An Automated System for Categorizing Transthoracic Echocardiography Indications According to the Echocardiography Appropriate Use Criteria

The Echocardiography Appropriate Use Criteria (EAUC) are a set of indications for transthoracic echocardiography (TTE) developed to guide physician decision making around ordering of TTE. In this study, an automated rule-based method for processing "indications" listed within TTE reports and classification into one of the major EAUC categories was developed and validated against a clinician-annotated reference standard. The system performed at a comparable level to trained physicians allowing for the automated classification of more than 30,000 TTE indications from a public database in less than ten minutes. The most common indication for TTE was Valvular assessment closely followed by General. Hypertension/Heart Failure/Cardiomyopathy, Acute, and Cardiac Structure assessment each contributed more than ten percent within this patient population. These results suggest potential for automated approaches for tracking appropriate use of TTE, as well as guide the development of systems for prospectively identifying when TTE use is recommended.

2017 ACC Expert Consensus Decision Pathway on the Management of Mitral Regurgitation: A Report of the American College of Cardiology Task Force on Expert Consensus Decision Pathways

Mitral regurgitation (MR) is a complex valve lesion that can pose significant management challenges for the cardiovascular clinician. This Expert Consensus Document emphasizes that recognition of MR should prompt an assessment of its etiology, mechanism, and severity, as well as indications for treatment. A structured approach to evaluation based on clinical findings, precise echocardiographic imaging, and when necessary, adjunctive testing, can help clarify decision making. Treatment goals include timely intervention by an experienced heart team to prevent left ventricular dysfunction, heart failure, reduced quality of life, and premature death.

The Supply and Demand of the Cardiovascular Workforce: Striking the Right Balance

As the burden of cardiovascular disease in the United States continues to increase, uncertainty remains on how well-equipped the cardiovascular workforce is to meet the challenges that lie ahead. In a time when health care is rapidly shifting, numerous factors affect the supply and demand of the cardiovascular workforce. This Council Commentary critically examines several factors that influence the cardiovascular workforce. These include current workforce demographics and projections, evolving health care and practice environments, and the increasing burden of cardiovascular disease. Finally, we propose 3 strategies to optimize the workforce. These focus on cardiovascular disease prevention, the effective utilization of the cardiovascular care team, and alterations to the training pathway for cardiologists.

Memory cells specific for myelin oligodendrocyte glycoprotein (MOG) govern the transfer of experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is an inflammatory disease of the CNS mediated by CD4(+) T cells directed against myelin antigens. Experimental autoimmune encephalomyelitis (EAE) is induced by immunization with myelin antigens like myelin oligodendrocyte glycoprotein (MOG). We have explored the transfer of EAE using MOG(35-55)-specific TCR transgenic (2D2) T cells. Unsorted 2D2 Th1 cells reliably transferred EAE. Further, we found that CD44(hi)CD62L(lo) effector/memory CD4(+) T cells are likely responsible for the disease transfer due to the up-regulation of CD44. Given the importance of MOG in MS pathogenesis, mechanistic insights into adoptively transferred EAE by MOG-specific Th1 cells could prove valuable in MS research.

A small-molecule inhibitor of macrophage migration inhibitory factor for the treatment of inflammatory disease

Multiple sclerosis (MS) is a chronic, debilitating disease of the central nervous system (CNS) characterized by demyelination and axon loss. The proinflammatory cytokine macrophage migration inhibitory factor (MIF) has been shown to be elevated in the cerebrospinal fluid of patients during relapses. The purpose of this study was to evaluate a new small-molecule inhibitor of MIF and its ability to reduce the severity of an animal model of MS, experimental autoimmune encephalomyelitis (EAE). We utilized 2 structurally related isoxazolines, which show in vitro inhibition of MIF tautomerase activity. We found that administration of an inhibitor of MIF to mice with established EAE immediately reduced the severity of clinical signs and expanded a population of regulatory T lymphocytes. We also noted that the inhibitor reduced relapses of disease in a relapsing/remitting model of EAE. An analysis of leukocyte migration into the brain revealed that administration of inhibitor reduced entry of these cells. No effects on inflammatory cytokine production or T-cell activation in the periphery were noted. From these studies, we conclude that a small-molecule inhibitor of MIF reduces the severity of EAE and prevents access of immune cells into the CNS, which could be of therapeutic relevance to MS.

