Ten-Year Survival in Patients with Idiopathic Pulmonary Fibrosis After Lung Transplantation

Current and Novel Treatment Modalities of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) presents a clinical challenge characterized by progressive fibrosis and destruction of lung tissue. Despite recent advancements, including antifibrotic medications like pirfenidone and nintedanib, IPF remains a chronic and often fatal condition with limited treatment options. This article provides an overview of the current treatment modalities for IPF and explores the need for new therapeutic approaches. Antifibrotic medications have shown efficacy in slowing disease progression but are not curative and may not be suitable for all patients. Ongoing research focuses on emerging therapies such as stem cell therapy, immunomodulatory agents, and novel pharmacological targets like phosphodiesterase 4B (PDE4B) inhibitors. While these treatments offer promise, there remains an unmet need for effective therapies capable of halting or reversing fibrotic lung damage.

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.

Relationship of Exercise Capacity, Physical Function, and Frailty Measures With Clinical Outcomes and Healthcare Utilization in Lung Transplantation: A Scoping Review

Measures of exercise capacity, frailty, and physical function are commonly used in lung transplant candidates and recipients to evaluate their physical limitations and the effects of exercise training and to select candidates for transplantation. It is unclear how these measures are related to clinical outcomes and healthcare utilization before and after lung transplantation. The purpose of this scoping review was to describe how measures of exercise capacity, physical function, and frailty are related to pre- and posttransplant outcomes.

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 Transplant Type & Donor Age in Idiopathic Pulmonary Fibrosis: A Single Center Study

BACKGROUD

Idiopathic pulmonary fibrosis (IPF) accounts for a marked proportion of diagnoses on the US lung transplant (LTx) list. The effects of single (SLT) versus double LTx (DLT) and lung donor age on survival in IPF remain unclear and were investigated in this study.

METHODS

We retrospectively assessed survival of LTx recipients with IPF at a single institution from February 2012-March 2020. Survival was analyzed and compared between LTx types (SLT and DLT), donor ages, and the combined groups (LTx type & donor age) using Kaplan-Meier survival analysis and compared by log-rank test. P-values less than 0.05 were considered significant.

RESULTS

Of 744 LTx patients at our institution, 307 (41.3%) were diagnosed with IPF, of which 208 (67.8%) were SLT, and 97 (31.6%) were DLT (2 excluded patients underwent heart-lung transplantation). There was no significant difference in survival due to LTx type (P = 0.41) or for patients with donor age <50 or ≥50 y (P = 0.46). Once stratified by both LTx type and donor age, analysis showed no significant difference in survival between the four groups (P = 0.69).

CONCLUSIONS

With ethical consideration for organ allocation, as the average age of the US population increases, donor lungs aged ≥50 are an increasingly useful resource in LTx. Our findings suggest donor age and LTx type do not significantly affect survival. Therefore, SLT, and donor lungs aged ≥50 ought to be more readily considered as non-inferior options for LTx in patients with IPF.

Exploring breath biomarkers in BLM-induced pulmonary fibrosis mice with associative ionization time-of-flight mass spectrometry

Pulmonary fibrosis (PF) is a common but fatal disease that threatens human health worldwide. Developing effective diagnostic methods is of great importance for the early detection of PF in patients. In this study, bleomycin (BLM) was used in mice to mimic idiopathic pulmonary fibrosis (IPF). The exhaled breath of BLM-induced PF, PF plus DDAH1 overexpression, and healthy control mice were analyzed in real-time using a newly developed associative ionization time-of-flight mass spectrometry method (AI-TOFMS), which is uniquely sensitive, especially to oxygenated volatile organic compounds (VOCs). Multivariate data analyses and discriminant modeling analyses revealed that four exhaled compounds, i.e., acrolein, ethanol, nitric oxide, and ammonia, had a strong correlation with PF symptoms. An Orthogonal Partial Least Square Discriminant Analysis (OPLS-DA) score plot showed an excellent separation between these three groups. The area under the receiver operating characteristic (ROC) curve for these four compounds distinguished PF mice from healthy controls at 0.989. In addition, the degrees of acute inflammation and fibrosis were assessed with Hematoxylin and Eosin (H&E) staining and Masson's Trichrome staining. Finally, combined with pathological characteristics and mRNA expression levels, the formation of the above-mentioned volatile compounds was explored. The obtained experimental results indicated that these four breath compounds, acrolein, ethanol, nitric oxide, and ammonia, were potential exhaled biomarkers for pulmonary fibrosis.

