Survival benefit of lung transplantation for chronic obstructive pulmonary disease in Sweden

Physical Activity, Exercise Capacity and Sedentary Behavior in People with Alpha-1 Antitrypsin Deficiency: A Scoping Review

Alpha-1 antitrypsin deficiency (AATD) is a hereditary disorder and a genetic risk factor for chronic obstructive pulmonary disease (COPD). Physical activity (PA) is important for the prevention and treatment of chronic disease. Little is known about PA in people with AATD. Therefore, we aimed to map the research undertaken to improve and/or measure PA, sedentary behaviour (SB) or exercise in people with AATD. Searches were conducted in CINAHL, Medline, EMBASE and clinical trial databases for studies published in 2021. Databases were searched for keywords (physical activity, AATD, exercise, sedentary behavior) as well as synonyms of these terms, which were connected using Boolean operators. The search yielded 360 records; 37 records were included for review. All included studies (n = 37) assessed exercise capacity; 22 studies reported the use of the six-minute walk test, the incremental shuttle walk test and cardiopulmonary exercise testing were reported in three studies each. Other objective measures of exercise capacity included a submaximal treadmill test, the Naughton protocol treadmill test, cycle ergometer maximal test, endurance shuttle walk test, constant cycle work rate test, a peak work rate test and the number of flights of stairs a participant was able to walk without stopping. A number of participant self-reported measures of exercise capacity were noted. Only one study aimed to analyze the effects of an intensive fitness intervention on daily PA. One further study reported on an exercise intervention and objectively measured PA at baseline. No studies measured SB. The assessment of PA and use of PA as an intervention in AATD is limited, and research into SB absent. Future research should measure PA and SB levels in people with AATD and explore interventions to enhance PA in this susceptible population.

Alpha-1 antitrypsin deficiency: current therapy and emerging targets

INTRODUCTION

Alpha1 antitrypsin deficiency (AATD), a common hereditary disorder affecting mainly lungs, liver and skin has been the focus of some of the most exciting therapeutic approaches in medicine in the past 5 years. In this review, we discuss the therapies presently available for the different manifestations of AATD and new therapies in the pipeline.

AREAS COVERED

We review therapeutic options for the individual lung, liver and skin manifestations of AATD along with approaches which aim to treat all three. Along with this renewed interest in treating AATD come challenges. How is AAT best delivered to the lung? What is the desired level of AAT in the circulation and lungs which therapeutics should aim to provide? Will treating the liver disease increase the potential for lung disease? Are there treatments to target the underlying genetic defect with the potential to prevent all aspects of AATDrelated disease?

EXPERT OPINION

With a relatively small population able to participate in clinical studies, increased awareness and diagnosis of AATD is urgently needed. Better, more sensitive clinical parameters will assist in the generation of acceptable and robust evidence of therapeutic effect for current and emerging treatments.

Lung and liver transplantation in patients with alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin (AAT) augmentation is effective in slowing the progression of emphysema due to AAT deficiency (AATD) but cannot prevent eventual progression to end-stage lung disease and complete respiratory failure, which is the leading cause of death for individuals with severe AATD. When patients develop end-stage lung disease, lung transplantation is the only treatment option available, and this can improve lung physiology and patient health status. The available data suggest that survival rates for lung transplantation are significantly higher for patients with AATD-related chronic obstructive pulmonary disease (COPD) compared with non-AATD-related COPD, but, conversely, there is a higher risk of common post-lung transplant complications in patients with AATD versus non-AATD COPD. Nevertheless, lung transplantation (single and bilateral) is favorable for patients with AATD. After respiratory failure, the second leading cause of death in patients with AATD is liver disease, for example, cirrhosis and hepatocellular carcinoma, caused by the accumulation of mutant forms of AAT retained within the liver. As with lung disease, the only treatment option for end-stage liver disease is liver transplantation. Survival rates for patients with AATD undergoing liver transplantation are also favorable, and patients, particularly pediatric patients, have benefitted from advancements in peri-/post-surgical care. As the majority of AAT is produced by the liver, the AAT phenotype of the recipient becomes that of the donor, meaning that AAT serum levels should be normalized (if the donor is AAT-replete), halting further lung and liver disease progression. However, post-liver transplant respiratory function may continue to decline in line with normal age-related lung function decline. In the most severe cases, where patients have simultaneous end-stage lung and liver disease, combined lung and liver transplantation is a treatment option with favorable outcomes. However, there is very little information available on this procedure in patients with AATD.

