Diagnostic value of circulating microRNA-21 in chronic lung allograft dysfunction after bilateral cadaveric and living-donor lobar lung transplantation

Background

MicroRNAs (miRNAs) involved in the pathogenesis of pulmonary fibrosis have been shown to be associated with the development of chronic lung allograft dysfunction (CLAD) after lung transplantation (LT). We investigated the role of circulating miRNAs in the diagnosis of CLAD after bilateral LT, including cadaveric LT (CLT) and living-donor lobar LT (LDLLT).

Methods

The subjects of this retrospective study were 37 recipients of bilateral CLT (n = 23) and LDLLT (n = 14), and they were divided into a non-CLAD group (n = 24) and a CLAD group (n = 13). The plasma miRNA levels of the two groups were compared, and correlations between their miRNAs levels and percent baseline forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and total lung capacity (TLC) values were calculated from one year before to one year after the diagnosis of CLAD.

Results

The plasma levels of both miR-21 and miR-155 at the time of the diagnosis of CLAD were significantly higher in the CLAD group than in the non-CLAD group (miR-21, P = 0.0013; miR-155, P = 0.042). The miR-21 levels were significantly correlated with the percent baseline FEV1, FVC, and TLC value of one year before and at the time of diagnosis of CLAD (P < 0.05). A receiver operating characteristic curve analysis of the performance of miR-21 levels in the diagnosis of CLAD yielded an area under the curve of 0.89.

Conclusion

Circulating miR-21 appears to be of potential value in diagnosing CLAD after bilateral LT.

Donor's long-term quality of life following living-donor lobar lung transplantation

INTRODUCTION

Living-donor lobar lung transplantation is an alternative procedure to deceased donation lung transplantation. It involves graft donation from healthy donors; however, only a few reports have discussed its long-term prognosis in living lung donors and their associated health-related quality of life. This study aimed to examine living lung donors' health-related quality of life.

METHODS

In our cross-sectional survey of living lung donors, we assessed health-related quality of life-based on three key aspects (physical, mental, and social health) using the 36-Item Short Form Health Survey. We also evaluated chronic postoperative pain and postoperative breathlessness using the numeric rating scale and the modified Medical Research Council Dyspnea scale, respectively.

RESULTS

We obtained consent from 117 of 174 living lung donors. The average scores of the living lung donors on the 36-Item Short Form Health Survey were higher than the national average. However, some donors had poorer physical, mental, and social health, with lower summary scores than the national averages. Low mental component summary predictors included donor age (<40 years; odds ratio = 10.2; p < .001) and recipient age (<18 years; odds ratio = 2.73; p < .032). Low role-social component summary predictors included high lung allocation score (≥50; odds ratio = 3.94, p < .002) and recipient death (odds ratio = 3.64; p = .005). There were no predictors for a physical component summary. Additionally, many donors did not complain of pain or dyspnea.

CONCLUSIONS

Living lung donors maintained an acceptable long-term health-related quality of life after surgery. Potential donors should be informed of relevant risk factors, and high-risk donors should receive appropriate support.

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.

Survival and prognostic factors in patients undergoing pulmonary metastasectomy for lung metastases from retroperitoneal sarcoma

BACKGROUND

Soft-tissue sarcomas are rare malignancies that consist of many different histologic subtypes and arise in various locations in the body. In patients with lung metastases from retroperitoneal sarcomas, the long-term outcomes and prognostic factors are unknown. This study is a retrospective review of patients undergoing pulmonary metastasectomy for retroperitoneal sarcoma metastases at one institution, with the purpose of determining prognostic factors and clinical outcomes.

METHODS

This is a single-center, retrospective cohort study of patients undergoing pulmonary metastasectomy for lung metastases from various sarcomas at Okayama University Hospital from January 2006 to December 2018. The Kaplan-Meier method and log-rank test were used for the analyses, and cut-off values of continuous variables were determined by a receiver operating characteristic curve analysis.

