Intravital Two-Photon Microscopy of the Transplanted Mouse Lung.

Complications after lung transplantation are largely related to the host immune system responding to the graft. Such immune responses are regulated by crosstalk between donor and recipient cells. A better understanding of these processes relies on the use of preclinical animal models and is aided by an ability to study intra-graft immune cell trafficking in real-time. Intravital two-photon microscopy can be used to image tissues and organs for depths up to several hundred microns with minimal photodamage, which affords a great advantage over single-photon confocal microscopy. Selective use of transgenic mice with promoter-specific fluorescent protein expression and/or adoptive transfer of fluorescent dye-labeled cells during intravital two-photon microscopy allows for the dynamic study of single cells within their physiologic environment. Our group has developed a technique to stabilize mouse lungs, which has enabled us to image cellular dynamics in naïve lungs and orthotopically transplanted pulmonary grafts. This technique allows for detailed assessment of cellular behavior within the vasculature and in the interstitium, as well as for examination of interactions between various cell populations. This procedure can be readily learned and adapted to study immune mechanisms that regulate inflammatory and tolerogenic responses after lung transplantation. It can also be expanded to the study of other pathogenic pulmonary conditions.

Fibrotic progression from acute cellular rejection is dependent on secondary lymphoid organs in a mouse model of chronic lung allograft dysfunction.

Chronic lung allograft dysfunction (CLAD) remains one of the major limitations to long-term survival after lung transplantation. We modified a murine model of CLAD and transplanted left lungs from BALB/c donors into B6 recipients that were treated with intermittent cyclosporine and methylprednisolone postoperatively. In this model, the lung allograft developed acute cellular rejection on day 15 which, by day 30 after transplantation, progressed to severe pleural and peribronchovascular fibrosis, reminiscent of changes observed in restrictive allograft syndrome. Lung transplantation into splenectomized B6 alymphoplastic (aly/aly) or splenectomized B6 lymphotoxin-ß receptor-deficient mice demonstrated that recipient secondary lymphoid organs, such as spleen and lymph nodes, are necessary for progression from acute cellular rejection to allograft fibrosis in this model. Our work uncovered a critical role for recipient secondary lymphoid organs in the development of CLAD after pulmonary transplantation and may provide mechanistic insights into the pathogenesis of this complication.

Smoking exposure-induced bronchus-associated lymphoid tissue in donor lungs does not prevent tolerance induction after transplantation.

The presence of bronchus-associated lymphoid tissue (BALT) in donor lungs has been suggested to accelerate graft rejection after lung transplantation. Although chronic smoke exposure can induce BALT formation, the impact of donor cigarette use on alloimmune responses after lung transplantation is not well understood. Here, we show that smoking-induced BALT in mouse donor lungs contains Foxp3+ T cells and undergoes dynamic restructuring after transplantation, including recruitment of recipient-derived leukocytes to areas of pre-existing lymphoid follicles and replacement of graft-resident donor cells. Our findings from mouse and human lung transplant data support the notion that a donor's smoking history does not predispose to acute cellular rejection or prevent the establishment of allograft acceptance with comparable outcomes to nonsmoking donors. Thus, our work indicates that BALT in donor lungs is plastic in nature and may have important implications for modulating proinflammatory or tolerogenic immune responses following transplantation.

Biased IL-2 signals induce Foxp3-rich pulmonary lymphoid structures and facilitate long-term lung allograft acceptance in mice.

