e13002 Background: Despite improvement in survival in breast cancer patients from advanced therapies, rates of chemotherapy-induced cardiotoxicity manifesting as a decline in left ventricular ejection fraction (LVEF) have offset some of these benefits in patients receiving anthracycline-based chemotherapy followed by trastuzumab. Results suggesting clinical biomarkers predict cardiotoxicity are inconsistent. Recently, expression of angiotensin II type 1 receptor (ATR1) and endothelin 1 (ET1) has shown to play a role in breast tumor growth. We sought to evaluate whether the presence of ATR1 and ET1 in breast cancer tissue using immunohistochemistry (IHC) and qRT-PCR can predict chemotherapy-induced cardiotoxicity. Methods: We hypothesized that elevated expression of ATR1 and ET1 in tumor tissue is associated with chemotherapy-induced cardiotoxicity (LVEF < 50%) compared to tissue from controls. Preliminarily, 34 paraffin-embedded breast tissue specimens from women with breast cancer treated with anthracycline-based chemotherapy and trastuzumab were retrieved for analysis. IHC and qRT-PCR for expression of ATR1 and ET1 was performed on all specimens. Results: We found that ET1 expression was significantly increased in patients with an LVEF < 50%. In addition, we noted the lower the LVEF, the higher the ET1 expression (p = 0.03). We also found patients with a change in LVEF of greater than 10% had more ET1 expression compared to those without a change in LVEF (p = 0.05). We did not find a significant relationship between ATR1 and LVEF. Conclusions: Increased ET1 expression in breast tumor tissue may predict cardiotoxicity. Our findings may aid in future research using novel biomarkers to predict breast cancer patients at risk for developing chemotherapy-induced cardiotoxicity. In addition, targeted therapies to these biomarkers may potentially help prevent the development of cardiotoxicity.
2418Th17 signature, autoimmunity and differentially expressed genes in cardiomyopathy and heart failure
Abstract Background Cardiomyopathy may occur due to viral infections or drug induced heart damage. Cardiac myosin released from damaged heart has been shown to be a damage associated molecular pattern which binds to TLR2 or TLR8 and can act as an adjuvant to induce a strong autoimmune response against the heart. The result is autoimmunity against the heart which can lead to apoptosis, fibrosis and heart failure. Purpose Immune biomarkers of the early stages of heart failure are needed to identify individuals who develop progressive heart failure, do not recover their ejection fraction and may be candidates for immunotherapies. Methods Forty-one patients with myocarditis and heart failure <6 months after onset were followed for 12 months and compared to age matched controls. Peripheral blood mononuclear cells were analyzed by FACS analysis and serum analyzed by ELISA for autoantibodies and cytokines. Statistical analysis was determined by Mann Whitney test. Peripheral blood of 10 patients with dilated cardiomyopathy (DCM) vs 19 healthy controls were analyzed for gene expression by RNA sequencing and pathway analysis using Reactome. Results Autoantibodies against human cardiac myosin and the beta-adrenergic receptor were significantly elevated in our cohort and functionally acted on cardiomyocytes to activate protein kinase A. Concomitantly, a Th17+ immunophenotype was significantly elevated in blood as well as in cardiac biopsies. CD4+IL17+ T cells (p=0.0008) and Th17-promoting cytokines TGF beta (p<0.0001), IL-6 (p<0.0001), IL-23 (p=0.0001), GMCSF (p=0.0336) and GMCSF-secreting CD4+ T cells (p=0.0006) were significantly elevated in blood. A Th17 immunophenotype was significantly associated with heart failure primarily in males (p=0.029). Persistent heart failure (NYHA class III and IV) and non-recovery of left ventricular function were associated with significantly higher percentages of IL17A-producing T cells at baseline, 6 and 12 months after onset, and IL-17A (p=0.019) and elevated Th17-promoting cytokines IL-6 (p=0.0001) and TGF-beta (p=0.0076). Decreased T regulatory immunosuppressive cells were significantly (p=0.0006) decreased and correlated with elevated Th17 cytokines in heart failure. Overrepresentation analysis of differentially expressed genes (adj p<0.05) in