Nutritional modulation of antitumor immunity.

The composition and quantity of food we eat have a drastic impact on the development and function of immune responses. In this review, we highlight defined nutritional interventions shown to enhance antitumor immunity, including ketogenic, low-protein, high-fructose, and high-fiber diets, as well as dietary restriction. We propose that incorporating such nutritional interventions into immunotherapy protocols has the potential to increase therapeutic responsiveness and long-term tumor control in patients with cancer.

Nutritional regulation of microbiota-derived metabolites: Implications for immunity and inflammation.

Nutrition profoundly shapes immunity and inflammation across the lifespan of mammals, from pre- and post-natal periods to later life. Emerging insights into diet-microbiota interactions indicate that nutrition has a dominant influence on the composition-and metabolic output-of the intestinal microbiota, which in turn has major consequences for host immunity and inflammation. Here, we discuss recent findings that support the concept that dietary effects on microbiota-derived metabolites potently alter immune responses in health and disease. We discuss how specific dietary components and metabolites can be either pro-inflammatory or anti-inflammatory in a context- and tissue-dependent manner during infection, chronic inflammation, and cancer. Together, these studies emphasize the influence of diet-microbiota crosstalk on immune regulation that will have a significant impact on precision nutrition approaches and therapeutic interventions for managing inflammation, infection, and cancer immunotherapy.

Divergent molecular networks program functionally distinct CD8+ skin-resident memory T cells.

Skin-resident CD8+ T cells include distinct interferon-γ-producing [tissue-resident memory T type 1 (TRM1)] and interleukin-17 (IL-17)-producing (TRM17) subsets that differentially contribute to immune responses. However, whether these populations use common mechanisms to establish tissue residence is unknown. In this work, we show that TRM1 and TRM17 cells navigate divergent trajectories to acquire tissue residency in the skin. TRM1 cells depend on a T-bet-Hobit-IL-15 axis, whereas TRM17 cells develop independently of these factors. Instead, c-Maf commands a tissue-resident program in TRM17 cells parallel to that induced by Hobit in TRM1 cells, with an ICOS-c-Maf-IL-7 axis pivotal to TRM17 cell commitment. Accordingly, by targeting this pathway, skin TRM17 cells can be ablated without compromising their TRM1 counterparts. Thus, skin-resident T cells rely on distinct molecular circuitries, which can be exploited to strategically modulate local immunity.

Elevated Soluble Suppressor of Tumorigenicity 2 Predict Hospital Admissions Due to Major Adverse Cardiovascular Events (MACE).

The role of soluble suppression of tumorigenicity (sST2) as a biomarker in predicting clinical outcomes in patients with cardiovascular diseases (CVD) has not been fully elucidated. In this study, we sought to determine the relationship between sST2 levels and any unplanned hospital readmissions due to a major adverse cardiovascular event (MACE) within 1 year of first admission. Patients (n = 250) admitted to the cardiology unit at John Hunter Hospital were recruited. Occurrences of MACE, defined as the composite of total death, myocardial infarction (MI), stroke, readmissions for heart failure (HF), or coronary revascularization, were recorded after 30, 90, 180, and 365 days of first admission. On univariate analysis, patients with atrial fibrillation (AF) and HF had significantly higher sST2 levels vs. those who did not. Increasing levels of sST2 by quartiles were significantly associated with AF, HF, older age, low hemoglobin, low eGFR, and high CRP levels. On multivariate analysis: high sST2 levels and diabetes remained as risk predictors of any MACE occurrence; an sST2 level in the highest quartile (Q4: >28.4 ng/mL) was independently associated with older age, use of beta-blockers, and number of MACE events within a 1 year period. In this patient cohort, elevated sST2 levels are associated with unplanned hospital admission due to MACE within 1 year, independent of the nature of the index cardiovascular admission.

Prevalence and survival associated with pulmonary hypertension after mitral valve replacement: National echocardiography database of Australia study.

