Safety and efficacy of losmapimod in facioscapulohumeral muscular dystrophy (ReDUX4): a randomised, double-blind, placebo-controlled phase 2b trial.

BACKGROUND: Facioscapulohumeral muscular dystrophy is a hereditary progressive myopathy caused by aberrant expression of the transcription factor DUX4 in skeletal muscle. No approved disease-modifying treatments are available for this disorder. We aimed to assess the safety and efficacy of losmapimod (a small molecule that inhibits p38α MAPK, a regulator of DUX4 expression, and p38ß MAPK) for the treatment of facioscapulohumeral muscular dystrophy. METHODS: We did a randomised, double-blind, placebo-controlled phase 2b trial at 17 neurology centres in Canada, France, Spain, and the USA. We included adults aged 18-65 years with type 1 facioscapulohumeral muscular dystrophy (ie, with loss of repression of DUX4 expression, as ascertained by genotyping), a Ricci clinical severity score of 2-4, and at least one skeletal muscle judged using MRI to be suitable for biopsy. Participants were randomly allocated (1:1) to either oral losmapimod (15 mg twice a day) or matching placebo for 48 weeks, via an interactive response technology system. The investigator, study staff, participants, sponsor, primary outcome assessors, and study monitor were masked to the treatment allocation until study closure. The primary endpoint was change from baseline to either week 16 or 36 in DUX4-driven gene expression in skeletal muscle biopsy samples, as measured by quantitative RT-PCR. The primary efficacy analysis was done in all participants who were randomly assigned and who had available data for assessment, according to the modified intention-to-treat principle. Safety and tolerability were assessed as secondary endpoints. This study is registered at ClinicalTrials.gov, number NCT04003974. The phase 2b trial is complete; an open-label extension is ongoing. FINDINGS: Between Aug 27, 2019, and Feb 27, 2020, 80 people were enrolled. 40 were randomly allocated to losmapimod and 40 to placebo. 54 (68%) participants were male and 26 (33%) were female, 70 (88%) were White, and mean age was 45·7 (SD 12·5) years. Least squares mean changes from baseline in DUX4-driven gene expression did not differ significantly between the losmapimod (0·83 [SE 0·61]) and placebo (0·40 [0·65]) groups (difference 0·43 [SE 0·56; 95% CI -1·04 to 1·89]; p=0·56). Losmapimod was well tolerated. 29 treatment-emergent adverse events (nine drug-related) were reported in the losmapimod group compared with 23 (two drug-related) in the placebo group. Two participants in the losmapimod group had serious adverse events that were deemed unrelated to losmapimod by the investigators (alcohol poisoning and suicide attempt; postoperative wound infection) compared with none in the placebo group. No treatment discontinuations due to adverse events occurred and no participants died during the study. INTERPRETATION: Although losmapimod did not significantly change DUX4-driven gene expression, it was associated with potential improvements in prespecified structural outcomes (muscle fat infiltration), functional outcomes (reachable workspace, a measure of shoulder girdle function), and patient-reported global impression of change compared with placebo. These findings have informed the design and choice of efficacy endpoints for a phase 3 study of losmapimod in adults with facioscapulohumeral muscular dystrophy. FUNDING: Fulcrum Therapeutics.

Quantitative Muscle Analysis in FSHD Using Whole-Body Fat-Referenced MRI: Composite Scores for Longitudinal and Cross-sectional Analysis.

