Coronary stent migration to aorta with successful recovery during aortobifemoral bypass.

We present with full and proper consent of the patient, the case of a 64-year-old man with severe peripheral arterial disease and a known chronic infrarenal aortic occlusion causing severe short-distance claudication. Preoperative computed tomography angiography was significant for a new "cylindrical" calcified lesion. During the elective surgery, the lesion was confirmed to be a coronary stent. The coronary stent was confirmed to be from the patient's prior percutaneous coronary intervention to the left anterior descending artery 1 year prior. The stent was removed without complications by the surgical team. To the best of our knowledge, this is the first such case to be described in current literature. This patient is currently alive, and a revision of his left anterior descending artery intervention was found to be unwarranted on repeat coronary angiography.

Early Growth Response Gene Upregulation in Epstein-Barr Virus (EBV)-Associated Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic multisystem disease exhibiting a variety of symptoms and affecting multiple systems. Psychological stress and virus infection are important. Virus infection may trigger the onset, and psychological stress may reactivate latent viruses, for example, Epstein-Barr virus (EBV). It has recently been reported that EBV induced gene 2 (EBI2) was upregulated in blood in a subset of ME/CFS patients. The purpose of this study was to determine whether the pattern of expression of early growth response (EGR) genes, important in EBV infection and which have also been found to be upregulated in blood of ME/CFS patients, paralleled that of EBI2. EGR gene upregulation was found to be closely associated with that of EBI2 in ME/CFS, providing further evidence in support of ongoing EBV reactivation in a subset of ME/CFS patients. EGR1, EGR2, and EGR3 are part of the cellular immediate early gene response and are important in EBV transcription, reactivation, and B lymphocyte transformation. EGR1 is a regulator of immune function, and is important in vascular homeostasis, psychological stress, connective tissue disease, mitochondrial function, all of which are relevant to ME/CFS. EGR2 and EGR3 are negative regulators of T lymphocytes and are important in systemic autoimmunity.

Epstein-Barr virus (EBV) reactivation and therapeutic inhibitors.

Epstein-Barr virus (EBV) is a ubiquitous human virus which infects almost all humans during their lifetime and following the acute phase, persists for the remainder of the life of the individual. EBV infects B lymphocytes leading to their immortalisation, with persistence of the EBV genome as an episome. In the latent phase, EBV is prevented from reactivating through efficient cytotoxic cellular immunity. EBV reactivates (lytic phase) under conditions of psychological stress with consequent weakening of cellular immunity, and EBV reactivation has been shown to occur in a subset of individuals with each of a variety of cancers, autoimmune diseases, the autoimmune-like disease, chronic fatigue syndrome/myalgic encephalitis and under other circumstances such as being an inpatient in an intensive care unit. Chronic EBV reactivation is an important mechanism in the pathogenesis of many such diseases, yet is rarely tested for in immunocompetent individuals. This review summarises the pathogenesis of EBV infection, EBV reactivation and its role in disease, and methods which may be used to detect it. Known inhibitors of EBV reactivation and replication are discussed, including drugs licensed for treatment of other herpesviruses, licensed or experimental drugs for various other indications, compounds at an early stage of drug development and nutritional constituents such as vitamins and dietary supplements.

Epstein-Barr Virus Induced Gene-2 Upregulation Identifies a Particular Subtype of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis.

Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) is a chronic multisystem disease characterized by a variety of symptoms, and exhibits various features of an autoimmune-like disease. Subtypes are well recognized but to date are difficult to identify objectively. The disease may be triggered by infection with a variety of micro-organisms, including Epstein-Barr virus (EBV). A subset of CFS/ME patients exhibit up regulation of EBV virus induced gene 2 (EBI2) mRNA in peripheral blood mononuclear cells (PBMC), and these patients appear to have a more severe disease phenotype and lower levels of EBNA1 IgG. EBI2 is induced by EBV infection and has been found to be upregulated in a variety of autoimmune diseases. EBI2 is a critical gene in immunity and central nervous system function; it is a negative regulator of the innate immune response in monocytes. Its heterogeneous expression in CFS/ME could explain the variable occurrence of a variety of immune and neurological abnormalities which are encountered in patients with CFS/ME. The EBI2 subtype occurred in 38-55% CFS/ME patients in our studies. Further work is required to confirm the role of EBV and of EBI2 and its oxysterol ligands in CFS/ME, and to identify the most practical means to identify patients of the EBI subtype. There are two EBI2 antagonists currently in development, and these may hold promise in the treatment of CFS/ME patients of the EBI subtype.

