years of treatment.

CONCLUSIONS

This study underlines the utility of a long-term treatment with omalizumab to improve asthma clinical outcomes in severe asthmatics.

Treatment with inhaled mometasone furoate reduces short-acting β(2) agonist claims and increases adherence compared to fluticasone propionate in asthma patients

OBJECTIVES

Differences between mometasone furoate (MF), administered once daily, and fluticasone propionate (FP), administered twice daily, dosing regimens may affect adherence and short-acting β(2) agonist (SABA) use. The objective of this analysis was to compare asthma control outcomes in matched cohorts of MF- and FP-treated asthma patients stratified by SABA claims.

METHODS

A retrospective pharmacy claims database analysis identified matched cohorts of asthma patients (aged 12-65 years) who initiated treatment with MF or FP. Patients with none, one to four, five to eight, or more than eight SABA preindex claims were stratified to categories A, B, C, and D, respectively. Bivariate analyses compared postindex SABA canister claims, adherence, and exacerbations; multivariate analyses compared postindex SABA canister claims.

RESULTS

Matched patients in categories A (n = 2517 per cohort) and B (n = 2329 per cohort) were analyzed; insufficient sample sizes were identified for categories C and D. Postindex bivariate analyses indicated that MF cohorts had fewer SABA claims compared to FP cohorts (category A, 0.80 vs. 1.17 [P < 0.0001]; category B, 1.39 vs. 1.58 [P < 0.0001]), better adherence to the index drug (category A, 24% vs. 15% [P < 0.0001]; category B, 27% vs. 15% [P < 0.0001]), and fewer exacerbations (category A, 0.17 vs. 0.19 [P = 0.011]; category B, 0.17 vs. 0.21 [P = 0.008]). Multivariate analyses indicated that MF cohorts had fewer postindex SABA claims compared to FP cohorts in categories A and B (P < 0.0001).

CONCLUSIONS

Data for SABA claims, treatment adherence, and exacerbations suggest that, compared to twice-daily FP, once-daily MF may provide better asthma control.

Uniform definition of asthma severity, control, and exacerbations: document presented for the World Health Organization Consultation on Severe Asthma

Asthma is a global health problem affecting around 300 million individuals of all ages, ethnic groups and countries. It is estimated that around 250,000 people die prematurely each year as a result of asthma. Concepts of asthma severity and control are important in evaluating patients and their response to treatment, as well as for public health, registries, and research (clinical trials, epidemiologic, genetic, and mechanistic studies), but the terminology applied is not standardized, and terms are often used interchangeably. A common international approach is favored to define severe asthma, uncontrolled asthma, and when the 2 coincide, although adaptation may be required in accordance with local conditions. A World Health Organization meeting was convened April 5-6, 2009, to propose a uniform definition of severe asthma. An article was written by a group of experts and reviewed by the Global Alliance against Chronic Respiratory Diseases review group. Severe asthma is defined by the level of current clinical control and risks as "Uncontrolled asthma which can result in risk of frequent severe exacerbations (or death) and/or adverse reactions to medications and/or chronic morbidity (including impaired lung function or reduced lung growth in children)." Severe asthma includes 3 groups, each carrying different public health messages and challenges: (1) untreated severe asthma, (2) difficult-to-treat severe asthma, and (3) treatment-resistant severe asthma. The last group includes asthma for which control is not achieved despite the highest level of recommended treatment and asthma for which control can be maintained only with the highest level of recommended treatment.

Overcoming heterogeneity in pediatric asthma: tobacco smoke and asthma characteristics within phenotypic clusters in an African American cohort

OBJECTIVE

Asthma in children and adolescents is a heterogeneous syndrome comprised of multiple subgroups with variable disease expression and response to environmental exposures. The goal of this study was to define homogeneous phenotypic clusters within a cohort of children and adolescents with asthma and to determine overall and within-cluster associations between environmental tobacco smoke (ETS) exposure and asthma characteristics.

METHODS

A combined hierarchical/k-means cluster analysis of principal component variables was used to define phenotypic clusters within a cohort of 6- to 20-year-old urban and largely minority subjects.

RESULTS

Among the 154 subjects, phenotypic cluster analysis defined three independent clusters (Cluster 1 [n = 57]; Cluster 2 [n = 33]; Cluster 3 [n = 58]). A small fourth cluster (n = 6) was excluded. Patients in Cluster 1 were predominantly males, with a relative abundance of neutrophils in their nasal washes. Patients in Cluster 2 were predominantly females with high body mass index percentiles and later-onset asthma. Patients in Cluster 3 had higher eosinophil counts in their nasal washes and lower Asthma Control Test (ACT) scores. Within-cluster regression analysis revealed several significant associations between ETS exposure and phenotypic characteristics that were not present in the overall cohort. ETS exposure was associated with a significant increase in nasal wash neutrophils (beta coefficient = 0.73 [95% confidence interval, CI: 0.11 to 1.35]; p = .023) and a significant decrease in ACT score (-5.17 [-8.42 to -1.93]; p = .003) within Cluster 1 and a significant reduction in the bronchodilator-induced % change in forced expiratory volume in one second (FEV(1)) (-36.32 [-62.18 to -10.46]; p = .009) within Cluster 3.