Macrophage migration inhibitory factor and the regulation of adhesion molecule expression on the blood brain barrier during experimental autoimmune encephalomyelitis (94.15)

Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disease of the central nervous system (CNS). Cerebrospinal fluid (CSF) isolated from patients during relapse was found to contain greater levels of macrophage migration inhibitory factor (MIF) relative to samples collected during remission, thus suggesting a role for MIF in the pathogenesis of MS. We have demonstrated that upon induction of experimental autoimmune encephalomyelitis (EAE), mice deficient in MIF exhibit reduced clinical signs as well as fewer inflammatory infiltrates in the brain and spinal cord. MIF deficient mice, however, do not differ from wild type controls in the function of autoreactive lymphocytes in the periphery. These findings suggest that MIF is necessary for progression of EAE in the CNS, particularly at the level of the blood brain barrier (BBB). Mice treated with anti-MIF antibody show impaired migration of lymphocytes into the CNS and down-regulation of adhesion molecules on the BBB. Thus, we hypothesize that MIF is acting at the level of the BBB, regulating adhesion molecule expression and therefore access to the CNS. We are analyzing the expression of adhesion molecules, such as VCAM-1 and ICAM-1 in the brain and spinal cord of MIF deficient and small molecule inhibitor-treated mice. (Supported by NIH grant AI 064320 and National MS Society grant RG3272)

A critical mediator of leukocyte extravasation during inflammatory disease (50.8)

Multiple sclerosis (MS) is a demyelinating neurological disease affecting more than 400,000 Americans. MS pathology involves activation of autoreactive lymphocytes and their migration across the blood-brain barrier (BBB) into the central nervous system (CNS). MS patients have a higher level of the ubiquitously expressed, proinflammatory cytokine MIF. Mice lacking MIF have fewer leukocytes in the CNS following induction of experimental autoimmune encephalomyelitis (EAE), an animal model for MS. We found using bone marrow chimeras that mice expressing MIF from myeloid cells had significantly more severe disease than MIF KO mice or mice expressing MIF only in non-myeloid cells (CDI±SD; 28.0±17.9 vs. 10.3±17.9 or 4.7±10.4). Using immunohistochemistry, we found more infiltrates in the CNS of mice expressing MIF from myeloid cells. We utilized a small molecule inhibitor of MIF to evaluate whether disruption of MIF activity could inhibit migration of leukocytes. Mice had reduced severity of EAE following inhibitor administration and reduced migration of leukocytes into the CNS. Other groups have shown that blocking MIF reduces expression of adhesion molecules on the BBB. Our data suggests that during inflammatory disease, MIF from myeloid cells is critical for leukocyte migration and an inhibitor of MIF reduces migration and subsequent clinical disease. (Supported by NIH grant AI 064320 and NMSS grant RG3272)

Disease-modifying capability of murine Flt3-ligand DCs in experimental autoimmune encephalomyelitis

Dendritic cells (DCs) bridge the innate and adaptive immune response, are uniquely capable of priming naïve T cells, and play a critical role in the initiation and regulation of autoimmune and immune-mediated disease. At present, in vivo expansion of DC populations is accomplished primarily through the administration of the recombinant human growth factor fms-like tyrosine kinase 3 ligand (hFL), and in vitro DCs are generated using cytokine cocktails containing GM-CSF +/- IL-4. Although hFL has traditionally been used in mice, differences in amino acid sequence and biological activity exist between murine FL (mFL) and hFL, and resultant DC populations differ in phenotype and immunoregulatory functional capabilities. This study developed and characterized mFL-generated DCs and determined the therapeutic capability of mFL DCs in the autoimmune disease experimental autoimmune encephalomyelitis (EAE). Our findings demonstrate that mFL and hFL expand splenic DCs equally in vivo but that mFL-expanded, splenic DCs more closely resemble normal, resting, splenic DCs. In addition, a novel method for generating mFL-derived bone marrow-derived DCs (BM-DCs) was developed, and comparison of mFL with hFL BM-DCs found mFL BM-DCs to be less mature (i.e., lower MHC Class II, CD80, and CD86) than hFL BM-DCs. These immature mFL DCs up-regulated costimulatory molecules in response to maturation stimuli LPS and TNF-alpha. Mature mFL BM-DCs were immunogenic and exacerbated the clinical disease course of EAE.

A novel approach to generating disease modifying dendritic cells (DCs) (129.13)

Dendritic cells (DCs) bridge the innate and adaptive immune responses and DC immunotherapy has shown promise in the treatment of transplantation, allergic and autoimmune diseases. One primary limitation in studying and utilizing DCs is their small numbers in vivo. While the growth factor Flt3-ligand (FL) is used to expand DCs in vivo, GM-CSF is predominantly used to generate DCs in vitro from bone marrow (BM-DC). The purpose of this study was to explore the use of murine FL (mFL), the mouse homologue of human FL, to generate DCs in vitro. In vivo (tumor-based) mFL delivery reliably expanded splenic DCs comparable to hFL In vitro BM-DCs generated with mFL were more similar to hFL than GM-CSF derived BM-DCs and appeared to be immature. Specifically, CD11c, CD11b and maturation markers CD80 and CD86 were lower in mFL and hFL versus GM-CSF BM-DCs. Maturation of mFL BM-DCs with TNF-α±LPS increased CD80, CD86 and CD40 expression. Transfer of matured mFL BM-DCs to mice prior to immunization with myelin oligodendrocyte glycoprotein (MOG35-55) significantly increased cumulative disease (26.79±10.12) and peak disease scores (3.07±1.16) compared to immature mFL BM-DCs (20.21 ±7.64 and 1.86±0.7, respectively). These results suggest that exposure to mFL in vitro is a novel method to generate large numbers of immature BM-DCs which can modulate the course of autoimmune disease.

