Objective
Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a frequent autoimmune neuropathy with a heterogeneous clinical spectrum. Clinical and experimental evidence suggests that ...autoantibodies may be involved in its pathogenesis, but the target antigens are unknown. Axoglial junction proteins have been proposed as candidate antigens. We examined the reactivity of CIDP patients' sera against neuronal antigens and used immunoprecipitation for antigen unraveling.
Methods
Primary cultures of hippocampal neurons were used to select patients' sera that showed robust reactivity with the cell surface of neurons. The identity of the antigens was established by immunoprecipitation and mass spectrometry, and subsequently confirmed with cell‐based assays, immunohistochemistry with teased rat sciatic nerve, and immunoabsorption experiments.
Results
Four of 46 sera from patients with CIDP reacted strongly against hippocampal neurons (8.6%) and paranodal structures on peripheral nerve. Two patients' sera precipitated contactin‐1 (CNTN1), and 1 precipitated both CNTN1 and contactin‐associated protein 1 (CASPR1). Reactivity against CNTN1 was confirmed in 2 cases, whereas the third reacted only when CNTN1 and CASPR1 were cotransfected. No other CIDP patient or any of the 104 controls with other neurological diseases tested positive. All 3 patients shared common clinical features, including advanced age, predominantly motor involvement, aggressive symptom onset, early axonal involvement, and poor response to intravenous immunoglobulin.
Interpretation
Antibodies against the CNTN1/CASPR1 complex occur in a subset of patients with CIDP who share common clinical features. The finding of this biomarker may help to explain the symptoms of these patients and the heterogeneous response to therapy in CIDP. ANN NEUROL 2013;73:370–380
Helicobacter pylori treatment may be viewed as an uncertain situation, where current knowledge is insufficient to provide evidence-based recommendations for all possible scenarios. Evidence suggests ...that, under uncertainty conditions, a few simple rules of thumb tend to work better than complex algorithms. Overall, five evidence-based rules of thumb are suggested: (1) Use four drugs; (2) Use maximal acid inhibition; (3) Treat for 2 weeks; (4) Do not repeat antibiotics after treatment failure; and (5) If your treatment works locally, keep using it. These simple rules of thumb may help the reader to select the best alternative for a given patient, choosing between the heterogeneous recommendations provided by the many different consensus conferences on H. pylori treatment recently published.
Proton pump inhibitors (PPI) are a major cause of false-negative Helicobacter pylori test results. Detecting PPI use and stopping it 2 weeks before testing is the preferred approach to improve the ...reliability of H pylori diagnostic tests. Immunoblot and molecular methods may be useful for the detection of H pylori infection in difficult cases. When conventional tests are negative and eradication is strongly indicated, empirical H pylori treatment should be considered. In this article, an updated critical review of the usefulness of the various invasive and noninvasive tests in the context of extensive PPI use is provided.
Dermatomyositis (DM) is inflammatory myopathy or myositis characterized by muscle weakness and skin manifestations. In the differential diagnosis of DM the evaluation of the muscle biopsy is of ...importance among other parameters. Perifascicular atrophy in the muscle biopsy is considered a hallmark of DM. However, perifascicular atrophy is not observed in all patients with DM and, conversely, perifascicular atrophy can be observed in other myositis such as antisynthetase syndrome (ASS), complicating DM diagnosis. Retinoic acid inducible-gene I (RIG-I), a receptor of innate immunity that promotes type I interferon, was observed in perifascicular areas in DM. We compared the value of RIG-I expression with perifascicular atrophy as a biomarker of DM.
We studied by immunohistochemical analysis the expression of RIG-I and the presence of perifascicular atrophy in 115 coded muscle biopsies: 44 patients with DM, 18 with myositis with overlap, 8 with ASS, 27 with non-DM inflammatory myopathy (16 with polymyositis, 6 with inclusion body myositis, 5 with immune-mediated necrotizing myopathy), 8 with muscular dystrophy (4 with dysferlinopathy, 4 with fascioscapulohumeral muscle dystrophy) and 10 healthy controls.
We found RIG-I-positive fibers in 50% of DM samples vs 11% in non-DM samples (p < 0.001). Interestingly, RIG-I staining identified 32% of DM patients without perifascicular atrophy (p = 0.007). RIG-I sensitivity was higher than perifascicular atrophy (p < 0.001). No differences in specificity between perifascicular atrophy and RIG-I staining were found (92% vs 88%). RIG-I staining was more reproducible than perifascicular atrophy (κ coefficient 0.52 vs 0.37).
