Augmented humoral response to third and fourth dose of SARS-CoV-2 mRNA vaccines in lung transplant recipients

BACKGROUND

Since lung transplant recipients (LTRs) exhibit low immunogenicity after two doses of SARS-CoV-2 mRNA vaccines, optimal vaccine strategies for SARS-CoV-2 are required in LTRs. This study aimed to investigate the efficacy and safety of the third and fourth doses of the SARS-CoV-2 mRNA vaccines in LTRs.

METHODS

We conducted a single-center study of 73 LTRs and 23 healthy controls (HCs). Participants received two-to-four doses of SARS-CoV-2 mRNA vaccines. The LTRs were divided into three groups based on the number of vaccine dose. IgG titers against SARS-CoV-2 spike protein were measured, and adverse events were assessed. Factors associated with humoral response were analyzed using univariate and multivariate analyses.

RESULTS

The Dose 4 group (n = 27) had a higher humoral response rate (P = 0.018) and higher levels of anti-SARS-CoV-2 IgG antibody (P = 0.04) than the Dose 2 group (n = 14). The Dose 3 group (n = 32) had lower humoral response rates (P = 0.005) and levels of anti-SARS-CoV-2 IgG antibody (P = 0.0005) than the HCs (n = 23) even after the same dose. Systemic adverse events were milder in the LTRs than in the HCs (P < 0.05). Increased number of vaccine dose was identified as a predictor of positive humoral response (P = 0.021).

CONCLUSION

Booster doses of SARS-CoV-2 mRNA vaccines may enhance humoral response with mild adverse events in LTRs. Repeated vaccination might be warranted for LTRs to prevent SARS-CoV-2 infection.

Impact of the neutrophil-to-lymphocyte ratio on patients with locally advanced non-small cell lung cancer who suffer radiation pneumonitis during the course of induction chemoradiotherapy followed by surgery

PURPOSE

Radiation pneumonitis (RP) is an obstacle for patients after surgery following induction chemoradiotherapy for locally advanced non-small cell lung cancer (LA-NSCLC). We performed a comparative analysis of the association between clinicopathological factors, including the neutrophil-to-lymphocyte ratio (NLR) and prognosis, in LA-NSCLC patients with or without RP during induction chemoradiotherapy followed by surgery.

METHODS

The subjects of this analysis were 168 patients undergoing trimodality therapy for LA-NSCLC between January, 1999 and May, 2019. Patients were divided into two groups: the RP group (n = 41) and the non-RP group (n = 127). We compared the clinicopathological factors including the NLR between the groups and analyzed the association between the NLR and prognosis.

RESULTS

The RP group had more patients with tumors located in the lower lobe, more bilobar resections, shorter operative times, no implementation of postoperative adjuvant chemotherapy, and a higher postoperative NLR than the non-RP group. There were no significant differences in serious postoperative complications and the prognosis. Patients with a low postoperative NLR had a significantly better prognosis in the non-RP group, and a trend toward a better prognosis even in the RP group.

CONCLUSION

Postoperative NLR may be a useful prognostic factor, even for patients who suffer RP after trimodality therapy for LA-NSCLC.

Prophylactic effect of tissue flap in the prevention of bronchopleural fistula after surgery for lung cancer

PURPOSE

Bronchopleural fistula (BPF) is a serious complication of lung resection. To avoid BPF, the bronchial stump/anastomotic site is often covered with a flap of surrounding tissue. One risk factor for BPF is radical lung resection after induction chemoradiotherapy for lung cancer. We retrospectively reviewed our database to elucidate the characteristics of tissue flaps that prevent BPF.

METHODS

This retrospective study included 152 patients treated between 1999 and 2019. We examined the clinicopathological characteristics, including the type and thickness of the tissue flap used to cover the bronchial stump/anastomotic site, and postoperative complications, including BPF.

