Comparison of health-related quality of life measures in asthma-COPD overlap

OBJECTIVE

The Asthma Quality of Life Questionnaire (AQLQ) and COPD assessment test (CAT) are used to assess the health status of asthma and chronic obstructive pulmonary disease (COPD), respectively. However, whether these questionnaires are appropriate in patients with asthma-COPD overlap (ACO) has not been reported. This study aimed to evaluate the performance of the AQLQ and CAT in subjects with ACO.

METHODS

Subjects were enrolled from two previously described observational studies in Beijing, China. ACO was defined by a consensus definition from a roundtable discussion. All subjects completed the AQLQ, CAT, St George's Respiratory Questionnaire (SGRQ), pulmonary function tests, and the Asthma Control Questionnaire (ACQ)-5. Cross-sectional construct validity was evaluated by correlating the AQLQ and CAT with SGRQ score and other measures of asthma and COPD severity.

RESULTS

147 subjects with ACO were recruited. There were floor effects on non-respiratory components of the CAT, and ceiling effects on emotion domains of the AQLQ. Both questionnaires were significantly correlated with ACQ-5 score but were not correlated with FEV1% predicted or FVC% predicted. The AQLQ and CAT were strongly correlated with SGRQ score (r = -0.657 and r = 0.623, respectively). Multivariable linear regression analysis showed that the AQLQ (standardized β-coefficient = -0.449, p < .001) had a stronger association with SGRQ score compared with CAT (standardized β-coefficient = 0.211, p = .023).

DISCUSSION

The AQLQ and CAT were both valid for assessing the health-related quality of life in subjects with ACO, but the AQLQ performed better than CAT.

Role of Type2 Inflammatory Biomarkers in Chronic Obstructive Pulmonary Disease

Airway inflammation in chronic obstructive pulmonary disease (COPD) is typically thought to be driven by Type1 immune responses, while Type2 inflammation appears to be present in definite proportions in the stable state and during exacerbations. In fact, some COPD patients showed gene expression of Type2 inflammation in the airway, and this subset was associated with the inhaled corticosteroid (ICS) response. Interestingly enough, the relationship between COPD and diseases associated with Type2 inflammation from the perspective of impaired lung development is increasingly highlighted by recent epidemiologic studies on the origin of COPD. Therefore, many researchers have shown an interest in the prevalence and the role of existent Type2 biomarkers such as sputum and blood eosinophils, exhaled nitric oxide fraction, and atopy, not only in asthma but also in COPD. Although the evidence about Type2 biomarkers in COPD is inconsistent and less robust, Type2 biomarkers have shown some potential when analyzing various clinical outcomes or therapeutic response to ICS. In this article, we review the existent and emerging Type2 biomarkers with clinically higher applicability in the management of COPD.

[The risk of bronchial asthma exacerbations among smokers with asthma-chronic obstructive pulmonary disease overlap after inpatient treatment]

AIM

To assess the risk of exacerbations of bronchial asthma (BA) in smoking patients with the asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) after inpatient treatment.

MATERIALS AND METHODS

36 smokers with ACO (main group) and 36 non-smoking patients (control group) with severe or moderate exacerbation of bronchial asthma were examined. Assessment of the severity of exacerbation of BA before treatment, levels of control and risk of exacerbations of BA after treatment was determined according to the Federal clinical guidelines for the diagnosis and treatment of BA (2016). Spirometry, monitoring of blood oxygenation using transcutaneous spectral pulse oximetry and enzyme immunoassay for determination of matrix metalloproteinases 9 were performed. Smoking experience, smoking index and pack/years index were taken into account in patients with ACO. The carboxyhaemoglobin level was analyzed by the carbon monoxide fraction in the exhaled air.

RESULTS

For the first time in patients with the ACO, the ability of heavy tobacco smoking and associated decrease in blood oxygenation to potentiate the negative impact of other predictors on the risk of exacerbations of the underlying disease was revealed. In smoking patients with the ACO, for the first time, a direct association of higher levels of matrix metalloproteinases 9 (measured before inpatient treatment) with such a predictor of the risk of further exacerbations of the disease as more frequent detection of symptoms of uncontrolled BA was revealed. In non-smoking patients with BA, a direct relationship between increased sputum secretion and eosinophilia of blood and/or sputum (a predictor of exacerbation of BA) and the relative duration of episodes of decreased blood oxygenation was established.