BACKGROUND AND OBJECTIVES: Facioscapulohumeral muscular dystrophy (FSHD) is a rare, debilitating disease characterized by progressive muscle weakness. MRI is a sensitive assessment of disease severity and progression. We developed a quantitative whole-body (WB) musculoskeletal MRI (WB-MSK-MRI) protocol analyzing muscles in their entirety. This study aimed to assess WB-MSK-MRI as a potential imaging biomarker providing reliable measurements of muscle health that capture disease heterogeneity and clinically meaningful composite assessments correlating with severity and more responsive to change in clinical trials. METHODS: Participants aged 18-65 years, with genetically confirmed FSHD1, clinical severity 2 to 4 (Ricci scale, range 0-5), and ≥1 short tau inversion recovery-positive lower extremity muscle eligible for needle biopsy, enrolled at 6 sites and were imaged twice 4-12 weeks apart. Volumetric analysis of muscle fat infiltration (MFI), muscle fat fraction (MFF), and lean muscle volume (LMV) in 18 (36 total) muscles from bilateral shoulder, proximal arm, trunk, and legs was performed after automated atlas-based segmentation, followed by manual verification. A WB composite score, including muscles at highest risk for progression, and functional cross-sectional composites for correlation with relevant functional outcomes including timed up and go (TUG), FSHD-TUG, and reachable workspace (RWS), were developed. RESULTS: Seventeen participants enrolled in this study; 16 follow-up MRIs were performed at 52 days (range 36-85 days). Functional cross-sectional composites (MFF and MFI) showed moderate to strong correlations: TUG (ρ = 0.71, ρ = 0.83), FSHD-TUG (ρ = 0.73, ρ = 0.73), and RWS (left arm: ρ = -0.71, ρ = -0.53; right arm: ρ = -0.61, ρ = -0.65). WB composite variability: LMVtot, coefficient of variation (CV) 1.9% and 3.4%; MFFtot, within-subject SD (Sw) 0.5% and 1.5%; and MFItot (Sw), 0.3% and 0.4% for normal and intermediate muscles, respectively. CV and Sw were higher in intermediate (MFI ≥0.10; MFF <0.50) than in normal (MFI <0.10, MFF <0.50) muscles. DISCUSSION: We developed a WB-MSK-MRI protocol and composite measures that capture disease heterogeneity and assess muscle involvement as it correlates with FSHD-relevant clinical endpoints. Functional composites robustly correlate with functional assessments. Stability of the WB composite shows that it could be an assessment of change in therapeutic clinical trials. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that quantitative WB-MSK-MRI findings associate with FSHD1 severity measured using established functional assessments.

Guía atrapada durante cambio de electrodo del seno coronario en terapia de resincronización cardiaca / Trapped guidewire during coronary sinus electrode exchange in cardiac resynchronization therapy

Resumen Se presenta el caso de una paciente con atrapamiento de guía al interior del seno coronario durante el procedimiento de cambio de un electrodo (Sentus ProMRI OTW BP L-85) por desalojo asociado a disfunción de la terapia de resincronización cardiaca. Durante el implante del nuevo electrodo se presentó atrapamiento y retención intravascular de la guía utilizada para su posicionamiento a nivel del seno coronario, lo cual hizo imposible su remoción. La paciente no aceptó tratamiento quirúrgico, se encuentra en vigilancia médica y permanece asintomática desde hace 3 años.

Abstract It is reported the case of a patient with guidewire trapping inside the coronary sinus during an electrode exchange procedure (Sentus ProMRI OTW BP L-85) due to dislocation associated with dysfunction of cardiac re-synchronization therapy. During the implantation of the new electrode, entrapment of the guidewire used for its positioning at the level of the coronary sinus and intravascular retention were presented, making it impossible to remove it. The patient did not accept surgical treatment and has been under medical surveillance, asymptomatic for three years.

Complications related to cardiac implantable electronic devices / Complicaciones asociadas al implante de dispositivos cardiacos electrónicos

Abstract Introduction: complications due to cardiac implantable electronic devices have been sparsely studied despite the increased number and complexity of these procedures in a population with multiple comorbidities. Objective: to determine the complication rate and associated risk factors at a reference center in Colombia. Methods: retrospective cohort study, which included patients who had a cardiac electronic device implanted between 2012 and 2015. Clinical records were reviewed to determine if patients developed complications during the year after the procedure, and, if so, which type and which clinical variables could be related to. Results: a total of 897 patients were included, 620 with pacemaker implants and 277 with other devices. The average age was 71.4 years, 63.9% were men, almost all the patients had a chronic disease, and 70% were de novo implants. The global complication rate was 10.9%; Lead displacement (3.6%) and pocket hematoma (3.3%) were the most frequent complications; 7.5% were major complications, and 73.5% occurred in the first month after procedure. The hospitalization rate associated with complications was 9.5%, and the median hospital stay was seven days, with 66.3% of these patients requiring new interventions. The mortality rate was 0.2% Conclusions: complications associated with cardiac implantable electronic devices occur red mainly in the first trimester after the initial intervention, were more frequent in patients under 80 years old, increased according to device complexity, and were not related to with the studied comorbidities.