MicroRNAs hsa-miR-99b, hsa-miR-330, hsa-miR-126 and hsa-miR-30c: Potential Diagnostic Biomarkers in Natural Killer (NK) Cells of Patients with Chronic Fatigue Syndrome (CFS)/ Myalgic Encephalomyelitis (ME).

BACKGROUND: Chronic Fatigue Syndrome (CFS/ME) is a complex multisystem disease of unknown aetiology which causes debilitating symptoms in up to 1% of the global population. Although a large cohort of genes have been shown to exhibit altered expression in CFS/ME patients, it is currently unknown whether microRNA (miRNA) molecules which regulate gene translation contribute to disease pathogenesis. We hypothesized that changes in microRNA expression in patient leukocytes contribute to CFS/ME pathology, and may therefore represent useful diagnostic biomarkers that can be detected in the peripheral blood of CFS/ME patients. METHODS: miRNA expression in peripheral blood mononuclear cells (PBMC) from CFS/ME patients and healthy controls was analysed using the Ambion Bioarray V1. miRNA demonstrating differential expression were validated by qRT-PCR and then replicated in fractionated blood leukocyte subsets from an independent patient cohort. The CFS/ME associated miRNA identified by these experiments were then transfected into primary NK cells and gene expression analyses conducted to identify their gene targets. RESULTS: Microarray analysis identified differential expression of 34 miRNA, all of which were up-regulated. Four of the 34 miRNA had confirmed expression changes by qRT-PCR. Fractionating PBMC samples by cell type from an independent patient cohort identified changes in miRNA expression in NK-cells, B-cells and monocytes with the most significant abnormalities occurring in NK cells. Transfecting primary NK cells with hsa-miR-99b or hsa-miR-330-3p, resulted in gene expression changes consistent with NK cell activation but diminished cytotoxicity, suggesting that defective NK cell function contributes to CFS/ME pathology. CONCLUSION: This study demonstrates altered microRNA expression in the peripheral blood mononuclear cells of CFS/ME patients, which are potential diagnostic biomarkers. The greatest degree of miRNA deregulation was identified in NK cells with targets consistent with cellular activation and altered effector function.

The role of parvovirus B19 in the pathogenesis of autoimmunity and autoimmune disease.

Human parvovirus B19 is a single-stranded DNA virus which preferentially targets the erythroblasts in the bone marrow. B19 infection commonly causes erythema infectiosum, arthralgia, fetal death, transient aplastic crisis in patients with shortened red cell survival, and persistent infection in people who are immunocompromised. Less common clinical manifestations include atypical skin rashes, neurological syndromes, cardiac syndromes, and various cytopenias. B19 infection has also been associated with development of a variety of different autoimmune diseases, including rheumatological, neurological, neuromuscular, cardiovascular, haematological, nephrological and metabolic. Production of a variety of autoantibodies has been demonstrated to occur during B19 infection and these have been shown to be key to the pathogenesis of the particular disease process in a significant number of cases, for example, production of rheumatoid factor in cases of B19-associated rheumatoid arthritis and production of anti-glutamic acid decarboxylase (GAD) in patients with B19-associated type 1 diabetes mellitus. B19 infection has also been associated with the development of multiple autoimmune diseases in 12 individuals. Documented mechanisms in B19-associated autoimmunity include molecular mimicry (IgG antibody to B19 proteins has been shown to cross react with a variety of recognised human autoantigens, including collagen II, keratin, angiotensin II type 1 receptor, myelin basic protein, cardiolipin, and platelet membrane glycoprotein IIb/IIIa), B19-induced apoptosis with presentation of self-antigens to T lymphocytes, and the phospholipase activity of the B19 unique VP1 protein.

A review of blood diseases and cytopenias associated with human parvovirus B19 infection.

