Single-cell sequencing on CD8+ TILs revealed the nature of exhausted T cells recognizing neoantigen and cancer/testis antigen in non-small cell lung cancer.

BACKGROUND: CD8+tumor infiltrating lymphocytes (TILs) are often observed in non-small cell lung cancers (NSCLC). However, the characteristics of CD8+ TILs, especially T-cell populations specific for tumor antigens, remain poorly understood. METHODS: High throughput single-cell RNA sequencing and single-cell T-cell receptor (TCR) sequencing were performed on CD8+ TILs from three surgically-resected lung cancer specimens. Dimensional reduction for clustering was performed using Uniform Manifold Approximation and Projection. CD8+ TIL TCR specific for the cancer/testis antigen KK-LC-1 and for predicted neoantigens were investigated. Differentially-expressed gene analysis, Gene Set Enrichment Analysis (GSEA) and single sample GSEA was performed to characterize antigen-specific T cells. RESULTS: A total of 6998 CD8+ T cells was analyzed, divided into 10 clusters according to their gene expression profile. An exhausted T-cell (exhausted T (Tex)) cluster characterized by the expression of ENTPD1 (CD39), TOX, PDCD1 (PD1), HAVCR2 (TIM3) and other genes, and by T-cell oligoclonality, was identified. The Tex TCR repertoire (Tex-TCRs) contained nine different TCR clonotypes recognizing five tumor antigens including a KK-LC-1 antigen and four neoantigens. By re-clustering the tumor antigen-specific T cells (n=140), it could be seen that the individual T-cell clonotypes were present on cells at different stages of differentiation and functional states even within the same Tex cluster. Stimulating these T cells with predicted cognate peptide indicated that TCR signal strength and subsequent T-cell proliferation and cytokine production was variable but always higher for neoantigens than KK-LC-1. CONCLUSIONS: Our approach focusing on T cells with an exhausted phenotype among CD8+ TILs may facilitate the identification of tumor antigens and clarify the nature of the antigen-specific T cells to specify the promising immunotherapeutic targets in patients with NSCLC.

Transtricuspid approach in redo surgery for post-infarction ventricular septal rupture.

A 59-year-old man, who had been treated using the infarction exclusion technique for inferior post-infarction ventricular septal rupture (VSR) 4 months previously, was readmitted because of deterioration of mitral valve regurgitation, residual shunt, and progression of pulmonary hypertension. We performed mitral valve replacement via the transseptal approach, patch closure of the defect via the transtricuspid approach, and tricuspid valve annuloplasty. The post-operative course was uneventful. The transtricuspid approach is useful in redo surgery for post-infarction VSR.

Acute aortic dissection associated with undetected congenital bicuspid aortic valve and infective endocarditis diagnosed intraoperatively.

The congenital bicuspid aortic valve (BAV) is recognized as a cause of acute aortic dissection (AAD) and also as a risk factor for infective endocarditis (IE) especially ring abscess. We experienced a case of all these combined and operated emergently. A 59-year-old man was transferred to us, and emergent operation was indicated for AAD and aortic stenosis (AS) due to BAV. However, he was strongly suspected of also having IE during the operation and the procedure was changed to a modified Bentall's method. The diagnosis was confirmed by pathological examination postoperatively. He recovered well after postoperative antimicrobial therapy without recurrent infection. It is important to remember that BAV is a risk factor for not only AAD but also IE, which sometimes occurs simultaneously and requires an emergent operation due to high mortality.

Emergent coronary artery bypass grafting after a broken Rotablator drive-shaft.