Resumen Introducción: las complicaciones secundarias al implante de dispositivos cardiacos electrónicos han sido poco estudiadas a pesar del aumento en número y complejidad de estos procedimientos en población con múltiples comorbilidades. Objetivo: determinar la tasa de complicaciones del implante de dispositivos y los factores de riesgo asociados, en un centro de referencia en Colombia. Métodos: estudio de cohorte retrospectiva, que incluyó pacientes a quienes se les implantó dispositivo electrónico cardiaco entre 2012 y 2015. Se revisó la historia clínica para determinar si durante un año posterior al procedimiento, presentaron complicaciones, de qué tipo y con qué variables clínicas podría asociarse. Resultados: se incluyeron 897 pacientes, 620 con implante de marcapaso y 277 otros dispositivos. La edad promedio fue 71.4 años, 63.9% hombres, con múltiples enfermedades crónicas, 70% fueron implantes de novo. Se observó una tasa de complicaciones del 10.9%, la cual varía de acuerdo con el tipo de dispositivo. El desalojo del electrodo (3.6%) y el hematoma del bolsillo (3.3%) fueron las complicaciones más frecuentes, 7.5% fueron complicaciones mayores y 73.5% se presentaron en el primer mes postoperatorio. La tasa de hospitalización asociada a complicación fue 9.5%, mediana de estancia de 7 días, con un 66.3% de los pacientes en requerimiento de reintervención. La tasa de mortalidad fue del 0.2%. Conclusiones: las complicaciones asociadas al implante de dispositivos eléctricos cardiacos se presentaron principalmente en el primer trimestre, fueron más frecuentes en menores de 80 años, aumentaron con la complejidad del dispositivo y no se relacionaron con las comorbilidades estudiadas.

Obstructive sleep apnea diagnosed by peripheral arterial tonometry in patients with cardiovascular disease / Apnea obstructiva del sueño diagnosticada por tonometría arterial periférica en pacientes con enfermedad cardiovascular

Abstract Introduction: Obstructive sleep apnea is an independent cardiovascular risk factor which can be diagnosed by means of a portable device (WatchPAT®) capable to perform automatic analysis of the peripheral artery tonometry, its amplitude and variability, with a high grade of correlation to polysomnography. Objective: To describe the use of WatchPAT® for diagnosing obstructive sleep apnea in patients with cardiovascular disease. Methods: A case series study of patients evaluated in cardiovascular consultation who underwent to home sleep monitoring using the WatchPAT®200U system between February 1, 2017 to February 1, 2018, due to suspected obstructive sleep apnea. Results: 37 patients were included, with an average age of 57.6 years, most of whom were male. Cardiovascular diseases were: uncontrolled or predominantly nocturnal hypertension (37.8%), recurrent palpitations and/or chronic fatigue (21.6%); sleep disturbances were informed only in 27% of the patients. Obstructive sleep apnea was identified in 97.3% of the patients (29.7% moderate and 56.8% severe), 37.8% had high blood pressure, 49.5% had established heart disease, and 18.9% were diabetic. Only, fifty percent of the patients with severe obstructive sleep apnea and 45% with moderate obstructive sleep apnea snored. Conclusion: Cardiovascular disease specialists should participate more actively in the search and diagnosis of obstructive sleep apnea; it is highly prevalent in patients with nocturnal or resistant high blood pressure, heart rhythm disorders or myocardial structural damage. Obstructive sleep apnea can be diagnosed using portable devices such as WatchPAT®.

Resumen Introducción: La apnea obstructiva del sueño es un factor independiente de riesgo cardiovascular. Para su diagnóstico existen dispositivos portátiles (WatchPAT®) que utilizan el análisis automático de la amplitud y variabilidad del tono arterial periférico logrando una alta correlación con la polisomnografía. Objetivo: Describir el uso del WatchPAT® para el diagnóstico de apnea obstructiva del sueño en pacientes con patología cardiovascular. Métodos: Serie de casos que incluyó pacientes valorados en consulta cardiovascular a quienes se les realizó monitorización del sueño en casa mediante WatchPAT®200U por sospecha de apnea obstructiva del sueño entre el 1( de febrero de 2017 y el 1( de febrero de 2018. Resultados: Se incluyeron 37 pacientes, edad promedio 57,6 años, la mayoría hombres. Las enfermedades cardiovasculares principales fueron: hipertensión arterial no controlada o de predominio nocturno (37,8%), palpitaciones recurrentes y/o fatiga crónica (21,6%); se informaron alteraciones del sueño solo en 27% de los pacientes. Se identificó apnea obstructiva del sueño en 97,3% de los pacientes (29,7% moderado y 56,8% severo); 3,8% eran hipertensos, 45,9% tenían enfermedad cardíaca establecida y 18,9% eran diabéticos. Solo 50% de los pacientes con apnea obstructiva del sueño severa y 45% moderada roncaban. Conclusión: Los especialistas en patología cardiovascular deben tener una participación más activa en la búsqueda y diagnóstico de apnea obstructiva del sueño, altamente prevalente en pacientes con hipertensión arterial nocturna o resistente, en trastornos del ritmo cardiaco o en aquellos con daño estructural del miocardio. Su diagnóstico puede realizarse con dispositivos portátiles como WatchPAT®.