The specific prevalence and outcome of pulmonary hypertension after mitral valve replacement (MVR) is not well documented. The aim of the study was to determine the prevalence and prognostic impact of pulmonary hypertension after MVR. In addition, we sought to determine the threshold of mortality risk according to echocardiography derived pulmonary pressures and those echocardiographic characteristics that are associated with increased mortality. Using the National Echocardiography Database of Australia, patients who had undergone MVR were identified with estimated right ventricular systolic pressure (eRVSP) assessed and linked to patient mortality during mean follow up of 1917 days. Classification and regression tree analysis was used to identify the most powerful predictors of mortality. A total of 10,994 patients who had undergone echocardiography following MVR (mean age 65.2 ± 16, 44.8% women) were studied (mean follow-up 1917 days). The prevalence of PH (defined as eRSVP ≥40 mmHg) was 64.1% (7042/10,994). Severe PH (eRVSP ≥60 mmHg) was seen in 42.3% (4671/10,994). Mortality in individuals with PH was greater than amongst individuals without PH (41.1% vs. 26.3%). Age, tricuspid regurgitation and left ventricular dysfunction were also associated with mortality. There is a high prevalence of PH after MVR which confers an adverse prognosis. Improved therapeutic approaches to mitral valve disease and the subsequent development of PH are essential.

Platypnea-Orthodeoxia Syndrome in the Setting of Patent Foramen Ovale Without Pulmonary Hypertension or Major Lung Disease.

Background Patent foramen ovale (PFO)-associated platypnea-orthodeoxia syndrome is characterized by dyspnea and hypoxemia when upright. The pathogenesis is thought to involve an increase in right atrial pressure or change in degree of right to left shunting with upright posture. Methods and Results We sought to characterize patients with platypnea-orthodeoxia syndrome related to PFO without pulmonary hypertension. We retrospectively reviewed databases at 3 tertiary referral hospitals in New South Wales, Australia from 2000 to 2019. Fourteen patients with a mean age of 69±14 years had a PFO with wide tunnel separation. Mean New York Heart Association Classification was II (±0.9) and 7 inpatients had been confined to bed (from postural symptoms). Baseline oxygen saturations supine were 93%±5% and 84%±6% upright. Two patients had a minor congenital heart defect and 4 had mild parenchymal lung disease with preserved lung function. The mean aortic root diameter was 37±6 mm and distance between aortic root and posterior atrial wall was 16±2 mm. Platypnea-orthodeoxia syndrome was preceded by surgery in 5 patients and 1 patient had mild pneumonia. Successful closure of the PFO using an Amplatzer device was performed in 11 of 14 patients. Post-closure, all patients had New York Heart Association Classification I (improvement 1.6±0.9, P<0.003) and semi-recumbent oxygen saturations increased by 13%±8% (P<0.001, n=10). Conclusions Platypnea-orthodeoxia syndrome is a debilitating condition, curable by PFO closure. Anatomical distortion of the atrial septum related to a dilated aortic root or shortening of the distance between the aortic root and posterior atrial wall may contribute to the syndrome.

Immune checkpoint inhibitors unleash pathogenic immune responses against the microbiota.

Immune checkpoint inhibitors (ICIs) are essential components of the cancer therapeutic armamentarium. While ICIs have demonstrated remarkable clinical responses, they can be accompanied by immune-related adverse events (irAEs). These inflammatory side effects are of unclear etiology and impact virtually all organ systems, with the most common being sites colonized by the microbiota such as the skin and gastrointestinal tract. Here, we establish a mouse model of commensal bacteria-driven skin irAEs and demonstrate that immune checkpoint inhibition unleashes commensal-specific inflammatory T cell responses. These aberrant responses were dependent on production of IL-17 by commensal-specific T cells and induced pathology that recapitulated the cutaneous inflammation seen in patients treated with ICIs. Importantly, aberrant T cell responses unleashed by ICIs were sufficient to perpetuate inflammatory memory responses to the microbiota months following the cessation of treatment. Altogether, we have established a mouse model of skin irAEs and reveal that ICIs unleash aberrant immune responses against skin commensals, with long-lasting inflammatory consequences.