RESULTS

Twenty-four patients underwent the first pulmonary metastasectomy for lung metastases from retroperitoneal sarcoma in our hospital. Leiomyosarcoma was the most common histologic subtype of retroperitoneal sarcoma (79.2%, n = 19). Median overall survival was 49.9 months, and the 3-year and 5-year survival rates after the first pulmonary metastasectomy were 62.5% and 26.4% respectively. In univariate analysis, age ≥56 years, disease-free interval < 15 months, and size of metastasis (≥ 27 mm) were associated with poor survival.

CONCLUSION

Pulmonary metastasectomy can be considered as an effective management strategy in retroperitoneal sarcoma patients with lung metastases in appropriately selected cases, just as it is for other sarcomas.

[Chronic Lung Allograft Dysfunction after Living-donor Lobar Lung Transplantation]

Long-term survival after living-donor lobar lung transplantation (LDLLT) is hampered by the development of chronic lung allograft dysfunction( CLAD), similar to the clinical courses seen in some recipients of cadaveric lung transplantation( CLT). CLAD after bilateral LDLLT has been shown to be characterized by the development in the unilateral lung due to differences in the immunological features of the two donors. Based on this characteristic, we found that lung perfusion scintigraphy, which can show a perfusion shift to the contralateral unaffected lung with the development of CLAD, had the potential to predict unilateral CLAD after bilateral LDLLT. Moreover, we found that CLAD, especially restrictive allograft syndrome, developed significantly later after bilateral LDLLT than after bilateral CLT, although the CLAD-free survival and overall survival after bilateral LDLLT were similar to those after bilateral CLT. We describe our experience of CLAD after bilateral LDLLT since the first case of LDLLT in Japan.

Paediatric lung transplantation: the impact of age on the survival

OBJECTIVES

We herein review the outcomes of paediatric lung transplantation (LTx) and analyse subgroups divided by age.

METHODS

We retrospectively reviewed 43 consecutive paediatric LTx recipients (< 18 years old: cadaveric LTx [n = 9], living-donor lobar LTx [n = 34]). We also analysed subgroups of patients 1-6 years old (n = 10) and 7-17 years old (n = 33).

RESULTS

The 1-, 5- and 10-year overall survival (OS) rates in paediatric recipients were 93%, 82% and 67%, respectively. The 1-, 5- and 10-year graft dysfunction (GD)-free survival rates in paediatric recipients were 85%, 59% and 31%, respectively. The 1- and 5-year OS in the 1- to 6-year-old vs. 7- to 17-year-old groups were 70% vs. 100% and 48% vs. 93%, respectively (p < 0.0001). The 1- and 5-year GD-free survival rates in the 1- to 6-year-old vs. 7- to 17-year-old groups were 60% vs. 93% and 24% vs. 69%, respectively (p = 0.024). The 1- to 6-year-old group showed higher rates of non-standard LTx (p = 0.0001), interstitial pneumonia (p = 0.004) and ventilator dependency (p = 0.007) than the 7- to 17-year-old group.

CONCLUSION

Paediatric recipients under 7 years old seemed to have a higher risk of mortality and GD than those 7 years old and older.

Completely Video-assisted Thoracoscopic Lobectomy for Congenital Lobar Emphysema in a Young Adult

Congenital lobar emphysema (CLE) is defined as the hyperinflation of pulmonary lobes due to obstruction of the flow of air via a known or unknown etiology, which causes pressure symptoms in the adjacent organs. CLE is mainly diagnosed in the neonatal period, and very few adult cases have been reported. Here we report a 34-year-old male with muscular dystrophy who was diagnosed with CLE on examination. He underwent a right lower lobectomy via 3-portal completely video-assisted thoracoscopic surgery, and his symptoms improved. Thoracoscopic surgery helped preserve the respiratory muscles and led to the improvement of respiratory function in this patient.

Acute Pulmonary Edema Due to Arteriovenous Shunt Placement after Lung Transplant

Lung transplant recipients are often complicated by immunosuppressant-induced nephropathy, which may require renal replacement therapy. We report a case of unilateral lung edema and pulmonary hypertension due to arteriovenous fistula placement in a patient with unilateral chronic lung allograft dysfunction after bilateral living-donor lobar lung transplantation. Lung transplant recipients with limited residual vascular beds, such as lobar graft or severe deviation in lung perfusion, are vulnerable to the acute increase in blood flow due to arteriovenous fistula placement and can easily develop pulmonary edema regardless of the left ventricular function. Hence, careful volume control is required.

