Usefulness of the CAT, LCOPD, EQ-5D and COPDSS Scales in Understanding the Impact of Lung Disease in Patients with Alpha-1 Antitrypsin Deficiency

Disease burden associated with alpha-1 antitrypsin deficiency: systematic and structured literature reviews

Alpha-1 antitrypsin deficiency (AATD) is a rare genetic disorder characterised by reduced levels of circulating alpha-1 antitrypsin and an increased risk of lung and liver disease. Recent reviews of AATD have focused on diagnosis, epidemiology and clinical management; comprehensive reviews examining disease burden are lacking. Therefore, we conducted literature reviews to investigate the AATD disease burden for patients, caregivers and healthcare systems. Embase, PubMed and Cochrane libraries were searched for AATD publications from database inception to June 2021, in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Most published AATD studies were small and short in duration, with variations in populations, designs, measures and outcomes, complicating cross-study comparisons. AATD was associated with significant pulmonary and hepatic morbidity. COPD, emphysema and bronchiectasis were common lung morbidities, where smoking was a key risk factor. Fibrosis and steatosis were the most common liver complications reported in patients with a PiZ allele. Health status analyses suggested a poorer quality of life for AATD patients diagnosed with COPD versus those with non-AATD-associated COPD. The burden for caregivers included loss of personal time due to caring responsibilities, stress and anxiety. AATD was also associated with high direct medical costs and healthcare resource utilisation.

Measurement properties of preference-based measures for economic evaluation in COPD: a systematic review

PURPOSE

Preference-based measures can provide measurements of health-related quality of life and be utilized for cost-effectiveness analyses of interventions in individuals with chronic obstructive pulmonary disease (COPD). The purpose of this study is to evaluate whether generic preference-based measures are reliable, valid, and responsive in COPD.

METHODS

A systematic review was performed using the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) guidelines. Three databases were searched: MEDLINE, EMBASE, and CINAHL. Studies were included if the sample represented individuals with COPD and the aim was to evaluate one or more psychometric properties or the interpretability of generic preference-based measures.

RESULTS

Six hundred and sixty-seven abstracts were screened, 65 full-text articles were reviewed and 24 articles met the inclusion criteria. Measures which emerged from the search were the EQ-5D, the SF-6D, the Quality of Well-being scale, the 15D, and the Health Utilities Index 3. Evidence for the test-retest reliability of these measures was limited. Construct validity of the measures was well supported with correlations with generic health profiles being 0.37-0.68, and correlations with COPD-specific health profiles being 0.53-0.75. Evidence for known-groups validity of these measures was poor and data on responsiveness were mixed.

CONCLUSION

Generic preference-based measures' sensitivity to change and ability to discriminate between different disease severities in COPD was poorly supported. Future research may consider examining the development of COPD-specific preference-based measures that may allow for a more accurate detection of change and discrimination among disease severities to facilitate cost-effectiveness evaluations.

Protocol for the EARCO Registry: a pan-European observational study in patients with α1-antitrypsin deficiency

Rationale and objectives

Alpha-1 antitrypsin deficiency (AATD) is a genetic condition that leads to an increased risk of emphysema and liver disease. Despite extensive investigation, there remain unanswered questions concerning the natural history, pathophysiology, genetics and the prognosis of the lung disease in association with AATD. The European Alpha-1 Clinical Research Collaboration (EARCO) is designed to bring together researchers from European countries and to create a standardised database for the follow-up of patients with AATD.

Study design and population

The EARCO Registry is a non-interventional, multicentre, pan-European, longitudinal observational cohort study enrolling patients with AATD. Data will be collected prospectively without interference/modification of patient's management by the study team. The major inclusion criterion is diagnosed severe AATD, defined by an AAT serum level <11 µM (50 mg·dL⁻¹) and/or a proteinase inhibitor genotype ZZ, SZ or compound heterozygotes or homozygotes of other rare deficient variants. Assessments at baseline and during the yearly follow-up visits include lung function testing (spirometry, body plethysmography and diffusing capacity of the lung), exercise capacity, blood tests and questionnaires (symptoms, quality of life and physical activity). To ensure correct data collection, there will be designated investigator staff to document the data in the case report form. All data will be reviewed by the EARCO database manager.

Summary

The EARCO Registry aims to understand the natural history and prognosis of AATD better with the goal to create and validate prognostic tools to support medical decision-making.

The EARCO Registry is a non-interventional, multicentre, pan-European, longitudinal observational cohort study enrolling patients with AATD to elucidate the natural history, pathophysiology, genetics and prognosis of this conditionhttp://bit.ly/369ScCc

Redefining Cut-Points for High Symptom Burden of the Global Initiative for Chronic Obstructive Lung Disease Classification in 18,577 Patients With Chronic Obstructive Pulmonary Disease

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) can be classified into groups A/C or B/D based on symptom intensity. Different threshold values for symptom questionnaires can result in misclassification and, in turn, different treatment recommendations. The primary aim was to find the best fitting cut-points for Global initiative for chronic Obstructive Lung Disease (GOLD) symptom measures, with an modified Medical Research Council dyspnea grade of 2 or higher as point of reference.

