Prediction of Responsiveness to PD-L1/PD-1 Inhibitors Using miRNA Profiles Associated With PD-L1 Expression in Lung Adenocarcinoma and Squamous Cell Carcinoma

BACKGROUND/AIM

MicroRNAs (miRNAs) regulate programmed cell death ligand 1 (PD-L1) and play a crucial role in tumor immune response. However, the relationship between miRNA expression patterns and PD-L1 remains unclear in both lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). We investigated PD-L1-related miRNAs that can predict treatment response in patients treated with PD-L1/PD-1 inhibitors.

PATIENTS AND METHODS

We selected miRNAs that were correlated with PD-L1 expression within the LUAD and LUSC datasets obtained from The Cancer Genome Atlas (TCGA) and Clinical Proteomic Tumor Analysis Consortium (CPTAC). We validated whether the miRNA profile could be used to predict the prognosis of patients treated with PD-L1/PD-1 inhibitors.

RESULTS

Based on four public datasets, we selected 66 and 23 miRNAs associated with PD-L1 expression in LUAD and LUSC, respectively. From the above miRNAs, we identified 5 miRNAs in LUSC and 1 miRNA in LUAD that could predict the response to PD-L1/PD-1 inhibitors in a validation set of patients treated with PD-L1/PD-1 inhibitors. In LUSC, the miRNA profile exhibited a high predictive capability for the response to PD-L1/PD-1 treatment [area under the curve (AUC)=0.963] and accurately predicted prognosis (p=0.031). In LUAD, the miRNA profile was relatively less predictive than in LUSC (AUC=0.691 and p=0.213). Additionally, we observed variations in the PD-L1-associated miRNA profiles, as well as in the associated pathways, between LUAD and LUSC.

CONCLUSION

The PD-L1-associated miRNA profile may predict treatment response in LUSC patients treated with PD-L1/PD-1 inhibitors and help select the PD-L1/PD-1 inhibitor treatment group.

Subnormothermic ex vivo lung perfusion possibly protects against ischemia-reperfusion injury via the mTORC-HIF-1α pathway

Background

Ex vivo lung perfusion (EVLP) is a useful technique for evaluating and repairing donor lungs for transplantation. However, studies examining the effects of perfusate temperature on graft function are limited. Thus, this study aimed to examine these effects during EVLP on ischemic-reperfusion injury in the donor lung.

Methods

Twenty-four male Sprague-Dawley rats were randomly divided into three groups, as follows: no treatment (sham group, n=5), normothermic EVLP (37 °C, n=5), and subnormothermic EVLP (30 °C, n=5). Lung function analyses, including oxygen capacity (OC), compliance, and pulmonary vascular resistance (PVR), were performed hourly during EVLP. Further, after 4 h of EVLP, histological evaluation of the right lobe was performed using the lung injury severity (LIS) scale. The expression levels of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-18 were evaluated. Metabolomic analysis of left lung tissues was conducted using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) after 4 h of EVLP in the EVLP groups and after 1 h of cold preservation in the sham group.

Results

Compared with those in the normothermic group, in the subnormothermic group, functional parameters during EVLP and subsequent histologic results were significantly superior, expression levels of inflammatory cytokines such as TNF-α, IL-1β, IL-6, and IL-18 were significantly lower, and glycolytic activity was significantly decreased. Furthermore, expression levels of mammalian target of rapamycin complex (mTORC), hypoxia-inducible factor (HIF) 1α, and nucleotide-binding domain, leucine-rich-containing family pyrin domain containing 3 (NLRP3) and its effector caspase-1 were significantly lower in the subnormothermic group than in the normothermic group.

Conclusions

EVLP with subnormothermic perfusion improves lung graft function by reducing the expression of pro-inflammatory cytokines and glycolytic activity during EVLP. Additionally, EVLP can be a useful target for the improvement of graft function after transplantation.

Factors in turnover intention of cardiothoracic surgery residents

Increasing numbers of cardiothoracic surgery residents are resigning, without completing their training. This study analyzes how their turnover intention is related to the training environment, and individual psychological factors. Responses by 57 Korean cardiothoracic surgery residents were analyzed. Their levels of depression, anxiety, grit, and empathy, working conditions, the effect of someone's presence to discuss their concerns with, burnout, and turnover intention were identified as the research variables. Descriptive statistical analysis, correlation analysis, and structural equation modeling were used for data analysis. Burnout has the most significant relationship with turnover intention. It has a mediating effect on the influence of depression, grit (sustained interest), and working conditions, over turnover intention. Empathy, and the presence of someone to discuss concerns with, also affect turnover intention directly. The study also confirmed that grit and work satisfaction affect turnover intention indirectly, through burnout. The study identified both individual- and systemic-level factors for an effective training environment, to reduce cardiothoracic surgery residents' tendencies of leaving the residency program, and supporting them for greater satisfaction with their career choice. In order to resolve negative emotions such as burnout and depression, and foster empathy, a human resource development program for the residents' psychological support must be prepared. The program director should be adequately educated to take charge of the training program, oversee the residents' education and welfare, and perform the roles of role-model and mentor.

Characteristics of the immune microenvironment associated with RRM2 expression and its application to PD-L1/PD-1 inhibitors in lung adenocarcinoma

Recent studies have indicated that RRM2 plays a crucial part in the tumor immune microenvironment. According to the expression of RRM2, we evaluated immune cell infiltration, immunotherapy biomarkers, and the expression of immune checkpoint molecules in four lung adenocarcinoma (LUAD) datasets. We employed the Tumor Immune Dysfunction and Exclusion (TIDE) and CIBERSORTx algorithms to examine the patterns of immune cell distribution and evaluate the responses to anti-programmed death protein-1/programmed death ligand-1 (PD-1/PD-L1) therapy in three publicly available LUAD datasets. These findings were corroborated using a validation group comprising patients who received treatment with PD-1/PD-L1 inhibitors. Additionally, we conducted experiments using LUAD cell lines to investigate how RRM2 affects the expression of PD-L1. In comparison to the low RRM2 group, the high RRM2 group exhibited a high interferon gamma signature, high T-cell-inflamed signature, high CD274 expression, high CD8+ T cell levels, low cancer-associated fibroblasts, and low M2 macrophages, according to TIDE analysis in the three LUAD datasets. Analysis of the three LUAD datasets using CIBERSORTx confirmed a positive correlation between RRM2 and CD8+ T cells, and this finding was validated by immunohistochemistry in a separate validation set. In the three LUAD datasets without PD-1/PD-L1 inhibitor treatment, higher RRM2 expression was associated with a poorer prognosis. However, in the LUAD dataset treated with PD-1/PD-L1 inhibitors, higher RRM2 expression was associated with better prognosis. In the three datasets, the high-RRM2 group exhibited higher expression of inhibitory immune checkpoint molecules. In a LUAD cell line study, we discovered that RRM2 regulates PD-L1 expression through the ANXA1/AKT pathway. The expression of RRM2 shows promise as a predictive biomarker for PD-1/PD-L1 inhibitors in LUAD patients, and it may represent a new target to overcome resistance to PD-L1/PD-1 therapies.