Developments in lung transplantation over the past decade

With an improved median survival of 6.2 years, lung transplantation has become an increasingly acceptable treatment option for end-stage lung disease. Besides survival benefit, improvement of quality of life is achieved in the vast majority of patients. Many developments have taken place in the field of lung transplantation over the past decade. Broadened indication criteria and bridging techniques for patients awaiting lung transplantation have led to increased waiting lists and changes in allocation schemes worldwide. Moreover, the use of previously unacceptable donor lungs for lung transplantation has increased, with donations from donors after cardiac death, donors with increasing age and donors with positive smoking status extending the donor pool substantially. Use of ex vivo lung perfusion further increased the number of lungs suitable for lung transplantation. Nonetheless, the use of these previously unacceptable lungs did not have detrimental effects on survival and long-term graft outcomes, and has decreased waiting list mortality. To further improve long-term outcomes, strategies have been proposed to modify chronic lung allograft dysfunction progression and minimise toxic immunosuppressive effects. This review summarises the developments in clinical lung transplantation over the past decade.

Many developments have taken place in lung transplantation over the last decade: indications have broadened, donor criteria expanded, allocations systems changed, and novel therapeutic interventions implemented, leading to improved long-term survivalhttp://bit.ly/2vnpwc1

Single versus bilateral lung transplantation in idiopathic pulmonary fibrosis: A systematic review and meta-analysis

Objective

Lung transplantation remains the only curative treatment for end-stage lung disease, conferring a better survival for some IPF patients, but whether they should receive double lung transplantation (DLT) or single lung transplantation (SLT) is still controversial. The aim of this study was to determine which type of lung transplantation was more effective and relatively safe in IPF patients by meta-analysis.

Methods

Publications comparing overall survival (OS) or other perioperative characteristics between IPF patients undergoing SLT and DLT were selected from electronic databases. The hazard ratios (HRs) were abstracted or calculated to evaluate the survival outcome. Odds ratios (ORs) or mean differences (MDs) were used to compare the causes of death or perioperative parameters. A random-effect model was used to combine data. Heterogeneity was quantified by means of an I² with 95% confidence interval (95% CI). The publication bias was estimated using the Eggers test with Begg’s funnel plots.

Results

16 studies with 17,872 IPF cases who met the inclusion criteria were included in this meta-analysis. SLT was associated with declined post-transplant FEV1% (MD = -15.37, 95% CI:-22.28,-8.47; P<0.001), FVC % (MD = -12.52, 95% CI:-19.45,-5.59; P<0.001) and DLCO% (MD = -13.85, 95% CI:-20.42,-7.29; P<0.001), but no significant advantage of DLT over SLT was seen in the overall survival outcome (HR = 1.08, 95% CI: 0.91–1.29; P = 0.391). Subgroup analyses for studies of follow-up period ≥ 60 months also showed similar results (all P-values>0.05). Moreover, there was fewer deaths attributable to primary graft dysfunction in SLT recipients (OR = 0.31, 95% CI: 0.2–0.48; P<0.001), while more patients with SLT died of malignancy (OR = 3.44, 95% CI: 2.06–5.77; P<0.001).

Conclusion

Our findings suggest that DLT was associated with better postoperative pulmonary function, but there was no difference in long-term overall survival between patients undergoing DLT and SLT. However, further high-quality and large-scale studies are needed to confirm these findings.

Single versus bilateral lung transplantation for idiopathic pulmonary fibrosis

BACKGROUND

Lung transplantation, either single or bilateral, serves as the only effective treatment for end-stage idiopathic pulmonary fibrosis (IPF), but their superiority is still being debated, and its application in Chinese patients has not been data analysed.