RESULTS

BPF occurred in 5 patients (3.3%). All 5 patients had complications that could have affected delayed wound healing, such as pneumonia. The covering tissue flap thickness was significantly greater in patients without BPF than in those who developed BPF (p = 0.0290). Additionally, the tissue flap thickness was significantly greater than in those with BPF (p = 0.0077), even in high-risk patients who developed pneumonia or radiation pneumonitis on the operative side within 6 months postoperatively.

CONCLUSION

Perioperative management is crucial to avoid complications affecting the healing of the bronchial stump/anastomotic site, and the covering tissue flap thickness may be an important factor in avoiding or minimizing BPF.

Utility of neutrophil-to-lymphocyte ratio as an indicator of tumor immune status in non-small cell lung cancer

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) has been reported as a prognostic biomarker in non-small cell lung cancer (NSCLC); however, the underlying biological rationale remains unclear. The present study aimed to explore the potential utility of NLR as a surrogate biomarker for immune response to cancer and to elucidate the underlying mechanism.

METHODS

This retrospective study included the medical records of 120 patients with NSCLC who underwent surgery at the study institution in 2012. NLR in peripheral blood was determined from blood test within 30 days before surgery. Tumor immune status was evaluated using immunohistochemical staining to identify CD3+, CD8+ and FOXP3+ tumor-infiltrating lymphocytes (TILs), and the relationship of NLR, with clinicopathologic characteristics including 5-year overall survival (OS), and the tumor immune status was investigated. The median values of NLR and TIL count were used as cutoff points.

RESULTS

The 5-year OS was significantly better in patients with low NLR (<2.2) than in those with high NLR (≥2.2) (70.1% vs. 56.8%, P = 0.042) and in patients with high CD3+ TIL count (≥242) than in those with low CD3+ TIL count (<242) (70% vs. 56.8%, P = 0.019). Additionally, the CD3+ TIL count was negatively correlated with preoperative NLR (P = 0.005).

CONCLUSION

NLR might potentially reflect the immune status of tumor microenvironment, explaining its impact on prognosis of patients with NSCLC.

Pulmonary Vein Repair on Extracorporeal Life Support: A Potential Surgical Complication for 2-Staged Lung Transplantation: Case Report

Double-lung transplantation (DLT) is favored for enhanced long-term survival despite the risk of major complications, particularly in elderly patients or those with comorbidities. Two-stage contralateral single-lung transplantation (SLT) leading to DLT is considered a valuable option to combine the advantages of less invasive SLT with DLT survival benefits. This study detailed the intraoperative challenges encountered during the procedure. A 54-year-old patient with chronic lung allograft dysfunction after right SLT underwent contralateral (left) SLT because of left lung dysfunction. During surgery, unexpected complications arose from robust adhesions on the right side, a consequence of prior transplantation, causing difficulty in manipulating the heart position. The deep bifurcation of the left pulmonary vein posed challenges, leading to damage to the left atrium, necessitating extracorporeal circulation. Despite these complexities, successful anastomosis was achieved. This case highlights the importance of recognizing potential surgical difficulties in contralateral lung transplantation, particularly in cases with adhesions, and emphasizes the need for caution when managing deep pulmonary veins. This 2-stage approach holds promise for patients with poor health but emphasizes the significance of addressing the potential challenges inherent in the surgical procedure.

Postoperative Complications in Living Donors for Lung Transplantation

Background

Living donor lobar lung transplantation is a life-saving procedure for critically ill patients. This requires 2 healthy donors exposed to risks and without medical benefit. Therefore, the donor's safety and minimal postoperative complications are crucial. This study aimed to investigate the short-term outcomes and identify the risk factors affecting these outcomes.

Methods

The data of 175 living donors enrolled between 1998 and 2022 were analyzed. Donors were divided into era 1 (1998-2009) and era 2 (2010-2022).

Results

The overall incidence of postoperative complications was 39%, of which 7% were major complications. Donors who underwent surgery on the right side had a higher incidence of delayed pulmonary fistulae (P = 0.01) and elevated liver enzyme levels (P = 0.028). Living donor surgery on the right side (P = 0.01), era 2 (P = 0.01), and the need for plasty (P = 0.04) were predictors of postoperative complications.

