Intratumoral follicular regulatory T cells curtail anti-PD-1 treatment efficacy.

Immune-checkpoint blockade (ICB) has shown remarkable clinical success in boosting antitumor immunity. However, the breadth of its cellular targets and specific mode of action remain elusive. We find that tumor-infiltrating follicular regulatory T (TFR) cells are prevalent in tumor tissues of several cancer types. They are primarily located within tertiary lymphoid structures and exhibit superior suppressive capacity and in vivo persistence as compared with regulatory T cells, with which they share a clonal and developmental relationship. In syngeneic tumor models, anti-PD-1 treatment increases the number of tumor-infiltrating TFR cells. Both TFR cell deficiency and the depletion of TFR cells with anti-CTLA-4 before anti-PD-1 treatment improve tumor control in mice. Notably, in a cohort of 271 patients with melanoma, treatment with anti-CTLA-4 followed by anti-PD-1 at progression was associated with better a survival outcome than monotherapy with anti-PD-1 or anti-CTLA-4, anti-PD-1 followed by anti-CTLA-4 at progression or concomitant combination therapy.

Tissue-resident memory features are linked to the magnitude of cytotoxic T cell responses in human lung cancer.

Therapies that boost the anti-tumor responses of cytotoxic T lymphocytes (CTLs) have shown promise; however, clinical responses to the immunotherapeutic agents currently available vary considerably, and the molecular basis of this is unclear. We performed transcriptomic profiling of tumor-infiltrating CTLs from treatment-naive patients with lung cancer to define the molecular features associated with the robustness of anti-tumor immune responses. We observed considerable heterogeneity in the expression of molecules associated with activation of the T cell antigen receptor (TCR) and of immunological-checkpoint molecules such as 4-1BB, PD-1 and TIM-3. Tumors with a high density of CTLs showed enrichment for transcripts linked to tissue-resident memory cells (TRM cells), such as CD103, and CTLs from CD103hi tumors displayed features of enhanced cytotoxicity. A greater density of TRM cells in tumors was predictive of a better survival outcome in lung cancer, and this effect was independent of that conferred by CTL density. Here we define the 'molecular fingerprint' of tumor-infiltrating CTLs and identify potentially new targets for immunotherapy.

A novel lung explant model for the ex vivo study of efficacy and mechanisms of anti-influenza drugs.

Influenza A virus causes considerable morbidity and mortality largely because of a lack of effective antiviral drugs. Viral neuraminidase inhibitors, which inhibit viral release from the infected cell, are currently the only approved drugs for influenza, but have recently been shown to be less effective than previously thought. Growing resistance to therapies that target viral proteins has led to increased urgency in the search for novel anti-influenza compounds. However, discovery and development of new drugs have been restricted because of differences in susceptibility to influenza between animal models and humans and a lack of translation between cell culture and in vivo measures of efficacy. To circumvent these limitations, we developed an experimental approach based on ex vivo infection of human bronchial tissue explants and optimized a method of flow cytometric analysis to directly quantify infection rates in bronchial epithelial tissues. This allowed testing of the effectiveness of TVB024, a vATPase inhibitor that inhibits viral replication rather than virus release, and to compare efficacy with the current frontline neuraminidase inhibitor, oseltamivir. The study showed that the vATPase inhibitor completely abrogated epithelial cell infection, virus shedding, and the associated induction of proinflammatory mediators, whereas oseltamivir was only partially effective at reducing these mediators and ineffective against innate responses. We propose, therefore, that this explant model could be used to predict the efficacy of novel anti-influenza compounds targeting diverse stages of the viral replication cycle, thereby complementing animal models and facilitating progression of new drugs into clinical trials.

Intra-tumoral T cells in pediatric brain tumors display clonal expansion and effector properties.