Clinical outcomes and survival following lung transplantation in patients with Alpha-1 antitrypsin deficiency

OBJECTIVE

The primary intention of our study is to describe disease-specific outcomes in patients with alpha-1 antitrypsin deficiency (AATD) following lung transplantation (LT).

METHODS

We reviewed the Organ Procurement and Transplant Network database to identify AATD patients who have undergone LT in the United States.

RESULTS

Two thousand two hundred and thirteen patients with AATD underwent LT between March 1992 and September 2019. A total of 1556 patients received LT with a median age at listing was 51 years. The median time spent on the LT waitlist was 263 days. The median ischemic time was 4.75 h. The Kaplan-Meier survival analysis following LT for AATD patients at 1-, 5-, and 10 years was 82%, 56%, and 34%, at 1-, 5-, and 10 years, respectively. The median survival time post-LT is 6.4 years (Interquartile range 5.6-6.8 years). The post-LT survival was significantly better in double LT compared to single LT (Median 7.7 vs 4.4 years, p < 0.001). Increasing age, presence of CMV mismatch, reintubation prior to discharge, and requiring treatment for rejection within one year of transplantation did impact post-LT mortality.

CONCLUSION

The median survival after LT in AATD is 6.4 years and is similar to other lung diseases. When compared to usual COPD LT, AATD patients have increased post-LT mortality due to infections and liver disease. Recipients of a double lung transplant had a favorable outcome compared to single lung transplant.

Lung transplantation for chronic obstructive pulmonary disease: past, present, and future directions

PURPOSE OF REVIEW

Lung transplantation offers an effective treatment modality for patients with end-stage chronic obstructive pulmonary disease (COPD). The exact determination of when to refer, list, and offer transplant as well as the preferred transplant procedure type remains unclear. Additionally, there are special considerations specific to patients with COPD being considered for lung transplantation, including the implications of single lung transplantation on lung cancer risk, native lung hyperinflation, and overall survival.

RECENT FINDINGS

The International Society for Heart and Lung Transplantation's most recent recommendations rely on an assessment of COPD severity based on BODE index. Despite the lack of evidence supporting a mortality benefit of bilateral over single lung transplantation for COPD patients, the majority of transplants performed in this population remain bilateral. Some of the concerns specific to single lung transplantation remain the possibility of de novo native lung cancer and the hemodynamic and physiologic implications of acute native lung hyperinflation.

SUMMARY

COPD remains the most common worldwide indication for lung transplantation. Ongoing study is still required to assess the overall survival benefit of lung transplantation and assess the overall quality of life impact on the COPD patient population.

Transplant options for end stage chronic obstructive pulmonary disease in the context of multidisciplinary treatments

Lung transplantation (LTx) in advanced stage chronic obstructive pulmonary disease (COPD) patients is associated with significant improvement in lung function and exercise capacity. However, demonstration that the procedure also provides a survival benefit has been more elusive compared to other respiratory conditions. Identification of patients with increased risk of mortality is crucial: a low forced expiratory volume in 1 second (FEV₁) is perhaps the most common reason for referral to a lung transplant center, but in itself is insufficient to identify which COPD patients will benefit from LTx. Many variables have to be considered in the selection of candidates, time for listing, and choice of procedure: age, patient comorbidities, secondary pulmonary hypertension, the balance between individual and community benefit. This review will discuss patient selection, transplant listing, potential benefits and critical issues of bilateral (BLTx) and single lung (SLTx) procedure, donor-to-recipient organ size-matching; furthermore, it will describe LTx outcomes and its effects on recipient survival and quality of life.