Conclusions

Updated data on complications and their correlation with postoperative quality of life from this study could aid in the selection of potential donors and facilitate informed consent.

Effective division of the intersegmental plane using a robotic stapler in robotic pulmonary segmentectomy

PURPOSES

Robot-assisted thoracoscopic (RATS) segmentectomy is becoming increasingly common because of the expanded indications for segmentectomy and the widespread adoption of robotic surgery. The precise division of the intersegmental plane is necessary to ensure oncologic margins from the tumor and to preserve the lung function. In this study, we present a strategy for accurately dividing the intersegmental plane using a robotic stapler and review the surgical outcomes.

METHODS

RATS portal segmentectomy was performed using the Da Vinci Xi system and the intersegmental plane was dissected using a robotic stapler. We evaluated the perioperative outcomes in 92 patients who underwent RATS portal segmentectomy between May 2020 and January 2023. These results were compared with those of 82 patients who underwent complete video-assisted thoracoscopic surgery (CVATS) during the same period.

RESULTS

The operative and console times were 162 and 97 min, respectively. No intraoperative complications occurred, and postoperative complications were observed in four cases (4.3%). The operative time, blood loss, postoperative complications, and maximum incision size were significantly lower in the RATS group than in the CVATS group. However, RATS requires a significantly higher number of staplers than CVATS.

CONCLUSIONS

The division of the intersegmental plane using a robotic stapler in RATS portal segmentectomy was, therefore, found to be safe and effective.

Restrictive allograft dysfunction rather than bronchiolitis obliterans syndrome had a major impact on the overall survival after living-donor lobar lung transplantation

PURPOSE

Chronic lung allograft dysfunction (CLAD) is a known long-term fatal disorder after lung transplantation. In this study, we evaluated the CLAD classification of the International Society for Heart and Lung Transplantation (ISHLT) for living-donor lobar lung transplantation (LDLLT).

METHODS

We conducted a single-center retrospective review of data from 73 patients who underwent bilateral LDLLT between 1998 and 2019. Factors related to opacity on computed tomography (CT) and restriction on pulmonary function tests (PFTs) were also analyzed.

RESULTS

Overall, 26 (36%) patients were diagnosed with CLAD, including restrictive allograft syndrome (RAS), n = 10 (38.5%); bronchiolitis obliterans syndrome (BOS), n = 8 (30.8%); mixed, n = 1 (3.8%); undefined, n = 2 (7.7%); and unclassified, n = 5 (19.2%). The 5-year survival rate after the CLAD onset was 60.7%. The survival of patients with BOS was significantly better than that of patients with RAS (p = 0.012). In particular, patients with restriction on PFT had a significantly worse survival than those without restriction (p = 0.001).

CONCLUSIONS

CLAD after bilateral LDLLT does not have a major impact on the recipient survival, especially in patients with BOS. Restriction on PFT may predict a particularly poor prognosis in patients with CLAD after bilateral LDLLT.

Long-term outcomes of lung transplantation requiring renal replacement therapy: A single-center experience

BACKGROUND

Life-long immunosuppressive therapy after lung transplantation (LT) may lead to end-stage renal disease (ESRD), requiring renal replacement therapy (RRT). We aimed to investigate the characteristics and long-term outcomes of patients undergoing LT and requiring RRT.

METHODS

This study was a single-center, retrospective cohort study. The patients were divided into the RRT (n = 15) and non-RRT (n = 170) groups. We summarized the clinical features of patients in the RRT group and compared patient characteristics, overall survival, and chronic lung allograft dysfunction (CLAD)-free survival between the two groups.

RESULTS

The cumulative incidences of ESRD requiring RRT after LT at 5, 10, and 15 years were 0.8 %, 7.6 %, and 25.2 %, respectively. In the RRT group, all 15 patients underwent hemodialysis but not peritoneal dialysis, and two patients underwent living-donor kidney transplantation. The median follow-up period was longer in the RRT group than in the non-RRT group (P < 0.001). The CLAD-free survival and overall survival did not differ between the two groups. The 5-year survival rate even after the initiation of hemodialysis was 53.3 %, and the leading cause of death in the RRT group was infection.