Brain tumors in children are a devastating disease in a high proportion of patients. Owing to inconsistent results in clinical trials in unstratified patients, the role of immunotherapy remains unclear. We performed an in-depth survey of the single-cell transcriptomes and clonal relationship of intra-tumoral T cells from children with brain tumors. Our results demonstrate that a large fraction of T cells in the tumor tissue are clonally expanded with the potential to recognize tumor antigens. Such clonally expanded T cells display enrichment of transcripts linked to effector function, tissue residency, immune checkpoints and signatures of neoantigen-specific T cells and immunotherapy response. We identify neoantigens in pediatric brain tumors and show that neoantigen-specific T cell gene signatures are linked to better survival outcomes. Notably, among the patients in our cohort, we observe substantial heterogeneity in the degree of clonal expansion and magnitude of T cell response. Our findings suggest that characterization of intra-tumoral T cell responses may enable selection of patients for immunotherapy, an approach that requires prospective validation in clinical trials.

Ambulatory chest drainage with advanced nurse practitioner-led follow-up facilitates early discharge after thoracic surgery.

OBJECTIVES: To demonstrate the safety and feasibility of advanced nurse practitioner-led (ANP-led) outpatient follow-up after discharge with ambulatory chest drains for prolonged air leak and excessive fluid drainage. METHODS: Patients discharged with ambulatory chest drains between January 2017 and December 2019 were retrospectively reviewed. Discharge criteria included air leak < 200 ml/min or fluid drainage > 100 ml/24 h on a digital drain. Patients were reviewed weekly in the clinic by ANPs, a highly skilled cohort of nurses with physician support available. Outcomes included length of stay, duration of air or fluid leak and complications. RESULTS: Two-hundred patients were included, amounting to 368 clinic episodes. The median age was 68 ± 13 years and 119 (60%) were male. 112 (56%) patients underwent anatomical lung resection (total anatomical lung resections during the study period = 917) equating to a discharge with ambulatory chest drain rate of 12.2% in this group. The median length of stay was 6 ± 3 days and 176 (88%) patients were discharged with air leak versus 24 (12%) with excessive fluid drainage. The median time to drain removal was 12 ± 11 days. Complications occurred in 16 patients (8%) and 12 (6%) required readmission. An estimated 2075 inpatient days were saved over the study period equating to an annual cost saving of £123,167 (US$149,032) per annum. CONCLUSIONS: Patients with air leak or excessive fluid drainage can safely be discharged with ambulatory chest drains, allowing them to return to their familiar home environment safely and quickly. ANP-led clinics are a robust and cost-effective follow-up strategy and are associated with a low complication rate.

Single-cell analysis reveals prognostic fibroblast subpopulations linked to molecular and immunological subtypes of lung cancer.

Fibroblasts are poorly characterised cells that variably impact tumour progression. Here, we use single cell RNA-sequencing, multiplexed immunohistochemistry and digital cytometry (CIBERSORTx) to identify and characterise three major fibroblast subpopulations in human non-small cell lung cancer: adventitial, alveolar and myofibroblasts. Alveolar and adventitial fibroblasts (enriched in control tissue samples) localise to discrete spatial niches in histologically normal lung tissue and indicate improved overall survival rates when present in lung adenocarcinomas (LUAD). Trajectory inference identifies three phases of control tissue fibroblast activation, leading to myofibroblast enrichment in tumour samples: initial upregulation of inflammatory cytokines, followed by stress-response signalling and ultimately increased expression of fibrillar collagens. Myofibroblasts correlate with poor overall survival rates in LUAD, associated with loss of epithelial differentiation, TP53 mutations, proximal molecular subtypes and myeloid cell recruitment. In squamous carcinomas myofibroblasts were not prognostic despite being transcriptomically equivalent. These findings have important implications for developing fibroblast-targeting strategies for cancer therapy.

Single-cell transcriptomic analysis of tissue-resident memory T cells in human lung cancer.

