Recurrence of Pulmonary Emphysema in an α-1 Proteinase Inhibitor-deficient Lung Transplant Recipient

Imaging in Lung Transplantation: Surgical Techniques and Complications

Lung transplant is an established treatment for patients with end-stage lung disease. As a result, there is increased demand for transplants. Despite improvements in pretransplant evaluation, surgical techniques, and postsurgical care, the average posttransplant life expectancy is only around 6.5 years. Early recognition of complications on imaging and treatment can improve survival. Knowledge of surgical techniques and imaging findings of surgical and nonsurgical complications is essential. This review covers surgical techniques and imaging appearance of postsurgical and nonsurgical complications, including allograft dysfunction, infections, neoplasms, and recurrence of primary lung disease.

Lung transplantation for COPD/pulmonary emphysema

COPD and α-1 antitrypsin deficiency emphysema remain one of the major indications for lung transplantation. If all other treatment possibilities are exhausted or not possible (including rehabilitation, oxygen therapy, noninvasive ventilation, lung volume reduction), patients may qualify for lung transplantation. Strict selection criteria are implemented with a lot of relative and absolute contraindications. Because of an ongoing donor shortage, only a minority of endstage COPD patients will finally get transplanted. The procedure may involve a single or a double lung transplantation, dependent on the experience of the centre, the waiting list, the availability of donor lungs and the patient's risk-benefit ratio. In general, the life expectancy as well as the health-related quality of life after lung transplantation for COPD are usually increased, and may be somewhat better after double compared with single lung transplantation. Several specific complications can be encountered, such as the development of solid organ cancer and chronic lung allograft dysfunction, which develops in up to 50% of patients within 5 years of their transplant and has a major impact on long-term survival, because of the current inefficient treatment modalities.

Recurrence of primary disease following lung transplantation

Lung transplant has become definitive treatment for patients with several end-stage lung diseases. Since the first attempted lung transplantation in 1963, survival has significantly improved due to advancement in immunosuppression, organ procurement, ex vivo lung perfusion, surgical techniques, prevention of chronic lung allograft dysfunction and bridging to transplant using extracorporeal membrane oxygenation. Despite a steady increase in number of lung transplantations each year, there is still a huge gap between demand and supply of organs available, and work continues to select recipients with potential for best outcomes. According to review of the literature, there are some rare primary diseases that may recur following transplantation. As the number of lung transplants increase, we continue to identify disease processes at highest risk for recurrence, thus shaping our future approaches. While the aim of lung transplantation is improving survival and quality of life, choosing the best recipients is crucial due to a shortage of donated organs. Here we discuss the common disease processes that recur and highlight its impact on overall outcome following lung transplantation.

This article reviews the underlying conditions leading to lung transplant with potential for recurrence and the impact of such recurrences on the overall outcome following transplanthttps://bit.ly/3v3gSvJ

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.

Recurrence of emphysema post-lung transplantation in a patient with alpha 1 antitrypsin deficiency (AATD)

The genetic disorder alpha 1 antitrypsin deficiency (AATD) results in reduced levels of alpha 1 antitrypsin (AAT) in the lung and an imbalance between AAT anti-protease activity and the activity of proteases that degrade elastin and connective tissues. This imbalance commonly leads to the excessive proteolysis of structural tissue of the alveoli, causing chronic obstructive pulmonary disease (COPD)/emphysema. While patients with AATD are encouraged to make lifestyle changes, including stopping smoking, and can be treated with alpha 1 antitrypsin therapy (AAT therapy) to slow progression of COPD/emphysema, damage to the lungs is irreparable, and therefore, lung transplantation is required in severe cases. However, following lung transplant, the genetic cause of AATD-related COPD/emphysema remains, and patients may continue to be at risk of redeveloping COPD/emphysema.

Recurrence of COPD/emphysema was observed in a patient with AATD 2 years after initial successful lung transplantation and cessation of AAT therapy who recommenced smoking after no signs of disease at the 1-year assessment. This case demonstrates that smoking cessation is critical in patients with AATD, even after lung transplant, and it highlights that patients with AATD may benefit from AAT therapy post-lung transplant.

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Patients with AATD can redevelop emphysema following lung transplantation.

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Abstinence from smoking remains crucial in all patients with AATD.

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AAT therapy may be required in patients who redevelop emphysema post-lung transplant.

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 hypersensitivity pneumonitis

BACKGROUND

Hypersensitivity pneumonitis (HP) is an inhaled antigen-mediated interstitial lung disease (ILD). Advanced disease may necessitate the need for lung transplantation. There are no published studies addressing lung transplant outcomes in HP. We characterized HP outcomes compared with referents undergoing lung transplantation for idiopathic pulmonary fibrosis (IPF).