CONCLUSIONS

Clustering techniques defined more homogeneous subgroups, allowing for the detection of otherwise undetectable associations between environmental tobacco smoke exposure and asthma characteristics.

Phenotypic characterization of severe asthma

PURPOSE OF REVIEW

To highlight recent literature that informs our understanding of severe asthma. Severe asthma is an increasingly important part of specialty practice, is responsible for disproportionate healthcare utilization, and contributes significantly to the costs of care. Better recognition of this subset of asthma can lead to improved healthcare.

RECENT FINDINGS

Key recent observations in severe asthma include demographic characterizations of several large study populations and the increasing understanding that relative steroid resistance is a virtually universal feature. In addition, strong associations with interleukin-13 and mammalian chitinase have emerged, and abnormalities of endogenous anti-inflammatory pathways have been examined. The role of protein biomarkers to identify and delineate severe asthma is now being investigated. The pathogenic significance of each of these observations is still being clarified, but it appears that severe asthma may have mechanistic underpinnings distinct from that of mild or moderate asthma.

SUMMARY

Severe asthma is a discrete, but variably defined phenotype of asthma. Steroid resistance is extremely common, patients may require doses of inhaled steroids for control that exceed usual guidelines and may also require multiple controller agents. New mechanistic insights could provide important avenues for novel therapeutic interventions.

Corticosteroid insensitivity in severe asthma: significance, mechanisms and aetiology

Chronic severe asthma remains a challenging clinical problem despite the availability of modern treatments. Relative corticosteroid insensitivity is present in severe asthma and may contribute to continuing disease severity. Advances in the understanding of molecular mechanisms underlying corticosteroid insensitivity may yield new therapeutic targets. Furthermore, aetiological factors for corticosteroid insensitivity have been identified and these may be amenable to modification.

Identification of asthma phenotypes using cluster analysis in the Severe Asthma Research Program

RATIONALE

The Severe Asthma Research Program cohort includes subjects with persistent asthma who have undergone detailed phenotypic characterization. Previous univariate methods compared features of mild, moderate, and severe asthma.

OBJECTIVES

To identify novel asthma phenotypes using an unsupervised hierarchical cluster analysis.

METHODS

Reduction of the initial 628 variables to 34 core variables was achieved by elimination of redundant data and transformation of categorical variables into ranked ordinal composite variables. Cluster analysis was performed on 726 subjects.

MEASUREMENTS AND MAIN RESULTS

Five groups were identified. Subjects in Cluster 1 (n = 110) have early onset atopic asthma with normal lung function treated with two or fewer controller medications (82%) and minimal health care utilization. Cluster 2 (n = 321) consists of subjects with early-onset atopic asthma and preserved lung function but increased medication requirements (29% on three or more medications) and health care utilization. Cluster 3 (n = 59) is a unique group of mostly older obese women with late-onset nonatopic asthma, moderate reductions in FEV(1), and frequent oral corticosteroid use to manage exacerbations. Subjects in Clusters 4 (n = 120) and 5 (n = 116) have severe airflow obstruction with bronchodilator responsiveness but differ in to their ability to attain normal lung function, age of asthma onset, atopic status, and use of oral corticosteroids.

CONCLUSIONS

Five distinct clinical phenotypes of asthma have been identified using unsupervised hierarchical cluster analysis. All clusters contain subjects who meet the American Thoracic Society definition of severe asthma, which supports clinical heterogeneity in asthma and the need for new approaches for the classification of disease severity in asthma.

Genome-wide association study of asthma identifies RAD50-IL13 and HLA-DR/DQ regions

BACKGROUND

Asthma is a heterogeneous disease that is caused by the interaction of genetic susceptibility with environmental influences. Genome-wide association studies (GWASs) represent a powerful approach to investigate the association of DNA variants with disease susceptibility. To date, few GWASs for asthma have been reported.

OBJECTIVES

A GWAS was performed on a population of patients with severe or difficult-to-treat asthma to identify genes that are involved in the pathogenesis of asthma.

METHODS

A total of 292,443 single nucleotide polymorphisms (SNPs) were tested for association with asthma in 473 The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) cases and 1892 Illumina general population controls. Asthma-related quantitative traits (total serum IgE, FEV(1), forced vital capacity, and FEV(1)/forced vital capacity) were also tested in identified candidate regions in 473 TENOR cases and 363 phenotyped controls without a history of asthma to analyze GWAS results further. Imputation was performed in identified candidate regions for analysis with denser SNP coverage.

RESULTS

Multiple SNPs in the RAD50-IL13 region on chromosome 5q31.1 were associated with asthma: rs2244012 in intron 2 of RAD50 (P = 3.04E-07). The HLA-DR/DQ region on chromosome 6p21.3 was also associated with asthma: rs1063355 in the 3' untranslated region of HLA-DQB1 (P = 9.55E-06). Imputation identified several significant SNPs in the T(H)2 locus control region 3' of RAD50. Imputation also identified a more significant SNP, rs3998159 (P = 1.45E-06), between HLA-DQB1 and HLA-DQA2.