CONCLUSION

It was found that intensive and prolonged smoking increases the duration and reduces the effectiveness of inpatient treatment of patients with ACO, contributing to the preservation of air traps and low (forced expiratory volume in 1 second 60%) ventilation capacity of the lungs with the persistence of moderately reduced blood oxygenation; the risk of further exacerbations of BA in this phenotype of patients is significantly higher than in non-smoking patients with BA without combination with COPD.

Prospective development of practical screening strategies for diagnosis of asthma-COPD overlap

BACKGROUND AND OBJECTIVE

ACO is a syndrome with high prevalence. However, a pragmatic diagnostic criterion to differentiate ACO is non-existent. We aimed to establish an effective model for screening ACO.

METHODS

A multicentre survey was developed to assess the clinical criteria considered important and applicable by pulmonologists for screening ACO. These experts were asked to take the surveys twice. The expert grading method, analytic hierarchy process and ROC curve were used to establish the model, which was then validated by a cross-sectional study of 1066 patients. The GINA/GOLD document was the gold standard in assessing this model.

RESULTS

Increased variability of symptoms, paroxysmal wheezing, dyspnoea, historical diagnosis of COPD or asthma, allergic constitution, exposure to risk factors, the FEV₁ /FVC < 70% and a positive BDT were important for screening ACO. According to the weight of each criterion, we confirmed that patients meeting six or more of these eight criteria should be considered to have ACO. We called this Chinese screening model for ACO 'CSMA'. It differentiated patients with ACO with a sensitivity of 83.33%, while the sensitivity of clinician-driven diagnosis had a sensitivity of only 42.73%.

CONCLUSION

CSMA is a workable model for screening ACO and provides a simple tool for clinicians to efficiently diagnose ACO.

[Correlation between expressions of myeloperoxidase and eosinophil cationic protein in sputum and clinical features of asthma-chronic obstructive pulmonary disease overlap]

OBJECTIVE

To observe the role of myeloperoxidase(MPO)and eosinophilic cationic protein(ECP)in the airway inflammation and their correlation with clinical feature in asthma-COPD overlap (ACO) patients.

METHODS

Twenty patients with COPD, 20 with asthma, 20 with ACO and 20 control subjects underwent pulmonary function test for measurement of forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), peak expiratory flow (PEF), and maximum midexpiratory flow (MMF_25/75). COPD assessment test (CAT) was used to evaluate the clinical symptoms of the patients with COPD and ACO. The asthma control test (ACT) was used to evaluate the asthma control in the patients with asthma and ACO. Induced sputum samples were collected from the subjects for analysis of neutrophil and eosinophil ratios, and enzyme-linked immunosorbent assay was used to determine the expression levels of MPO and ECP in the sputum.

RESULTS

No significant difference was observed in the CAT scores between ACO group and COPD group (P&gt; 0.05). Compared with the asthma group, the patients with ACO had significantly lower ACT scores and lower FEV₁, PEF and MMF_25/75 (P &lt; 0.05). The patients with ACO had significantly higher FVC and sputum eosinophil ratio than those with COPD (P &lt; 0.05), and a higher sputum neutrophil ratio than those with asthma (P &lt; 0.01). In ACO group, the MPO level in sputum was significantly higher than that in the asthma group (P &lt; 0.05), while sputum ECP level was significantly higher than that in both the asthma group and COPD group (P &lt; 0.05 or 0.01). In ACO group, sputum MPO level was positively correlated with sputum neutrophil ratio (r=0.8358, P &lt; 0.01) but was not correlated with CAT score or FEV₁ (P&gt; 0.05); sputum ECP level was positively correlated with sputum eosinophil ratio (r=0.4666, P &lt; 0.05) and was inversely correlated with ACT score (r=-0.4966, P &lt; 0.05) and FEV₁ (r=-0.4610, P &lt; 0.05).

CONCLUSIONS

Both neutrophilic and eosinophilic inflammations occur in the airway of patients with ACO, and their sputum ECP level is negatively correlated with asthma control and obstructive airflow limitation.