Clinical characteristics of Japanese candidates for lung transplant for interstitial lung disease and risk factors for early death while on the waiting list

Japanese guidelines for the treatment of idiopathic pulmonary fibrosis 2023:Revised edition

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease with a poor prognosis and an unknown cause that generally progresses to pulmonary fibrosis and leads to irreversible tissue alteration. The "Guidelines for the treatment of idiopathic pulmonary fibrosis 2017," specializing in the treatment of IPF for the first time in Japan and presenting evidence-based standard treatment methods suited to the state of affairs in Japan, was published in 2017, in line with the 2014 version of "Formulation procedure for Minds Clinical Practice Guidelines." Because new evidence had accumulated, we formulated the "Guidelines for the treatment of Idiopathic Pulmonary Fibrosis 2023 (revised 2nd edition)." While keeping the revision consistent with the ATS/ERS/JRS/ALAT IPF treatment guidelines, new clinical questions (CQs) on pulmonary hypertension were added to the chronic stage, in addition to acute exacerbation and comorbid lung cancer, which greatly affect the prognosis but are not described in the ATS/ERS/JRS/ALAT IPF guidelines. Regarding the advanced stages, we additionally created expert consensus-based advice for palliative care and lung transplantation. The number of CQs increased from 17 in the first edition to 24. It is important that these guidelines be used not only by respiratory specialists but also by general practitioners, patients, and their families; therefore, we plan to revise them appropriately in line with ever-advancing medical progress.

Assessment of listing criteria for lung transplant candidates with interstitial lung disease

OBJECTIVES

Lung transplantation (LT) is an effective treatment for patients with interstitial lung disease (ILD) refractory to medical treatment. Although the cases of cadaveric LT (CLT) have increased, the donor shortage in Japan has remained severe. This study aimed to evaluate the International Society of Heart and Lung Transplantation (ISHLT) listing criteria for LT in patients with ILD by predicting outcomes during the waiting time for CLT.

METHODS

We retrospectively identified 166 patients with fibrotic ILDs who were evaluated and registered for CLT at Kyoto Universal Hospital from April 1, 2008, to December 31, 2017. We examined the correlation between individual parameters of the ISHLT listing criteria and patient outcomes.

RESULTS

Among 166 patients, 57 (34.3%) underwent CLT, whereas 83 (50.0%) died before CLT. The median survival time from the date of registration was 22.5 months. The 2-year survival rate was 47.8%. On multivariate Cox proportional hazards analysis, relative decline of percent predicted forced vital capacity (%FVC) in 6 months ≥ 10% (hazard ratio [HR]: 1.72; 95% confidence interval [95%CI]: 1.03-2.87, p = 0.04) and 6-min walking distance (6MWD) < 250 m (HR: 2.77; 95%CI: 1.64-4.69, p < 0.001) were independently associated with worse outcome (i.e., death or living-donor lobar LT).

CONCLUSIONS

The 2014 ISHLT criteria could appropriately identify patients with ILD who have a potentially poor prognosis. In particular, 6-month decline in %FVC and shorter 6 min walk distance may be useful for selecting patients with higher risks of mortality.

The impact of prognostic nutrition index on the waitlist mortality of lung transplantation

OBJECTIVE

The prognostic nutrition index (PNI), calculated using serum albumin and total lymphocyte count, is a recent topical index related to inflammation. Preoperative PNI is regarded as a new preoperative prognostic score in lung transplantation (LTx). This study aimed to investigate the impact of PNI at the time of registration as a prognostic parameter of mortality on the waiting list for LTx.

METHODS

A retrospective review was conducted on the data of 132 adult patients registered for LTx in our department between January 2013 and June 2020. Patients who finally received LTx were analyzed as censored data. The overall survival was evaluated using the Kaplan-Meier method for pre-registered clinical factors including the PNI at the time of registration. Overall survival was calculated from the date of listing to the Japan Organ Transplant Network to the date of death.

RESULTS

The low-PNI group had a significantly worse prognosis. Multivariate analysis demonstrated that age (p = 0.023), idiopathic interstitial pneumonia (p < 0.001), lung allocation score (LAS) (p < 0.001), and PNI (p < 0.001) were independent prognostic factors for waitlist mortality.

CONCLUSIONS

PNI at the time of registration can be an independent prognostic parameter in registered candidates for LTx.

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.

Identification of targetable kinases in idiopathic pulmonary fibrosis

Background

Tyrosine kinase activation plays an important role in the progression of pulmonary fibrosis. In this study, we analyzed the expression of 612 kinase-coding and cancer-related genes using next-generation sequencing to identify potential therapeutic targets for idiopathic pulmonary fibrosis (IPF).

Methods

Thirteen samples from five patients with IPF (Cases 1–5) and eight samples from four patients without IPF (control) were included in this study. Six of the thirteen samples were obtained from different lung segments of a single patient who underwent bilateral pneumonectomy. Gene expression analysis of IPF lung tissue samples (n = 13) and control samples (n = 8) was performed using SureSelect RNA Human Kinome Kit. The expression of the selected genes was further confirmed at the protein level by immunohistochemistry (IHC).

Results

Gene expression analysis revealed a correlation between the gene expression signatures and the degree of fibrosis, as assessed by Ashcroft score. In addition, the expression analysis indicated a stronger heterogeneity among the IPF lung samples than among the control lung samples. In the integrated analysis of the 21 samples, DCLK1 and STK33 were found to be upregulated in IPF lung samples compared to control lung samples. However, the top most upregulated genes were distinct in individual cases. DCLK1, PDK4, and ERBB4 were upregulated in IPF case 1, whereas STK33, PIM2, and SYK were upregulated in IPF case 2. IHC revealed that these proteins were expressed in the epithelial layer of the fibrotic lesions.