Transplantation of solid organs can be life-saving in patients with end-stage organ failure, however, graft rejection remains a major challenge. In this study, by pre-conditioning with interleukin-2 (IL-2)/anti-IL-2 antibody complex treatment biased toward IL-2 receptor α, we achieved acceptance of fully mismatched orthotopic lung allografts that remained morphologically and functionally intact for more than 90 days in immunocompetent mice. These allografts are tolerated by the actions of forkhead box p3 (Foxp3)+ regulatory T (Treg) cells that home to the lung allografts. Although counts of circulating Treg cells rapidly return to baseline following cessation of IL-2 treatment, Foxp3+ Treg cells persist in peribronchial and peribronchiolar areas of the grafted lungs, forming organized clusters reminiscent of inducible tertiary lymphoid structures (iTLS). These iTLS in lung allografts are made of Foxp3+ Treg cells, conventional T cells, and B cells, as evidenced by using microscopy-based distribution and neighborhood analyses. Foxp3-transgenic mice with inducible and selective deletion of Foxp3+ cells are unable to form iTLS in lung allografts, and these mice acutely reject lung allografts. Collectively, we report that short-term, high-intensity and biased IL-2 pre-conditioning facilitates acceptance of vascularized and ventilated lung allografts without the need of immunosuppression, by inducing Foxp3-controlled iTLS formation within allografts.

Native lung complications after living-donor lobar lung transplantation.

BACKGROUND: Living-donor lobar lung transplantation (LDLLT) is viable for critically ill patients in situations of donor shortage. Because it is sometimes difficult to find 2 ideal living donors with suitable graft sizes, we developed native lung-sparing procedures, including single LDLLT and native upper lobe-sparing LDLLT. This study aimed to investigate native lung complications (NLCs) in native lung-sparing LDLLT. METHODS: Between April 2002 and March 2019, 92 LDLLTs and 124 cadaveric lung transplantations (CLTs) were performed at the Kyoto University Hospital. Our prospectively maintained database and clinical records were reviewed to compare NLCs among recipients who underwent native lung-sparing LDLLT (n = 21) with those among recipients who underwent single CLT (n = 61). RESULTS: Among 21 recipients who underwent native lung-sparing LDLLT, 11 NLCs occurred in 8 recipients. No fatal NLC was noted; however, 2 required surgical intervention. Post-transplant survival was not significantly different between native lung-sparing LDLLT recipients with NLCs and those without NLCs. The incidence of NLCs was comparable between native lung-sparing LDLLT recipients and single CLT recipients (8/21 vs 26/61, p = 0.80); however, NLCs occurred significantly later in LDLLT recipients than in CLT recipients (median: 665 vs 181.5 days after transplantation, p = 0.014). CONCLUSIONS: NLCs after native lung-sparing LDLLT had favorable outcomes. Therefore, native lung-sparing LDLLT is a useful treatment option for severely ill patients who cannot wait for CLT. However, it is important to recognize that NLCs may occur later in LDLLT than in CLT.

Model-based registration for pneumothorax deformation analysis using intraoperative cone-beam CT images.

Because the lung deforms during surgery because of pneumothorax, it is important to be able to track the location of a tumor. Deformation of the whole lung can be estimated using intraoperative cone-beam CT (CBCT) images. In this study, we used deformable mesh registration methods for paired CBCT images in the inflated and deflated states, and analyzed their deformation. We proposed a deformable mesh registration framework for deformations of partial organ shapes involving large deformation and rotation. Experimental results showed that the proposed methods reduced errors in point-to-point correspondence. As a result of registration using surgical clips placed on the lung surface during imaging, it was confirmed that an average error of 3.9 mm occurred in eight cases. The result of analysis showed that both tissue rotation and contraction had large effects on displacement.

Diagnostic yield of endobronchial ultrasound-guided transbronchial needle aspiration to assess tumor-programmed cell death ligand-1 expression in mediastinal lymph nodes metastasized from non-small cell lung cancer.