Experiencia clínica en monitorización cardiaca extendida con el sistema inalámbrico satelital tipo SEEQ / Clinical experience in extended cardiac monitoring with the SEEQ( satellite wireless system

Resumen Objetivos: Dar a conocer la experiencia clínica con un nuevo sistema de monitorización cardiaca extendida (por 15 días), inalámbrica y satelital en un grupo de pacientes con sospecha de arritmias cardíacas. Metodología: Cohorte de 100 pacientes atendidos en la unidad de Electrofisiología cardiovascular de un centro de referencia, con sospecha de arritmia cardíaca, sin diagnóstico electrocardiográfico causal, a pesar de exámenes previos. Se les aplicó una monitorización cardiaca externa tipo SEEQ (Medtronic) por 15 días y se registró el desenlace. Resultados: De un total de 100 sujetos estudiados, 51% eran hombres, con mediana de edad de 60 años (rango: 5 - 91 años). El principal síntoma fueron las palpitaciones (42%) y la comorbilidad más prevalente la hipertensión arterial (47%); 98% tenían estudio de Holter previo y 46% dos estudios sin resultado conclusivo que explicara los síntomas. La monitorización tipo SEEQ documentó anormalidad electrocardiográfica significativa en 22% de los pacientes. El implante de marcapaso fue el tratamiento más aplicado y la fibrilación auricular fue la arritmia más frecuente en el 50% de los hallazgos positivos. Hubo una proporción mayor y significativa de diagnósticos positivos en el sexo masculino. Conclusiones: La monitorización cardiaca externa inalámbrica, satelital, extendida por 15 días es una herramienta novedosa que incrementa la probabilidad de documentar una anormalidad electrocardiográfica clínicamente significativa en quienes padecen síntomas cardiovasculares recurrentes.

Abstract Objectives: To present the clinical experience with a new extended (for 15 days), wireless, and satellite cardiac monitoring system in a group of patients with suspicion of cardiac arrhythmia. Method: The study included a cohort of 100 patients seen in the Cardiovascular Electrophysiology Unit of a reference hospital. They were suspected of having a cardiac arrhythmia, with no electrocardiographic diagnosis of the cause, despite previous examinations. They were subjected to SEEQ-type (Medtronic) external cardiac monitoring for 15 days, with the outcomes recorded. Results: Of the total of 100 subjects studied, 51% were male, and the median age was 60 years (range: 5 - 91 years). The main symptoms were palpitation, and the most prevalent comorbidity was arterial hypertension (47%). Almost all (98%) of them had a previous Holter study, and 46% had two studies, which were inconclusive in explaining the symptoms. The SEEQ monitoring recorded a significant electrocardiographic abnormality in 22% of the patients. A pacemaker implant was the treatment most applied and atrial fibrillation was the most frequent arrhythmia in 50% of the positive findings. There was a higher and significant percentage of positive diagnoses in males. Conclusions: External, satellite, wireless cardiac monitoring extended for 15 days, is a novel tool that can increase the probability of documenting a clinically significant electrocardiographic abnormality in those patients who suffer recurrent cardiovascular symptoms.

Antibodies to endothelial cell growth factor and obliterative microvascular lesions in the synovium of patients with antibiotic-refractory lyme arthritis.