METHODS

After a computerized search, data from 41 cohorts and whose authors agreed to provide data were pooled. COPD studies were eligible for analyses if they included, at least age, sex, postbronchodilator spirometry, modified Medical Research Council, and COPD Assessment Test (CAT) total scores.

MAIN OUTCOMES

Receiver operating characteristic curves and the Youden index were used to determine the best calibration threshold for CAT, COPD Clinical Questionnaire, and St. Georges Respiratory Questionnaire total scores. Following, GOLD A/B/C/D frequencies were calculated based on current cut-points and the newly derived cut-points.

FINDINGS

A total of 18,577 patients with COPD [72.0% male; mean age: 66.3 years (standard deviation 9.6)] were analyzed. Most patients had a moderate or severe degree of airflow limitation (GOLD spirometric grade 1, 10.9%; grade 2, 46.6%; grade 3, 32.4%; and grade 4, 10.3%). The best calibration threshold for CAT total score was 18 points, for COPD Clinical Questionnaire total score 1.9 points, and for St. Georges Respiratory Questionnaire total score 46.0 points.

CONCLUSIONS

The application of these new cut-points would reclassify about one-third of the patients with COPD and, thus, would impact on individual disease management. Further validation in prospective studies of these new values are needed.

Alpha-1 antitrypsin deficiency: outstanding questions and future directions

Background

Alpha-1 antitrypsin deficiency (AATD) is a rare hereditary condition that leads to decreased circulating alpha-1 antitrypsin (AAT) levels, significantly increasing the risk of serious lung and/or liver disease in children and adults, in which some aspects remain unresolved.

Methods

In this review, we summarise and update current knowledge on alpha-1 antitrypsin deficiency in order to identify and discuss areas of controversy and formulate questions that need further research.

Results

1) AATD is a highly underdiagnosed condition. Over 120,000 European individuals are estimated to have severe AATD and more than 90% of them are underdiagnosed.

Conclusions

2) Several clinical and etiological aspects of the disease are yet to be resolved. New strategies for early detection and biomarkers for patient outcome prediction are needed to reduce morbidity and mortality in these patients; 3) Augmentation therapy is the only specific approved therapy that has shown clinical efficacy in delaying the progression of emphysema. Regrettably, some countries reject registration and reimbursement for this treatment because of the lack of larger randomised, placebo-controlled trials. 4) Alternative strategies are currently being investigated, including the use of gene therapy or induced pluripotent stem cells, and non-augmentation strategies to prevent AAT polymerisation inside hepatocytes.

Long-term clinical outcomes following treatment with alpha 1-proteinase inhibitor for COPD associated with alpha-1 antitrypsin deficiency: a look at the evidence

Alpha-1 antitrypsin deficiency (AATD) is a common hereditary disorder caused by mutations in the SERPINA1 gene, which encodes alpha-1 antitrypsin (AAT; also known as alpha 1-proteinase inhibitor, A₁-PI). An important function of A₁-PI in the lung is to inhibit neutrophil elastase, one of various proteolytic enzymes released by activated neutrophils during inflammation. Absence or deficiency of A₁-PI leads to an imbalance between elastase and anti-elastase activity, which results in progressive, irreversible destruction of lung tissue, and ultimately the development of chronic obstructive pulmonary disease with early-onset emphysema. AATD is under-diagnosed, patients can experience long delays before obtaining an accurate diagnosis, and the consequences of delayed diagnosis or misdiagnosis can be severe. Currently, A₁-PI therapy is the only available treatment that addresses disease etiology in patients with AATD; however, demonstrating clinical efficacy of A₁-PI therapy is challenging. In order to show therapeutic efficacy with traditional endpoints such as forced expiratory volume in one second and mortality, large sample sizes and longer duration trials are required. However, AATD is a rare, slow progressive disease, which can take decades to manifest clinically and recruiting sufficient numbers of patients into prolonged placebo-controlled trials remains a significant obstacle. Despite this, the Randomized, placebo-controlled trial of augmentation therapy in Alpha 1-Proteinase Inhibitor Deficiency (RAPID) and RAPID Extension trial, the largest clinical program completed to date, utilized quantitative chest computed tomography as a sensitive and specific measure of the extent of emphysema. Findings from the RAPID/RAPID Extension program definitively confirmed the benefits of A₁-PI therapy in slowing disease progression and provided evidence of a disease-modifying effect of A₁-PI therapy in patients with AATD. These findings suggest that the early introduction of treatment in patients with severe emphysema-related AATD may delay the time to death, lung transplantation or crippling respiratory complaints. In addition, there is now limited evidence that A₁-PI therapy provides a gain of more than five life-years, supporting previous observations based on registry data. With the clinical efficacy of A₁-PI therapy now demonstrated, further studies are required to assess long-term outcomes.