Lung transplantation and survival outcomes in patients with oxygen-dependent COPD with regard to their alpha-1 antitrypsin deficiency status

Background

Individuals with severe alpha-1 antitrypsin deficiency (AATD) have an increased risk of developing COPD. However, outcomes during long-term oxygen therapy (LTOT) in patients with severe AATD and hypoxemia are unknown.

Patients and methods

This was a prospective, population-based, consecutive cohort study of patients on LTOT due to COPD in the period from January 1, 1987, to June 30, 2015, in the Swedish National Registry for Respiratory Failure (Swedevox). Severe AATD was identified using the Swedish AATD registry and confirmed by isoelectric focusing. Data on lung transplantation (LTx) were obtained from the two lung transplantation centers in Sweden. Mortality and causes of death were assessed based on the National Causes of Death Registry and analyzed using multivariable Cox regression.

Results

A total of 14,644 patients who started LTOT due to COPD were included in this study. No patient was lost to follow up. Patients with AATD were younger, included more males and more never smokers, and had fewer comorbidities. During a median follow-up of 1.6 years (interquartile range [IQR], 2.7) on LTOT, patients without severe AATD had a higher mortality, hazard ratio [HR] 1.53 (95% CI, 1.24–1.88), adjusting for age, sex, smoking status, body mass index, performance status, level of hypoxemia, and comorbidities. Cardiovascular deaths were increased. A higher proportion of AATD patients underwent LTx, 53 (19%) vs 118 (1%). Survival after LTx was similar for AATD and non-AATD patients and was predicted by age.

Conclusion

In oxygen-dependent COPD, patients with severe AATD have a longer survival time on LTOT, but they have a similar prognosis after lung transplantation compared with patients without AATD.

Risk of cancer after lung transplantation for COPD

Background

The risk of cancer is increased and affects survival after lung transplantation (LTx), but has not been well characterized in COPD. We aimed to evaluate the incidence and prognosis of cancer following LTx for COPD.

Methods

A prospective, population-based study of patients undergoing LTx for end-stage COPD at the two transplantation centers in Sweden between 1990−2013, with follow-up for incident cancer and death, using national registers. The excess risk of cancer was calculated as standardized incidence ratios compared with the general population matched for age, sex, and calendar year. Risk factors for cancer were analyzed using Fine-Gray regression, and survival after cancer diagnosis with Kaplan–Meier.

Results

In total, 331 patients (mean age 55.4 years; 64% women; 97% former smokers) were included. At a median follow-up of 2.8 years, 35% of patients had developed cancer and the risk was increased more than 10-fold ([95% CI] 8.1−11.8). The highest excess risks were for non-Hodgkin lymphoma (20.8−66.7), skin cancer (20.3−35.2), lung (11.7−31.2), liver (3.6−51.6), and colorectal cancer (6.1−19.5). Median survival was longer for skin cancer (8 years; 95% CI, 3−15) compared with non-skin cancer (4 years; 95% CI, 2.8−4.8; p<0.001).

Conclusion

The cancer risk is markedly increased after LTx for COPD. It could not be predicted by the factors evaluated, but contributed significantly to a negative prognosis.