OBJECTIVE: Endothelial cell growth factor (ECGF) was recently identified as the first autoantigen known to be a target of T cell and B cell responses in ~20% of patients with antibiotic-refractory Lyme arthritis. The goal of the current study was to look for a pathologic correlate between ECGF autoantibody responses and histologic findings in synovial tissue. METHODS: Synovial tissue was examined from 14 patients with antibiotic-refractory Lyme arthritis and 6 patients with other forms of chronic inflammatory arthritis, primarily rheumatoid arthritis. The tissue sections were subjected to chemical and immunostaining, and IgG antibody responses to ECGF were determined by enzyme-linked immunosorbent assay (ELISA). Each finding was ranked for statistical analysis. RESULTS: In each disease, synovial tissue showed synovial hypertrophy, vascular proliferation, immune cell infiltrates, and fibrosis. However, among the 14 patients with antibiotic-refractory arthritis, 8 (57%) had obliterative microvascular lesions in the tissue, compared with none of the 6 patients with other forms of chronic inflammatory arthritis (P = 0.04). Among the patients with Lyme arthritis, 5 (36%) had autoantibody responses to ECGF, and all 5 had obliterative lesions, as compared with only 3 of 9 patients who lacked ECGF antibody responses (P = 0.009). Moreover, the magnitude of ECGF antibody responses correlated directly with the extent of obliterative lesions (P = 0.02) and with greater vascularity in the tissue (P = 0.05). CONCLUSION: The correlations of ECGF autoantibody reactivity with obliterative microvascular lesions imply that these autoantibodies may be involved in the obliterative process, suggesting that anti-ECGF antibodies have specific pathologic consequences in the synovial tissue of patients with antibiotic-refractory Lyme arthritis.

The chameleon of neuroinflammation: magnetic resonance imaging characteristics of natalizumab-associated progressive multifocal leukoencephalopathy.

Natalizumab is a monoclonal antibody against α4-integrin approved for the treatment of multiple sclerosis (MS) due to a positive effect on clinical and magnetic resonance imaging (MRI) outcome measures. However, one relatively rare but serious side effect of this drug is a higher risk of developing progressive multifocal leukoencephalopathy (PML). Since the FDA approval, more than 300 natalizumab-associated PML cases have been documented among more than 100,000 treated MS patients. MRI is a crucial tool in the surveillance of patients treated with natalizumab in order to detect possible signs of PML in the asymptomatic stage. Although classical imaging characteristics of PML are well established, MRI findings in natalizumab-associated PML, particularly in early disease stages, show rather new and heterogeneous imaging findings including different patterns of inflammation with contrast enhancement. This review provides a comprehensive overview of the heterogeneous imaging findings in natalizumab-associated PML in the context of the underlying pathophysiology, histopathology, and the diagnostic procedure. We describe the MRI patterns of PML lesion evolution and complications including immune reconstitution inflammatory syndrome (IRIS). Finally, we present guidelines to differentiate MRI findings in PML from inflammatory demyelinating lesions, to facilitate the early diagnosis of PML in patients treated with natalizumab.

Razón y diseño del estudio utilidad clínica del monitor cardíaco implantable en pacientes con enfermedad de chagas: estudio reveal Chagas / Rationale and Design clinical utility of the implantable loop recorder in patients with Chagas disease

Resumén: El estudio “Utilidad clínica del monitor cardiaco implantable en pacientes con Enfermedadde Chagas”. El Estudio Reveal Chagas es un estudio prospectivo e intervencionista a realizarse en varios centros de Latinoamérica con el propósito de estudiar el posible beneficio en la detección precoz de arritmias cardiacas (bradi y/o taquiarritmias) utilizando un monitor cardiaco implantable (MCI) en pacientes con Enfermedad de Chagas diagnosticados por serologia, que cursen asintomáticos y/o mínimamente sintomáticos, que tengan trastornos electrocardiográficos y/o arrítmicos y que de manera inmediata no requieran el implante de un dispositivo de estimulación cardiaca y/o cardiodesfibrilador de acuerdo a las indicaciones universalmente aceptadas.

Abstract: Rationale and Design “Clinical Utility of the Implantable Loop Recorder in Patients with Chagas Disease “. Reveal Chagas Study is a prospective, multi center, randomized study planned to be performed in Latin-America. The main objective is to look for potential benefits of an early detection of cardiac arrhythmias (brady/tachyarrhythmias) by means of an implantable Cardiac Monitor applied to Chagas Disease´ patients. The target population will be patients without or minimal expression of symptoms, with documented ECG abnormalities or cardiac arrhythmias, in whom there is no an acceptedindication for immediate pacemaker, ICD or other cardiac device implant based on the internationalguidelines.

Impact of inflammation on brain volume in multiple sclerosis.