Development of Machine Learning Model for VO2max Estimation Using a Patch-Type Single-Lead ECG Monitoring Device in Lung Resection Candidates

A cardiopulmonary exercise test (CPET) is essential for lung resection. However, performing a CPET can be challenging. This study aimed to develop a machine learning model to estimate maximal oxygen consumption (VO2max) using data collected through a patch-type single-lead electrocardiogram (ECG) monitoring device in candidates for lung resection. This prospective, single-center study included 42 patients who underwent a CPET at a tertiary teaching hospital from October 2021 to July 2022. During the CPET, a single-lead ECG monitoring device was applied to all patients, and the results obtained from the machine-learning algorithm using the information extracted from the ECG patch were compared with the CPET results. According to the Bland-Altman plot of measured and estimated VO2max, the VO2max values obtained from the machine learning model and the FRIEND equation showed lower differences from the reference value (bias: -0.33 mL·kg-1·min-1, bias: 0.30 mL·kg-1·min-1, respectively). In subgroup analysis, the developed model demonstrated greater consistency when applied to different maximal stage levels and sexes. In conclusion, our model provides a closer estimation of VO2max values measured using a CPET than existing equations. This model may be a promising tool for estimating VO2max and assessing cardiopulmonary reserve in lung resection candidates when a CPET is not feasible.

Transient hyperthermia during ex vivo lung perfusion has no protective effect in rat model

BACKGROUND

Although ex vivo lung perfusion (EVLP) is a useful technique for evaluating and repairing donor lungs for transplantation, EVLP itself can lead to inflammation in the lung. Heat shock proteins (HSPs) have anti-inflammatory effects and can reduce ischemic reperfusion injury in the donor's lungs after transplantation. In this study, the effects of transient hyperthermia during EVLP on the expression of HSPs and inflammatory pathways were examined.

METHODS

Fifteen male Sprague-Dawley rats were randomly divided into three groups: sham (n = 5), normothermic EVLP (37 °C, n = 5), and transient hyperthermia during EVLP (42 °C, n = 5). Lung function analyses regarding PaO2/FiO2 ratio, compliance, and pulmonary vascular resistance were conducted. The expression levels of HSPs and inflammatory cytokines were also evaluated. The degree of lung injury was histopathologically evaluated. Transcriptome analysis was performed on lung tissues from the sham (n = 2), normothermic EVLP (n = 2), and heat stress-EVLP (n = 2) groups.

RESULTS

There were no significant differences in functional or histological parameters between the three groups. The expression of HSPs had significantly increased, especially that of HSPs 40 and 60 in the heat stress EVLP group; this was consistent with the inflammatory response. Inflammatory cytokine levels were significantly higher during EVLP and intensified with transient hyperthermia.

CONCLUSION

Transient hyperthermia during EVLP has no protective effect on the donor lung graft or activation of the inflammatory pathway at the gene level.

Percutaneous Dilatational Tracheostomy in Patients with COVID-19 Supported by Extracorporeal Membrane Oxygenation

Background

Pneumonia caused by severe acute respiratory syndrome coronavirus 2 can cause acute respiratory distress syndrome, often requiring prolonged mechanical ventilation and eventually tracheostomy. Both procedures occur in isolation units where personal protective equipment is needed. Additionally, the high bleeding risk in patients with extracorporeal membrane oxygenation (ECMO) places a great strain on surgeons. We investigated the clinical characteristics and outcomes of percutaneous dilatational tracheostomy (PDT) in patients with coronavirus disease 2019 (COVID-19) supported by ECMO, and compared the outcomes of patients with and without ECMO.

Methods

This retrospective, single-center, observational study included patients with severe COVID-19 who underwent elective PDT (n=29) from April 1, 2020, to October 31, 2021. The patients were divided into ECMO and non-ECMO groups. Data were collected from electronic medical records at Ajou University Hospital in Suwon, Korea.

Results

Twenty-nine COVID-19 patients underwent PDT (24 men [82.8%] and 5 women [17.2%]; median age, 61 years; range, 26-87 years; interquartile range, 54-71 years). The mean procedure time was 17±10.07 minutes. No clinically or statistically significant difference in procedure time was noted between the ECMO and non-ECMO groups (16.35±7.34 vs. 18.25±13.32, p=0.661). Overall, 12 patients (41.4%) had minor complications; 10 had mild subdermal bleeding from the skin incision, which was resolved with local gauze packing, and 2 (6.9%) had dislodgement. No healthcare provider infection was reported.

Conclusion

Our PDT approach is safe for patients and healthcare providers. With bronchoscopy assistance, PDT can be performed quickly and easily even in isolation units and with acceptable risk, regardless of the hypo-coagulable condition of patients on ECMO.

Immune profiles according to EGFR mutant subtypes and correlation with PD-1/PD-L1 inhibitor therapies in lung adenocarcinoma

Background

We examined the distributions of 22 immune cell types and the responses to PD-1/PD-L1 inhibitors according to EGFR mutation profile, in three independent datasets of lung adenocarcinoma (LUAD).

Methods

We used CIBERSORTx to analyze the distributions of immune cells, and tumor immune dysfunction and exclusion (TIDE) or tumor mutation burden (TMB) to analyze responses to anti-PD-1/PD-L1 therapy, in two public LUAD datasets. The results were verified with a validation set that included patients treated with PD-1/PD-L1 inhibitors.

Results

Compared to EGFR mutants, EGFR wild-type carcinomas had higher numbers of CD8+ T cells, CD4 memory activated T cells and neutrophils, and lower numbers of resting dendritic cells and resting mast cells, in two of the datasets. In our subgroup analyses, CD8+ T cells and CD4 memory activated T cells were more numerous in EGFR rare variants than in wild-types, L858R mutants, and exon 19 deletion mutants. In our TIDE or TMB analyses, EGFR rare variants were predicted to respond better to PD-1/PD-L1 inhibitors than wild-types, L858R mutants, and exon 19 deletion mutants. In the validation set verified by immunohistochemical staining, levels of CD8+ T cells in the EGFR rare variant or wild-type groups were significantly higher than in the EGFR L858R and exon 19 deletion groups. In patients treated with PD-1/PD-L1 inhibitors, the survival rates of patients with EGFR wild-type and rare mutant carcinomas were higher than those with L858R and exon 19 deletion carcinomas.

Conclusion

The EGFR rare mutation form of LUAD shows a higher immune activation state compared to wild-type, L858R, and exon 19 deletion variants, indicating it as a potential target for PD-1/PD-L1 inhibitor therapy.

Prognostic and predictive value of YTHDF1 and YTHDF2 and their correlation with tumor-infiltrating immune cells in non-small cell carcinoma

BACKGROUND

YTH domain-containing family protein 1 (YTHDF1) or YTHDF2 play crucial roles in cancer immunotherapy. We examine the expression of YTHDF1, YTHDF2, CD8, CD4, and FOXP3 to identify their prognostic or predictive role for PD-1/PD-L1 inhibitor in non-small cell lung cancer (NSCLC).

METHODS

Immunohistochemical expression of YTHDF1, YTHDF2, CD8, CD4, and FOXP3 was investigated in 266 patients not receiving PD-1/PD-L1 inhibitors and in 59 patients receiving PD-1/PD-L1 inhibitors. Immunohistochemical results were verified using mRNA dataset obtained from The Cancer Genome Atlas (TCGA) database.