CONCLUSIONS

Favorable long-term outcomes can be achieved by RRT for ESRD after LT.

Effects of case volume on short- and long-term outcomes following cadaveric lung transplantation in Japan

Background

Despite the low number of lung transplantations (LTs) in Japan, 10 LT facilities are accredited and good outcomes have been reported. A database review was conducted to clarify the impact of case volume at LT facilities in Japan on short- and long-term outcomes.

Methods

All cadaveric LT cases treated between 2000 and 2021 in Japan were analyzed using the database of the Japanese Society of Lung and Heart-Lung Transplantation (JSLHT). The nine institutions represented were categorized into the low-volume (LV; <80 cumulative LT cases, <8 LTs/year, n=5) and high-volume (HV; ≥80 cumulative LT cases, ≥8 LTs/year, n=4) centers. Ninety-day and 1-year mortality, as well as 5- and 10-year survival data were evaluated.

Results

A total of 658 cadaveric LTs were performed at the nine institutions. The 90-day rates of mortality at the HV and LV centers were 3.5% and 3.9%, respectively (P=0.801), while the 1-year mortality rates were 9.2% and 11.5%, respectively (P=0.199). Additionally, log-rank analysis of Kaplan-Meier curves showing case volume did not reveal a significant difference in long-term survival between the HV and LV centers (P=0.272), though the LV centers had wide differences for long-term outcomes (P=0.030).

Conclusions

Case volume did not have effects on short- or long-term outcomes following LT in Japan, while there were large variations in long-term outcomes among the LV centers compared to those of the HV centers.

Plasma concentrations of histidine-rich glycoprotein in primary graft dysfunction after lung transplantation

OBJECTIVES

Histidine-rich glycoprotein has been reported as an anti-inflammatory glycoprotein that inhibits acute lung injury in mice with sepsis and as a prognostic biomarker in patients with sepsis. We investigated the relationship between plasma concentrations of histidine-rich glycoprotein and the risk of occurrence of primary graft dysfunction.

METHODS

According to the primary graft dysfunction grade at post-transplant 72 h, patients who underwent lung transplantation were divided into three groups: non-primary graft dysfunction group (grade 0-1), moderate primary graft dysfunction group (grade 2), and severe primary graft dysfunction group (grade 3). The plasma concentrations of histidine-rich glycoprotein measured daily during the first post-transplant 7 days were compared among the three groups. Appropriate cutoff values of the concentrations were set for survival analyses after lung transplantation.

RESULTS

A total of 68 patients were included. The plasma histidine-rich glycoprotein concentration at post-transplant 72 h was significantly lower in the severe primary graft dysfunction group (n = 7) than in the other two groups [non-primary graft dysfunction group (n = 43), P = 0.042; moderate primary graft dysfunction group (n = 18), P = 0.040]. Patients with plasma histidine-rich glycoprotein concentration ≥34.4 µg/ml at post-transplant 72 h had significantly better chronic lung allograft dysfunction-free survival (P = 0.012) and overall survival (P = 0.037) than those with the concentration <34.4 µg/ml.

CONCLUSIONS

Plasma histidine-rich glycoprotein concentrations at post-transplant 72 h might be associated with the risk of development of primary graft dysfunction.

In vivo lung perfusion for prompt recovery from primary graft dysfunction after lung transplantation

BACKGROUND

No proven treatment after the development of primary graft dysfunction (PGD) is currently available. Here, we established a novel strategy of in vivo lung perfusion (IVLP) for the treatment of PGD. IVLP involves the application of an in vivo isolated perfusion circuit to an implanted lung. This study aimed to explore the effectiveness of IVLP vs conventional post-lung transplant (LTx) extracorporeal membrane oxygenation (ECMO) treatment using an experimental swine LTx PGD model.