Parvovirus B19 is a single-stranded DNA virus which preferentially targets the erythroblast resulting in red cell aplasia, which is temporary in immunocompetent persons. Since the discovery of B19 virus in 1975, a wide variety of blood diseases and cytopenias affecting several blood cell lineages have been documented during or following B19 infection. These include cytopenias affecting the erythroid, megakaryoblastoid, myeloid and lymphoid lineages, as well as a variety of bicytopenias, pancytopenia, bone marrow necrosis / fat embolism syndrome, myelodysplastic syndrome, leucoerythroblastopenia, and hemophagocytic lymphohistiocytosis. B19 infection may also complicate and precede the course of acute leukemia, the significance of which remains to be determined. This review describes the current state of knowledge of the abnormalities of individual blood cell lineages encountered during parvovirus B19 infection, over the almost 40 years since its discovery, and reveals some very interesting themes, which improve our understanding of the pathogenesis of B19 infection with particular reference to the bone marrow.

Increased prevalence of two mitochondrial DNA polymorphisms in functional disease: Are we describing different parts of an energy-depleted elephant?

About 20% of the population suffers from "functional syndromes". Since these syndromes overlap greatly in terms of co-morbidity, pathophysiology (including aberrant autonomic activity) and treatment responses, common predisposing genetic factors have been postulated. We had previously showed that two common mitochondrial DNA (mtDNA) polymorphisms at positions 16519 and 3010 are statistically associated with the functional syndromes of migraine, cyclic vomiting syndrome and non-specific abdominal pain. Herein, among individuals with mtDNA haplogroup H (HgH), the presence of these two mtDNA polymorphisms were ascertained in additional functional syndromes: chronic fatigue syndrome, complex regional pain syndrome, sudden infant death syndrome, and major depressive disorder. Polymorphic prevalence rates were compared between disease and control groups, and within each disease group in participants with and without specific clinical findings. In all four conditions, one or both of the polymorphisms was significantly associated with the respective condition and/or co-morbid functional symptomatology. Thus, we conclude that these two mtDNA polymorphisms likely modify risk for the development of multiple functional syndromes, likely constituting a proportion of the postulated common genetic factor, at least among individuals with HgH. Pathophysiology likely involves broad effects on the autonomic nervous system.

Idiotypic DNA vaccination for the treatment of multiple myeloma: safety and immunogenicity in a phase I clinical study.

We report on the safety and immunogenicity of idiotypic DNA vaccination in a phase I, non-randomised, open-label study in patients with multiple myeloma. The study used DNA fusion gene vaccines encoding patient-specific single chain variable fragment, or idiotype (Id), linked to fragment C (FrC) of tetanus toxin. Patients in complete or partial response following high-dose chemotherapy and autologous stem cell transplant were vaccinated intramuscularly with 1 mg DNA on six occasions, beginning at least 6 months post-transplant; follow-up was to week 52. Fourteen patients were enrolled on study and completed vaccinations. Idiotypic DNA vaccines were well tolerated with vaccine-related adverse events limited to low-grade constitutional symptoms. FrC- and Id-specific T-cell responses were detected by ex vivo ELISPOT in 9/14 and 3/14 patients, respectively. A boost of pre-existing anti-FrC antibody (Ab) was detected by ELISA in 8/14 patients, whilst anti-Id Ab was generated in 1/13 patients. Overall, four patients (29 %) made an immune response to FrC and Id, with six patients (43 %) responding to FrC alone. Over the 52-week study period, serum paraprotein was undetectable, decreased or remained stable for ten patients (71 %), whilst ongoing CR/PR was maintained for 11 patients (79 %). The median time to progression was 38.0 months for 13/14 patients. Overall survival was 64 % after a median follow-up of 85.6 months.

The role of parvovirus B19 and the immune response in the pathogenesis of acute leukemia.