OBJECTIVE: To study changes in brain volume measured monthly in patients treated for relapsing multiple sclerosis due to loss of tissue and the appearance of inflammation. DESIGN AND PATIENTS: The results from T2/fluid-attenuated inversion recovery axial images from 13 consecutive monthly 3-T brain magnetic resonance imaging tests conducted on 74 patients diagnosed with relapsing multiple sclerosis in the BECOME study were used to calculate whole brain volumes using automated software analysis tools. The patients had been randomized to receive treatment with interferon beta-1b or glatiramer acetate. Ongoing inflammation was studied by counting the number of combined active lesions and measuring the volume of gadolinium enhancement. A mixed-effects model was used to analyze brain volumes over time. RESULTS: There was a significant decrease in brain volume over time but there was no difference in its rate of change by age, sex, frequency of ongoing inflammation, multiple sclerosis type, or randomized treatment assignment. The mean rate of brain volume change per month from multivariable models was -1.1 cm(3) (95% CI, -1.5 to -0.6) and during times of magnetic resonance imaging activity, it increased transiently by an average of 1.2 cm(3)/lesion (95% CI, 0.7 to 1.7) and 7.1 cm(3)/1 cm(3 )of gadolinium volume. In a model with both measures, combined active lesions were independent predictors of brain volume but gadolinium volume was not. CONCLUSION: Two major changes in brain volume occur in patients with relapsing multiple sclerosis, a steady decrease likely due to tissue loss with overlapping transient increases due to the appearance of inflammation.

Magnetic resonance imaging pattern in natalizumab-associated progressive multifocal leukoencephalopathy.

OBJECTIVE: Natalizumab is an effective treatment for patients with multiple sclerosis (MS) that is associated with a risk of progressive multifocal leukoencephalopathy (PML). Recommendations were published in 2006 to improve early diagnosis of PML using magnetic resonance imaging (MRI). However, due to the small number of MS patients initially diagnosed with PML, the imaging criteria could only be derived from PML lesions in patients with human immunodeficiency virus. Therefore, there is an urgent need to assess the MRI characteristics of PML in MS patients to update the existing recommendations. METHODS: In this retrospective review, the first 40 natalizumab-treated MS patients diagnosed with PML in the postmarketing setting were identified, of whom 22 (10 with clinically diagnosed immune reconstitution inflammatory syndrome) fulfilled the inclusion criteria for this study. Magnetic resonance images were analyzed according to predefined criteria by 5 independent readers. RESULTS: The most frequent lesion pattern in early scans from PML patients was that of large (>3 cm, 15 of 18), subcortical (18 of 18), T2 or fluid-attenuated inversion recovery hyperintense (18 of 18), T1-hypointense (17 of 18), and diffusion-hyperintense (15 of 15) lesions, with a sharp border toward the gray matter and an ill-defined border toward the white matter (18 of 18) on T2-weighted images. We could detect contrast enhancement in 41% (7 of 17) of the cases on the first scan at clinical presentation. INTERPRETATION: Attention to characteristic MRI patterns, especially the presence of contrast enhancement, and the subcortical location may have utility in screening and early diagnosis of PML in natalizumab-treated MS patients.

Clinical consequences of MRI activity in treated multiple sclerosis.

BACKGROUND: Inflammation on brain MRI is the most sensitive marker of disease activity in multiple sclerosis (MS) but its clinical consequences remain controversial. OBJECTIVE: Here we investigated the clinical consequences of MRI activity in MS subjects treated with two different first line disease modifying agents. METHODS: Seventy-five treatment-naïve subjects with relapsing-remitting MS (N = 61) or clinically isolated syndromes at risk of MS (N = 14) from the BECOME study that had been randomized to interferon beta-1b (N = 39) or glatiramer acetate (N = 36) and followed for up to two years by monthly brain MRI optimized to detect inflammatory activity were studied for the clinical consequences of lack of MRI remission. RESULTS: MRI remission occurred in 46.4% of participants transiently and in 23.2% completely while it was never achieved in 30.4%. There was no difference by treatment in MRI remission, progression of physical disability, or cognitive function. The percentage of relapse-free subjects was 87.5% for the group in complete MRI remission, 47.6% in the group never in remission and 59.4% in the group in transient remission (p = 0.017). Similar differences were observed for six-month-confirmed worsening of ambulatory function as measured by the timed 25 foot walk (p = 0.026) and by Expanded Disability Status Scale (EDSS) (p = 0.10). Cognitive function was lowest at baseline for the group that never reached MRI remission on treatment; this group improved the least upon repeated cognitive testing during the two years of treatment (p < 0.001). CONCLUSIONS: Lack of MRI remission during treatment with interferon beta-1b or glatiramer acetate is associated with higher relapse rate and worsening of physical and cognitive function.