The perifascicular pattern of RIG-I expression supports the diagnosis of DM. Of importance for clinical and therapeutic studies, the inclusion of RIG-I in the routine pathological staining of samples in inflammatory myopathy will allow us to gather more homogeneous subgroups of patients in terms of immunopathogenesis.
The type I interferon (IFN-I) pathway is implicated in the pathophysiology of dermatomyositis, but whether its blockade would have therapeutic benefits is unknown. Ladislau et al. show that the Janus ...kinase (JAK) 1/2 inhibitor ruxolitinib inhibits IFN-I pathway activation and prevents IFN-I-mediated damage in skeletal muscle cells and dermatomyositis patients.
Abstract
Dermatomyositis is an acquired auto-immune disease characterized by skin lesions and muscle-specific pathological features such as perifascicular muscle fibre atrophy and vasculopathy. Dermatomyositis patients display an upregulation of type I interferon-inducible genes in muscle fibres, endothelial cells, skin and peripheral blood. However, the effect of type I interferon on muscle tissue has not yet been determined. Our aim was to study the pathogenicity of type I interferon in vitro and to evaluate the efficacy of the type I interferon pathway blockade for therapeutic purposes. The activation of type I interferon in differentiating myoblasts abolished myotube formation with reduced myogenin expression while in differentiated myotubes, we observed a reduction in surface area and an upregulation of atrophy-associated genes. In vitro endothelial cells exposure to type I interferon disrupted vascular network organization. All the pathogenic effects observed in vitro were abolished by ruxolitinib. Finally, four refractory dermatomyositis patients were treated with ruxolitinib and improvement ensued in skin lesions, muscle weakness and a reduced serum type I interferon levels and interferon-inducbile genes scores. We propose JAK inhibition as a mechanism-based treatment for dermatomyositis, a finding that is relevant for the design of future clinical trials targeting dermatomyositis.
This update of the 2010 International Consensus Recommendations on the Management of Patients With Nonvariceal Upper Gastrointestinal Bleeding (UGIB) refines previous important statements and ...presents new clinically relevant recommendations.
An international multidisciplinary group of experts developed the recommendations. Data sources included evidence summarized in previous recommendations, as well as systematic reviews and trials identified from a series of literature searches of several electronic bibliographic databases from inception to April 2018. Using an iterative process, group members formulated key questions. Two methodologists prepared evidence profiles and assessed quality (certainty) of evidence relevant to the key questions according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Group members reviewed the evidence profiles and, using a consensus process, voted on recommendations and determined the strength of recommendations as strong or conditional.
Preendoscopic management: The group suggests using a Glasgow Blatchford score of 1 or less to identify patients at very low risk for rebleeding, who may not require hospitalization. In patients without cardiovascular disease, the suggested hemoglobin threshold for blood transfusion is less than 80 g/L, with a higher threshold for those with cardiovascular disease. Endoscopic management: The group suggests that patients with acute UGIB undergo endoscopy within 24 hours of presentation. Thermocoagulation and sclerosant injection are recommended, and clips are suggested, for endoscopic therapy in patients with high-risk stigmata. Use of TC-325 (hemostatic powder) was suggested as temporizing therapy, but not as sole treatment, in patients with actively bleeding ulcers. Pharmacologic management: The group recommends that patients with bleeding ulcers with high-risk stigmata who have had successful endoscopic therapy receive high-dose proton-pump inhibitor (PPI) therapy (intravenous loading dose followed by continuous infusion) for 3 days. For these high-risk patients, continued oral PPI therapy is suggested twice daily through 14 days, then once daily for a total duration that depends on the nature of the bleeding lesion. Secondary prophylaxis: The group suggests PPI therapy for patients with previous ulcer bleeding who require antiplatelet or anticoagulant therapy for cardiovascular prophylaxis.
Background
Oculopharyngeal muscular dystrophy (OPMD) is an autosomal dominant, late‐onset myopathy characterized by ptosis, dysphagia, and progressive proximal limb muscle weakness. The disease is ...produced by a short expansion of the (GCN)n triplet in the PABPN1 gene. The size of expansion has been correlated to the disease onset and severity. We report the clinical features of a large cohort of OPMD patients harboring the (GCN)15 allele from the Canary Islands.
Methods
A retrospective observational study was performed analyzing the clinical, demographic, and genetic data of 123 OPMD patients. Clinical data from this cohort were compared with clinical data collected in a large European study including 139 OPMD patients.