RESULTS

Immunohistochemical expression of YTHDF1 or YTHDF2 was negatively associated with CD8- and CD4-positive T cells; however, the same expression was positively associated with FOXP3-positive T cells. YTHDF1 or YTHDF2 mRNA expression was also negatively associated with CD8- and CD4-positive T cells. Gene set enrichment analysis revealed that low YTHDF1 was related to immune hot tumor gene sets. Expression of YTHDF1 or YTHDF2 was negatively associated with expression of most immune checkpoints. YTHDF1 and YTHDF2 were predictive markers of response to PD-1/PD-L1 inhibitors. YTHDF1 or YTHDF2 expression was associated with better prognosis. YTHDF1 has an immune hot profile in both cell types, whereas YTHDF2 is only seen in adenocarcinoma.

CONCLUSION

Low YTHDF1 or YTHDF2 reflects an immune hot tumor signature and may serve as a predictor or prognostic marker.

New Atrial Anastomosis Technique for an Inadequate Left Atrial Cuff in Lung Transplantation

In lung transplantation surgery, the pulmonary veins are anastomosed by connecting each atrium of the donor and recipient. However, occasionally the recipient’s left atrium is not suitable for anastomosis for various reasons. In these cases, several techniques for atrial anastomosis have been introduced, but these are somewhat complicated for an inexperienced surgeon. Here, we propose a new atrial anastomosis technique that is easier and safer than previously introduced techniques.

Donation after Circulatory Death in Lung Transplantation

The shortage of donor lungs has become a serious obstacle to implementing lung transplantation (LTx). Donation after circulatory death (DCD) donors are among the several donor pools utilized to overcome the problem posed by the shortage of donation after brain death (DBD) donors. The active use of DCD donors is expected to significantly reduce mortality on the waiting list for LTx, as LTx from DCD donors has comparable outcomes to LTx from DBD donors. Further studies on efforts to shorten the warm ischemic time and use uncontrolled DCD are required.

Ex Vivo Lung Perfusion in Lung Transplantation

Ex vivo lung perfusion (EVLP) is a technique that enables active metabolism of the lung by creating an environment similar to that inside the body, even though the explanted lungs are outside the body. The EVLP system enables the use of lung grafts that do not satisfy the acceptance criteria for lung transplantation (LTx) by making it possible to evaluate the function of the lung grafts and repair lungs in poor condition, thereby reducing the waiting time of patients requiring LTx and consequently mortality.

Changes in Thoracic Cavity Volume After Bilateral Lung Transplantation

Purpose

End-stage lung diseases result in anatomical changes of the thoracic cavity. However, very few studies have assessed changes in the thoracic cavity after lung transplantation (LTx). This study aimed to evaluate the relationships between thoracic cavity volume (TCV) changes after LTx and underlying lung disease.

Methods

We reviewed 89 patients who underwent a pre-LTx pulmonary function test (PFT), chest computed tomography (CT) scan, and 1-year follow-up CT after LTx. These patients were classified into two groups according to pre-LTx PFT as follows: obstructive group [forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio < 70%] and restrictive group (FEV1/FVC ratio > 70%). We measured TCV using CT scan before and at 1 year after LTx and compared the TCV change in the two groups.

Results

In the restrictive group, TCV increased after LTx (preop: 2,347.8 ± 709.5 mL, 1-year postop: 3,224.4 ± 919.0 mL, p < 0.001). In contrast, in the obstructive group, it decreased after LTx (preop: 4,662.9 ± 1,296.3 mL, 1-year postop: 3,711.1 ± 891.7 mL, p < 0.001). We observed that restrictive lung disease, taller stature, lower body mass index, and larger donor lung were independently associated with increased TCV after LTx.

Conclusion

The disease-specific chest remodeling caused by restriction and hyperinflation is at least, in part, reversible. After LTx, the chest remodeling appears to occur in the opposite direction to the disease-specific remodeling caused by the underlying lung disease in recipients.

Assessment of textbook outcome after lobectomy for early‐stage non‐small cell lung cancer in a Korean institution: A retrospective study

Background

Textbook outcome (TO) has been introduced as a novel composite measure for lung cancer surgery. We investigated TO after lobectomy for early‐stage non‐small cell lung cancer (NSCLC) in a Korean tertiary hospital and its prognostic implications for overall survival and recurrence.

Methods

Between January 2012 and December 2017, 418 consecutive patients who underwent lobectomy for clinical stages I and II NSCLC were identified and retrospectively reviewed. TO was defined as complete resection (negative resection margins and sufficient lymph node dissection), no 30‐day or in‐hospital mortality, no reintervention within 30 days, no readmission to the intensive care unit, no prolonged hospital stay (<14 days), no hospital readmission within 30 days, and no major complications. Propensity score matching analysis was performed to investigate the association between TO, medical costs, and long‐term outcomes.

Results

Of 418 patients, 277 (66.3%) achieved TO. The most common events leading to TO failure were prolonged air leakage (n = 54, 12.9%) and prolonged hospital stay (n = 53, 12.7%). Male sex (odds ratio [OR] = 2.148, p = 0.036) and low diffusing capacity for carbon monoxide (OR = 0.986, p = 0.047) were significant risk factors for failed TO in multivariate analysis. In matched cohorts, achieving TO was associated with lower medical costs and better overall survival but not cancer recurrence.

Conclusions

TO is associated with low medical cost and favorable overall survival; thus, surgical teams and hospitals should make efforts to improve the quality of care and achieve TO.

Prognostic Impact of Postoperative Complications in High-Risk Operable Non-small Cell Lung Cancer

Background

Patients with high-risk (HR) operable non-small cell lung cancer (NSCLC) may have unique prognostic factors. This study aimed to evaluate surgical outcomes in HR patients and to investigate prognostic factors in HR patients versus standard-risk (SR) patients.

Methods

In total, 471 consecutive patients who underwent curative lung resection for NSCLC between January 2012 and December 2017 were identified and reviewed retrospectively. Patients were classified into HR (n=77) and SR (n=394) groups according to the American College of Surgeons Oncology Group criteria (Z4099 trial). Postoperative complications were defined as those of grade 2 or higher by the Clavien-Dindo classification.

Results

The HR group comprised more men and older patients, had poorer lung function, and had more comorbidities than the SR group. The patients in the HR group also experienced more postoperative complications (p≤0.001). More HR patients died without disease recurrence. The postoperative complication rate was the only significant prognostic factor in multivariable Cox regression analysis for HR patients but not SR patients. HR patients without postoperative complications had a survival rate similar to that of SR patients.

Conclusion

The overall postoperative survival of HR patients with NSCLC was more strongly affected by postoperative complications than by any other prognostic factor. Care should be taken to minimize postoperative complications, especially in HR patients.

A Complication of Diaphragm Repair Using a Gore-Tex (Expanded Polytetrafluorethylene) Membrane: A Case Report

A 65-year-old man underwent right trisectionectomy of the liver and reconstruction of the chest wall and diaphragm with a 2-mm Gore-Tex membrane due to recurrent hepatocellular carcinoma. After 3 years, the Gore-Tex membrane in the diaphragm migrated to the abdominal cavity and perforated the colon. We report a rare complication of a Gore-Tex membrane after diaphragm repair.