METHODS

To identify HP cases, we reviewed records for all ILD lung transplantation cases at our institution from 2000 to 2013. We compared clinical characteristics, survival, and acute and chronic rejection for lung transplant recipients with HP to referents with IPF. We also reviewed diagnoses of HP discovered only by explant pathology and looked for evidence of recurrent HP after transplant. Survival was compared using Kaplan-Meier methods and Cox proportional hazard modeling.

RESULTS

We analyzed 31 subjects with HP and 91 with IPF among 183 cases undergoing lung transplantation for ILD. Survival at 1, 3, and 5 years after lung transplant in HP compared with IPF was 96%, 89%, and 89% vs 86%, 67%, and 49%, respectively. Subjects with HP manifested a reduced adjusted risk for death compared with subjects with IPF (hazard ratio, 0.25; 95% CI, 0.08-0.74; P = .013). Of the 31 cases, the diagnosis of HP was unexpectedly made at explant in five (16%). Two subjects developed recurrent HP in their allografts.

CONCLUSIONS

Overall, subjects with HP have excellent medium-term survival after lung transplantation and, relative to IPF, a reduced risk for death. HP may be initially discovered only by review of the explant pathology. Notably, HP may recur in the allograft.

Augmentation therapy of alpha-1 antitrypsin deficiency associated emphysema

INTRODUCTION

Alpha-1 antitrypsin, secreted by the liver, inhibits neutrophil elastase. Its deficiency favours the development of emphysema. Restoring a "protective" serum level in deficient patients should make it possible to inhibit the development of emphysema.

STATE OF THE ART

Human plasma-derived alpha-1 antitrypsin is a blood-derived drug sold in France under the name Alfalastin(®). The recommended posology is an I.V. administration of 60 mg/kg once a week. Human plasma-derived alpha-1 antitrypsin restores anti-elastase protection in the lower lung and prevents experimental emphysema induced by the elastasis of human neutrophils in hamster. The low number of patients with alpha-1 antitrypsin deficiency is one of the difficulties to perform sufficiently powerful randomised studies. However, randomised studies have reported the efficacy of human plasma-derived alpha-1 antitrypsin perfusions on mortality, FEV1 decline and the frequency of exacerbations. Randomised control trials have demonstrated the efficacy of human plasma-derived alpha-1 antitrypsin perfusions on the loss of lung density assessed by CT scan.

CONCLUSION

Augmentation therapy is simple in its conception and implementation, but it is expensive. However, there are currently no other solutions.

Augmentation therapy in alpha-1 antitrypsin deficiency: advances and controversies

Alpha-1 antitrypsin (AAT) deficiency is a hereditary condition characterized by low levels of AAT in plasma and hence diffusion into tissues. One of the most relevant characteristics of the disease is the development of panacinar emphysema due to an imbalance between proteases and antiproteases in the presence of environmental triggers. Left untreated, severe obstructive lung disease may develop. Avoidance of environmental triggers such as cigarette smoking constitutes a critical component of AAT deficiency treatment. Intravenous augmentation therapy is the only specific therapy for the condition that has been approved by the US Food and Drug Administration (FDA). While this therapy likely slows the rate of progression of emphysema and may improve survival in selected individuals with severe AAT deficiency, the gold standard for proof of efficacy is lacking. Areas where controversy exists regarding the use of AAT augmentation therapy include: (1) indications for treatment, (2) selection of specific AAT augmentation therapy, (3) appropriate dose and interval of administration, (4) cost effectiveness, (5) frequency and mode of follow up of treated patients, (6) use of augmentation therapy after lung transplantation, (7) use of recombinant AAT supplementation, (8) alternative delivery routes, and (9) genetic therapy. In this review we describe the advances in treatment and try to address some of the current controversies in AAT deficiency management.

The possible role of granzyme B in the pathogenesis of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a highly prevalent inflammatory lung condition characterized by airways disease and emphysema, and the precise mechanism of pathogenesis is poorly understood. The consistent features of COPD include protease-antiprotease imbalance, inflammation and accelerated aging caused by apoptosis or senescence. One family of molecules involved in all of these processes is the granzymes, serine proteases with the best-known member being granzyme B (GzmB). The majority of GzmB is released unidirectionally towards target cells, but GzmB can also be released nonspecifically and escape into the extracellular environment. GzmB is capable of cleaving extracellular matrix (ECM) proteins in vitro, and the accumulation of GzmB in the extracellular milieu during chronic inflammation in COPD could contribute to ECM degradation and remodelling and, consequently, the emphysematous phenotype in the lung. Preliminary studies suggest that increased GzmB expression is associated with increased COPD severity, and this may represent a promising new target for drug and biomarker discovery in COPD. In this paper, we review the potential pathogenic contributions of GzmB to the pathogenesis of COPD.