A 75-year-old man, who presented with acute myocardial infarction and cardiogenic shock underwent emergency cardiac catheterization, assisted by catecholamine administration, respiratory support with intubation and intra-aortic balloon pumping (IABP). The coronary arteriogram showed a high-grade obstruction of two main branches of the left coronary artery. The occlusion of the left anterior descending coronary artery required immediate treatment. As it was heavily calcified, the cardiologists were forced to use Rotablator®, but the device became stuck and the drive-shaft broke. An emergency coronary artery bypass grafting (CABG) with left internal thoracic artery and saphenous vein graft and mitral valve annuloplasty was performed successfully. The patient was weaned off IABP on the fourth postoperative day, and a defibrillator was implanted on the 81st postoperative day because of heart failure. After these procedures, his general state improved gradually and he was able to leave the hospital, walking alone on the 101st postoperative day. Various reports have appeared describing residual foreign bodies in coronary arteries, and almost 90% of these cases can be dealt with by intravascular procedures, but some need removal by open-chest surgery. An early decision by the cardiologists to go to surgery is recommended to save lives. There has been no previous report of emergent CABG after a stuck Rotablator® tip due to a 'broken drive-shaft'. However, because damage is possible even with reliable devices, there should be no hesitation converting to open-heart surgery in such cases.

Clinical outcome of aortic valve replacement with 16-mm ATS-advanced performance valve for small aortic annulus.

BACKGROUND: Various surgical techniques have been proposed to treat small aortic annulus. We have used small-diameter mechanical valves for small aortic annulus. The present study examined aortic valve replacement with small diameter mechanical valves to determine their effectiveness. METHODS: The study included 67 patients who underwent elective, isolated aortic valve replacement with ATS-Advanced Performance (AP) valves (ATS Medical, Inc, Minneapolis, MN) within our department. The patients were divided into two groups; patients receiving the 16-mm AP valve (16-mm group) and those receiving valves 18-mm AP or larger (>16-mm group). RESULTS: The mean age of the 16-mm group was significantly higher than that of the >16-mm group. Body surface area was significantly smaller in the 16-mm group than the >16-mm group. We found no significant differences in preoperative conditions between the groups. The effective orifice area index of the mechanical valve was lower in the 16-mm group (0.87+/-0.06 vs 1.12+/-0.13 cm2/m2, p<0.0001). Six patients (40%) in the 16-mm group fell into the category of prosthesis-patient mismatch cases. Although the postoperative pressure gradient was higher in the 16-mm group (33.7+/-12.5 vs 23.16+/-8.78, p<0.01), left ventricular mass index and left ventricular ejection fraction at early and at late follow-up improved from the preoperative period in both groups. We found no significant differences in incidence of postoperative complications, including death. CONCLUSIONS: We believe aortic valve replacement with small-diameter mechanical valves (the ATS-AP valves) in patients with a small annulus provides satisfactory remote prognosis. The use of mechanical valves in elderly patients is considered acceptable with strict clinical monitoring to prevent thromboembolism and anticoagulation therapy-induced complications.

Reinforcement of saphenous vein graft with ePTFE graft for axillocoronary bypass grafting.

Arteriosclerosis in the ascending aorta is widely accepted as a strong risk factor for the occurrence of stroke after coronary artery bypass grafting (CABG). The aortic no-touch technique, with a variety of modifications, has been used to reduce the risk of post-CABG stroke. Saphenous vein grafts (SVGs) have been used for axillocoronary bypass grafting, a modification of the aortic no-touch technique. However, kinking or compression often occurs with SVGs. We report here the successful application of an 8-mm expanded polytetrafluoroethylene graft, of the external bead support type, that was used to cover an SVG during axillocoronary bypass grafting.

[Successful management of traumatic aortic valve insufficiency; report of a case].

A case of the successful management of traumatic aortic valve insufficiency is reported. A previously healthy 48-year-old man sustained multiple injuries in a traffic accident. One month after the accident, heart failure, derived from aortic insufficiency, was noted. Three years and 5 months after the injuries, aortic valve replacement was performed, and a large tear, approximately 7 mm in length, was found in the aortic right coronary cusp. This finding corresponded to the traumatic aortic valve insufficiency. Traumatic aortic valve insufficiency is rare, and early diagnosis may be difficult. Examinations for associated intracardiac injuries should be carefully undertaken.