CONCLUSION

This GWAS confirmed the important role of T(H)2 cytokine and antigen presentation genes in asthma at a genome-wide level and the importance of additional investigation of these 2 regions to delineate their structural complexity and biologic function in the development of asthma.

Factors associated with severity and exacerbation of asthma: a baseline analysis of the cohort for reality and evolution of adult asthma in Korea (COREA)

BACKGROUND

Asthma presents with heterogeneous features, and patients show various phenotypes of differing severities. Therefore, it is necessary to define reliable predictable clinical factors that influence severity. To date, few large-scale studies have gathered clinical data on adult asthma patients in Asia.

OBJECTIVES

To establish an adult asthma cohort in Korea and to define significant factors associated with asthma severity and exacerbation.

METHODS

Researchers from 11 university hospitals have established an asthma cohort termed the COhort for Reality and Evolution of adult Asthma in Korea (COREA). We classified the severity of asthma into 3 groups: mild, moderate, and severe. In this article, the first analysis of our cohort, we evaluate various clinical factors associated with the severity and exacerbation of asthma using data from 1,260 asthma patients.

RESULTS

Physician-evaluated severity of asthma was associated with a history of asthma exacerbation (P < .001), a history of smoking (P < .001), symptom duration (P = .007), and treatment duration (P < .001). It was also significantly correlated with predicted forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) values and FEV1/FVC ratio (all P < .001). Previous exacerbation was associated with smoking (P = .02), predicted FVC and FEV1 values (both P < .001), FEV1/FVC ratio (P = .02), airway hyperresponsiveness (P = .002), and duration of disease (P < .001).

CONCLUSIONS

Previous exacerbation, duration of disease, and decrease in lung function were important clinical indices associated with asthma severity in the COREA study patients. Our long-term follow-up study is expected to soon yield more accurate and detailed outcomes.

Low-dose fluticasone propionate with and without salmeterol in steroid-naïve patients with mild, uncontrolled asthma

BACKGROUND

The role of combination ICS/LABA as initial controller therapy in mild, persistent asthma is uncertain. Therefore, the objective of this study was to compare the efficacy of initial controller therapy with fluticasone propionate (FP) 100 microg twice daily to the efficacy of fluticasone propionate/salmeterol xinafoate (FSC) 100/50 microg twice daily in patients with persistent asthma symptoms while using as-needed SABA alone.

METHODS

This randomized, double-blind, parallel-group study was conducted at 45 general practice and 15 specialist centers. A total of 526 adult patients were randomized to receive FP or FSC for 24 weeks. The primary efficacy endpoint was change in morning peak expiratory flow (PEF) from baseline. Secondary efficacy endpoints included symptom- and rescue-free days; asthma exacerbation rate; asthma-related health-care utilization; and the onset of effect. Safety was assessed by monitoring adverse events.

RESULTS

Mean morning PEF was significantly greater in the FSC versus the FP group (P<0.001); this greater effect was evident as early as the first week of treatment (P<0.001). The percentages of symptom-free days and rescue-free days in the FSC group were 7.7% (P=0.009) and 8.4% (P=0.001) higher than the FP group, respectively. Trends toward lower exacerbation-related health care-utilization for FSC versus FP were not statistically significant and exacerbation rates were not significantly different. The incidence of adverse events was low with both treatments.

CONCLUSIONS

:Treatment with FSC was a more effective initial controller therapy than FP monotherapy in ICS-naïve patients who had uncontrolled asthma while using as-needed SABA alone.

Consistently very poorly controlled asthma, as defined by the impairment domain of the Expert Panel Report 3 guidelines, increases risk for future severe asthma exacerbations in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study

BACKGROUND

Identification of patients at risk for asthma exacerbations can assist physicians in addressing disease management and improve asthma-related health outcomes.

OBJECTIVE

We sought to evaluate whether level of impairment, as defined by the 2007 asthma guidelines, predicts risk for future asthma exacerbations.

METHODS

The study included children aged 6 to 11 years (n = 82) and adolescent/adult patients aged 12 years and older (n = 725) from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens study with data representing all components of the impairment domain of the asthma guidelines at baseline, month 12, and month 24. Patients were categorized into 2 cohorts: (1) consistently very poorly controlled (VPC) asthma from baseline through 2 years of follow-up and (2) improved from VPC asthma at baseline (including patients who improved to not well-controlled or well-controlled asthma), with improvement maintained through 2 years of follow-up. Odds ratios (ORs) and 95% CIs for risk of asthma exacerbations at month 30 were generated by using multivariable logistic regression by age group.

RESULTS

After adjustment, children with consistently VPC asthma over the 2-year period demonstrated a 6-fold increased risk of hospitalization, emergency department visit, or corticosteroid burst (OR, 6.4; 95% CI, 1.2-34.5) compared with the improved group. Adolescent/adult patients with consistently VPC asthma were more likely to have a corticosteroid burst (OR, 2.8; 95% CI, 1.7-4.8) or have a hospitalization, emergency department visit, or corticosteroid burst (OR, 3.2; 95% CI, 1.9-5.3).

CONCLUSIONS

Consistently VPC asthma, as defined by the impairment domain of the 2007 asthma guidelines, is strongly predictive of future asthma exacerbations.