Text Messages to Improve Medication Adherence and Secondary Prevention After Acute Coronary Syndrome: The TEXTMEDS Randomized Clinical Trial.

BACKGROUND: TEXTMEDS (Text Messages to Improve Medication Adherence and Secondary Prevention After Acute Coronary Syndrome) examined the effects of text message-delivered cardiac education and support on medication adherence after an acute coronary syndrome. METHODS: TEXTMEDS was a single-blind, multicenter, randomized controlled trial of patients after acute coronary syndrome. The control group received usual care (secondary prevention as determined by the treating clinician); the intervention group also received multiple motivational and supportive weekly text messages on medications and healthy lifestyle with the opportunity for 2-way communication (text or telephone). The primary end point of self-reported medication adherence was the percentage of patients who were adherent, defined as >80% adherence to each of up to 5 indicated cardioprotective medications, at both 6 and 12 months. RESULTS: A total of 1424 patients (mean age, 58 years [SD, 11]; 79% male) were randomized from 18 Australian public teaching hospitals. There was no significant difference in the primary end point of self-reported medication adherence between the intervention and control groups (relative risk, 0.93 [95% CI, 0.84-1.03]; P=0.15). There was no difference between intervention and control groups at 12 months in adherence to individual medications (aspirin, 96% vs 96%; ß-blocker, 84% vs 84%; angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, 77% vs 80%; statin, 95% vs 95%; second antiplatelet, 84% vs 84% [all P>0.05]), systolic blood pressure (130 vs 129 mm Hg; P=0.26), low-density lipoprotein cholesterol (2.0 vs 1.9 mmol/L; P=0.34), smoking (P=0.59), or exercising regularly (71% vs 68%; P=0.52). There were small differences in lifestyle risk factors in favor of intervention on body mass index <25 kg/m2 (21% vs 18%; P=0.01), eating ≥5 servings per day of vegetables (9% vs 5%; P=0.03), and eating ≥2 servings per day of fruit (44% vs 39%; P=0.01). CONCLUSIONS: A text message-based program had no effect on medical adherence but small effects on lifestyle risk factors. REGISTRATION: URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=364448; Unique identifier: ANZCTR ACTRN12613000793718.

Long-term antibiotic exposure promotes mortality after systemic fungal infection by driving lymphocyte dysfunction and systemic escape of commensal bacteria.

Antibiotics are a modifiable iatrogenic risk factor for the most common human nosocomial fungal infection, invasive candidiasis, yet the underlying mechanisms remain elusive. We found that antibiotics enhanced the susceptibility to murine invasive candidiasis due to impaired lymphocyte-dependent IL-17A- and GM-CSF-mediated antifungal immunity within the gut. This led to non-inflammatory bacterial escape and systemic bacterial co-infection, which could be ameliorated by IL-17A or GM-CSF immunotherapy. Vancomycin alone similarly enhanced the susceptibility to invasive fungal infection and systemic bacterial co-infection. Mechanistically, vancomycin reduced the frequency of gut Th17 cells associated with impaired proliferation and RORγt expression. Vancomycin's effects on Th17 cells were indirect, manifesting only in vivo in the presence of dysbiosis. In humans, antibiotics were associated with an increased risk of invasive candidiasis and death after invasive candidiasis. Our work highlights the importance of antibiotic stewardship in protecting vulnerable patients from life-threatening infections and provides mechanistic insights into a controllable iatrogenic risk factor for invasive candidiasis.

Myocardial perfusion imaging failed to improve patient risk classification compared with the revised cardiac risk index for early cardiac complications after major non-cardiac surgery.