High numbers of tissue-resident memory T (TRM) cells are associated with better clinical outcomes in cancer patients. However, the molecular characteristics that drive their efficient immune response to tumors are poorly understood. Here, single-cell and bulk transcriptomic analysis of TRM and non-TRM cells present in tumor and normal lung tissue from patients with lung cancer revealed that PD-1-expressing TRM cells in tumors were clonally expanded and enriched for transcripts linked to cell proliferation and cytotoxicity when compared with PD-1-expressing non-TRM cells. This feature was more prominent in the TRM cell subset coexpressing PD-1 and TIM-3, and it was validated by functional assays ex vivo and also reflected in their chromatin accessibility profile. This PD-1+TIM-3+ TRM cell subset was enriched in responders to PD-1 inhibitors and in tumors with a greater magnitude of CTL responses. These data highlight that not all CTLs expressing PD-1 are dysfunctional; on the contrary, TRM cells with PD-1 expression were enriched for features suggestive of superior functionality.

VATS Plication of the Diaphragm: A Descriptive Observational 10-Year Southampton Experience.

OBJECTIVE: The aim of the study was to report the safety and efficacy of video-assisted thoracoscopic (VATS) plication of the diaphragm at our institution between 2006 and 2016. METHODS: Adult patients selected on etiology and combination of investigations including plain chest x-ray, computed tomography of chest and abdomen, lung functions in supine and sitting positions, radiological/ultrasonic screening for diaphragmatic movement, and phrenic nerve conduction studies. We incorporated a triportal VATS and Endostitch device for plication, using CO2 insufflation to maximum 12 mm Hg. Bilateral simultaneous plication and high-risk patients were electively admitted to intensive therapy unit postoperatively. RESULTS: Thirty-five patients (24 males) had their diaphragm plicated. The mean age was 56.6 years (range = 23-76 years). The mean body mass index was 32.1 (range = 22.2-45.4). Twenty one were right, 13 left, 2 patients had VATS simultaneous bilateral plication, and 1 had sequential VATS bilateral plication. Paralysis was idiopathic in 17, posttraumatic in 5, postremoval of mediastinal tumor in 4, and postcardiac surgery in 3. All patients presented with lifestyle-limiting dyspnea and orthopnea, three were on nocturnal noninvasive ventilation. Five were diabetic and 16 were smokers. The mean supine forced expiratory volume in the first second was 62.5% of predicted. Twenty two were performed by VATS (63%), three converted to thoracotomy, and 13 were open limited thoracotomy (historic). The mean hospital stay was 4.5 days (range = 1-18, mode 2 days). Intensive therapy unit admission was required in six patients for mechanical ventilation 0 to 3 days. Five patients (14%) had no improvement in symptoms. There were no deaths, no 30-day readmissions, and no long-term neuralgia in this series. CONCLUSIONS: We found minimal access VATS plication of the diaphragm to be feasible and safe, but no firm conclusions should be drawn from our limited resources. We report the feasibility of concomitant bilateral VATS plication of the diaphragm in two adults, and this was not previously reported in the adult population. There is a need for further good quality, prospective studies, and randomized controlled studies evaluating efficacy of VATS diaphragmatic plication.

Video-assisted thoracoscopic surgery versus sternotomy in thymectomy for thymoma and myasthenia gravis.

Thymectomy involves the removal of all the soft tissue in the pre-vascular plane of the anterior mediastinum between the two phrenic nerves. Surgical success in controlling myasthenia and the most important factor influencing survival in patients with thymoma depends on complete clearance of thymic tissue. Currently there is a perception that the open (median sternotomy) approach offers better visualisation of the thymic tissue. This perceived advantage is thought to justify the invasive nature of the procedure associated with increased morbidity. Video-assisted thoracoscopic surgery (VATS) for thymectomy has evolved significantly over the last decade, including bilateral and unilateral VATS (either left or right) approaches. The laterality of the approach remains largely on surgeon preferences, with the decision influenced by their experience and training. VATS offers superior illumination and magnification, particularly with the availability of advanced cameras with variable angles that provide better exposure and lighting of the operative field. The use of three-dimensional-operating imaging has also revolutionised the VATS technique. VATS thymectomy is a superior and radical technique in minimising access trauma and removing all thymic tissue that may be scattered in the anterior mediastinum and cervical fat. Other advantages of VATS include less intraoperative blood loss, early removal of chest drains, less requirement for blood products, decreased inflammatory cytokine response, shorter hospital stay and superior cosmesis. There is also a decreased risk of respiratory and cardiac related complications compared to the open (sternotomy) technique. Furthermore, no significant difference has been found in long-term complications and survival rate between VATS and open approaches. Subsequently, the VATS approach should be encouraged as more surgeons are adopting the minimally invasive practice as routine.