(Support: NIH AI-43376, K01 R022198 and NMSS RG3272).

Late Pregnancy Serum Factors Suppress T Cell Activation in Experimental Autoimmune Encephalomyelitis (EAE) (42.14)

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the CNS thought to be due to an autoimmune response directed against myelin antigens. EAE is a commonly used animal model for MS and shares clinical, histopathologic and immunologic similarities with MS. Profound suppression of the MS and EAE relapse rate is observed during late pregnancy and is followed by a marked increase in disease severity postpartum. We have recently observed that histopathologic progression of EAE is diminished during late pregnancy and is exacerbated post partum. During EAE and late pregnancy, mice were found to have less mononuclear CNS infiltrates, demyelination and axon severing than virgin controls. The purpose of this study was to explore the hypothesis that decreased autoimmune disease during pregnancy is due to immunosuppressive factors present in the serum during late pregnancy. Female SJL/J mice were immunized for EAE using myelin proteolipid protein (PLP) 139–151. T cell proliferation assays were carried out using lymph node (LN) cells stimulated with PLP or anti-CD3 in the presence of 0–3% late pregnancy or virgin mouse sera. LN cells from age and gender matched naïve mice served as controls. Three percent late pregnancy serum suppressed both anti-CD3 and PLP stimulated T cell proliferation as compared to cells cultured with virgin mouse sera. These results demonstrate the broad suppressive potential of late pregnancy serum on T cell activation and may be responsible for amelioration of clinical signs of EAE during late pregnancy.

(Supported by NIH grants NS48316 and T32AI055411).

A distinct role for PI3Kgamma in suppressing the development and progression of experimental autoimmune encephalomyelitis (EAE) (129.30)

Phosphoinositide 3-kinases (PI3K) are intracellular signaling proteins involved in cellular responses such as chemotaxis, proliferation and apoptosis. Selective inhibitors of the PI3Kγ-isoform have recently become available. This study explores the role of PI3Kγ in the development and progression of EAE. PI3Kγ +/+ (wt) and PI3Kγ −/− (ko) mice were immunized for EAE using myelin oligodendrocyte glycoprotein p35-55 (MOG) and assessed for clinical signs, CNS histopathology and T cell activation. WT mice showed a progressive disease course with elevations in inflammatory cytokines increased CNS mononuclear infiltrates. In contrast, ko mice exhibited a delayed onset and dramatically less severe EAE course characterized by decreased T cell activation and inflammatory cytokines (TNF-α, IFN-γ, IL-2, IL-12p40, IL-6, IL-17 and MCP-1). Male ko mice were significantly more protected than ko females. Adoptive transfer of MOG-activated T cells into ko recipients show that ko mice are resistant to passive disease induction. Interestingly, wt recipients of ko donors immunized for EAE were also protected. Furthermore, adoptive transfer of activated GFP+ T cells show marked decreased infiltration of GFP+ T cells into the CNS. Taken together, these findingssuggest that depletion of PI3Kγ results in a down-regulation of the inflammatoryresponse caused by impaired trafficking of cells critical to generation of the immune response.

(Supported by NIH grant AI 064320 and National MS Society Grant RG 3272).

Migration inhibitory factor modulates experimental autoimmune encephalomyelitis through a novel combination of suppressive mediators (131.34)

Multiple sclerosis (MS), an autoimmune disease of the central nervous system (CNS), is more prevalent in women than men. Recent studies suggest that the cytokine migration inhibitory factor (MIF) plays a role in the progression of MS and experimental autoimmune encephalomyelitis (EAE). We have shown that MIF−/− mice have decreased EAE severity relative to wt controls. Here, we evaluate the role of MIF in the context of known suppressive hormones. Serum levels of corticosterone (CORT) and testosterone (TEST) were measured prior to and following EAE induction in the presence and absence of MIF. Basal levels of TEST in MIF−/− mice were notably higher than controls; basal levels of CORT were low and similar between groups. Following EAE, there was little change in CORT and TEST in wt mice; however, TEST decreased and CORT increased in MIF−/− mice following immunization. To evaluate the role of TEST, we removed the testes of male MIF−/− mice and induced EAE. We found no difference in disease severity whether MIF−/− mice were gonadectomized or not; control mice had significantly more severe EAE in the absence of TEST. These findings suggest that CORT plays a larger role than TEST in disease progression, although both hormones appear to be influenced by MIF. Further study of the mechanism of MIF could lead to improved therapies for a variety of autoimmune diseases.

(Supported by NIH grant AI 064320 and National MS Society grant RG3272)