Lung recruitment after cardiac arrest during procurement of atelectatic donor lungs is a protective measure in lung transplantation

Background

Brain-dead donors are susceptible to pulmonary atelectasis (AT). In procurement surgery, lung recruitment under circulatory conditions and cold-flushing for atelectatic donor lungs often provoke graft injury due to the acute blood inflow. We hypothesized that lung recruitment without blood circulation can mitigate graft injury. This study aimed to examine the benefits of lung recruitment subsequent to cardiac arrest using a porcine lung-transplant model.

Methods

Thirteen donor pigs were categorized into the non-atelectatic (No-AT) group (n=3) representing a healthy control group; AT-BCR group (n=5), in which AT was reverted by conventional blood-circulated recruitment (BCR); and AT-no-BCR group (n=5), in which AT was reverted by no-BCR following circulatory arrest. In the atelectatic donor models, the left main bronchus was ligated for 24 hours prior to lung procurement. Left lung transplantation (LTx) was subsequently performed in the thirteen recipient pigs. After 6 hours evaluation, the recipients were euthanized and the lung grafts were excised.

Results

The post-transplant PaO₂/FiO₂ ratio was significantly higher in the AT-no-BCR group than in the AT-BCR group (P=0.015). Wet/dry ratio, histological findings of graft injury and tissue interleukin-8 expression in the AT-no-BCR group were similar to those of the No-AT group.

Conclusions

Lung recruitment without circulation after circulatory arrest could be more protective for atelectatic donor lung than the conventional procedure.

Pulmonary Enteric Adenocarcinoma Harboring a BRAF G469V Mutation

Pulmonary enteric adenocarcinoma (PEAC) is a rare subtype of lung cancer that should be differentiated from colorectal cancer metastasis. Little is known about its genetic background. An 84-year-old male with adenocarcinoma of the lung underwent left upper lobectomy. The histology of the surgical specimen was suggestive of PEAC. Gastrointestinal and colorectal fiberscopy revealed no evidence of colorectal cancer. Next-generation sequencing of the tumor identified a G469V substitution in serine/threonine-protein kinase B-raf (BRAF). Based on the higher prevalence of the G469 substitution in BRAF-mutant lung adenocarcinoma than in BRAFmutant colorectal cancer, the tumor likely originated from the lung. Identification of mutational genotype may be of some help in distinguishing PEAC from the lung metastasis of colorectal cancer.

Meticulous closure of collateral vessels in the perihilar mediastinal pleura to control intraoperative bleeding during lung transplantation for pulmonary hypertension

Background

Massive blood transfusion compensating hemorrhage during lung transplantation (LT) results in primary graft dysfunction (PGD) and worse outcomes after LT. Collateral vessels in the perihilar mediastinal pleura could be the source of hemorrhage during LT in patients with pulmonary hypertension (PH). The purpose of this study was to examine the effect of closure with hemoclips of the vessels in the perihilar mediastinal pleura on the risk of intraoperative hemorrhage and outcomes after LT in patients with PH.

Methods

We retrospectively reviewed 80 patients who underwent LT, including 13 patients with primary PH, 29 patients with secondary PH, and 38 patients with non-PH.

Results

The median number of hemoclips was significantly higher in the primary PH group than in the non-PH group (P=0.0045) or secondary PH group (P=0.0060). The intraoperative blood loss, transfusion volume, maximum PGD grade, and the 30-day and 90-day mortality rates in the primary PH group were equivalent to those in the other two groups.

Conclusions

Meticulous closure of collateral vessels in the perihilar mediastinal pleura during LT in patients with primary PH allowed intraoperative hemorrhage to be controlled and might be associated with acceptable mortality rate in these patients similar to that of LT in patients with other diseases.

Long-term outcomes of living-donor lobar lung transplantation

OBJECTIVE

Although living-donor lobar lung transplantation (LDLLT) enables an intermediate survival similar to cadaveric lung transplantation, the long-term outcome remains unknown. We examined the long-term outcomes of 30 patients who received LDLLT more than 16 years previously.