Modified thoracoplasty using a breast implant to obliterate an infected pleural space: an alternative to traditional thoracoplasty.

Thoracoplasty is a technique used to obliterate residual intrapleural spaces after lung resection for infection or other causes. It involves multiple osteotomies on several ribs and then collapsing them into the space to be obliterated; however, this results in a distorted and asymmetrical chest wall. We report a case of a 34-year-old female with completely destroyed right upper lobe secondary to chronic Aspergillus infection. She underwent a completion right upper lobectomy and modified thoracoplasty with the use of a breast implant to obliterate the residual pleural space without any distortion of the chest wall, with an excellent outcome.

Avoiding ischemia in latissimus dorsi muscle grafts: electrical prestimulation versus vascular delay.

BACKGROUND: Surgical mobilization of the latissimus dorsi muscle produces regional ischemic damage that may compromise its function in clinical applications such as cardiomyoplasty. We compared the effectiveness of two procedures designed to maintain blood flow throughout the mobilized muscle. METHODS: Adult pigs were assigned to two experimental groups: an electrically prestimulated group (n = 10) and a vascular delay group (n = 10). In the prestimulated group the left latissimus dorsi muscle was activated in situ at 2 Hz for 24 h/d. In the vascular delay group, the intercostal perforating arteries to the left latissimus dorsi muscle were divided. Two weeks later, hyperemic blood flow was measured by means of fluorescent microspheres immediately before and after mobilizing the latissimus dorsi muscle and again after recovery for a further 2 days. RESULTS: In the prestimulated group, blood flow was not significantly depressed in any region of the muscle immediately after mobilization, and blood flow increased significantly in proximal (p = 0.01), middle (p = 0.02), and distal (p = 0.007) regions following recovery. In muscles subjected to vascular delay the proximal and middle regions showed no significant changes in blood flow after mobilization or recovery, but flow in the distal region was 50% lower after mobilization (p = 0.003), and it remained significantly depressed even after recovery (p = 0.008). CONCLUSIONS: Prestimulation was significantly more effective than vascular delay in preserving distal blood flow. Because it is also less invasive and initiates metabolic transformation before mobilization, this technique should allow cardiac assistance to be introduced at an earlier postoperative stage without compromising the viability of the grafted muscle.

Dopamine therapy for patients at risk of renal dysfunction following cardiac surgery: science or fiction?

OBJECTIVES: We aimed to evaluate the renoprotective role of renal-dose dopamine on cardiac surgical patients at high risk of postoperative renal dysfunction. The latter included older patients or those with pre-existing renal disease, elevated preoperative serum creatinine (Cr), poor ventricular function, hypertension, diabetes mellitus and unstable angina requiring intravenous therapy. METHODS: Fifty patients undergoing cardiopulmonary bypass (CPB) who fulfilled the entry criteria were prospectively randomized into two groups: Group 1 received a 'renal-dose' (3 microg kg(-1) min(-1)) dopamine infusion starting at anaesthetic induction for 48 h whilst saline infusion acted as placebo in Group 2. The anaesthetic and CPB regimes were standardized. Urinary excretion of retinol binding protein (RBP) indexed to Cr, an accurate and sensitive marker of early renal tubular damage, was assessed daily for 6 days. Additional outcome measures included daily fluid balance, blood urea and serum Cr. Statistical comparisons were made using ANOVA and Mann-Whitney U-test. RESULTS: No significant difference was found between the groups in their age, gender, preoperative NYHA class, ejection fraction, baseline serum Cr and duration of CPB and aortic cross-clamping. Renal replacement therapy was not required in any instance. Both groups demonstrated a similar and significant rise in urinary RBP throughout the study period. Dopamine-treated patients achieved more negative average fluid balance than those on placebo (5 vs. 229 ml, P<0.05). CONCLUSIONS: Renal-dose dopamine therapy failed to offer additional renoprotection to patients considered at increased risk of renal dysfunction after CPB.