METHODS

We reviewed 109 IPF patients who received lung transplantation at our centre between January 1, 2015 and December 31, 2017. The patients were divided into single lung transplantation (SLT) group and bilateral lung transplantation (BLT) group. We compared the two groups' demographic characteristics and clinical indexes (intraoperative conditions, postoperative complications, follow-ups and life qualities).

RESULTS

Patients in BLT group were significantly younger than those in SLT group (P < 0.001), and had more pretransplant infections (P = 0.007). The total ischemic time (P < 0.001) was shorter and intraoperative blood loss was less (P = 0.001) in SLT group. No significant difference was found in the proportion of patients in using anti-fibrosis drugs, pulmonary artery pressure, extracorporeal membrane oxygenation during the surgery; the length of intensive care unit stay; the incidence of complication; and the overall survival rate between two groups. However, the hierarchical analysis found that patients aged > 60 years showed a better survival in SLT group (P = 0.008). Both groups got normal MOS 36-item Short Form (SF-36) scores, and the scores of BLT were higher than those of SLT. The BLT group had better lung function than SLT group 1 year post-lung transplantation.

CONCLUSIONS

Both SLT and BLT are effective and SLT is more favourable for the patients of > 60 years.

Lung transplantation for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with a poor prognosis. Lung transplantation is the only intervention shown to increase life expectancy for patients with IPF, but it is associated with disease-specific challenges. In this Review, we discuss the importance of a proactive approach to the management of IPF comorbidities, including gastro-oesophageal reflux, pulmonary hypertension, coronary artery disease, and malignancy. With a donor pool too small to meet demand and unacceptably high mortality on transplant waiting lists, we discuss different systems used internationally to facilitate organ allocation. We explore the rapidly evolving landscape of transplantation for patients with IPF with regards to antifibrotic therapy, technological advances in extracorporeal life support, advances in understanding of the genetics of the disease, and the importance of a holistic multidisciplinary approach to care. Finally, we consider potential advances over the next decade that are envisaged to improve transplantation outcomes in patients with advanced IPF.

Determinants of survival in lung transplantation patients with idiopathic pulmonary fibrosis: a retrospective cohort study

Survival after lung transplantation (LTx) for idiopathic pulmonary fibrosis (IPF) is worse compared to other indications for LTx. We investigated the effect of several pretransplant variables including the use of pretransplant corticosteroids (CS) on post-transplant graft and chronic lung allograft dysfunction (CLAD)-free survival and functional testing (maximum inspiratory and expiratory pressure, six-minute walk test, quadriceps and hand pinch force) in a small cohort of IPF patients. We retrospectively compared two groups of IPF patients (n = 36 on CS vs. n = 18 not on CS) who underwent LTx between 2000 and 2016. Analysis of 54 IPF-LTx patients showed no significant effect on graft survival or functional tests except for maximum inspiratory pressure (P = 0.033) between these two groups (all LTx patients, CS vs. no CS). Regression analysis showed significant impact of procedure with a hazard ratio of 0.423 (CI 95% 0.194, 0.924) favoring sequential single LTx (SSLTx) compared to single lung transplantation (SLTx). When analyzing only the 40 SSLTx patients, corticosteroid-free patients showed significantly better graft survival compared to patients on CS (P = 0.045) and CLAD-free survival (P = 0.019). The possible detrimental effect of corticosteroid therapy before LTx was demonstrated in this cohort of SSLTx patients, which questions the use of corticosteroids in a pretransplantation setting.

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.

Recipient selection process and listing for lung transplantation

Lung transplantation remains the ultimate treatment option for selected patients with end-stage (cardio) pulmonary disease. Given the current organ shortage, it is without any doubt that careful selection of potential transplant candidates is essential as this may greatly influence survival after the procedure. In this paper, we will review the current guidelines for referral and listing of lung transplant candidates in general, and in more depth for the specific underlying diseases. Needless to state that these are not absolute guidelines, and that decisions depend upon center's activity, waiting list, etc. Therefore, every patient should be discussed with the transplant center before any definite decision is made to accept or decline a patient for lung transplantation.