METHODS

We retrospectively reviewed the clinical data of 30 patients who underwent LDLLT (bilateral LDLLT, 29 patients; single LDLLT, 1 pediatric patient) between October 1998 and April 2004.

RESULTS

LDLLT was performed for 25 female and 5 male patients ranging in age from 8 to 55 years. The diagnoses included pulmonary hypertension (n = 11), pulmonary fibrosis (n = 7), bronchiolitis obliterans (n = 5), and others (n = 7). At a median follow-up of 205 months, 22 patients were alive and 8 were dead. The causes of death were infection (n = 3), malignancy (n = 2), acute rejection (n = 2), and chronic lung allograft dysfunction (CLAD; n = 1). Unilateral CLAD occurred in 17 patients (56.7%), but only 1 of these patients subsequently developed bilateral CLAD. Two patients underwent bilateral cadaveric lung retransplantations. The 5-, 10-, and 15-year CLAD-free survival rates were 80.0%, 62.8%, and 44.3%, respectively. Malignancy occurred in 7 patients. Two of 5 patients with chronic kidney disease requiring hemodialysis underwent living-donor kidney transplantation. The 5-, 10-, and 15-year overall survival rates were 96.7%, 86.7%, and 73.3%, respectively.

CONCLUSIONS

Although only 2 lobes are implanted, LDLLT provides encouraging long-term outcomes. In patients with unilateral CLAD, the functioning contralateral graft might contribute to a favorable long-term outcome.

Effect of preoperative long-term use of corticosteroids on the development of post-transplant lymphoproliferative disorders after lung transplantation: a single-center experience in Japan

PURPOSE

Post-transplant lymphoproliferative disorder (PTLD) is a major complication of lung transplantation (LTx). However, few studies on PTLD in Asian populations have been reported. We explored the characteristics of Japanese PTLD cases after LTx.

METHODS

We retrospectively reviewed 195 cases of LTx at our institute. We summarized the clinical experiences of 7 PTLD cases and analyzed the patient characteristics and survival outcomes of patients with (n = 7) and without (n = 188) PTLD.

RESULTS

All PTLD patients were taking corticosteroids preoperatively (p = 0.0030), and the duration of preoperative corticosteroid therapy was significantly longer in the PTLD group (p = 0.0064) than in the non-PTLD group. The overall survival after LTx was significantly worse in the PTLD group (p = 0.027) than in the non-PLTD group. Among the three patients who died within 1 year after the PTLD onset, two died of opportunistic infections without residual PTLD lesions. Chronic lung allograft dysfunction (CLAD) or bronchiolitis obliterans at an autopsy were diagnosed after PTLD treatment in four cases.

CONCLUSIONS

Long-term preoperative corticosteroid therapy may be a risk factor for PTLD after LTx. Opportunistic infections are lethal complications of PTLD, regardless of the effectiveness of PTLD treatment. CLAD occurs at a high rate after PTLD treatment, and close monitoring is required.

Protective effects of anti-HMGB1 monoclonal antibody on lung ischemia reperfusion injury in mice

During ischemia reperfusion (IR) injury, high mobility group box 1 (HMGB1), a chromatin binding protein, is released from necrotic cells and triggers inflammatory responses. We assessed the therapeutic effect of a neutralizing anti-HMGB1 monoclonal antibody (mAb) on lung IR injury. A murine hilar clamp model of IR was used, where mice were divided into sham and IR groups with intravenous administration of anti-HMGB 1 mAb or control mAb. We analyzed the effect of anti-HMGB1 mAb against IR injury by assessing lung oxygenation, lung injury score, neutrophil infiltration, expression of proinflammatory cytokines and chemokines, levels of mitogen-activated protein kinase (MAPK) signaling, and measurement of apoptotic cells. Anti-HMGB1 mAb significantly decreased the plasma level of HMGB1 elevated by IR. The severity of IR injury represented by oxygenation capacity, lung injury score, and neutrophil infiltration was significantly improved by anti-HMGB1 mAb treatment. The expression of proinflammatory factors, including IL-1β, IL-6, IL-12, TNF-α, CXCL-1, and CXCL-2, and phosphorylation of p38 MAPK were both significantly reduced by anti-HMGB1 mAb treatment. Furthermore, anti-HMGB1 mAb treatment suppressed apoptosis, as determined through TUNEL assays. Overall, anti-HMGB1 mAb ameliorated lung IR injury by reducing inflammatory responses and apoptosis. Our findings indicate that anti-HMGB1 mAb has potential for use as a therapeutic to improve IR injury symptoms during lung transplantation.