Early and mid-term outcomes of trans-sternal and video-assisted thoracoscopic surgery for thymoma.

OBJECTIVES: Video-assisted thoracoscopic surgery (VATS) for thymoma has uncertain safety and effectiveness in comparison with trans-sternal resection. This feasibility study compared short- and mid-term outcomes for patients undergoing these two procedures, highlights weaknesses in current research and makes recommendations for long-term technological evaluations in this field. METHODS: Consecutive thymoma cases between 2004 and 2010 were identified. Patients were divided into two groups according to surgical approach (Group I trans-sternal; Group II VATS) and comparisons were made between groups. The primary outcome was overall survival. Secondary outcomes included operative morbidity and mortality, hospital stay, recurrence rate and disease-free survival. RESULTS: Thirty-nine patients were included (Group I: n = 22 vs Group II: n = 17). There were no differences between groups at baseline for all measured covariates. No deaths occurred within 30 days of surgery. More patients in Group I developed complications (Group I: n = 10 vs Group II: n = 3; P = 0.093), while hospital stay was shorter in Group II (Group I: 6.4 ± 4.6 days vs Group II: 4.4 ± 1.8 days; P = 0.030). Five-year overall survival (Group I: 93.8 ± 6.1% vs Group II: 83.3 ± 11.2%; P = 0.425), 5-year disease-free survival (Group I: 71.0 ± 15.3% vs Group II: 83.3 ± 11.2%; P = 0.827) and recurrence rates at final follow-up (Group I: n = 2 vs Group II: n = 1; P = 0.363) were similar between the groups. CONCLUSION: VATS thymectomy for thymoma is feasible, safe and has comparable mid-term oncological outcomes to trans-sternal thymectomy. Future research is required to evaluate long-term oncological outcomes of VATS thymectomy for thymoma in national registries and randomized, controlled trials.

Pulmonary infarction after repair of type B aortic dissection.

Lung infarction after intrathoracic surgery is a life-threatening complication that needs urgent intervention. Although the exact etiology is not known, pulmonary infarction may be suspected for patients presenting with consolidation of the lung after intrathoracic surgery. We report a very rare case of pulmonary infarction after successful surgical treatment of a type B aortic dissection. The pulmonary infarction was treated by intrapericardial pneumonectomy. This article discusses possible etiology and management of such patients. A high index of clinical suspicion and timely investigations may allow early detection of this unusual event and avoid fatal outcomes.

Long-term event-free survival with an embolised prosthetic valve leaflet in the thoracic aorta.

We report the case of a patient who underwent a redo surgery for a leaflet escape from a Bjork-Shiley tilting disc mitral prosthesis inserted 18 years previously. The escaped disc remained lodged in the thoracic aorta without any complication. She ultimately died of terminal heart failure 13 years after the second operation. We believe this to be the longest survival with a dislodged leaflet from a mechanical valve. Removal of dislodged disc is recommended in literature but there may be a place for watchful observation in exceptional cases with no haemodynamic compromise.

Improved viability of latissimus dorsi muscle grafts after electrical prestimulation.

Surgical mobilization of the latissimus dorsi muscle (LDM) produces fiber degeneration, particularly in the distal part of the graft, that may compromise its function in clinical applications such as dynamic cardiomyoplasty. In five rats, the left LDM was stimulated continuously at 10 HZ. After 5 weeks, vessels perforating the chest wall were divided and the left LDM was mobilized as a pedicle graft based on the thoracodorsal artery. Twenty-four hours later, animals were killed and left and right LDMs were incubated with the vital stain nitroblue tetrazolium. Five control rats underwent a similar procedure without prestimulation. Mobilization of the LDM resulted in a loss of viability in the distal third of the muscle graft. This was reduced significantly by prestimulation (P = 0.006). Blood flow to the distal LDM graft is known to be augmented by electrical stimulation in situ before mobilization; the present results show that there is an associated enhancement of viability. The clinical implications of this finding are discussed.