Results
A total of 113 patients (94.2%) carried the (GCN)15 expanded PABN1 allele. Age of symptoms’ onset was 45.1 years. The most frequent symptom at onset was ptosis (85.2%) followed by dysphagia (12%). The severity of the disease was milder in the Canary cohort compared to European patients as limb weakness (35.1% vs. 50.4%), the proportion of patients that require assistance for walking or use a wheelchair (9.3% vs. 27.4%), and needed of surgery because of severe dysphagia (4.6% vs. 22.8%) was higher in the European cohort.
Conclusions
Nearly 95% of patients with OPMD from the Canary Islands harbored the (GCN)15 expanded allele supporting a potential founder effect. Disease progression seemed to be milder in the (GCN)15 OPMD Canary cohort than in other cohorts with shorter expansions suggesting that other factors, apart from the expansion size, could be involved in the progression of the disease.
Nearly 95% of OPMD patients from the Canary Islands harbored the expanded allele (GCN)15 supporting a possible founder effect. Disease progression and severity appeared to be milder, suggesting that factors other than the size of the expansion, could be involved in the progression of the disease.
Treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) or low-dose aspirin is associated with increased risk of upper gastrointestinal bleeding. There is little evidence on the risk of lower ...gastrointestinal bleeding with NSAIDs, antiplatelet agents (APAs), or anticoagulants. We aimed to quantify the relative risk (RR) of upper and lower gastrointestinal bleeding associated with use of NSAIDs, APAs, or anticoagulants.
We performed a case-control study that used data collected from consecutive patients hospitalized for gastrointestinal bleeding (563 upper, mean age, 63.6 ± 16.7 years and 415 lower, mean age, 70.8 ± 13.8 years), confirmed by endoscopy or other diagnostic procedures. Unhospitalized patients were used as controls (n = 1008) and matched for age, hospital, and month of admission. Drug use was considered current when taken within 7 days or less before hospitalization. RRs and 95% confidence intervals (CIs) were estimated by unconditional logistic regression analysis.
Use of anticoagulants, low-dose aspirin, and other drugs (non-aspirin-APA, 82.3% thienopiridines) was associated with upper and lower gastrointestinal bleeding; the risk was 2-fold higher for anticoagulants (RR, 4.2; 95% CI, 2.9-6.2) than for low-dose aspirin (RR, 2.1; 95% CI, 1.4-3.3) or other non-aspirin-APA drugs (RR, 2.0; 95% CI, 1.6-2.6). NSAID use was also associated with increased risk of gastrointestinal bleeding and greater for upper (RR, 2.6; 95% CI, 2.0-3.5) than lower gastrointestinal bleeding (RR, 1.4; 95% CI, 1.0-1.9). Use of proton pump inhibitors was associated with reduced risk of upper, but not lower, gastrointestinal bleeding.
Anticoagulants, low-dose aspirin, NSAIDs, and other non-aspirin-APA drugs are associated with increased risk of upper and lower gastrointestinal bleeding. Use of anticoagulants appears to be the strongest risk factor for gastrointestinal bleeding.
Duchenne muscular dystrophy (DMD) is characterized by a progressive loss of muscle fibers, and their substitution by fibrotic and adipose tissue. Many factors contribute to this process, but the ...molecular pathways related to regeneration and degeneration of muscle are not completely known. Platelet-derived growth factor (PDGF)-BB belongs to a family of growth factors that regulate proliferation, migration, and differentiation of mesenchymal cells. The role of PDGF-BB in muscle regeneration in humans has not been studied. We analyzed the expression of PDGF-BB in muscle biopsy samples from controls and patients with DMD. We performed in vitro experiments to understand the effects of PDGF-BB on myoblasts involved in the pathophysiology of muscular dystrophies and confirmed our results in vivo by treating the mdx murine model of DMD with repeated i.m. injections of PDGF-BB. We observed that regenerating and necrotic muscle fibers in muscle biopsy samples from DMD patients expressed PDGF-BB. In vitro , PDGF-BB attracted myoblasts and activated their proliferation. Analysis of muscles from the animals treated with PDGF-BB showed an increased population of satellite cells and an increase in the number of regenerative fibers, with a reduction in inflammatory infiltrates, compared with those in vehicle-treated mice. Based on our results, PDGF-BB may play a protective role in muscular dystrophies by enhancing muscle regeneration through activation of satellite cell proliferation and migration.
PDF