Conclusions

We performed a comprehensive kinase expression analysis to explore the potential therapeutic targets for IPF. We found that DCLK1 and STK33 may serve as potential candidate targets for molecular targeted therapy of IPF. In addition, PDK4, ERBB4, PIM2, and SYK might also serve as personalized therapeutic targets of IPF. Additional large-scale studies are warranted to develop personalized therapies for patients with IPF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01940-y.

Elucidation of prognostic factors and the effect of anti-fibrotic therapy on waitlist mortality in lung transplant candidates with idiopathic interstitial pneumonias

BACKGROUND

Lung transplantation (LTx) is the last resort for patients who fail to respond to drug therapy and progress to advanced idiopathic interstitial pneumonias (IIPs). However, more than one-third of patients registered for LTx face despair because of rapid disease progression and donor shortage. This study aimed to identify the risk factors of waitlist mortality in LTx candidates with IIPs and investigate the association of anti-fibrotic therapy with waitlist mortality.

METHODS

We retrospectively investigated 56 patients with IIPs, including 29 patients with idiopathic pulmonary fibrosis (51.7%) and 11 patients with idiopathic pleuroparenchymal fibroelastosis (19.6%), registered for LTx at Fukuoka University Hospital between January 2006 and June 2020. The risk factors affecting transplantation-censored survival were evaluated.

RESULTS

The waitlist mortality rate of patients with nonspecific interstitial pneumonia was significantly lower than that of others. Multivariate survival analysis using Cox's model identified a history of pneumothorax (P = 0.029) and short 6-min walk distance (6MWD) (P = 0.012) to be significant variables affecting waitlist mortality. Patients receiving anti-fibrotic therapy (n = 27, 48.2%) had a lower risk of pneumothorax (P = 0.017) and their 6MWD was longer than that of non-therapy patients (P < 0.001). The waitlist mortality rate of patients on anti-fibrotic therapy was significantly lower (P = 0.012).

CONCLUSIONS

History of pneumothorax and short 6MWD were independent predictors of waitlist mortality in LTx candidates with IIPs. The anti-fibrotic therapy may potentially reduce mortality in patients with IIPs on the waiting list for LTx.

Changes in serum KL-6 levels during short-term strict antigen avoidance are associated with the prognosis of patients with fibrotic hypersensitivity pneumonitis caused by avian antigens

BACKGROUND

Bird-related hypersensitivity pneumonitis (BRHP) is the most common type of fibrotic hypersensitivity pneumonitis (HP). Antigen avoidance (AA) is a key step in the diagnosis and management of HP, but not all fibrotic HP patients improve through AA. Because of the poor prognosis of fibrotic HP, predictive biomarkers to identify patients showing rapid progression during AA are urgently needed.

METHODS

From a retrospective review of the medical records of 1941 patients with interstitial lung disease, 75 cases of fibrotic BRHP confirmed by a provocation test or surgical lung biopsy were identified. To identify potential prognostic markers obtained at or around diagnosis, physiological and serological variables at diagnosis and the relative changes in those variables during strict AA were evaluated. Cox proportional hazards models with log-rank testing were used to compare the associations between these variables and survival.

RESULTS

Univariate analyses showed that gender, smoking status, and the relative change in the serum levels of Krebs von den Lungen-6 (KL-6) were associated with prognosis (P = 0.02, 0.04, and 0.02, respectively), but the presence of honeycombing and the forced vital capacity were not associated with survival. The relative change in KL-6 levels (greater than vs. less than a 10% decrease) was significantly associated with survival in a stratified analysis (73.9 vs. 34.9 months; P = 0.04).

CONCLUSIONS

The relative change in KL-6 levels is associated with the prognosis of patients with fibrotic BRHP independent of previously identified prognostic biomarkers. This finding could help pulmonologists identify fibrotic BRHP patients that are likely to show rapid progression.

Lung transplant candidates with idiopathic pulmonary fibrosis and long-term pirfenidone therapy: Treatment feasibility influences waitlist survival

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronically progressive lung disease with exceptionally poor prognosis. While lung transplantation (LTx) is considered the last-resort therapeutic option, dismal waitlist mortality still hampers the salvage of patients with IPF. Pirfenidone, originally designed for IPF treatment, has increasingly been utilized. This study aimed to evaluate whether Pirfenidone could influence outcomes of patients with IPF on the Japanese LTx waitlist.

METHODS

This retrospective single-center cohort study included 25 consecutive patients with IPF who were registered as LTx candidates at our institution between July 1999 and August 2016. Patients with a history of pretransplant Pirfenidone therapy (Pirfenidone group) were compared with those with no history (non-Pirfenidone group).

RESULTS

In total, 6 (24%) patients received Pirfenidone as pretransplant therapy for 45.2 (range, 18.6-66.8) months. During the treatment period, the Pirfenidone group achieved a significant reduction in the decline rate of the forced vital capacity (-6.2% vs. -0.3%, p = 0.04) and a lower lung allocation score (31 vs. 41, p = 0.013) compared with the non-Pirfenidone group. The Pirfenidone group exhibited 100% waitlist survival three years after registration that was comparable to other indications, and 66% of the patients were still alive at the time of organ availability. No patient in the Pirfenidone group developed Pirfenidone-related surgical complications postoperatively.

CONCLUSIONS

Patients with IPF successfully managed with long-term Pirfenidone therapy achieved favorable outcomes after LTx registration, comparable to other patients with LTx indications. The tolerability to antifibrotic therapy can be a predictor of waitlist survival.