BACKGROUND: Myocardial perfusion imaging (MPI) is frequently used for cardiac risk assessment before major non-cardiac surgery, but its ability to improve patient risk classification beyond simple clinical assessment is unknown. AIM: To explore the prognostic utility of MPI above a simple clinical risk calculator, the revised cardiac risk index (RCRI). METHODS: A retrospective cohort study of at-risk patients who underwent MPI before major non-cardiac surgery in a tertiary hospital was conducted. Major adverse cardiac events (MACE) was defined as any myocardial infarction, acute pulmonary oedema, ventricular arrhythmia or cardiac death within 30 days of surgery. We analysed the predictive value of MPI for MACE using multivariable logistic regression and categorical net reclassification index. RESULTS: MACE occurred in 47 (7.4%) cases from 635 surgical procedures in 629 patients. MPI-identified medium or large-sized reversible perfusion defects (P = 0.02; odds ratio 2.9; 95% confidence interval 1.1-7.1) and RCRI score two or more (P = 0.03; odds ratio 2.3; 95% confidence interval 1.1-4.8) were significantly associated with MACE after adjusting for age, coronary revascularisation, surgical priority, need for general anaesthesia, left ventricular ejection fraction (LVEF) and fixed perfusion defects. MPI risk factors (LVEF, reversible perfusion and fixed perfusion defects) did not improve risk classification above baseline risk factors (age, RCRI and surgical priority). CONCLUSION: MPI risk factors are weak predictors for early cardiac complications after major non-cardiac surgery and failed to improve patient risk classification beyond essential assessment using age, RCRI and surgical priority. Clinicians should consider alternative risk assessment strategies because of MPI's poor prognostic utility and its associated time and financial costs.

Cardiac risk assessment with the Revised Cardiac Risk Index index before elective non-cardiac surgery: A retrospective audit from an Australian tertiary hospital.

Clinicians assessing cardiac risk as part of a comprehensive consultation before surgery can use an expanding set of tools, including predictive risk calculators, cardiac stress tests and measuring serum natriuretic peptides. The optimal assessment strategy is unclear, with conflicting international guidelines. We investigated the prognostic accuracy of the Revised Cardiac Risk Index for risk stratification and cardiac outcomes in patients undergoing elective non-cardiac surgery in a contemporary Australian cohort.We audited the records for 1465 consecutive patients 45 years and older presenting to the perioperative clinic for elective non-cardiac surgery in our tertiary hospital. We calculated individual Revised Cardiac Risk Index scores and documented any use of preoperative cardiac tests. The primary outcome was any major adverse cardiac events within 30 days of surgery, including myocardial infarction, pulmonary oedema, complete heart block or cardiac death.Myocardial perfusion imaging was the most common preoperative stress test (4.2%, 61/1465). There was no routine investigation of natriuretic peptide levels for cardiac risk assessment before surgery. Major adverse cardiac events occurred in 1.3% (18/1366) of patients who had surgery. The Revised Cardiac Risk Index score had modest prognostic accuracy for major cardiac complications, area under receiver operator curve 0.73, 95% confidence interval 0.60 to 0.86. Stratifying major adverse cardiac events by the Revised Cardiac Risk Index scores 0, 1, 2 and 3 or greater corresponded to event rates of 0.6% (4/683), 0.8% (4/488), 4.1% (6/145) and 8.0% (4/50), respectively.The Revised Cardiac Risk Index had only modest predictive value in our single-centre experience. Patients with a revised cardiac risk index score of 2 or more had an elevated risk of early cardiac complications after elective non-cardiac surgery.

Video assisted, transaortic removal of left ventricular thrombus during concurrent cardiac surgery: a case report.

INTRODUCTION: Left ventricular (LV) thrombus is a complication of acute myocardial infarction and is associated with systemic thromboembolism. We describe a trans-aortic endoscopic approach to the removal of an LV thrombus in a patient undergoing concurrent coronary artery bypass grafting and aortic valve replacement. CASE PRESENTATION: A 47 year old male presented following an embolic middle cerebral artery stroke and underwent transthoracic echocardiography demonstrating a mobile LV thrombus. Additional investigation revealed a moderately stenosed bicispid aortic valve, two vessel coronary artery disease and ischemic cardiomyopathy. The patient underwent early surgery to reduce the risk of further embolic episodes. A trans-aortic approach was utilized with videoscopy and single shafted instrumentation to aide in removal of the thrombus. The patient then underwent aortic valve replacement and coronary artery bypass grafting. CONCLUSION: We report an alternative technique for the removal of a left ventricular thrombus in a patient undergoing concurrent coronary and aortic valve surgery. The transaortic video-assisted approach provided excellent visualisation of the apex and near complete removal of the thrombus without damaging the surrounding trabeculae. The main benefit of this technique is sparing of LV tissue, thereby preserving left ventricular function.