Video-Assisted Thoracic Surgery Pneumonectomy

Video-assisted thoracic surgery (VATS) for lobectomy or segmentectomy is considered a favorable alternative to thoracotomy because of its usefulness and safety; it reduces postoperative pain, lowers morbidity, and shortens the hospital stay. However, despite these advantages of VATS, it has been difficult to perform VATS pneumonectomy due to the high morbidity and mortality rate of pneumonectomy. Recently, as VATS techniques have been developed and the usefulness of VATS pneumonectomy has continued to be reported, the frequency of VATS pneumonectomy is gradually increasing at large-volume centers. This article describes VATS pneumonectomy with a focus on the surgical technique.

An immune-related gene expression signature predicts brain metastasis in lung adenocarcinoma patients after surgery: gene expression profile and immunohistochemical analyses

Background

Lung adenocarcinoma (LUAD) with brain metastasis (BM) occurs frequently and has a poor prognosis. In this study, we aimed to assess the correlation between gene expression signatures and the development of BM after surgical resection of LUAD.

Methods

We analyzed the immune-related gene expression profiles of 72 LUADs with and without BM after surgery and verified them using NanoString method and immunohistochemistry (IHC). We matched the Tumor, Node, Metastasis (TNM) stage in the groups with and without BM to minimize the effect of TNM stage. Pathway enrichment studies were also performed.

Results

In the NanoString results, we identified 11 upregulated immune-related gene signature that correlated specifically with BM in the discovery and validation sets [area under the curve (AUC) =0.750 and 0.787, respectively]. The discovery set achieved 94% sensitivity and 62% specificity and the validation set displayed 100% sensitivity and 50% specificity. Eight out of the 11 genes were verified by IHC and had profiles similar to the gene expression profile results (AUC =0.844 for the discovery set and AUC =0.795 for the validation set). Subgroup analysis revealed that 11 immune-related gene signature enabled prediction of BM at all TNM stages. There were no differences in the 11 immune-related gene expression signatures between the primary LUAD samples and the matched brain samples. Pathway enrichment analysis revealed that the cytokine-cytokine receptor interaction pathway was closely correlated with BM.

Conclusions

The 11 identified immune-related gene expression signatures may be potentially clinically useful predictors for BM and can provide patient-specific treatment options.

Expression of PD-L1, cancer stem cell and epithelial-mesenchymal transition phenotype in non-small cell lung cancer

The purpose of this study was to investigate the expression of PD-L1, cancer stem cells (CSC) markers (CD44, NANOG, and ALDH1) and epithelial-mesenchymal transition (EMT) markers and to evaluate their correlation and prognostic significance in non-small cell lung cancer (NSCLC) patients. PD-L1 protein expression was evaluated in resected 277 NSCLC cases and its correlation with CSC and EMT marker expression and survival was determined based on immunohistochemical (IHC) analysis. mRNA expression obtained from The Cancer Genome Atlas and the Kaplan-Meier plotter database were compared with the IHC results. PD-L1 expression was negatively correlated with ALDH1 expression in adenocarcinoma by IHC and mRNA expression. PD-L1 expression was also associated with mesenchymal phenotype (vimentin and TWIST) adenocarcinoma by IHC and mRNA expression. PD-L1 expression was associated with poor prognosis in adenocarcinoma by IHC. However, NANOG or ALDH1 expression measured by IHC and mRNA expression was correlated with a favourable prognosis in adenocarcinoma. Epithelial marker p120-catenin detected by IHC and mRNA expression was associated with a favourable prognosis in adenocarcinoma, however mesenchymal marker TWIST was associated with a worse prognosis. Patients with low PD-L1 and high ALDH1 expression showed more favourable prognoses than adenocarcinoma patients with other expression patterns. In multivariate analysis, ALDH1 detected by IHC and mRNA expression was an independent favourable prognostic marker for adenocarcinoma. Our study results support the hypothesis that PD-L1 interacts with CSC and EMT features and that PD-L1, ALDH1, and the mesenchymal phenotype may serve as tandem markers as prognostic factor in NSCLC.

HIP1R Expression and Its Association with PD-1 Pathway Blockade Response in Refractory Advanced NonSmall Cell Lung Cancer: A Gene Set Enrichment Analysis

Huntingtin-interacting protein 1-related protein (HIP1R) plays an important role in the regulation of programmed death-ligand 1 (PD-L1). The aim of this study was to investigate the expression of HIP1R and confirm its predictive or prognostic roles in anti-PD-1 therapy in nonsmall cell lung cancer (NSCLC) patients. HIP1R and PD-L1 immunohistochemical expression was examined in 52 refractory advanced NSCLC patients treated with anti-PD-1 inhibitors. We performed gene set enrichment analysis (GSEA) to detect HIP1R-specific gene sets. Patients in the PD-1 inhibitor responder group had lower HIP1R expression by univariate logistic regression analysis (odds ratio (OR) = 0.235, p = 0.015) and multivariate logistic regression analysis (OR = 0.209, p = 0.014). Patients with high HIP1R expression had poorer progression-free survival (PFS) than patients with low HIP1R expression in univariate analysis (p = 0.037) and multivariate Cox analysis (hazard ratio = 2.098, p = 0.019). The web-based mRNA dataset also showed that high HIP1R expression correlated with inferior overall survival in lung adenocarcinoma (p = 0.026). GSEA revealed that HIP1R levels correlate with a set of genes that reflect PD-L1-related immune pathways. HIP1R expression may be a promising predictor for determination of patient responses to anti-PD-1 treatment.

A Neuropilin-1 Antagonist Exerts Antitumor Immunity by Inhibiting the Suppressive Function of Intratumoral Regulatory T Cells

Regulatory T cells (Treg) are targeted for cancer immunotherapy because they suppress antitumor immunity. Although the importance of neuropilin-1 (NRP1) in the stability and function of intratumoral Tregs is well-documented, targeting of NRP1⁺ Tregs for anticancer immunotherapy has not been well explored. Here, we found that an NRP1 antagonist [Fc(AAG)-TPP11], generated by fusion of the NRP1-specific binding peptide TPP11 with the C-terminus of an effector function-deficient immunoglobulin Fc(AAG) variant, inhibits intratumoral NRP1⁺ Treg function and stability. Fc(AAG)-TPP11 triggered the internalization of NRP1, reducing its surface expression on Tregs and thereby inhibiting the suppressive function of Tregs. In two murine syngeneic tumor models, Fc(AAG)-TPP11 retarded tumor growth, comparable with a Treg-depleting anti-CTLA-4 antibody, without noticeable toxicity. Fc(AAG)-TPP11 inhibited NRP1-dependent Treg function, inducing unstable intratumoral Tregs, with reduced expression of Foxp3 and enhanced production of IFNγ, which subsequently increased the functionality and frequency of intratumoral CD8⁺ T cells. We also observed selective expression of NRP1 on Tregs isolated from human tumors, but not from the blood of healthy donors and patients with cancer, as well as ex vivo inhibition of intratumoral NRP1⁺ Treg function by Fc(AAG)-TPP11. Our results suggest that the NRP1 antagonist Fc(AAG)-TPP11 has therapeutic potential for the inhibition of intratumoral NRP1⁺ Tregs with limited unfavorable effects on peripheral Tregs.