In this article, we review the evidence suggesting a possible role for B19 virus in the pathogenesis of a subset of cases of acute leukemia. Human parvovirus B19 infection may complicate the clinical course of patients with acute leukemia and may also precede the development of acute leukemia by up to 180 days. Parvovirus B19 targets erythroblasts in the bone marrow and may cause aplastic crisis in patients with shortened-red cell survival. Aplastic crisis represents a prodrome of acute lymphoblastic leukemia in 2% patients. There is a significant overlap between those HLA classes I and II alleles that are associated with a vigorous immune response and development of symptoms during B19 infection and those HLA alleles that predispose to development of acute leukemia. Acute symptomatic B19 infection is associated with low circulating IL-10 consistent with a vigorous immune response; deficient IL-10 production at birth was recently found to be associated with subsequent development of acute leukemia. Anti-B19 IgG has been associated with a particular profile of methylation of human cancer genes in patients with acute leukemia, suggesting an additional hit and run mechanism. The proposed role for parvovirus B19 in the pathogenesis of acute leukemia fits well with the delayed infection hypothesis and with the two-step mutation model, which describes carriage of the first mutation prior to birth, followed by suppression of hematopoiesis, which allows rapid proliferation of cells harboring the first mutation, acquisition of a second activating mutation, and expansion of cells carrying both mutations, resulting in acute leukemia.

Use of single-nucleotide polymorphisms (SNPs) to distinguish gene expression subtypes of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME).

AIMS: We have reported gene expression changes in patients with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) and the fact that such gene expression data can be used to identify subtypes of CFS/ME with distinct clinical phenotypes. Due to the difficulties in using a comparative gene expression method as an aid to CFS/ME disease and subtype-specific diagnosis, we have attempted to develop such a method based on single-nucleotide polymorphism (SNP) analysis. METHODS: To identify SNP allele associations with CFS/ME and CFS/ME subtypes, we tested genomic DNA of patients with CFS/ME (n=108), patients with endogenous depression (n=17) and normal blood donors (n=68) for 504 human SNP alleles located within 88 CFS-associated human genes using the SNP Genotyping GoldenGate Assay (Illumina, San Diego, California, USA). 360 ancestry informative markers (AIM) were also examined. RESULTS: 21 SNPs were significantly associated with CFS/ME compared with depression and normal groups. 148 SNP alleles had a significant association with one or more CFS/ME subtypes. For each subtype, associated SNPs tended to be grouped together within particular genes. AIM SNPs indicated that 4 subjects were of Asian origin while the remainder were Caucasian. Hierarchical clustering of AIM data revealed the relatedness between 2 couples of patients with CFS only and confirmed the overall heterogeneity of all subjects. CONCLUSIONS: This study provides evidence that human SNPs located within CFS/ME associated genes are associated with particular genomic subtypes of CFS/ME. Further work is required to develop this into a clinically useful subtype-specific diagnostic test.

Differential impact of CD27 and 4-1BB costimulation on effector and memory CD8 T cell generation following peptide immunization.

The factors that determine differentiation of naive CD8 T cells into memory cells are not well understood. A greater understanding of how memory cells are generated will inform of ways to improve vaccination strategies. In this study, we analyzed the CD8 T cell response elicited by two experimental vaccines comprising a peptide/protein Ag and an agonist that delivers a costimulatory signal via CD27 or 4-1BB. Both agonists increased expansion of Ag-specific CD8 T cells compared with Ag alone. However, their capacity to stimulate differentiation into effector and memory cells differed. CD27 agonists promoted increased expression of perforin and the generation of short-lived memory cells, whereas stimulation with 4-1BB agonists favored generation of stable memory. The memory-promoting effects of 4-1BB were independent of CD4 T cells and were the result of programing within the first 2 d of priming. Consistent with this conclusion, CD27 and 4-1BB-stimulated CD8 T cells expressed disparate amounts of IL-2, IFN-γ, CD25, CD71, and Gp49b as early as 3 d after in vivo activation. In addition, memory CD8 T cells, generated through priming with CD27 agonists, proliferated more extensively than did 4-1BB-generated memory cells, but these cells failed to persist. These data demonstrate a previously unanticipated link between the rates of homeostatic proliferation and memory cell attrition. Our study highlights a role for these receptors in skewing CD8 T cell differentiation into effector and memory cells and provides an approach to optimize vaccines that elicit CD8 T cell responses.

CD27 costimulation contributes substantially to the expansion of functional memory CD8(+) T cells after peptide immunization.