METHODS

After 1.5-hour warm ischemia of the donor lungs, a left LTx was performed. Following the confirmation of PGD development, pigs were divided into 3 groups (n = 5 each): control (no intervention), ECMO, and IVLP. After 2 hours of treatment, a 4-hour functional assessment was conducted, and samples were obtained.

RESULTS

Significantly better oxygenation was achieved in the IVLP group (p ≤ 0.001). Recovery was confirmed immediately and maintained during the following 4-hour observation. The IVLP group also demonstrated better lung compliance than the control group (p = 0.045). A histologic evaluation showed that the lung injury score and terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed significantly fewer injuries and a better result in the wet-to-dry weight ratio in the IVLP group.

CONCLUSIONS

A 2-hour IVLP is technically feasible and allows for prompt recovery from PGD after LTx. The posttransplant short-duration IVLP strategy can complement or overcome the limitations of the current practice for donor assessment and PGD management.

Impact of changes in skeletal muscle mass and quality during the waiting time on outcomes of lung transplantation

INTRODUCTION

The association of changes in skeletal muscle mass and quality during the waiting time with outcomes of lung transplantation (LT) remains unclear. We aimed to examine the association of changes in skeletal muscle mass and quality during the waiting time, as well as preoperative skeletal muscle mass and quality, with outcomes of LT.

METHODS

This study included individuals who underwent LT from brain-dead donors. Skeletal muscle mass (cm2 /m2 ) and quality (mean Hounsfield units [HU]) of the erector spinae muscle at the 12th thoracic level were evaluated using computed tomography. Preoperative skeletal muscle mass and quality, and their changes during the waiting time were calculated. We evaluated the associations among mechanical ventilation (MV) duration, intensive care unit (ICU) length of stay (LOS), hospital LOS, 6-minute walk distance at discharge, and 5-year survival after LT.

RESULTS

This study included 98 patients. The median waiting time was 594.5 days (interquartile range [IQR], 355.0-913.0). The median changes in skeletal muscle mass and quality were -4.4% (IQR, -13.3-3.1) and -2.9% (IQR, -16.0-4.1), respectively. Severe low skeletal muscle mass at LT was associated with prolonged ICU LOS (B = 8.46, 95% confidence interval [CI]: .51-16.42) and hospital LOS (B = 36.00, 95% CI: 3.23-68.78). Pronounced decrease in skeletal muscle mass during the waiting time was associated with prolonged MV duration (B = 7.85, 95% CI: .89-14.81) and ICU LOS (B = 7.97, 95% CI: .83-15.10).

CONCLUSION

Maintaining or increasing skeletal muscle mass during the waiting time would be beneficial to improve the short-term outcomes of LT.

Prognostic Impact of Tumor-Infiltrating Lymphocytes, Tertiary Lymphoid Structures, and Neutrophil-to-Lymphocyte Ratio in Pulmonary Metastases from Uterine Leiomyosarcoma

BACKGROUND

The presence of tumor-infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLSs) in tumor tissue has been related to the prognosis in various malignancies. Meanwhile, neutrophil-to-lymphocyte ratio (NLR) as a systemic inflammation marker also has been associated with the prognosis in them. However, few reports have investigated the relationship between pulmonary metastases from sarcoma and these biomarkers.

METHODS

We retrospectively recruited 102 patients undergoing metastasectomy for pulmonary metastases from uterine leiomyosarcoma at Okayama University Hospital from January 2006 to December 2019. TILs and TLSs were evaluated by immunohistochemical staining of surgically resected specimens of pulmonary metastases using anti-CD3/CD8/CD103/Foxp3/CD20 antibodies. NLR was calculated from the blood examination immediately before the most recent pulmonary metastasectomy. We elucidated the relationship between the prognosis and these factors. Because we considered that the status of tumor tissue and systemic inflammation were equally valuable, we also assessed the impact of the combination of TILs or TLSs and NLR on the prognosis.