Carcinoembryonic antigen predicts waitlist mortality in lung transplant candidates with idiopathic pulmonary fibrosis

OBJECTIVES

Elevated serum carcinoembryonic antigen (CEA) has been reported in lung transplant candidates with idiopathic pulmonary fibrosis, but its association with waitlist mortality is not known. In this study, we evaluated the ability of the serum CEA level to predict waitlist mortality in these patients.

METHODS

Fifty-nine patients with idiopathic pulmonary fibrosis who were enrolled as lung transplant candidates between January 2004 and December 2014 were retrospectively reviewed. Serum CEA was measured as part of routine evaluation.

RESULTS

Thirty-seven of the 59 patients underwent lung transplantation with a median waiting time of 91 days. Twenty-two patients died while on the waitlist. In univariable analysis, 6-min walking distance, lung allocation score and serum CEA level were identified as being significant prognostic factors. We constructed 2 multivariable models using forced vital capacity, CEA and 6-min walking distance (Model 1, concordance index 0.758) and CEA and lung allocation score (Model 2, concordance index 0.689). CEA was independently associated with waitlist mortality in Model 1 [hazard ratio 1.074, 95% confidence interval (CI)_ 1.004-1.137] and in Model 2 (hazard ratio 1.065, 95% CI 1.008-1.126). The cut-off values that best discriminated 30-day mortality and 6-month mortality by receiver-operating characteristic curve analysis were 8.55 ng/ml and 4.50 ng/ml, respectively.

CONCLUSIONS

There was a significant association between elevated serum CEA and increased risk of mortality in waitlisted transplant candidates with idiopathic pulmonary fibrosis.

Increased CMTM6 can predict the clinical response to PD-1 inhibitors in non-small cell lung cancer patients

CKLF-like MARVEL transmembrane domain containing 6 (CMTM6) plays a crucial role in the stability of the programmed death-ligand 1 (PD-L1). However, there has been no previous study of CMTM6 in non-small cell lung cancer (NSCLC) and its association with PD-L1 has not been confirmed. The aim of this study was to investigate the expression of CMTM6 and PD-L1 and to confirm their predictive roles for anti-PD-1 therapy in non-small cell lung cancer. CMTM6 and PD-L1 immunohistochemical expressions were evaluated in 35 advanced, treatment-refractory NSCLC patients who received PD-1 inhibitor therapy. The correlation between CMTM6 and PD-L1 expression was also determined based on immunohistochemistry and RNA-sequencing data obtained from The Cancer Genome Atlas (TCGA) database. CMTM6 expression was positively correlated with PD-L1 expression in immunohistochemical data (Pearson's r = 0.342 and p = .044). A positive correlation was also identified in the mRNA expression data. Using receiver operating characteristic curves, the levels of CMTM6 and PD-L1 expression which provided the best distinguishing point between responder versus non-responder to PD-1 inhibitors were 70 and 75 H-scores, respectively. The patients in the PD-1 inhibitor responder group had higher CMTM6 expressions in univariate logistic regression analysis (odds ratio (OR) = 5.333, p = .037). However, PD-L1 expression was not associated with response to PD-1 inhibitor (p = .288). In multivariate analysis, CMTM6 was also found to be an independent predictor of the response to PD-1 inhibitors (OR = 6.226, p = .032). CMTM6 expression can be a promising predictor useful for therapeutic decision-making regarding PD-1 inhibitors.

Genomic Common Data Model for Seamless Interoperation of Biomedical Data in Clinical Practice: Retrospective Study

Background

Clinical sequencing data should be shared in order to achieve the sufficient scale and diversity required to provide strong evidence for improving patient care. A distributed research network allows researchers to share this evidence rather than the patient-level data across centers, thereby avoiding privacy issues. The Observational Medical Outcomes Partnership (OMOP) common data model (CDM) used in distributed research networks has low coverage of sequencing data and does not reflect the latest trends of precision medicine.

Objective

The aim of this study was to develop and evaluate the feasibility of a genomic CDM (G-CDM), as an extension of the OMOP-CDM, for application of genomic data in clinical practice.

Methods

Existing genomic data models and sequencing reports were reviewed to extend the OMOP-CDM to cover genomic data. The Human Genome Organisation Gene Nomenclature Committee and Human Genome Variation Society nomenclature were adopted to standardize the terminology in the model. Sequencing data of 114 and 1060 patients with lung cancer were obtained from the Ajou University School of Medicine database of Ajou University Hospital and The Cancer Genome Atlas, respectively, which were transformed to a format appropriate for the G-CDM. The data were compared with respect to gene name, variant type, and actionable mutations.

Results

The G-CDM was extended into four tables linked to tables of the OMOP-CDM. Upon comparison with The Cancer Genome Atlas data, a clinically actionable mutation, p.Leu858Arg, in the EGFR gene was 6.64 times more frequent in the Ajou University School of Medicine database, while the p.Gly12Xaa mutation in the KRAS gene was 2.02 times more frequent in The Cancer Genome Atlas dataset. The data-exploring tool GeneProfiler was further developed to conduct descriptive analyses automatically using the G-CDM, which provides the proportions of genes, variant types, and actionable mutations. GeneProfiler also allows for querying the specific gene name and Human Genome Variation Society nomenclature to calculate the proportion of patients with a given mutation.

Conclusions

We developed the G-CDM for effective integration of genomic data with standardized clinical data, allowing for data sharing across institutes. The feasibility of the G-CDM was validated by assessing the differences in data characteristics between two different genomic databases through the proposed data-exploring tool GeneProfiler. The G-CDM may facilitate analyses of interoperating clinical and genomic datasets across multiple institutions, minimizing privacy issues and enabling researchers to better understand the characteristics of patients and promote personalized medicine in clinical practice.

Time to tracheal intubation over a fibreoptic bronchoscope using a silicone left double-lumen endobronchial tube versus polyvinyl chloride single-lumen tube with bronchial blocker: a randomized controlled non-inferiority trial

Background

Direct insertion of a double-lumen endobronchial tube (DLT) over a fibreoptic bronchoscope (FOB) is considered more difficult and traumatic than that of a single-lumen tube (SLT). We hypothesized that time to intubation over an FOB using a silicone left DLT would be non-inferior to that using a polyvinyl chloride (PVC) SLT.

Methods

Eighty patients were enrolled in this open-label, randomized controlled, non-inferiority trial. Patients were randomly allocated to fibreoptic tracheal intubation with either a silicone DLT or PVC SLT (DLT and SLT groups, respectively). Time to tracheal intubation [time to insertion of FOB plus railroading (advancement over the FOB) time]; total time for correct tube and bronchial blocker positioning; difficulty of railroading; and the incidence of sore throat, swallowing difficulty, and hoarseness were compared between groups.

Results

The median time to intubation over the FOB was 20 s in the DLT group and 23 s in the SLT group. The upper limit of the confidence interval of this difference was below the non-inferiority margin of 10 s (median difference: -2 s; 95% confidence interval: -4 to 0 s). Railroading time was significantly shorter in the DLT group than in the SLT group (median time: 10 vs. 11 s; median difference: -1 s; 95% confidence interval: -3 to 0 s; P=0.03). Railroading over the FOB (rated on a four-point scale) was less difficult in the DLT group than in the SLT group (P<0.01).