Naive T cells require signals from multiple costimulatory receptors to acquire full effector function and differentiate to long-lived memory cells. The costimulatory receptor, CD27, is essential for optimal T-cell priming and memory differentiation in a variety of settings, although whether CD27 is similarly required during memory CD8(+) T-cell reactivation remains controversial. We have used OVA and anti-CD40 to establish a memory CD8(+) T-cell population and report here that their secondary expansion, driven by peptide and anti-CD40, polyI:C, or LPS, requires CD27. Furthermore, antigenic peptide and a soluble form of the CD27 ligand, CD70 (soluble recombinant CD70 (sCD70)), is sufficient for secondary memory CD8(+) T-cell accumulation at multiple anatomical sites, dependent on CD80/86. Prior to boost, resting effector- and central-memory CD8(+) T cells both expressed CD27 with greater expression on central memory cells. Nonetheless, both populations upregulated CD27 after TCR engagement and accumulated in proportion after boosting with Ag and sCD70. Mechanistically, sCD70 increased the frequency of divided and cytolytic memory T cells, conferred resistance to apoptosis and enabled retardation of tumor growth in vivo. These data demonstrate the central role played by CD27/70 during secondary CD8(+) T-cell activation to a peptide Ag, and identify sCD70 as an immunotherapeutic adjuvant for antitumor immunity.

Two new aspects of continuity of care.

OBJECTIVE: To determine whether the original continuity of care framework is still applicable to family medicine today. DESIGN: Qualitative descriptive study. SETTING: Kingston, Ont. PARTICIPANTS: Three groups of first-year family medicine residents (18 in total), 2 groups of family physicians in established comprehensive practices (9 in total), and 2 groups of family physicians working in episodic care settings (10 in total). METHODS: Using focus groups, a semistructured discussion guide, and a qualitative descriptive design, we explored the residents' and practising physicians' conceptions about continuity of care. Qualitative content analysis was used to identify themes. MAIN FINDINGS: Focus group participants consisting of family physicians providing comprehensive care, episodic care physicians, and family medicine residents exposed 2 new dimensions of continuity of care-community continuity of care (the physicians' roles in understanding the lives of their patients, and how this affects their overall health) and continuity of care within the health care team (the continuity between a patient and members of the interprofessional team, including the family physician). Geographic continuity of care (the care of a patient in various settings by the same physician) was not prominently discussed, perhaps reflecting the paucity of family physicians in the hospital setting. CONCLUSION: Both of these new dimensions of continuity of care are consistent with the ongoing evolution of family medicine as a discipline, and have important implications for how family medicine training programs should be designed to best prepare trainees for future practice.

How do we manage emergency department patients diagnosed with transient ischemic attack?

INTRODUCTION: Multiple studies have demonstrated low rates of antithrombotic use, low neuroimaging rates, and high subsequent risk of stroke at 90 days following an emergency department (ED) diagnosis of transient ischemic attack (TIA). This study assessed the use of antithrombotic medications, neuroimaging, and subsequent 90-day stroke rate for patients in a more recent cohort of ED patients discharged home with TIA. METHODS: We conducted a 1-year historical cohort study of all patients discharged with a TIA at a tertiary care ED (census 60,000 visits/year), which was one of the four sites participating in one of the aforementioned studies. Data were extracted from paper and electronic records onto standardized data extraction forms. Clinical findings, medications, and tests were recorded. RESULTS: A total of 211 patients were enrolled in the study. The patients had the following characteristics: the mean age was 71.2 years (SD 13.8 years), 56.9% were female, 53.1% had a history of hypertension, 26.5% had a history of ischemic heart disease, and 17.1% had a previous stroke. The most frequent neurologic deficit was unilateral weakness (53.6%), and most deficits lasted for more than 60 minutes (71.6%). Antithrombotic medications were used for 96.7% of patients at ED discharge. Neuroimaging was conducted in 94.3% of patients while in the ED. Our cohort had a 90-day stroke rate of 1.9%. CONCLUSION: This study established that most TIA patients receive neuroimaging in the ED and are started on or maintained on antithrombotic agents. Clinicians are encouraged to ensure that electrocardiography is done routinely and to involve Neurology in follow-up care.