RESULTS

As for TILs, CD3-positive cells and CD8-positive cells were correlated with the prognosis. The prognosis was significantly better in patients with CD3-high group, CD8-high group, TLSs-high group, and NLR-low group, respectively. The prognosis of CD8-high/NLR-low group and TLSs-high/NLR-low group was significantly better than that of CD8-low/NLR-high group and TLSs-low/NLR-high group, respectively.

CONCLUSIONS

CD3-positive TILs, CD8-positive TILs, TLSs, and NLR are correlated with the prognosis, respectively. The combination of CD8-positive TILs or TLSs and NLR may be the indicators to predict the prognosis of patients with pulmonary metastases from uterine leiomyosarcoma.

Elderly lung transplant recipients show acceptable long-term outcomes for lung transplantation: A propensity score-matched analysis

PURPOSE

Although the performance lung transplantation (LTx) in the elderly (≥ 60 years) has increased globally, the situation in Japan remains quite different, because the age limit at registration for cadaveric transplantation is 60 years. We investigated the long-term outcomes of LTx in the elderly in Japan.

METHODS

This was a single-center retrospective study. We divided the patients into two groups according to age: the younger group (< 60 years; Y group; n = 194) and the elderly group (≥ 60 years; E group; n = 10). We performed three-to-one propensity score matching to compare the long-term survival between the E and Y groups.

RESULTS

In the E group, the survival rate was significantly worse (p = 0.003), and single-LTx was more frequent (p = 0.036). There was a significant difference in the indications for LTx between the two groups (p < 0.001). The 5-year survival rate after single-LTx in the E group was significantly lower than that in the Y group (p = 0.006). After propensity score matching, the 5-year survival rates of the two groups were comparable (p = 0.55). However, the 5-year survival rate after single-LTx in the E group was significantly lower than that in the Y group (p = 0.007).

CONCLUSION

Elderly patients showed acceptable long-term survival after LTx.

Percentage of low attenuation area on computed tomography detects chronic lung allograft dysfunction, especially bronchiolitis obliterans syndrome, after bilateral lung transplantation

INTRODUCTION

The percentage of low attenuation area (%LAA) on computed tomography (CT) is useful for evaluating lung emphysema, and higher %LAA was observed in patients with chronic lung allograft dysfunction (CLAD). This study investigated the relationship between the %LAA and the development of CLAD after bilateral lung transplantation (LT).

METHODS

We conducted a single-center retrospective study of 75 recipients who underwent bilateral LT; the recipients were divided into a CLAD group (n = 30) and a non-CLAD group (n = 45). The %LAA was calculated using CT and compared between the two groups from 4 years before to 4 years after the diagnosis of CLAD. The relationships between the %LAA and the percent baseline values of the pulmonary function test parameters were also calculated.

RESULTS

The %LAA was significantly higher in the CLAD group than in the non-CLAD group from 2 years before to 2 years after the diagnosis of CLAD (P < .05). In particular, patients with bronchiolitis obliterans syndrome (BOS) exhibited significant differences even from 4 years before to 4 years after diagnosis (P < .05). Significant negative correlations between the %LAA and the percent baseline values of the forced expiratory volume in 1 s (r = -.36, P = .0031), the forced vital capacity (r = -.27, P = .027), and the total lung capacity (r = -.40, P < .001) were seen at the time of CLAD diagnosis.

CONCLUSION

The %LAA on CT was associated with the development of CLAD and appears to have the potential to predict CLAD, especially BOS, after bilateral LT.

Prognostic factors for lung transplant recipients focusing on age and gender: the Japanese lung transplantation report 2022

PURPOSE

To clarify the impact of donor and recipient characteristics on the survival of recipients before and after lung transplantation in the Japanese population.

METHODS

Patients' data were collected for retrospective analysis from all authorized lung transplant centers in Japan. We included 1963 patients listed for lung transplantation by the end of December 2021, comprised of 658 deceased-donor and 270 living-donor lung transplants.