Evolution of asthma severity in a cohort of young adults: is there any gender difference?

INTRODUCTION

Little is known about the distribution of asthma severity in men and women in the general population. The objective of our study was to describe asthma severity and change in severity according to gender in a cohort of adult asthmatics

METHODS

Subjects with asthma were identified from random samples of the 22 to 44 year-olds from the general population, screened for asthma from 1991 to 1993 in 48 centers from 22 countries and followed-up during 1998-2002, as part of the European Community Respiratory Health Survey (ECRHS). All participants to follow-up with current asthma at baseline were eligible for the analysis. To assess change over the follow-up, asthma severity at the two surveys was defined using standardized data on respiratory symptoms, lung function and medication according to the Global Initiative for Asthma (GINA) Guidelines. Another quantitative score (Ronchetti) further considering hospitalizations was also analysed.

RESULTS

The study included 685 subjects with asthma followed-up over a mean period of 8.65 yr (min 4.3-max 11.7). At baseline, asthma severity according to GINA was distributed as intermittent: 40.7%, 31.7% as mild persistent, 14% as moderate persistent, and 13.5% as severe persistent. Using the Ronchetti score derived classification, the distribution of asthma severity was 58% mild, (intermittent and mild persistent), 25.8% moderate, and 15.4% severe. Whatever the classification, there was no significant difference in the severity distribution between men and women. There was also no gender difference in the severity distribution among incident cases which developed asthma between the two surveys. Men with moderate-to-severe asthma at baseline were more likely than women to have moderate-to-severe asthma at follow-up. Using GINA, 69.2% of men vs. 53.1% of women (p = 0.09) with moderate-to-severe asthma at baseline were still moderate-to-severe at follow-up. Using Ronchetti score, 53.3% of men vs. 36.2% of women (p = 0.03) with moderate-to-severe asthma at baseline were still moderate-to-severe at follow-up.

CONCLUSIONS

There was no gender difference in asthma severity at the two surveys. However, our findings suggest that asthma severity might be less stable in women than in men.

Relationship between the characteristics of hospitalised acute asthma patients and the severity of their asthma. A case-control study

BACKGROUND

The EAGLE project database was analysed to assess the characteristics of patients with severe (SA) who required hospitalisation as a result of an acute episode during the period 1994-2004, and the relationship with asthma severity.

METHODS

A total od 2593 clinical records corresponding to an equal number of patients hospitalised for acute asthma (15-69 years), with sufficient information to characterize their asthma severity in agreement with GNA criteria were identified (727 patients with SA compared with 1866 patients with non-severe asthma).

RESULTS

Patients with SA were older, displayed a greater predominance of female asthmatics, lower antecedents of atopy, and a higher frequency of previous hospitalisations compared with non-severe asthmatics (86.1% vs. 50.5%, p< or = 0.01). Additionally, SA patients showed more severe exacerbations characterized by acidosis, significant spirometric deterioration, greater length of hospital stay (9.4 days vs. 7.0 days), as well as a higher frequency of intubation (16.8% vs. 2.1%), intensive care unit admission (11.3% vs.4.9%), cardiopulmonary arrest (5.5% vs. 1.3%), and asthma deaths (2.1% vs. 0.4%) (all < or = 0.01) compared wit non-severe patients.

CONCLUSIONS

This study suggests that SA patients have greater morbidity and a disproportionate need for health care as a result of more severe exacerbations. However, non-severe asthmatics can also still present acute severe episodes (although with a lower frequency) with risk of life.

Conundrums in childhood asthma severity, control, and health care use: Puerto Rico versus Rhode Island

BACKGROUND

The lifetime prevalence of self-reported asthma among Puerto Ricans is very high, with increased asthma hospitalizations, emergency department visits, and mortality rates. Differences in asthma severity between the mainland and island, however, remain largely unknown.

OBJECTIVE

We sought to characterize differences in asthma severity and control among 4 groups: (1) Island Puerto Ricans, (2) Rhode Island (RI) Puerto Ricans, (3) RI Dominicans, and (4) RI whites.

METHODS

Eight hundred five children aged 7 to 15 years completed a diagnostic clinic session, including a formal interview, physical examination, spirometry, and allergy testing. Using a visual grid adapted from the Global Initiative for Asthma, asthma specialists practicing in each site determined an asthma severity rating. A corresponding level of asthma control was determined by using a computer algorithm.

RESULTS

Island Puerto Ricans had significantly milder asthma severity compared with RI Puerto Ricans, Dominicans, and whites (P < .001). Island Puerto Ricans were not significantly different from RI whites in asthma control. RI Puerto Ricans showed a trend toward less control compared with island Puerto Ricans (P = .061). RI Dominicans had the lowest rate of controlled asthma. Paradoxically, island Puerto Ricans had more emergency department visits in the past 12 months (P < .001) compared with the 3 RI groups.

CONCLUSIONS

Potential explanations for the paradoxic finding of milder asthma in island Puerto Ricans in the face of high health care use are discussed. Difficulties in determining guideline-based composite ratings for severity versus control are explored in the context of disparate groups.