Conclusions

Tracheal intubation using an FOB can be achieved at least as fast using the silicone DLT as using the PVC SLT. The silicone DLT exhibited superior railroading performance to the PVC SLT.

Amylase level in cervical drain fluid and anastomotic leakage after cervical oesophagogastrostomy

OBJECTIVES

Anastomotic leakage after oesophageal cancer surgery is a serious complication. The purpose of this study was to evaluate the possibility of anastomotic leakage by repeatedly measuring amylase levels in the fluid obtained from the drainage tube inserted at the cervical anastomotic site.

METHODS

Ninety-nine patients who underwent oesophagectomy and cervical oesophagogastrostomy between April 2014 and March 2017 were retrospectively reviewed. A drainage tube was placed at the anastomotic site, and amylase levels were measured daily from postoperative day (POD) 1 until oral feeding or confirmation of anastomotic leakage. The amylase levels were analysed with a linear mixed model.

RESULTS

The mean age of the patients was 64.9 ± 9.0 years, and there were 89 (89%) male patients. Almost all pathologies (92%) were squamous cell carcinomas. The anastomotic methods were as follows: 63 (63%) circular stapled, 33 (33%) hand-sewn and 3 (3%) semistapled. Anastomotic leakage was confirmed in 10 (10%) patients. The amylase levels increased until POD 2 in both the leakage and non-leakage groups, but the levels subsequently decreased in the non-leakage group, whereas the levels peaked on POD 3 in the leakage group. On performing the linear mixed model analysis, anastomotic leakage was significantly associated with the trends in postoperative amylase levels in the drainage tube (P < 0.001). Trends in the serum C-reactive protein levels and white blood cell count were not significantly associated with anastomotic leakage.

CONCLUSIONS

Amylase level trends measured in the cervical drain fluid can be a useful indicator of anastomotic leakage after cervical oesophagogastrostomy.

PD-L1 protein expression in non-small-cell lung cancer and its relationship with the hypoxia-related signaling pathways: A study based on immunohistochemistry and RNA sequencing data

OBJECTIVES

Therapies that target programmed cell death protein-1 (PD-1)/programmed death-ligand 1 (PD-L1) have shown promising efficacy in non-small-cell lung cancer (NSCLC). Hypoxia-related genes are also important regulators of PD-L1, and the role of PD-L1 in NSCLC is still not clear. The objective of this study was to investigate PD-L1 expression and its correlation with hypoxic-inducible factor 1α (HIF1A), vascular endothelial growth factor A (VEGFA), glucose transporter 1 (GLUT1), and carbonic anhydrase 9 (CAIX) expression in NSCLC patients. The association between PD-L1 expression and survival was also determined.

MATERIALS AND METHODS

PD-L1/protein expression was evaluated in 295 resected NSCLCs and its correlation with HIF1A, VEGFA, GLUT1, CAIX expression and survival was determined based on immunohistochemical and RNA sequencing data obtained from The Cancer Genome Atlas (TCGA) database.

RESULTS

PD-L1 protein expression was significantly correlated with HIF1A, VEGFA, GLUT1, and CAIX expression only in adenocarcinoma when a 10% or a 50% cut-off was used. PD-L1 mRNA expression was also significantly correlated with HIF1A, VEGFA, GLUT1, and CAIX expression in adenocarcinoma. Univariate analysis revealed that HIF1A expression was associated with poor recurrence-free survival (RFS), and GLUT1 was associated with poor overall survival (OS) and RFS. GLUT1 was an independent prognostic factor for OS in multivariate analysis of immunohistochemical and TCGA data (p = 0.024 and 0.029, respectively). Patients with low expression of both PD-L1 and GLUT1 had longer OS than other patterns in immunohistochemical and TCGA data (p = 0.003 and 0.051, respectively).

CONCLUSIONS

PD-L1 protein and mRNA expression were correlated with HIF1A, VEGFA, GLUT1, and CAIX expression in adenocarcinoma alone. Low expression of GLUT1 and low expression of both PD-L1 and GLUT1 were associated with improved prognosis. Our findings support the rationale for co-targeting hypoxia-related genes and PD-L1 in cancer therapy. Expression of hypoxia-related genes may be helpful in selecting patients appropriate for PD-L1 therapy.

Hydrogen gas inhalation during ex vivo lung perfusion of donor lungs recovered after cardiac death

BACKGROUND

Ex vivo lung perfusion (EVLP) is a system that circulates normothermic perfusate into procured lungs, allowing for improved lung function and lung assessment. We investigated whether ventilation with hydrogen gas during EVLP improves the donation after cardiac death lung function and whether this effect persists after actual transplantation.

METHODS

Ten pigs were randomly divided into a control group (n = 5) and a hydrogen group (n = 5). No treatment was administered to induce warm ischemic injury for 1 hour after cardiac arrest, and EVLP was applied in procured lungs for 4 hours. During EVLP, the control group was given room air for respiration, and the hydrogen group was given 2% hydrogen gas. After EVLP, the left lung graft was orthotopically transplanted into the recipient and reperfused for 3 hours. During EVLP and reperfusion, the functional parameters and arterial blood gas analysis (ABGA) were measured every hour. Superoxide dismutase, heme oxygenase, interleukin (IL)-6, IL-10, tumor necrosis factor-α, and nucleotide-binding oligomerization domain-like receptor protein 3 were evaluated in lung tissue after reperfusion. Pathologic evaluations were performed, and the degree of apoptosis was evaluated. The wet/dry ratio was measured.

RESULTS

During EVLP and reperfusion, functional parameters and ABGA results were better in the hydrogen group. The expressions of superoxide dismutase (p = 0.022) and heme oxygenase-1 (p = 0.047) were significantly higher in the hydrogen group. The expressions of IL-6 (p = 0.024) and nucleotide-binding oligomerization domain-like receptor protein 3 (p = 0.042) were higher in the control group, but IL-10 (p = 0.037) was higher in the hydrogen group. The lung injury severity score and the number of apoptotic cells were higher and the degree of pulmonary edema was more severe in the control group than in the hydrogen group.

CONCLUSIONS

Hydrogen gas inhalation during EVLP improved donation after cardiac death lung function via reduction of inflammation and apoptosis, and this effect persisted after LTx.

Pulmonary Nodular Lymphoid Hyperplasia in a 33-Year-Old Woman

Pulmonary nodular lymphoid hyperplasia is a reactive lymphoproliferative disease. It is very rare, which means that many aspects of the disease are unknown or have not been proven. Pulmonary nodular lymphoid hyperplasia can be symptomatic or asymptomatic, progressive or not, and solitary or multiple, and a surgical approach is the current treatment of choice. We present a case of pulmonary nodular lymphoid hyperplasia that was visualized as multiple ground glass opacities on a computed tomography (CT) scan, and observed for 1 year because the patient was pregnant. Over this period, the number and extent of the opacities progressed, but no symptoms were reported. A surgical biopsy was done and some remaining lesions regressed on follow-up CT scans, while others progressed, without any appearance of symptoms.