RESULTS

Primary disease had a significant impact on the mortality of patients waiting for transplantation. The indications for transplant significantly affected the post-transplant survival rate of deceased-donor lung transplant recipients. The recipient's age also significantly affected the post-transplant survival rate of the deceased-donor and living-donor lung transplant recipients. The recipients of grafts transplanted from donors aged 61 years or older showed a worse post-transplant survival rate (≧60 years old). The survival rate for the combination of a female donor to a male recipient among the deceased-donor lung transplant recipients was the worst among the four combinations.

CONCLUSION

The donor and recipient characteristics significantly impacted the survival of recipients after lung transplantation. The underlying mechanism of the negative impact of the gender mismatch of female donor to male recipient on post-transplant survival needs to be investigated further.

Long-term management and outcome of lung transplantation in Japan

The long-term survival after lung transplantation (LT) is favorable in Japan. However, long-term survivors after LT are subject to late complications, including chronic lung allograft dysfunction (CLAD), malignancy, infection, and chronic kidney disease (CKD) because of the need for lifelong immunosuppression. The rates of single cadaveric LT (CLT) and living-donor lobar LT (LDLLT) are higher than that of bilateral CLT in Japan. Here, we will describe the management of late complications and long-term outcome after LT in Japan. Attention should be paid to not only the phenotype of CLAD but also the difference in CLAD after CLT and after LDLLT as well as the timing of lung re-transplantation for advanced CLAD, especially after single CLT. Since post-transplant lymphoproliferative disorder is the most common malignancy after LT, infection monitoring for infection-related malignancies and appropriate screening are keys to the early diagnosis and treatment of malignancy after LT. The long-term management of infection after LT is also important, especially with regard to community-acquired pathogens, Aspergillus, and cytomegalovirus. When providing long-term care after LT, physicians should be aware of CKD and the timing of renal replacement therapy in cases with severe CKD. The widespread use of computed tomography and dialysis in Japan are beneficial for long-term survivors of LT. The similar survival outcomes of single CLT and LDLLT, compared with bilateral CLT, might contribute to improved long-term survival in Japan. Pulmonologists are encouraged to become further involved in long-term management after LT in Japan.

Successful management of temporary veno-venous extracorporeal membrane oxygenation for a pediatric lung transplant recipient with bronchiolitis obliterans syndrome awaiting lung re-transplantation: a case report

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation is an uncommon strategy in Japan owing to the severe donor shortage and absence of urgent allocation policy. Moreover, the use of veno-venous (VV) ECMO for immunosuppressed patients is controversial; thus, applying ECMO to patients who await lung re-transplantation is challenging.

CASE PRESENTATION

A 16-year-old lung transplant recipient with grade 3 bronchiolitis obliterans syndrome was waitlisted for lung re-transplantation. Eleven months later, he fell into severe respiratory acidosis with hypercapnia, which were not resolved with mechanical ventilation. VV ECMO was introduced to minimize lung stress and strain. Tracheostomy was additionally performed on day 5 after the start of ECMO, and respiratory condition swiftly improved; hence, the weaning process from VV ECMO began on day 9. Rehabilitation became implementable, and bilateral re-lung transplantation was successfully performed 6 months after the ECMO treatment. No critical complication related to the precedent use of ECMO was noted.

CONCLUSIONS

VV ECMO can be a feasible treatment option even for lung transplant candidates awaiting re-transplantation for a prolonged period. Introduction of ECMO and tracheostomy in the early deterioration stage may be crucial to successful subsequent patient management.

S100A8/A9 as a prognostic biomarker in lung transplantation

OBJECTIVES

S100A8/A9 is a damage-associated molecule that augments systemic inflammation. However, its role in the acute phase after lung transplantation (LTx) remains elusive. This study aimed to determine S100A8/A9 levels after lung transplantation (LTx) and evaluate their impact on overall survival (OS) and chronic lung allograft dysfunction (CLAD)-free survival.

METHODS

Sixty patients were enrolled in this study, and their plasma S100A8/A9 levels were measured on days 0, 1, 2, and 3 after LTx. The association of S100A8/A9 levels with OS and CLAD-free survival was assessed using univariate and multivariate Cox regression analyses.