blood of patients with DCM >1year were identified using Reactome which revealed significant (FDR = 1.52E-13) enrichment of neutrophil degranulation (48 genes). Conclusion Our study illustrates a strong Th17 signature in more severe heart failure early in disease with elevated anti-cardiac myosin autoantibodies in non-recovery of left ventricular function. We observed a strong correlation with Th17-related neutrophil degranulation pathways in later disease, which may be biomarkers of fibrosis progression and disease severity in patients with heart failure. Cardiomyopathy with a Th17 signature might be treated with preventive immunomodulatory therapies such as anti-IL17A. Acknowledgement/Funding National Heart Lung and Blood Institute, Bethesda, MD, USA
Sex Differences in Nonalcoholic Fatty Liver Disease: State of the Art and Identification of Research Gaps
Despite tremendous research advancements in nonalcoholic fatty liver disease (NAFLD), our understanding of sex differences in NAFLD remains insufficient. This review summarizes the current knowledge on sex differences in NAFLD, identifies gaps, and discusses important considerations for future research. The prevalence and severity of NAFLD are higher in men than in women during the reproductive age. However, after menopause, NAFLD occurs at a higher rate in women, suggesting that estrogen is protective. Sex differences also exist for the major risk factors of NAFLD. In general, animal models of NAFLD recapitulate the sex differences observed in patients, with more severe steatosis and steatohepatitis, more proinflammatory/profibrotic cytokines, and a higher incidence of hepatic tumors in male than female subjects. Based on computer modeling, female and male livers are metabolically distinct with unique regulators modulating sex‐specific metabolic outcomes. Analysis of the literature reveals that most published clinical and epidemiological studies fail to examine sex differences appropriately. Considering the paucity of data on sex differences and the knowledge that regulators of pathways relevant to current therapeutic targets for NAFLD differ by sex, clinical trials should be designed to test drug efficacy and safety according to sex, age, reproductive stage (i.e., menopause), and synthetic hormone use. Conclusion: Sex differences do exist in the prevalence, risk factors, fibrosis, and clinical outcomes of NAFLD, suggesting that, while not yet incorporated, sex will probably be considered in future practice guidelines; adequate consideration of sex differences, sex hormones/menopausal status, age, and other reproductive information in clinical investigation and gene association studies of NAFLD are needed to fill current gaps and implement precision medicine for patients with NAFLD.
Abstract 386: Sex Differences in Vitamin D Alter Inflammation During Heart Disease
An estimated 1 billion people worldwide have deficient or insufficient levels of vitamin D (VitD). Considerable evidence indicates that VitD deficiency is associated with an increased risk of autoimmune and cardiovascular disease (CVD), yet it remains unclear whether low VitD is simply a biomarker or has a true pathologic role. In this study we examined how sex differences in VitD influences various CVDs. We found that patients with CVD had significantly lower VitD than healthy controls (no ICD9/10 codes). In myocarditis patients low VitD correlated to poor ejection fraction (EF) in women with myocarditis (p=0.02), but high VitD correlated with low EF in men (p=0.04). In VDR knockout mice we found that VDR decreased myocarditis in females (p=2E-8) but increased inflammation in males (p=0.03) with an increase in total immune cells (p=0.02), CD3, CD4 and CD8 T cells (p=0.04), and the inflammasome in females. VDR altered Treg (p=0.04), mast cells (p=0.04) and cytokine profiles in males. Additionally, sera VitD levels were significantly higher in WT male mice with myocarditis compared to females. Our findings in VDR mice indicate that VitD/VDR reduces myocarditis in females, but increases disease in males. These data suggest that VitD sufficiency may increase inflammation in men, while VitD deficiency may make disease worse in women. These findings suggest that Vitamin D may have a role in the pathogenesis of inflammatory and cardiovascular disease.