Airway remodeling in subjects with severe asthma with or without chronic persistent airflow obstruction

BACKGROUND

The patterns of airway remodeling and the biomarkers that distinguish different subtypes of severe asthma are unknown.

OBJECTIVES

We sought to characterize subjects with severe asthma with and without chronic persistent airflow obstruction with respect to airway wall remodeling (histopathologic and radiologic) and specific sputum biomarkers.

METHODS

Subjects with severe asthma with chronic persistent (n = 16) or intermittent (n = 18) obstruction were studied. Endobronchial biopsy specimens were analyzed for airway smooth muscle area, epithelial detachment, basement membrane thickness, and submucosal fibrosis. Levels of eosinophil cationic protein, myeloperoxidase, matrix metalloproteinase 9, tissue inhibitor of matrix metalloproteinase 1 (ELISA), and 27 cytokines (multiplex assay) and differential cell counts were measured in induced sputum. Airway thickness was measured by means of high-resolution computed tomographic scanning.

RESULTS

Chronic persistent obstruction was associated with earlier age of onset, longer disease duration, more inflammatory cells in the sputum, and greater smooth muscle area (15.65% +/- 2.69% [n = 10] vs 8.96% +/- 1.99% [n = 14], P = .0325). No differences between groups were found for any of the biomarker molecules measured in sputum individually. However, principal component analysis revealed that the dominant variables in the chronic persistent obstruction group were IL-12, IL-13, and IFN-gamma, whereas IL-9, IL-17, monocyte chemotactic protein 1, and RANTES were dominant in the other group. Airway imaging revealed no differences between groups.

CONCLUSION

Subjects with severe asthma with chronic persistent obstruction have increased airway smooth muscle with ongoing T(H)1 and T(H)2 inflammatory responses. Neither airway measurements on high-resolution computed tomographic scans nor sputum analysis seem able to identify such patients.

Clinical phenotypes of severe asthma

OBJECTIVE

To characterize clinical phenotypes of severe asthma.

METHODS

A total of 111 patients were retrospectively evaluated at a specialized outpatient clinic. A systematic protocol for patient evaluation and follow-up was applied. Treatment compliance and control of the disease at the end of follow-up were defined by clinical and functional data. Patients who did not meet asthma control criteria after six months despite compliance with treatment and correct use of medication were characterized as treatment-resistant. Phenotypes were determined by factorial analysis and compared using various tests.

RESULTS

At the end of follow-up, 88 patients were considered treatment compliant and 23 were considered noncompliant. Factorial analysis of the compliant patients identified four phenotypes: phenotype 1 (28 patients) comprised patients who were treatment-resistant, more often presenting nocturnal symptoms and exacerbations, as well as more often using rescue bronchodilators; phenotype 2 (48 patients) comprised patients with persistent airflow limitation, lower ratios of forced expiratory volume in one second/forced vital capacity at baseline, more advanced age and longer duration of symptoms; phenotype 3 (42 patients) comprised patients with allergic rhinosinusitis who were nonsmokers and presented predominantly reversible airflow obstruction; and phenotype 4 (15 patients) comprised cases with a history of aspirin intolerance to acetylsalicylic acid associated with near-fatal asthma.

CONCLUSIONS

A significant number of patients with severe asthma are noncompliant with treatment. Although many patients with severe asthma have persistent airflow obstruction, the most relevant clinical phenotype comprises patients who are resistant to the typical treatment.

Impact of medical residency on knowledge of asthma

OBJECTIVES

To assess resident physician knowledge of pathophysiology, diagnosis, and management of asthma and to assess the impact of an interactive curriculum on that knowledge.

PARTICIPANTS

A total of 720 resident and attending physicians at 15 internal medicine residency programs.

METHODS

An educational module and two multiple choice tests were developed using established methods of curriculum development and knowledge assessment, then disseminated online to 15 internal medicine residency programs. Baseline and post-intervention knowledge was analyzed according to year of training using Chi square to detect differences in group performance.

RESULTS

Baseline knowledge on asthma was poor. The average baseline score on all questions was 54.2%, and was worst on questions on diagnosis of asthma (47.5% correct) and questions on management of asthma (54.8% correct). Baseline knowledge was best on questions on the pathophysiology of asthma (71.5% correct). On specific concepts, only 41.9% correctly knew which pharmacotherapeutic agents were used as controller agents, and only 43.5% were able to correctly diagnose asthma severity. Knowledge on questions on diagnosis of asthma was no better in post-graduate year (PGY) 3 residents than in PGY1 residents (p = 0.054), but PGY3 residents performed better on questions about management of asthma than did PGY1 residents (p < 0.001). Knowledge improved for all concepts and at all levels of training after completion of an interactive module on asthma guidelines (p < 0.001).

CONCLUSION

Resident physician knowledge of asthma guidelines is poor and can be improved by an interactive curriculum.

A retrospective study of the use of fluticasone propionate/salmeterol combination as initial asthma controller therapy in a commercially insured population

BACKGROUND

Asthma management guidelines state that a low-dose inhaled corticosteroid (ICS) is the preferred treatment for mild persistent asthma and that coadministration of a long-acting beta(2)-agonist (LABA) should be reserved for patients whose asthma is uncontrolled by single-entity ICS. However, it appears that many patients in the United States with mild persistent asthma are initially treated with combinations of fluticasone propionate/salmeterol (FPS).