PURPOSE: We investigated the utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) to evaluate programmed cell death ligand-1 (PD-L1) expression in patients with advanced non-small cell lung cancer (NSCLC). METHODS: A retrospective chart review of patients who underwent EBUS-TBNA between April 2017 and April 2019 was conducted. Among patients diagnosed with NSCLC, we investigated the rate of successful evaluation of tumor PD-L1 expression, compared the relevant factors between patients with evaluable and those with unevaluable PD-L1 expression, and examined the response to immune checkpoint inhibitors (ICIs) after EBUS-TBNA. RESULTS: Of the 40 patients assessed, 32 (80%) had evaluable PD-L1 expression. Patients with evaluable PD-L1 expression were older than those with unevaluable PD-L1 expression (p = 0.017), and we noted a tendency for a larger diameter of the biopsied lymph node (p = 0.12). The response rate to ICIs was 100% in patients with a tumor proportion score (TPS) ≥ 50%, 33% in those with a TPS 1-49%, and 0% in those with a TPS < 1%. CONCLUSION: The diagnostic yield of EBUS-TBNA to evaluate PD-L1 expression in advanced NSCLC appeared acceptable in association with relevant clinical outcomes after treatment with ICIs. A further prospective study with a larger sample size is required to confirm our findings.

Living-donor single-lobe lung transplantation for pulmonary hypertension due to alveolar capillary dysplasia with misalignment of pulmonary veins.

This is a case report of a successful single-lobe lung transplantation for pulmonary hypertension secondary to alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV). A 6-year-old boy underwent living-donor single-lobe transplantation with the right lower lobe from his 31-year-old mother. The pretransplantation graft size matching was acceptable: the estimated graft forced vital capacity (FVC) was 96.5% of the recipient's predicted FVC, and the graft size measured by computed tomography (CT) volumetry was 166% of the recipient's chest cavity volume. Right pneumonectomy followed by implantation was performed under cardiopulmonary bypass (CPB). The pulmonary arterial pressure was significantly decreased to 31/12 mm Hg immediately after transplantation, and the first PaO2 /FiO2 in the intensive-care unit (ICU) was 422 mm Hg. Lung perfusion scintigraphy showed 97.5% perfusion to the right implanted lung 3 months after transplantation. Chest CT showed a mass rapidly growing in the native left upper lobe 6 months after transplantation, which was diagnosed as posttransplant lymphoproliferative disorder (PTLD) by a CT-guided biopsy. After immunosuppressant reduction and six courses of chemotherapy with rituximab, he underwent native left upper lobectomy for salvage lung resection 13 months after transplantation. Seven months after lobectomy, he has returned to normal school life without any sign of tumor recurrence.

A rare case of mediastinal functioning parathyroid adenoma removed successfully with thoracoscopy.

We report here a rare case of primary hyperparathyroidism that was associated with an ectopic parathyroid adenoma located in the mediastinum. A 66-year-old woman suffering from primary hyperparathyroidism had been followed-up on an outpatient basis for over 10 years. She suffered from persistent urolithiasis and osteopenia due to hypercalcemia. After technetium-99-sestamibi (99mTc-MIBI) scintigraphy revealed an ectopic adenoma in the superior mediastinum, thoracoscopic resection of the tumor was performed. Subsequently, her serum parathyroid hormone (PTH) level decreased dramatically and her serum calcium concentration was restored to normal. Two years following surgery, her serum PTH and Ca levels remain stable.

Ciliated muconodular papillary tumor of the lung: report of five cases.

We report five serial cases of ciliated muconodular papillary tumor (CMPT) of the lung. CMPT is characterized as a low-grade malignant tumor with ciliated columnar epithelial cells combined with goblet cells, typically presenting as peripheral lung tumor and often causing diagnostic or therapeutic problems. In the cases described here, all patients presented with abnormal chest shadow but no definitive symptoms. Although all tumors were peripheral, computed tomography (CT) revealed various radiographic findings including small lung nodules, ground-grass opacity or irregular-shaped consolidation. All patients underwent complete surgical resection, and no recurrence has been noted over follow-up. In all cases, pathological findings included columnar ciliated cells with mucus lakes, consistent with the immunohistochemical staining. As there are few reports on this tumor entity, which has not yet received a WHO classification, we believe our case series may be of interest.