The repeatability of computed tomography lung volume measurements: Comparisons in healthy subjects, patients with obstructive lung disease, and patients with restrictive lung disease

In this study, we examined the repeatability of computed tomography (CT) lung volume measurements in healthy individuals and patients with obstructive and restrictive lung diseases. To do this, we retrospectively enrolled 200 healthy individuals (group 1), 100 patients with obstructive lung disease (group 2), and 100 patients with restrictive lung disease (group 3) who underwent two consecutive chest CT scans within a 1-year period. The CT lung volume was measured using a threshold-based, three-dimensional auto-segmentation technique at a default range from -200 to -1024 HU. The within-subject standard deviation, repeatability coefficient, within-subject coefficient variability, and intraclass correlation coefficient were evaluated. No significant differences were identified between the two consecutive CT lung volume measurements in any of the groups (p> 0.05). The within-subject standard deviations for groups 1, 2, and 3 were 441.1, 387.0, and 288.6, respectively, while the repeatability coefficients were 1222.6, 1072.6, and 800.1, respectively. The within-subject coefficient variabilities for groups 1, 2, and 3 were 0.097, 0.083, and 0.090, respectively, while the intraclass correlation coefficients were 0.818, 0.881, and 0.910, respectively. The two CT lung volume measurements showed excellent agreement in healthy individuals and patients with obstructive or restrictive lung disease. However, the repeatability was lower in healthy individuals than it was in patients with lung diseases.

Postoperative change of the psoas muscle area as a predictor of survival in surgically treated esophageal cancer patients

BACKGROUND

Although a decrease in the psoas muscle area (PMA) has been reported as a risk factor for survival after esophagectomy in esophageal cancer, no previous studies have focused on the change in the PMA after surgery. We investigated the prognostic role of PMA changes in patients with surgically treated esophageal cancer.

METHODS

Fifty-eight patients with esophageal cancer who underwent surgical resection and complete lymph node dissection were reviewed retrospectively. The PMA was measured at the level of the L3 vertebrae on preoperative and one-year postoperative follow-up computed tomography images. The percentage change of the PMA was calculated as follows: delta (%) = (postoperative PMA - preoperative PMA) / (preoperative PMA × 100).

RESULTS

The study patients included 54 (93.1%) males and 4 females (mean age, 60.59±9.16 years), of whom 17 (29.3%) were pathological Stage I, 18 (31.0%) were Stage II, and 23 (39.7%) were Stage III. The mean change of the PMA was -10.17% and the postoperative PMA was decreased significantly compared with the preoperative PMA (P<0.001). The PMA was increased in 13 (22.4%) patients, whereas it was decreased in 45 (77.6%). Multivariate analysis revealed that the change of the PMA (hazard ratio, HR =0.688; P=0.001) and the pathologic stage (Stage III vs. Stage I, HR =3.388; P=0.016) were risk factors for overall survival (OS). The 3-year OS in patients with a PMA decrease of more than 10%, and those with a PMA decrease of less than 10% or an increase, were 18.9% and 59.5%, respectively (P=0.049).

CONCLUSIONS

The decrease in the PMA had a negative prognostic effect on OS in patients with surgically treated esophageal cancer.

Omental flap for treatment of dead space after left upper lobectomy due to aspergilloma

Dead space formation in the thoracic cavity as a result of lung parenchymal resection is particularly prone to intra-thoracic infections, which are often hard to treat with systemic antibiotics; secondary interventions, such as thoracoplasty, eloesser flap, or muscle flap may be required to treat this complication. Alternatively, use of an omental flap represents an attractive option in cases of surgical cavities, due to the volumetric and immunologic advantages associated with the omentum. A 55-year-old male patient, who underwent left upper lobectomy due to an aspergilloma, was left with a surgical cavity that became infected with Pseudomonas aeruginosa. To address this complication, we performed a reconstruction of the left upper lung field through the substernal route using a section of the omental flap, and the infection was clinically eradicated.

Prognostic value of preoperative total psoas muscle area on long-term outcome in surgically treated oesophageal cancer patients

OBJECTIVES

Although a decrease in psoas muscle area (PMA) has been reported as a risk factor for survival in several malignancies, there have been few studies regarding its prognostic value in oesophageal cancer. We investigated the prognostic role of PMA and its F-18 fluorodeoxyglucose uptake in patients who had surgically treated oesophageal cancer.

METHODS

From 2004 to 2013, 131 patients who underwent surgical resection and complete lymph node dissection for oesophageal cancer were retrospectively reviewed. The PMA and mean standardized uptake value (SUVmean) of the psoas muscle were measured at the L3 spine level on preoperative positron emission tomography/computed tomography images.

RESULTS

The mean age was 63.38 ± 8.47 years and male patients were 125 (95.4%). The pathological stage I, II and III were 38 (29.0%), 41 (31.3%) and 52 (39.7%), respectively. The mean body mass index (BMI), PMA and SUVmean of the psoas muscle were 59.50 ± 10.14, 14.42 ± 4.30 and 1.51 ± 0.27, respectively. Operative mortality occurred in 7 (5.3%) patients. The BMI and PMA were lower in patients with operative mortality than in patients who survived. The median follow-up time was 32.52 months. A multivariate analysis revealed that PMA was an adverse risk factor for overall survival (OS) (hazard ratio, HR = 0.930; P= 0.004), whereas BMI was related to OS. The 3-year OS rates were 64.9% in high-PMA (≥15.8) patients; however, it was only 37.1% in low-PMA (less than 15.8) patients (P= 0.002). Akaike information criterion was the lowest by including PMA in the multivariate model.

CONCLUSIONS

Decreased PMA was an adverse significant prognostic factor for OS in patients with oesophageal cancer.

Efficacy of subpleural continuous infusion of local anesthetics after thoracoscopic pulmonary resection for primary lung cancer compared to intravenous patient-controlled analgesia

BACKGROUND

This study compared the efficacy and side effects of intravenous patient-controlled analgesia (IV-PCA) with those of a subpleural continuous infusion of local anesthetic (ON-Q system) in patients undergoing thoracoscopic pulmonary resection for primary lung cancer.

METHODS

We retrospectively reviewed 66 patients who underwent thoracoscopic pulmonary resection for primary lung cancer from January 2014 to August 2015 (36 in the IV-PCA group and 30 in the ON-Q group). The numeric pain intensity scale (NPIS), additional IV injections for pain control, side effects, and early discontinuation of the pain control device were compared.

RESULTS

There were no differences in the general characteristics of the two groups. The NPIS scores gradually decreased with time (P<0.001), but the two groups had differences in pattern of NPIS scores (P=0.111). There were no differences in the highest NPIS score during admission (4.75±2.35 vs. 5.27±1.87, P=0.334) or the number of additional IV injections for pain control in the same period (0.72±0.94 for IV-PCA vs. 0.83±0.65 for ON-Q; P=0.575). Side effects such as nausea, dizziness, and drowsiness were significantly more frequent with IV-PCA (36.1% vs. 10.0%, P=0.014), and early discontinuation of the pain control device was more frequent in the IV-PCA group (33.3% vs. 6.7%, P=0.008).