OBJECTIVE

The aim of this study was to examine whether use of FPS was consistent with asthma management guidelines.

METHODS

A commercial insurance database was analyzed retrospectively to identify patients aged 12 to 62 years who had >or=1 pharmacy claim for FPS between October 1, 2004, and September 30, 2006. An index date corresponding to the date of the first FPS pharmacy claim was assigned to each patient. Medical and pharmacy claims data were analyzed for the 365-day period before the index date (preindex period). The severity of patients' asthma was inferred from their history of claims. Patients were identified as having more severe asthma if, during the preindex period, they either received >365 doses of short-acting beta(2)-agonists (SABAs), an oral corticosteroid (OCS), or an emergency department (ED) asthma visit with an OCS prescription, or were hospitalized for their asthma.

RESULTS

Among 87,459 patients with new FPS claims, 60.8% were female, and the mean age was 37.3 years. Of these patients, 60,453 (69.1%) had no preindex ICS pharmacy claim or claims that would indicate moderate or severe asthma. In the preindex period, only 6.3% had received an ICS, 7.4% had >365 SABA doses, 22.7% had used an OCS, 1.1% had an ED visit with an OCS prescription, and 1.5% had been hospitalized.

CONCLUSION

More than two thirds of the patients who initiated FPS treatment had neither received an ICS prescription before their first FPS pharmacy claim nor had evidence of asthma severity that would appear to warrant the use of an ICS/LABA combination.

International differences in asthma guidelines for children

BACKGROUND

Over the last decade, a number of clinical practice guidelines that include guidance for the management of pediatric asthma have been introduced. The consistency across pediatric asthma guidelines is unknown and the emphasis on establishing asthma control may vary. The objective of this paper was to depict the evolution of guidelines for pediatric asthma and to compare current international guidelines in terms of their organization, presentation of evidence and consideration of children, with special emphasis on definitions of asthma control and severity.

METHODS

A systematic search to identify asthma guidelines was conducted, and guidelines were searched for pediatric terms. The approaches used by guidelines to define assessments of asthma severity and control were compared between the United States, the Global Initiative for Asthma, Canada, the United Kingdom and Australia.

RESULTS

Pediatric considerations in the management of asthma have been integrated into the various guidelines to different degrees and through varied strategies. There were differences in the conceptual and operational approach used to assess asthma which emphasized either asthma severity or control.

CONCLUSIONS

It will be important for future guidelines to clearly define whether the primary assessment parameter is asthma severity or control. Delineating the guideline development process and supporting evidence may improve transparency, consistency and guideline adherence.

[Follow up of asthmatic children: definition and measurement tools]

The guidelines for the management of asthma currently emphasise the concept of monitoring that reflects the activity of the disease over a period of several weeks. This principle is valid whatever the severity of the asthma. The monitoring tools are essentially clinical and functional. The clinical parameters (daytime and/or nocturnal symptoms, discomfort on exercise, beta-2 agonist usage) should be evaluated systematically at each consultation just as at the onset of exacerbations. A number of questionnaires have been developed (ATAQ, ACT...). At the functional level every asthmatic child should have the benefit of a respiratory function assessment, the frequency of which depends on the therapeutic management programme. Among the non-invasive measurements of airway inflammation the measurement of expired nitric oxide (NO) is the best established. The measurement of expired NO could improve some paraclinical parameters that are not monitored routinely.

Asthma 2008: targeting immunoglobulin E to achieve disease control

Traditionally, practice guidelines have recommended a step-wise approach to treatment based on asthma severity and lung function. However, increasing evidence suggests that asthma may not be adequately controlled in many patients with moderate-to-severe disease despite aggressive therapy, and that regularly evaluating the level of asthma control achieved in individual patients may be more effective than disease severity in guiding treatment decisions. This is reflected in updated asthma guidelines from the National Asthma Education and Prevention Program, which advocate regular assessment of asthma control in terms of the current impairment and future risk associated with the disease. Guideline-recommended options for patients with persistent, moderate-to-severe immunoglobulin E (IgE)-mediated asthma have recently been enhanced by the inclusion of omalizumab. This change is based on growing evidence for the central role of IgE in airway inflammation and asthma and the clinical effectiveness of blocking IgE with omalizumab, a recombinant humanized monoclonal antibody. Omalizumab significantly reduced asthma exacerbations and improved lung function and symptoms in randomized controlled studies of patients inadequately controlled on inhaled corticosteroids plus long-acting beta(2)-agonist therapy; these benefits for reducing asthma impairment and risk were maintained during steroid dose reductions. Omalizumab is well tolerated, although patients should be monitored for possible rare anaphylactic reactions.

Severe exacerbations in children with mild asthma: characterizing a pediatric phenotype

BACKGROUND

NHLBI guidelines classify asthma in children as intermittent, mild persistent, moderate persistent, and severe persistent asthma based on baseline symptoms and pulmonary function. However, this may not capture the spectrum of asthma in children, since even mild baseline disease can have significant effects on quality of life. Our objective was to describe a population of children with mild asthma admitted to the ICU with severe exacerbations.