Deterioration of quality of life is associated with the exacerbation frequency in individuals with alpha-1-antitrypsin deficiency - analysis from the German Registry

BACKGROUND

Alpha-1-antitrypsin deficiency (AATD) is a rare hereditary disease that is associated with a higher risk to develop chronic obstructive pulmonary disease and liver cirrhosis. Previous cross-sectional studies on AATD individuals have shown a relationship between worse St George's Respiratory Questionnaire (SGRQ) scores and elevated exacerbation rate or high cigarette consumption. There is a lack of longitudinal data on the relationship between the exacerbation rate and worsening of SGRQ during disease. The aim of this study was to provide not only cross-sectional data but also information about the deterioration in quality of life over a follow-up period up to 7 years (median follow-up period of 3.33 years).

METHODS

We investigated questionnaire-based data of the German AATD registry concerning the relationship between SGRQ and exacerbation frequency, smoking history, forced expiratory volume in 1 second (FEV1) and carbon monoxide diffusion capacity (DLCO) first in cross-sectional analysis and later in longitudinal analysis.

RESULTS

Eight hundred sixty-eight individuals with protease inhibitor ZZ (PiZZ) genotype with an average age of 52.6±12.8 years had an SGRQ score of 45.7±20.6. SGRQ significantly correlated with the exacerbation frequency within the last 2 years (r=0.464; P<0.001), smoking history (r=0.233; P<0.001), FEV1 (r=-0.436; P<0.001), DLCO (r=-0.333; P<0.001), and patients' age (r=0.292; P<0.001). Individuals with occupational dust exposure had significantly worse quality of life (P<0.001). Mean annual deterioration of SGRQ in all patients with available follow-up data (n=286) was 1.21±4.45 points per year. Univariate and multivariate analysis showed a significant relationship between worsening of SGRQ/year and exacerbation frequency in the follow-up period (r=0.144; P=0.015).

CONCLUSION

Worsening of SGRQ is associated with the exacerbation frequency in individuals with PiZZ AATD.

Costs and health-related quality of life in Alpha-1-Antitrypsin Deficient COPD patients

BACKGROUND

Alpha-1-Antitrypsin Deficiency (AATD) is an economically unexplored genetic disease.

METHODS

Direct and indirect costs (based on self-reported information on healthcare utilization) and health-related quality of life (HRQL, as assessed by SGRQ, CAT, and EQ-5D-3 L) were compared between 131 AATD patients (106 with, 25 without augmentation therapy (AT)) and 2,049 COPD patients without AATD participating in the COSYCONET COPD cohort. The medication costs of AT were excluded from all analyses to reveal differences associated with morbidity profiles. The association of AATD (with/without AT) with costs or HRQL was examined using generalized linear regression modelling (GLM) adjusting for age, sex, GOLD grade, BMI, smoking status, education and comorbidities.

RESULTS

Adjusted mean direct annual costs were €6,099 in AATD patients without AT, €7,117 in AATD patients with AT (excluding costs for AT), and €7,460 in COPD patients without AATD. AATD with AT was significantly associated with higher outpatient (+273%) but lower inpatient (-35%) and medication costs (-10%, disregarding AT) compared with COPD patients without AATD. There were no significant differences between groups regarding indirect costs and HRQL.

CONCLUSION

Apart from AT costs, AATD patients tended to have lower, though not significant, overall costs and similar HRQL compared to COPD patients without AATD. AT was not associated with lower costs or higher HRQL.

TRIAL REGISTRATION

NCT01245933.

Health-related quality of life in patients with alpha-1 antitrypsin deficiency: the French experience

The French registry of patients with alpha-1 antitrypsin deficiency (AATD)-associated emphysema was launched in 2006. Here, we aimed to report on the baseline characteristics of these patients, their health-related quality of life (HRQoL) and factors associated with HRQoL. Another goal was to survey the practices of French physicians regarding augmentation therapy. We included 273 patients with AATD, emphysema, obstructive-pattern [forced expiratory volume in 1 sec/forced volume capacity (FEV1/FVC) < 0.7], FEV1 ≤ 80% predicted. Mean (SD) age was 51.8 (11.1) years, 240 (87.9%) of patients were smokers or ex-smokers, mean (SD) FEV1 was 40.5% (15.7) predicted. Mean (SD) SGRQ score was 49.0 (20.0) and was higher for females than males (52.7 [20.7] vs 46.8 [18.2]; p = 0.01). Dyspnea showed the strongest association with SGRQ score (r = 0.65; p < 0.0001), followed by chronic bronchitis (r = 0.33; p < 0.0001) and wheezing (r = 0.32; p < 0.0001). Number of exacerbations in the year before inclusion was also significantly associated with SGRQ score (r = 0.36; p < 0.0001). The SGRQ score was associated with the 6-min walking distance (r = -0.53, p < 0.0001), FEV1 (% predicted, r = -0.53, p < 0.0001) and DLCO (% predicted, r = -0.52, p < 0.0001). It was also associated with the GOLD 2006 (r = 0.53; p < 0.0001) and GOLD 2011 (r = 0.63; p< 0.0001) classifications and with the BODE index (r = 0.37; p < 0.0001). Age, history of tobacco smoking or current smoking did not show any association with SGRQ total scores. On multivariate analysis, a model including age, chronic bronchitis, dyspnea (MRC scale), diffusing lung capacity and 6-min walking distance explained 57% of the variation in the score. The French registry provides important insights into the clinical characteristics of French patients with AATD-related emphysema.