Prognostic value of cluster analysis of severe asthma phenotypes.

BACKGROUND: Cross-sectional severe asthma cluster analysis identified different phenotypes. We tested the hypothesis that these clusters will follow different courses. OBJECTIVE: We aimed to identify which asthma outcomes are specific and coherently associated with these different phenotypes in a prospective longitudinal cohort. METHODS: In a longitudinal cohort of 112 patients with severe asthma, the 5 Severe Asthma Research Program (SARP) clusters were identified by means of algorithm application. Because patients of the present cohort all had severe asthma compared with the SARP cohort, homemade clusters were identified and also tested. At the subsequent visit, we investigated several outcomes related to asthma control at 1 year (6-item Asthma Control Questionnaire [ACQ-6], lung function, and medication requirement) and then recorded the 3-year exacerbations rate and time to first exacerbation. RESULTS: The SARP algorithm discriminated the 5 clusters at entry for age, asthma duration, lung function, blood eosinophil measurement, ACQ-6 scores, and diabetes comorbidity. Four homemade clusters were mostly segregated by best ever achieved FEV1 values and discriminated the groups by a few clinical characteristics. Nonetheless, all these clusters shared similar asthma outcomes related to asthma control as follows. The ACQ-6 score did not change in any cluster. Exacerbation rate and time to first exacerbation were similar, as were treatment requirements. CONCLUSION: Severe asthma phenotypes identified by using a previously reported cluster analysis or newly homemade clusters do not behave differently concerning asthma control-related outcomes, which are used to assess the response to innovative therapies. This study demonstrates a potential limitation of the cluster analysis approach in the field of severe asthma.

Impact of rhinitis on asthma control in children: association with FeNO.

BACKGROUND: The prevalence of rhinitis is high and frequently observed in association with asthma. Although the persistence of predisposing factors such as rhinitis is frequently observed in adults, this has not yet been confirmed in children. AIMS: The aim of this present work is to show the relationship between rhinitis and asthma control in asthmatic children. METHODS: The authors carried out a cross-sectional study by collecting clinical, spirometric, and fractional exhaled nitric oxide (FeNO) data in children aged from 4 to 17 years. RESULTS: One hundred seventeen children were included. Asthma control was optimal in 37.6%, suboptimal in 55.5% and poor in 7.3% of cases. A 74.3% of children were atopic and 62.5% had symptoms 34 of rhinitis. Rhinitis was more frequent when control of asthma was worse (p = .0001). Age (p = .002), asthma control (p < .001), atopy (p = .001), and presence of rhinitis (p = .012) were significantly associated with FeNO. CONCLUSIONS: Our study confirms the strong relationship between upper airways and poor asthma control in the asthmatic child. Symptoms of rhinitis may be partly responsible for the increased fractional exhaled nitric oxide (FeNO) level, independently of the control of asthma. Evaluation of rhinitis should be included to improve assessment of asthma control in children.

Interference of psychological factors in difficult-to-control asthma.

BACKGROUND: Most patients with asthma can be controlled with suitable medication, but 5-10% of them remain difficult to control despite optimal management. OBJECTIVE: We investigated whether patients with difficult-to-control asthma (DCA) or controlled asthma (CA) differ with respect to psychological factors, such as general control beliefs on life events. METHODS: DCA was defined as an absence of control despite optimal management. Recent control was measured using the Asthma Control Questionnaire. General control beliefs were investigated using a Locus of Control scale (LOC). RESULTS: Patients with DCA had a significantly higher external LOC as compared to patients with CA (P=0.01). In the DCA group, the hospital admission rate was highly significant in association with the external LOC (P=0.004) as compared to the internal LOC trend. CONCLUSION: This study showed that patients with DCA had different general control beliefs which might have hampered their management and interfered with their therapeutic adherence. The present findings could enhance management of DCA in a clinical setting.

Persistent severe hypereosinophilic asthma is not associated with airway remodeling.

Hypereosinophilic asthma (HEA) is considered as a specific severe asthma phenotype. Whether eosinophils have a link with airway remodeling characterized by pathological (thickening of the basement membrane), functional (persistent airflow impairment and decline in lung function) and imaging features (increase airway wall thickness at CT scan) is still debated. In a one year prospective cohort of 142 severe asthma patients (according to IMI), 14 persistent HEA patients (defined by a persistent blood eosinophilia >500/mm(3) at two consecutive visits) were identified and compared with ten patients without any blood eosinophilia during the follow-up period (NEA, blood eosinophilia always <500/mm(3)). Airflow and lung volumes were recorded. Bronchial biopsies obtained at enrollment were stained for eosinophils (EG2) and basement membrane thickness (BM) was quantified. Imaging by CT scan acquisition was standardized and bronchial abnormalities quantified. ACQ score and exacerbations were prospectively recorded. HEA was not associated with preeminent features of airway remodeling assessed by airflow impairment (Best ever FEV1 values 97% ± 20 in HEA vs. 80 ± 24% in NEA, p = 0.020), decline of FEV1 (FEV1 Decline 40 ± 235 ml/y in HEA vs. 19 ± 40 ml/y in NEA, P = 0.319), submucosal abnormalities (BM thickness 7.80 ± 2.66 µm in HEA vs. 6.84 ± 2.59 in NEA, p = 0.37) and airway wall thickening at CT-scan (0.250 ± 0.036 mm vs. 0.261 ± 0.043, p = 0.92). Eosinophils blood count was inversely correlated with semiquantitative imaging score (rho -0.373, p = 0.039). Smoking history and positive skin prick tests were independent risk factors for increased BM thickening. Outcomes were similar in both populations (Control and exacerbations). Persistent HEA is not associated with evidences of airway remodeling.

Severe asthma and adherence to peak flow monitoring: longitudinal assessment of psychological aspects.

BACKGROUND: Adherence in severe asthma is a difficult health problem. Although psychosocial factors may be responsible for non-adherence, few longitudinal studies have investigated their link with adherence, with most studies having focused on pharmacology. METHODS: Sixty patients with severe asthma were recruited. Adherence was electronically monitored using peak flow measurements at entry and after 1 year of follow-up. Eysenck's Personality Inventory, Rotter's Locus of Control (LOC), and health control beliefs were all studied. Multiple logistic regression (MLR) was used for risk calculations. RESULTS: Initially, subjects with poor adherence had an external LOC (P=.001) and a high extraversion score (P=.003) compared to those with good adherence. The lie score was high in all patients. Nocturnal awakenings were highly significantly correlated with poor adherence (P=.006). After 1 year, patient adherence, extraversion, and neuroticism remained unchanged. The LOC changed in subjects with poor adherence, showing a less "external" orientation (P=.007). The health parameters were better at the end of the study. By MLR analysis, externality, extraversion, and low social desirability were associated with poor adherence. Patients with poor adherence had a greater probability of nocturnal symptoms. CONCLUSION: No specific personality type was associated with lack of adherence in the present study, but a high extraversion score, a low social desirability score, and a high level of externality were all predictors of poor adherence.