Self-reactive CD4+ IL-3+ T cells amplify autoimmune inflammation in myocarditis by inciting monocyte chemotaxis
Acquisition of self-reactive effector CD4+ T cells is a major component of the autoimmune response that can occur during myocarditis, an inflammatory form of cardiomyopathy. Although the processes by which self-reactive T cells gain effector function have received considerable attention, how these T cells contribute to effector organ inflammation and damage is less clear. Here, we identified an IL-3–dependent amplification loop that exacerbates autoimmune inflammation. In experimental myocarditis, we show that effector organ–accumulating autoreactive IL-3+ CD4+ T cells stimulate IL-3R+ tissue macrophages to produce monocyte-attracting chemokines. The newly recruited monocytes differentiate into antigen-presenting cells that stimulate local IL-3+ CD4+ T cell proliferation, thereby amplifying organ inflammation. Consequently, Il3−/− mice resist developing robust autoimmune inflammation and myocardial dysfunction, whereas therapeutic IL-3 targeting ameliorates disease. This study defines a mechanism that orchestrates inflammation in myocarditis, describes a previously unknown function for IL-3, and identifies IL-3 as a potential therapeutic target in patients with myocarditis.
Elevated Sera sST2 Is Associated With Heart Failure in Men ≤50 Years Old With Myocarditis
Background Myocarditis is an important cause of acute and chronic heart failure. Men with myocarditis have worse recovery and an increased need for transplantation compared with women, but the reason for the sex difference remains unclear. Elevated sera soluble (s) ST 2 predicts mortality from acute and chronic heart failure, but has not been studied in myocarditis patients. Methods and Results Adults with a diagnosis of clinically suspected myocarditis (n=303, 78% male) were identified according to the 2013 European Society of Cardiology position statement. Sera sST 2 levels were examined by ELISA in humans and mice and correlated with heart function according to sex and age. Sera sST 2 levels were higher in healthy men ( P =8×10 −6 ) and men with myocarditis ( P =0.004) compared with women. sST 2 levels were elevated in patients with myocarditis and New York Heart Association class III ‐ IV heart failure ( P =0.002), predominantly in men ( P =0.0003). Sera sST 2 levels were associated with New York Heart Association class in men with myocarditis who were ≤50 years old ( r =0.231, P =0.0006), but not in women ( r =0.172, P =0.57). Sera sST 2 levels were also significantly higher in male mice with myocarditis ( P =0.005) where levels were associated with cardiac inflammation. Gonadectomy with hormone replacement showed that testosterone ( P <0.001), but not estradiol ( P =0.32), increased sera sST 2 levels in male mice with myocarditis. Conclusions We show in a well‐characterized subset of heart failure patients with clinically suspected and biopsy‐confirmed myocarditis that elevated sera sST 2 is associated with an increased risk of heart failure based on New York Heart Association class in men ≤50 years old.
Sex Determines Cardiac Myocyte Stretch and Relaxation
In human myocarditis and its sequela dilated cardiomyopathy (DCM), the mechanisms and immune phenotype governing disease and subsequent heart failure are not known. Here, we identified a Th17 cell immunophenotype of human myocarditis/DCM with elevated CD4 + IL17 + T cells and Th17-promoting cytokines IL-6, TGF-β, and IL-23 as well as GM-CSF–secreting CD4 + T cells. The Th17 phenotype was linked with the effects of cardiac myosin on CD14 + monocytes, TLR2, and heart failure. Persistent heart failure was associated with high percentages of IL-17–producing T cells and IL-17–promoting cytokines, and the myocarditis/DCM phenotype included significantly low percentages of FOXP3 + Tregs, which may contribute to disease severity. We demonstrate a potentially novel mechanism in human myocarditis/DCM in which TLR2 peptide ligands from human cardiac myosin stimulated exaggerated Th17-related cytokines including TGF-β, IL-6, and IL-23 from myocarditic CD14 + monocytes in vitro, and an anti-TLR2 antibody abrogated the cytokine response. Our translational study explains how an immune phenotype may be initiated by cardiac myosin TLR ligand stimulation of monocytes to generate Th17-promoting cytokines and development of pathogenic Th17 cells in human myocarditis and heart failure, and provides a rationale for targeting IL-17A as a therapeutic option.
Biomarker and More: Can Translocator Protein 18 kDa Predict Recovery from Brain Injury and Myocarditis?