RESULTS

S100A8/A9 levels were elevated in a time-dependent manner until 3 days after LTx. Ischemic time was significantly longer in the high S100A8/9 group than in the low S100A8/A9 group (p = .017). Patients with high S100A8/A9 levels (> 2844 ng/mL) had worse prognosis (p = .031) and shorter CLAD-free survival (p = .045) in the Kaplan-Meier survival analysis than those with low levels. Furthermore, multivariate Cox regression analysis showed that high S100A8/A9 levels were a determinant of poor OS (hazard ratio [HR]: 3.7; 95% confidence interval [CI]: 1.2-12; p = .028) and poor CLAD-free survival (HR: 4.1; 95% CI: 1.1-15; p = .03). In patients with a low primary graft dysfunction grade (0-2), a high level of S100A8/A9 was also a poor prognostic factor.

CONCLUSIONS

Our study provided novel insights into the role of S100A8/A9 as a prognostic biomarker and a potential therapeutic target for LTx.

Identification of genetic loci associated with renal dysfunction after lung transplantation using an ethnic-specific single-nucleotide polymorphism array

Renal dysfunction is a long-term complication associated with an increased mortality after lung transplantation (LT). We investigated the association of single-nucleotide polymorphisms (SNPs) with the development of renal dysfunction after LT using a Japanese-specific SNP array. First, eligible samples of 34 LT recipients were genotyped using the SNP array and divided into two groups, according to the presence of homozygous and heterozygous combinations of mutant alleles of the 162 renal-related SNPs. To identify candidate SNPs, the renal function tests were compared between the two groups for each SNP. Next, we investigated the association between the candidate SNPs and the time course of changes of the estimated glomerular filtration rate (eGFR) in the 99 recipients until 10 years after the LT. ΔeGFR was defined as the difference between the postoperative and preoperative eGFR values. Eight SNPs were identified as the candidate SNPs in the 34 recipients. Validation analysis of these 8 candidate SNPs in all the 99 recipients showed that three SNPs, namely, rs10277115, rs4690095, and rs792064, were associated with significant changes of the ΔeGFR. Pre-transplant identification of high-risk patients for the development of renal dysfunction after LT based on the presence of these SNPs might contribute to providing personalized medicine.

Endobronchial Metastasis with Bloody Sputum 20 Years after Complete Resection of type A Non-Invasive Thymoma

Masaoka stage I type A thymomas rarely recur. We report the case of an 82-year-old man who developed endobronchial metastasis after thymothymectomy for Masaoka stage I type A thymoma. Twenty years after surgery, the patient developed bloody sputum, and chest computed tomography revealed a neoplasm obstructing the right upper lobe bronchus of the lung with enlarged mediastinal lymph nodes. He underwent right upper lobectomy and mediastinal lymph node dissection. Although preoperative pathological diagnosis was squamous cell carcinoma of the lung, postoperative histopathology revealed endobronchial metastasis of the thymoma. Nine years later, at age 89, the patient is alive and well.

Pulmonary alveolar proteinosis after lung transplantation: Two case reports and literature review

Pulmonary alveolar proteinosis (PAP) affecting transplanted lungs is not well recognized. Herein, we report two cases of PAP after lung transplantation (LTx). The first case was a 4-year-old boy with hereditary pulmonary fibrosis who underwent bilateral LTx and presented with respiratory distress on postoperative day (POD) 23. He was initially treated for acute rejection, died due to infection on POD 248, and was diagnosed with PAP at autopsy. The second case involved a 52-year-old man with idiopathic pulmonary fibrosis who underwent bilateral LTx. On POD 99, chest computed tomography revealed ground-glass opacities. Bronchoalveolar lavage and transbronchial biopsy led to a diagnosis of PAP. Follow-up with immunosuppression tapering resulted in clinical and radiological improvement. PAP after lung transplantation mimics common acute rejection; however, is potentially transient or resolved with tapering immunosuppression, as observed in the second case. Transplant physicians should be aware of this rare complication to avoid misconducting immunosuppressive management.