IL-10 Prevents apoptosis of brain endothelium during bacteremia.

IL-10-deficient mice infected with the relapsing fever bacterium Borrelia turicatae rapidly succumb to a brain hemorrhage if they are unable to clear peak bacteremia. In this study, we investigated the protective role of IL-10 during relapsing-remitting bacteremia and explored the molecular events involved in the protection of brain endothelium by IL-10. Brain endothelial injury was measured with cytotoxicity and diverse apoptotic assays, whereas the signaling pathway analysis was done by quantitative PCR array. The results showed that severe endothelial cell injury leading to hemorrhage in the brain and other organs occurred in IL-10-deficient mice during relapsing-remitting infection. Human brain microvascular endothelial cells (HBMEC) produced abundant proinflammatory mediators upon exposure to whole bacteria or purified bacterial lipoprotein but did not produce any detectable IL-10. Whole bacteria and purified outer membrane lipoprotein rapidly killed HBMEC by apoptosis in a time- and concentration-dependent manner. Exogenous IL-10 protected HBMEC from apoptosis. HBMEC apoptosis during exposure to a low number of bacteria was associated with downregulation of TNF and TNFAIP3 and upregulation of BAX. In contrast, HBMEC apoptosis during exposure to high concentrations of purified outer membrane lipoprotein was associated with marked upregulation of FAS, FAS ligand, and the adaptor molecules RIPK1 and CFLAR. Exogenous IL-10 reversed all the apoptotic signaling changes induced by whole bacteria or its purified lipoprotein. The results indicate that prominent brain endothelial cell apoptosis occurs during relapsing-remitting bacteremia in the absence of IL-10 and point to a prominent role for bacterial lipoprotein-mediated activation of FAS and caspase-3 in this process.

Serum levels of CXCL13 are elevated in active multiple sclerosis.

There is increasing recognition of the important role that B cells play in the pathogenesis of multiple sclerosis (MS). Recently it was reported that the B cell chemokine CXCL13 is elevated in MS serum and cerebrospinal fluid. Here we study whether serum levels of CXCL13 are associated with active MS. We measured serum levels of CXCL13 by enzyme-linked immunosorbent assay in 74 patients with relapsing MS randomized to interferon beta 1b or glatiramer acetate and examined with monthly 3 T brain MRI scans optimized for detection of gadolinium-enhancement for up to 2 years. The median (range) serum levels of CXCL13 pre-treatment were 40 (3-171) pg/ml. Serum levels of CXCL13 were significantly higher at times of active brain MRI scans (p < 0.01). Furthermore, serum levels were higher in patients who never reached MRI remission compared with those in complete (p < 0.01) or partial (p = 0.01) remission. There was a significant positive correlation between the pattern of serum levels of CXCL13 and MRI activity during the first (r = 0.33, p < 0.05) and the full 2 years (r = 0.35, p < 0.01) of the study. Treatment with interferon beta 1b or glatiramer acetate did not affect serum CXCL13. We conclude that the serum levels of the B cell chemokine CXCL13 are associated with active MS.

Interleukin 10 protects the brain microcirculation from spirochetal injury.

Spirochetal infections are an important cause of neurological disease. In previous studies of the pathogenesis of spirochetal brain infection, mice inoculated with Borrelia turicatae, an agent of tick-borne relapsing fever in North America, developed mild meningitis and parenchymal activation/infiltration by interleukin 10 (IL-10)-producing microglia/macrophages. Here, we investigated the neuroprotective effects of IL-10 during spirochetal infection by comparing the outcomes of B. turicatae infection in wild-type and IL-10-deficient RAG2-deficient mice. Mice were infected with either serotype 1 (Bt1), which causes more brain infection but lower bacteremia, or Bt2, which causes less brain infection but higher bacteremia. Interleukin 10 deficiency resulted in early death from subarachnoid/intraparenchymal brain hemorrhage in Bt2-infected mice. These mice had marked apoptosis of brain microvascular endothelial cells as assessed by terminal transferase-mediated DNA nick end-labeling staining. In contrast, Bt1 infection caused milder subarachnoid hemorrhage. Neuronal apoptosis was observed in mice infected with both serotypes and was prominent in the cerebellum. Neutralization of tumor necrosis factor prevented death and reduced morbidity and brain injury in mice infected by both serotypes. We conclude that IL-10 plays a critical role protecting the cerebral microcirculation from spirochetal injury possibly by inhibition effects of tumor necrosis factor.