CONCLUSIONS

The ON-Q system was equivalent to the IV-PCA for postoperative pain control after thoracoscopic pulmonary resection for primary lung cancer, and it also had fewer effects and early discontinuations.

The feasibility of CT lung volume as a surrogate marker of donor-recipient size matching in lung transplantation

Donor-recipient size matching in lung transplantation (LTx) by computed tomography lung volume (CTvol) may be a reasonable approach because size matching is an anatomical issue. The purpose of this study is to evaluate the feasibility of CTvol as a surrogate marker of size matching in LTx by comparing CTvol and predicted total lung capacity (pTLC) to reference total lung capacity (TLC) values.From January to December 2014, data from 400 patients who underwent plethysmography, pulmonary function testing (PFT), and chest computed tomography scans were reviewed retrospectively. Enrolled 264 patients were divided into 3 groups according to PFT results: Group I, obstructive pattern; Group II, restrictive pattern; Group III, normal range. The correlations between pTLC and TLC and between CTvol and TLC were analyzed, and the linear correlation coefficients were compared. The percentage error rates of pTLC and CTvol were calculated and absolute error rates were compared.The correlation coefficient between CTvol and TLC in Group I was larger than that of pTLC and TLC (0.701 vs 0.432, P = 0.002). The absolute percentage error rate between CTvol and pTLC was lower than that of pTLC in Group II (15.3% ± 11.9% vs 42.2% ± 28.1%, P < 0.001).CTvol showed similar or better correlation with TLC compared to the pTLC in normal participants and patients with obstructive or restrictive pulmonary diseases. CTvol showed a smaller error rate in patients with restrictive disease. The results suggest that CTvol may be a feasible method for size matching in LTx.

Comparison of Predicted Total Lung Capacity and Total Lung Capacity by Computed Tomography in Lung Transplantation Candidates

PURPOSE

Lung size mismatch is a major cause of poor lung function and worse survival after lung transplantation (LTx). We compared predicted total lung capacity (pTLC) and TLC measured by chest computed tomography (TLC(CT)) in LTx candidates.

MATERIALS AND METHODS

We reviewed the medical records of patients on waiting lists for LTx. According to the results of pulmonary function tests, patients were divided into an obstructive disease group and restrictive disease group. The differences between pTLC calculated using the equation of the European Respiratory Society and TLC(CT) were analyzed in each group.

RESULTS

Ninety two patients met the criteria. Thirty five patients were included in the obstructive disease group, and 57 patients were included in the restrictive disease group. pTLC in the obstructive disease group (5.50±1.07 L) and restrictive disease group (5.57±1.03 L) had no statistical significance (p=0.747), while TLC(CT) in the restrictive disease group (3.17±1.15 L) was smaller than that I the obstructive disease group (4.21±1.38 L) (p<0.0001). TLC(CT)/pTLC was 0.770 in the obstructive disease group and 0.571 in the restrictive disease group.

CONCLUSION

Regardless of pulmonary disease pattern, TLC(CT) was smaller than pTLC, and it was more apparent in restrictive lung disease. Therefore, we should consider the difference between TLC(CT) and pTLC, as well as lung disease patterns of candidates, in lung size matching for LTx.

Comparisons of the clinical outcomes of thoracoscopic sympathetic surgery for palmar hyperhidrosis: R4 sympathicotomy versus R4 sympathetic clipping versus R3 sympathetic clipping

BACKGROUND

Thoracoscopic sympathetic surgery is regarded as a definitive treatment for palmar hyperhidrosis. However, the optimal surgical strategy remains unclear. The aim of this study was to compare outcomes based on the level and type of sympathetic disconnection in patients with palmar hyperhidrosis.

METHODS

From January 2009 to December 2014, 101 patients with palmar hyperhidrosis underwent thoracoscopic sympathetic surgery at Gangnam Severance Hospital. Complete follow-up information was obtained from 59 patients. We retrospectively analyzed the results of operation, degree of palmar sweating (%), grade of compensatory sweating (none, mild, moderate, severe, very severe), grade of satisfaction (very satisfied, satisfied, moderate, dissatisfied, very dissatisfied), and recurrence/failure.

RESULTS

R4 sympathicotomy, R4 sympathetic clipping, and R3 sympathetic clipping were performed in 16, 20, and 23 patients, respectively. The mean degree of palmar sweating after sympathetic surgery was not significantly different between these three groups (17.50% vs. 27.00% vs. 29.78%; P=0.38). The rate of life-bothering compensatory sweating was lower in the R4 sympathicotomy group compared with those of other two groups (0% vs. 25%, 47.8%; P=0.09). The rate of very satisfied to moderate grades of satisfaction were lower in the R3 sympathetic clipping group compared with those of other two groups (93.8%, 100% vs. 73.9%; P=0.07). The rate of recurrence/failure rates were lower in the R4 sympathicotomy group compared with those of other two groups (12.50% vs. 35.00%, 34.8%; P=0.25). Sympathetic surgery at the R3 level was the only significant risk factor for patient dissatisfaction (odd ratio =12.353, 95% confidence interval =1.376-110.914; P=0.025).

CONCLUSIONS

Our data support that R4 sympathicotomy had lower grades of compensatory sweating, higher grades of satisfaction, and lower rates of recurrence/failure. We therefore consider R4 sympathicotomy as an optimal surgical treatment for palmar hyperhidrosis.

The effects of hydrogen gas inhalation during ex vivo lung perfusion on donor lungs obtained after cardiac death

OBJECTIVES

Lung transplantation is a well-established treatment of end-stage lung disease; however, it is limited by a shortage of donor lungs. To overcome this problem, donation after cardiac death (DCD) and ex vivo lung perfusion (EVLP) are being widely investigated. In this study, the effect of hydrogen gas, a known antioxidant, was investigated on a DCD lung model during EVLP.

METHODS

Ten pigs were randomized into either a control (n = 5) or a hydrogen group (n = 5). After fibrillation by electric shock, no further treatment was administered in order to induce warm ischaemic injury for 1 h. The lungs were then procured, followed by 4 h of EVLP. During EVLP, the lungs were ventilated with room air in the control group, and with 2% hydrogen gas in the hydrogen group. Oxygen capacity (OC), pulmonary vascular resistance (PVR) and peak airway pressure (PAP) were measured every hour, and the expressions of interleukin-1 beta (IL-1β), IL-6 (IL-6), IL-8 (IL-8) and tumour necrosis factor-alpha (TNF-α) were evaluated in lung tissue after EVLP. Pathological evaluations were performed using lung injury severity (LIS) scores and the wet/dry ratio was also measured.

RESULTS

The OC in the hydrogen group was higher than in the control group, but the difference was not statistically significant (P = 0.0862). PVR (P = 0.0111) and PAP (P = 0.0189) were statistically significantly lower in the hydrogen group. Compared with the control group, the hydrogen group had a statistically significantly lower expression of IL-1β (P = 0.0317), IL-6 (P = 0.0159), IL-8 (P = 0.0195) and TNF-α (P = 0.0159). The LIS scores (P = 0.0358) and wet/dry ratios (P = 0.040) were also significantly lower in the hydrogen group.

CONCLUSIONS

Hydrogen gas inhalation during EVLP improved the function of DCD lungs, which may increase the utilization of DCD lungs.