METHODS

We examined data from all children with asthma who were admitted to the ICU with an acute exacerbation between April 1997, and December 2006. Children were defined as having mild asthma if their disease was classified as intermittent or mild persistent according to NHLBI criteria.

RESULTS

Of the 298 children admitted to the ICU with asthma, 164 (55%) were classified as having mild baseline asthma. Compared with children with more severe baseline asthma, mild asthmatic children were younger and less likely to have been previously admitted to the hospital for asthma. Other demographics, including admission severity of illness, gender, and prevalence of overweight, were similar in the two groups. There were no differences between the groups in ICU length of stay, hospital length of stay or types of therapies received. Thirteen children with mild asthma were intubated, although less frequently than those with more severe disease.

CONCLUSIONS

Children with mild asthma have severe exacerbations. This suggests that chronic asthma severity does not necessarily predict asthma phenotypes during acute exacerbations.

Subspecialty differences in asthma characteristics and management

OBJECTIVE

To determine the nature and extent to which asthma characteristics and management differ between allergy and pulmonary subspecialists.

PATIENTS AND METHODS

We used baseline data from 3342 adults enrolled in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study, a multicenter, observational cohort recruited from subspecialty practices across the United States. Information on physician subspecialty, asthma history, allergic status, lung function, medication use, and recent health care use was collected from January 1, 2001, through April 30, 2004, via study coordinator-administered interviews and self-administered validated questionnaires.

RESULTS

In the TENOR study, 2407 patients (72%) were treated by allergists and 935 (28%) by pulmonologists. Patients treated by pulmonologists were more likely to be black, be less educated, and have lower incomes than those treated by allergists. Pulmonary patients had more severe asthma as indicated by physician assessment, Global Initiative for Asthma classification, lung function, and number of asthma control problems. Regular use of a short-acting beta-agonist and systemic corticosteroid use were also higher among pulmonologist-treated patients than allergist-treated patients, consistent with greater asthma severity. Although evidence of allergic disease was prevalent in both types of patients, those treated by an allergist were more likely to receive skin testing or immunotherapy. In multivariate analyses adjusted for demographic differences, patients treated by pulmonologists were more likely to report health care use for asthma in the past 3 months.

CONCLUSION

In general, asthma patients treated by pulmonologists have lower socioeconomic status, have more severe disease, require more medication, and report greater health care use than those treated by allergists.

Assessing productivity loss and activity impairment in severe or difficult-to-treat asthma

OBJECTIVES

Asthma can be associated with substantial productivity loss and activity impairment, particularly among those with the most severe disease. We sought to assess the performance characteristics of an asthma-specific adaptation of the Work Productivity and Activity Impairment Questionnaire (WPAI:Asthma) in patients with either severe or difficult-to-treat asthma.

METHODS

We analyzed 2529 subjects from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study. The WPAI:Asthma was administered at baseline and at 12 months. Asthma control and quality-of-life were simultaneously assessed using the Asthma Therapy Assessment Questionnaire and Mini-Asthma Quality-of-Life Questionnaire, respectively.

RESULTS

Severe versus mild-to-moderate asthma was associated with a greater percentage of impairment at work (28% vs. 14%), at school (32% vs. 18%), and in daily activities (41% vs. 21%). At baseline, greater asthma control problems correlated with higher levels of impairment as measured by the WPAI (work: r = 0.54, school: r = 0.37, activity: r = 0.55). Over the 12-month follow-up period, improved quality-of-life correlated with decreased levels of impairment (work: r = -0.42, school: r = -0.36, activity: r = -0.48). In multivariate analyses, greater than 10% overall work impairment at baseline predicted emergency visits (OR 2.6 [1.6, 4.0]) and hospitalization (OR 4.9 [1.8, 13.1]) at 12 months.

CONCLUSIONS

The WPAI:Asthma correlates with other self-reported asthma outcomes in the expected manner and predicts health-care utilization at 12 months when administered to patients with severe or difficult-to-treat asthma.

Near-fatal asthma: recognition and management

PURPOSE OF REVIEW

Near-fatal asthma continues to be a significant problem despite the decline in overall asthma mortality. The purpose of this review is to discuss recent advances in our understanding of the pathophysiology, diagnosis and treatment of near-fatal asthma.

RECENT FINDINGS

Two distinctive phenotypes of near-fatal asthma have been identified: one with eosinophilic inflammation associated with a gradual onset and a slow response to therapy and a second phenotype with neutrophilic inflammation that has a rapid onset and rapid response to therapy. Patients who develop sudden-onset near-fatal asthma seem to have massive allergen exposure and emotional distress. In stable condition, near-fatal asthma frequently cannot be distinguished from mild asthma. Diminished perception of dyspnea plays a relevant role in treatment delay, near-fatal events, and death in patients with severe asthma. Reduced compliance with anti-inflammatory therapy and ingestion of medications or drugs (heroin, cocaine) have been associated with fatal or near-fatal asthma.

SUMMARY

Near-fatal asthma is a subtype of asthma with unique risk factors and variable presentation that requires early recognition and aggressive intervention.