Relapsing fever borreliosis in interleukin-10-deficient mice.

Relapsing fever (RF) is a spirochetal infection characterized by periods of sickness with fever at time of high bacteremia that alternate with afebrile periods of relative well being during low bacteremia. Patients with epidemic RF who are doing relatively well have extraordinarily high levels of interleukin-10 (IL-10) in the circulation. We investigated the possibility that IL-10 plays an important protective role in this infection using wild-type and IL-10-deficient mice inoculated with virulent serotype 2 of the RF spirochete Borrelia turicatae. During peak bacteremia there was increased systemic production of IL-10 that quickly resolved in the postpeak period; in contrast, IL-6 and CXCL13 production increased during the peak but remained elevated during postpeak bacteremia. IL-10 deficiency resulted in lower bacteremia, increased specific antibody production, higher production of CXCL13 and IL-6, and thrombotic and hemorrhagic complications affecting multiple organs with secondary tissue injury. Our results revealed that production of IL-10 is highly regulated during RF and plays an important protective role in the prevention of hemorrhagic and thrombotic complications at the cost of reduced pathogen control.

IL-10 helps control pathogen load during high-level bacteremia.

During relapsing fever borreliosis, a high pathogen load in the blood occurs at times of peak bacteremia. Specific IgM Abs are responsible for spirochetal clearance so in absence of B cells there is persistent high-level bacteremia. Previously, we showed that B cell-deficient mice persistently infected with Borrelia turicatae produce high levels of IL-10 and that exogenous IL-10 reduces bacteremia. This suggested that IL-10 helps reduce bacteremia at times of high pathogen load by a B cell-independent mechanism, most likely involving innate immunity. To investigate this possibility, we compared B. turicatae infection in RAG2/IL-10(-/-) and RAG2(-/-) mice. The results showed that IL-10 deficiency resulted in significantly higher bacteremia, higher TNF levels, and early mortality. Examination of the spleen and peripheral blood showed markedly increased apoptosis of immune cells in infected RAG2/IL-10(-/-) mice. Neutralization of TNF reduced apoptosis of leukocytes and splenocytes, increased production of IFN-gamma by NK cells, increased phagocytosis in the spleen, decreased spirochetemia, and rescued mice from early death. Our results indicate that at times of high pathogen load, as during peak bacteremia in relapsing fever borreliosis, IL-10 protects innate immune cells from apoptosis via inhibition of TNF resulting in improved pathogen control.

The mammalian host response to borrelia infection.

Tick-borne relapsing fever (RF) and Lyme disease (LD) are spirochetal infections of humans caused by different Borrelia species in endemic areas throughout the world. Our laboratory is studying the response of mammalian hosts to borrelia infection in RF and LD. For this, we use mice and non-human primates infected with B. burgdorferi sensu stricto strain N40 (N40) and the Oz1 strain of Borrelia turicatae (Bt), agents of LD and RF in North America, respectively. Our results have revealed that outbred non-human primates are significantly less susceptible than outbred mice to persistent infection with N40. In contrast, the majority of mice inoculated with the RF agent B. turicatae clear the infection, with the notable exception of residual brain or blood infection in up to 25% of cases. Little if any tissue injury occurs in immunocompetent animals with either LD or RF. In contrast, impairment of specific antibody production results in significant tissue injury, most notably in the heart, in both LD and RF. The inflammatory infiltrate is rich in plasma cells, activated macrophages and T cells, and there is significant deposition of antibody and complement, including membrane attack complex, in inflamed tissues and spirochetes. Significant loss of cardiomyocytes with apoptosis and caspase activation was observed in the heart of immunosuppressed non-human primates infected with N40 and in B cell-deficient mice infected with B. turicatae. Unlike the heart, the brain of B cell-deficient mice infected with B. turicatae showed prominent microglial activation but no detectable tissue injury. Tissues from immunosuppressed non-human primates infected with N40 produce large amounts of immunoglobulin and the B cell chemokine CXCL13, both of which significantly correlate with the spirochetal load. We conclude that the main response of mammalian hosts in LD and RF is the production of specific antibody to clear the infection. Failure of this response leads to persistent infection, which can lead to tissue injury, most notably in the heart.