Survival after lung transplantation in recipients with alpha-1-antitrypsin deficiency compared to other forms of chronic obstructive pulmonary disease: a national cohort study

Alpha-1-antitrypsin deficiency (AATD) is grouped with chronic obstructive pulmonary disease (COPD); however, this may not be appropriate. This study assessed whether AATD confers a different prognosis than COPD following lung transplantation. We employed the United Network for Organ Sharing (UNOS) database, grouping patients by diagnoses of AATD or COPD. Kaplan-Meier methods and Cox modeling were performed to determine the association of diagnosis and overall survival. Of 9569 patients, 1394 (14.6%) had a diagnosis of AATD. Patients with AATD who received a single-lung transplant had reduced 1-year survival [adjusted hazard ratio (AHR): 1.68, 95% CI: 1.26, 2.23]. Among patients who received a bilateral lung transplant, there was no significant difference in survival by diagnosis (AHR for AATD as compared to COPD: 0.96, 95% CI: 0.82, 1.12). After the implementation of the lung allocation score (LAS), there was no significant difference in survival among patients who received a single (AHR: 1.15, 95% CI: 0.69, 1.95) or bilateral (AHR: 0.99, 95% CI: 0.73, 1.34) lung transplant by diagnosis. Lung transplantation is increasingly employed in the care of the patient with COPD. Although recipients undergoing LTX for AATD are at increased risk of both acute rejection and airway dehiscence post-transplant, in the post-LAS era, survival rates are similar for recipients with AATD in comparison with COPD.

α1-Antitrypsin Deficiency

α1-Antitrypsin deficiency is an autosomal codominant condition that predisposes to emphysema and cirrhosis. The condition is common but grossly under-recognized. Identifying patients' α1-antitrypsin deficiency has important management implications (ie, smoking cessation, genetic and occupational counseling, and specific treatment with the infusion of pooled human plasma α1-antitrypsin). The weight of evidence suggests that augmentation therapy slows the progression of emphysema in individuals with severe α1-antitrypsin deficiency.

Lung transplantation in chronic obstructive pulmonary disease: patient selection and special considerations

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality and morbidity. Lung transplantation is one of the few treatments available for end-stage COPD with the potential to improve survival and quality of life. The selection of candidates and timing of listing present challenges, as COPD tends to progress fairly slowly, and survival after lung transplantation remains limited. Though the natural course of COPD is difficult to predict, the use of assessments of functional status and multivariable indices such as the BODE index can help identify which patients with COPD are at increased risk for mortality, and hence which are more likely to benefit from lung transplantation. Patients with COPD can undergo either single or bilateral lung transplantation. Although many studies suggest better long-term survival with bilateral lung transplant, especially in younger patients, this continues to be debated, and definitive recommendations about this cannot be made. Patients may be more susceptible to particular complications of transplant for COPD, including native lung hyperinflation, and development of lung cancer.

Lung transplantation in chronic obstructive pulmonary disease: long-term survival, freedom from bronchiolitis obliterans syndrome, and factors influencing outcome

OBJECTIVES

Lung transplantation (LTx) remains the definitive treatment for end-stage lung failure, whereas chronic obstructive pulmonary disease (COPD) represents one of the main diagnoses leading to the indication for a transplant. We sought to assess long-term outcomes after LTx in patients diagnosed with COPD and analyze factors influencing outcome in this frequent patient cohort.

METHODS

Between January 2007 and November 2013, a total of 88 LTx were performed in patients with COPD in our institution. Patients with emphysema associated with alpha1-antitrypsin deficiency were excluded from this observation. The study design was a retrospective review of the prospectively collected data. A large number of pre-, intra-, and postoperative variables were analyzed including long-term survival and freedom from bronchiolitis obliterans syndrome (BOS). Furthermore, impact of different variables on survival was analyzed.

RESULTS

Preoperative donor data indicated a large proportion of marginal donors. While the overall cumulative survival after six yr was 57.4%, the results in terms of BOS-free survival in long-term follow-up were 39.7% after six yr. Patients with COPD were also associated with a low incidence (2.3%) of the need for postoperative extracorporeal life support (ECLS).

CONCLUSIONS

Long-term results after LTx in patients with COPD are acceptable with excellent survival, freedom from BOS, and low use of ECLS postoperatively despite permanently increasing proportion of marginal organs used.