Lung function in adults with stable but severe asthma: air trapping and incomplete reversal of obstruction with bronchodilation

Five to ten percent of asthma cases are poorly controlled chronically and refractory to treatment, and these severe cases account for disproportionate asthma-associated morbidity, mortality, and health care utilization. While persons with severe asthma tend to have more airway obstruction, it is not known whether they represent the severe tail of a unimodal asthma population, or a severe asthma phenotype. We hypothesized that severe asthma has a characteristic physiology of airway obstruction, and we evaluated spirometry, lung volumes, and reversibility during a stable interval in 287 severe and 382 nonsevere asthma subjects from the National Heart, Lung, and Blood Institute Severe Asthma Research Program. We partitioned airway obstruction into components of air trapping [indicated by forced vital capacity (FVC)] and airflow limitation [indicated by forced expiratory volume in 1 s (FEV(1))/FVC]. Severe asthma had prominent air trapping, evident as reduced FVC over the entire range of FEV(1)/FVC. This pattern was confirmed with measures of residual lung volume/total lung capacity (TLC) in a subgroup. In contrast, nonsevere asthma did not exhibit prominent air trapping, even at FEV(1)/FVC <75% predicted. Air trapping also was associated with increases in TLC and functional reserve capacity. After maximal bronchodilation, FEV(1) reversed similarly from baseline in severe and nonsevere asthma, but the severe asthma classification was an independent predictor of residual reduction in FEV(1) after maximal bronchodilation. An increase in FVC accounted for most of the reversal of FEV(1) when baseline FEV(1) was <60% predicted. We conclude that air trapping is a characteristic feature of the severe asthma population, suggesting that there is a pathological process associated with severe asthma that makes airways more vulnerable to this component.

Does current asthma control predict future health care use among black preschool-aged inner-city children?

OBJECTIVES

Factors predictive of future asthma must be identified among young inner-city children, who suffer disproportionately from asthma. We investigated whether current asthma control predicts future asthma-related health care use among inner-city preschool-aged children with asthma.

METHODS

A total of 150 inner-city preschool-aged children with asthma were followed prospectively for 6 months. At baseline, symptom frequency and reliever-medication use were assessed to classify children into National Asthma Education and Prevention Program-derived control categories. Long-term controller-medication use was also assessed, as well as asthma-related health care use at baseline and at 3 and 6 months.

RESULTS

The mean age was 4.4 years, 92% were black, and 39% reported long-term controller use. At baseline, 37% were classified as having mild-intermittent, 17% had mild-persistent, 21% had moderate-persistent, and 25% had severe-persistent asthma control. Significant changes in asthma control were observed over time, including 46% of children originally categorized with mild-intermittent asthma who had worsened asthma control by 3 months. Asthma control significantly predicted future health care use 3 months later but not 6 months later. Multivariate analyses showed that, once control status was known, reported use of long-term controller medication added little additional predictive value.

CONCLUSIONS

Among inner-city preschool-aged children, significant fluctuations in asthma control occur as early as 3 months after assessment. Poor control but not long-term controller-medication use is an independent predictor of future asthma-related health care use at 3 months but is not significantly predictive of 6-month outcomes. Therefore, clinicians caring for inner-city children with asthma should consider reassessing asthma control at least every 3 months to identify those at highest future risk and to provide early interventions.

Patients' perception of asthma severity

OBJECTIVES

To identify variables patients use to determine the severity of their asthma, the perceived severity (PS), using a fuzzy decision-making analysis (FDMA). To compare these variables with those involved in the assessment of asthma severity according to the global initiative for asthma (GINA) guidelines, the objective severity (OS).

PATIENTS

Outpatients (51 men, 62 women), aged (m+/-SD) 42.9+/-16.3 years with (% patients) mild intermittent (6.2), mild persistent (15.9), moderate (65.5) and severe (12.4) asthma.

DESIGN

Cross sectional, observational study.

METHODS

Both OS (rated by doctors) and PS (rated by patients) were rated as mild intermittent, mild persistent, moderate, or severe. Variables involved in OS assessment, variables self-assessed by patients (dyspnea, perceived treatment efficacy, asthma-related quality of life questionnaire [AQLQ]), patients' sociodemographic characteristics, and asthma characteristics, were evaluated with questionnaires. These variables were pooled, and considered as potential variables patients might use to determine their PS. They were tested against the PS measurement using FDMA. This identified variables patients actually used to determine PS.

RESULTS

On the day of consultation, 68.1% of patients classed their asthma as mild intermittent or mild persistent, 23.9% as moderate persistent, and 8.0% as severe persistent. There was a significant discrepancy (p<0.01) between PS and OS with a clear patient tendency to underestimate asthma severity as compared to OS. Patients determined PS level according to variables assessing their asthma perception, i.e., AQLQ measures and dyspnea, but not variables involved in OS assessment, such as symptom frequency or knowledge of their peak flow rates. Duration of asthma and treatment characteristics were also involved.

CONCLUSION

FDMA identified variables patients used to determine PS. It highlighted a discrepancy between patients' and doctors' perceptions of asthma severity, suggesting that assessment of asthma severity should consider both patients' and doctors' perceptions of the disease and includes an AQLQ measure.