Natural history and prognostic implications of left ventricular end-diastolic pressure in reperfused ST-segment elevation myocardial infarction: an analysis of the thrombolysis in myocardial infarction (TIMI) II randomized controlled trial.

BACKGROUND: The aim of the current study is to assess the natural history and prognostic value of elevated left ventricular end-diastolic pressure (LVEDP) in patients with ST-segment elevation myocardial infarction (STEMI) after reperfusion with thrombolysis; we utilize data from the Thrombolysis in Myocardial Infarction (TIMI) II study. METHODS: A total of 3339 patients were randomized to either an invasive (n = 1681) or a conservative (n = 1658) strategy in the TIMI II study following thrombolysis. To make the current cohort as relevant as possible to modern pharmaco-invasively managed cohorts, patients in the invasive arm with TIMI flow grade ≥ 2 (N = 1201) at initial catheterization are included in the analysis. Of these, 259 patients had a second catheterization prior to hospital discharge, and these were used to define the natural history of LVEDP in reperfused STEMI. RESULTS: The median LVEDP for the whole cohort was 18 mmHg (IQR: 12-23). Patients were divided into quartiles by LVEDP measured during the first cardiac catheterization. During a median follow up of 3 (IQR: 2.1-3.2) years, quartile 4 (highest LVEDP) had the highest incidence of mortality and heart failure admissions. In the cohort with paired catheterization data, the LVEDP dropped slightly from 18 mmHg (1QR: 12-22) to 15 mmHg (IQR: 10-20) (p = 0.01) from the first to the pre-hospital discharge catheterization. CONCLUSIONS: LVEDP remains largely stable during hospitalisation post-STEMI. Elevated LVEDP is a predictor of death and heart failure hospitalization in STEMI patients undergoing successful thrombolysis.

Impact of Delay in Surgery on Outcome in Patients Undergoing Cardiac Revascularisation Surgery.

BACKGROUND: Diagnosis of critical coronary artery disease, including after acute coronary syndrome presentation (ACS), represents an important indication for early coronary artery bypass graft (CABG) surgery. The study aims to investigate the influence of time from diagnosis to CABG on outcomes and document barriers to early revascularisation. METHODS: All patients 18 years and older with an acute presentation due to ACS or critical coronary artery disease who were considered to require urgent inpatient cardiac surgery between January 2016-February 2019 were included in the study. The primary endpoints were 30-day all-cause mortality or readmission, 1-year all-cause mortality, all-cause readmission. The secondary endpoint was the rate of complications while waiting for surgery. The time duration between diagnostic coronary angiography and surgery was considered as the time interval. RESULTS: Of 266 eligible patients, 251 underwent surgical revascularisation with 15 (6%) not undergoing surgery due to preoperative complications (n=12) or due to perceived prohibitively high surgical risk (n=3). The majority (85%) were male (mean age 67 years), 37% of patients had diabetes and 71% had hypertension. Non-ST elevation myocardial infarction was documented in 51% of the patients. The median time between diagnosis and inpatient CABG was 7 days (IQR 5-11). Thirty-five per cent (35%) of patients experienced complications while awaiting surgery. Of the 266 patients, 140 patients (53% - cohort 1) underwent surgery within 7 days. The cohort 1 rate of complications was lower than in cohort 2 (surgery after 7 days) (24 vs 47%, p<0.001). Moreover, 1-year mortality was less in cohort 1 (2 vs 8%, p=0.029). CONCLUSION: In patients requiring urgent inpatient CABG, delay for more than 7 days is associated with a higher rate of in-hospital complications and worse 30 day and 12-month outcomes.

Dietary Regulation of Memory T Cells.