Lung transplantation for idiopathic multicentric Castleman disease: potential efficacy and tolerability of a humanized anti-interleukin-6 receptor monoclonal antibody

BACKGROUND

Idiopathic multicentric Castleman disease (iMCD) is a rare polyclonal lymphoproliferative disease caused by the overrepresentation of interleukin-6 (IL-6). Tocilizumab (TCZ) is a humanized monoclonal antibody that binds to the IL-6 receptor and is approved for the treatment of iMCD. The efficacy and tolerability of TCZ in patients with iMCD undergoing lung transplantation (LTx) remain unknown.

CASE PRESENTATION

We present the case of a 48-year-old iMCD patient with end-stage lung disease (ESLD) who was successfully treated with cadaveric single-LTx. Intravenous TCZ was used to stabilize the iMCD patient every 2 weeks, except for withdrawal immediately after LTx. At 32 month post-transplant, the patient remained asymptomatic without evidence of rejection, development of de novo donor-specific antibody (DSA), and recurrent iMCD in the native lung.

CONCLUSIONS

Single-LTx can be a feasible treatment option for ESLD caused by iMCD. TCZ can be used safely and may be beneficial in recipients with iMCD, and TCZ in combination with usual immunosuppression can be helpful in stabilizing iMCD patients pre- and post-LTx.

Robot-assisted thoracoscopic lobectomy for severe incomplete interlober fissure

An incomplete interlobar fissure makes thoracoscopic lobectomy difficult and is predictive of morbidity after thoracoscopic lobectomy. This report demonstrates the robot-assisted thoracoscopic (RATS) lobectomy technique for patients with severe incomplete interlobar fissures. A fissureless approach was chosen for pulmonary resection. Near-infrared fluorescence imaging with intravenous indocyanine green (ICG) was used to detect the interlobar line after transection of the bronchus, pulmonary artery and vein. Interlobar fissure was identified and divided by robotic staplers. This combined technique using ICG and fissureless lobectomy made RATS lobectomy safe for patients with severe incomplete interlobar fissures.

Emphysematous changes and lower levels of plasma irisin are associated with bronchiolitis obliterans syndrome after bilateral living-donor lobar lung transplantation

PURPOSE

Decreased irisin levels may be associated with the development of emphysema. Similarly, emphysematous changes may develop in patients with chronic lung allograft dysfunction (CLAD) after living-donor lobar lung transplantation (LDLLT). We investigated the severity of emphysematous changes and the relationship between irisin levels and CLAD after bilateral LDLLT and cadaveric lung transplantation (CLT).

METHODS

The subjects of this retrospective study were 59 recipients of bilateral LDLLT (n = 31) or CLT (n = 28), divided into a non-CLAD group (n = 41), a LDLLT-CLAD group (n = 11), and a CLT-CLAD group (n = 7). We compared the severity of emphysematous changes, the skeletal muscle mass, and the plasma irisin levels among the groups.

RESULTS

The emphysematous changes were significantly more severe in the LDLLT-CLAD and CLT-CLAD groups (p = 0.046 and 0.036), especially in patients with bronchiolitis obliterans syndrome (BOS), than in the non-CLAD group. Although the skeletal muscle mass was similar in all the groups, the plasma irisin levels were significantly lower in the LDLLT-CLAD group (p = 0.022), especially in the patients with BOS after LDLLT, than in the non-CLAD group.

CONCLUSION

Emphysematous changes and lower levels of plasma irisin were associated with CLAD, especially in patients with BOS, after bilateral LDLLT.