Comorbidities impacting on prognosis after lung transplant

Lung transplantation for interstitial lung disease: evolution over three decades

BACKGROUND

Interstitial lung disease (ILD) has emerged as the most common indication for lung transplantation globally. However, post-transplant survival varies depending on the underlying disease phenotype and comorbidities. This study aimed to describe the demographics, disease classification, outcomes and factors associated with post-transplant survival in a large single-centre cohort.

METHODS

Data were retrospectively assessed for 284 recipients who underwent lung transplantation for ILD in our centre between 1987 and 2020. Patient characteristics and outcomes were stratified by three eras: 1987-2000, 2001-2010 and 2011-2020.

RESULTS

Median patients' age at time of transplantation was significantly higher in the most recent decade (56 (51-61) years, p<0.0001). Recipients aged over 50 years had worse overall survival compared with younger patients (adjusted HR, aHR 2.36, 95% CI 1.55 to 3.72, p=0.0001). Better survival was seen with bilateral versus single lung transplantation in patients younger than 50 years (log-rank p=0.0195). However, this survival benefit was no longer present in patients aged over 50 years. Reduced survival was observed in fibrotic non-specific interstitial pneumonia compared with idiopathic pulmonary fibrosis, which remained the most common indication throughout (aHR 2.61, 95% CI 1.40 to 4.60, p=0.0015).

CONCLUSION

In patients transplanted for end-stage ILD, older age and fibrotic non-specific interstitial pneumonia were associated with poorer post-transplant survival. The benefit of bilateral over single lung transplantation diminished with increasing age, suggesting that single lung transplantation might still be a feasible option in older candidates.

Current trends in candidate selection, contraindications, and indications for lung transplantation

Lung transplantation is an established treatment option that can improve quality of life and prolong survival for select patients diagnosed with end-stage lung disease. Given the gaps in organ donation and failures to make effective use of available organs, careful selection of candidates for lung transplant remains one of the most important considerations of the transplant community. Toward this end, we briefly reviewed recent trends in pretransplant evaluation, candidate selection, organ allocation, and organ preservation techniques. Since the latest consensus statement regarding appropriate selection of lung transplant candidates, many advances in the science and practice of lung transplantation have emerged and influenced our perspective of 'contraindications' to transplant. These advances have made it increasingly possible to pursue lung transplant in patients with risk factors for decreased survival-namely, older recipient age, increased body mass index, previous chest surgery, poorer nutritional status, and presence of chronic infection, cardiovascular disease, or extrapulmonary comorbid conditions. Therefore, we reviewed the updated evidence demonstrating the prognostic impact of these risk factors in lung transplant recipients. Lastly, we reviewed the salient evidence for current trends in disease-specific indications for lung transplantation, such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis, emphysema due to alpha-1 antitrypsin deficiency, and pulmonary arterial hypertension, among other less common end-stage diseases. Overall, lung transplant remains an exciting field with considerable hope for patients as they experience remarkable improvements in quality of life and survival in the modern era.

Lung Transplantation in Idiopathic Pulmonary Fibrosis

Despite the advances in recent years in the treatment of idiopathic pulmonary fibrosis (IPF), it continues to be a progressive disease with poor prognosis. In selected patients, lung transplantation may be a treatment option, with optimal results in survival and quality of life. Currently, pulmonary fibrosis is the main cause of lung transplantation. However, mortality on the waiting list of these patients is high, since many patients are referred to the transplant units with advanced disease. There is not a parameter that can predict the survival of a specific patient. Different variables are to be considered in order to decide the right time to send them to a transplant unit. It is also very difficult to decide when to include these patients on the waiting list. Every patient diagnosed with IPF, without contraindications for surgery, should be referred early to a transplant unit for assessment. A uni or bilateral transplantation will be decided based on the characteristics of the patient and the experience of each center. The post-transplant survival of recipients with IPF is lower than that observed in other diseases, such as cystic fibrosis or chronic obstructive pulmonary disease as a consequence of their older age and the frequent presence of associated comorbidity. Post-transplant follow-up must be tight in order to assure optimal level of immunosuppressive treatment, detect complications associated with it, and avoid graft rejection. The main cause of long-term mortality is late graft dysfunction as a consequence of chronic rejection. Other complications, such as infections and tumors, must be considered.

Lung transplantation and esophageal dysfunction

Lung transplants belong in the group of organ transplants with poorer outcomes, with acute rejection and bronchiolitis obliterans being cited as major causes of this. Poor allograft evolution has been associated with multiple factors, including those related to esophagogastric disease. In patients with end-stage pulmonary conditions eligible for a lung transplant gastroesophageal reflux (GER), esophageal dysmotily, and gastroparesis are highly prevalent and worsen upon transplantation, which may compromise transplant viability. High-resolution impedance manometry and long-term impedance pH-metry studies provide a new perspective where reflux and dysmotility share the limelight with changes in the diagnostic approach and in potential therapies.