Memory T cells are a fundamental component of immunological memory, providing rapid and potent host protection against secondary challenges. As such, memory T cells are key targets in the design of vaccination strategies and cancer immunotherapies, making it critical to understand the factors and mechanisms that regulate their biology. Diet is an environmental feature that impacts virtually all aspects of host physiology. However, the influence of specific dietary regiments and nutritional components on the immune system is only just starting to be uncovered. This article will review literature regarding the impact of diet and nutrition on memory T cell development, maintenance and function. It was recently shown that caloric restriction without undernutrition enhances memory T cell function, while diets high in fiber are also beneficial. However, memory T cell responses are dysfunctional in extreme nutritional states, such as undernutrition and diet-induced obesity. Therefore, diet and host nutritional status are major regulators of memory T cell biology and host fitness. To define the dietary balance required to promote optimal memory T cell responses could allow for the implementation of rational diet-based therapies that prevent or treat disease. Furthermore, that certain dietary regiments can enhance memory T cell function indicates the possibility of harnessing the underlying mechanisms in the design of novel vaccination strategies and cancer immunotherapies.

The Bone Marrow Protects and Optimizes Immunological Memory during Dietary Restriction.

Mammals evolved in the face of fluctuating food availability. How the immune system adapts to transient nutritional stress remains poorly understood. Here, we show that memory T cells collapsed in secondary lymphoid organs in the context of dietary restriction (DR) but dramatically accumulated within the bone marrow (BM), where they adopted a state associated with energy conservation. This response was coordinated by glucocorticoids and associated with a profound remodeling of the BM compartment, which included an increase in T cell homing factors, erythropoiesis, and adipogenesis. Adipocytes, as well as CXCR4-CXCL12 and S1P-S1P1R interactions, contributed to enhanced T cell accumulation in BM during DR. Memory T cell homing to BM during DR was associated with enhanced protection against infections and tumors. Together, this work uncovers a fundamental host strategy to sustain and optimize immunological memory during nutritional challenges that involved a temporal and spatial reorganization of the memory pool within "safe haven" compartments.

Ibrutinib-related atrial fibrillation: A single center Australian experience.

BACKGROUND: Ibrutinib increases the risk of atrial fibrillation (AF) and is associated with bleeding tendencies. Reported rates of arrhythmia are variable in different studies. The aim of the current analysis was to evaluate the incidence of AF in a single-center cohort of patients. METHODS: This analysis was conducted at Hunter New England Local Health District, Australia between April 1, 2015 and June 30, 2017. We included all consecutive patients commenced on ibrutinib for hematological malignancies. Patients with a history of paroxysmal AF were excluded. The primary end point was incidence of AF. Time to diagnosis and management were secondary outcomes of interest. RESULTS: A total of 24 patients (age 73 ± 9 years, males n = 16 [67%]) were commenced on ibrutinib treatment during the study period with chronic lymphocytic leukemia (n = 21, 88%) as the main indication. During a median follow-up of 12 months, four (17%) patients were diagnosed with AF with increasing age, duration of ibrutinib treatment as associations. The median time to AF diagnosis was 9 (interquartile range [IQR]: 7-18) months. All patients were managed with a rate control strategy with beta blockers as the preferred agents. Three (75%) patients were commenced on anticoagulation for stroke prevention. During a follow-up of 18 (IQR: 17-23) months following AF onset, one patient required hospitalization for AF. There were no bleeding complications reported. CONCLUSIONS: In conclusion, this series noted a higher incidence of AF than previously reported. Oncologists and cardiologists need to be aware of the increased risk of AF in patients receiving ibrutinib.

Contemporary Management of Coronary Artery Perforation.

While coronary artery perforation remains an uncommon complication of percutaneous coronary intervention, appropriate recognition, early stabilisation and definitive treatment are essential. The immediate goals are to prevent progressive haemodynamic deterioration complicating cardiac tamponade, avoid the need for surgical intervention and limit accompanying mortality. Understanding the role and utility of newer devices that may influence procedural planning and improve procedural results when these complications occur is essential to minimise morbidity and mortality.