Assessing robustness and generalization of a deep neural network for brain MS lesion segmentation on real-world data

OBJECTIVES

Evaluate the performance of a deep learning (DL)-based model for multiple sclerosis (MS) lesion segmentation and compare it to other DL and non-DL algorithms.

METHODS

This ambispective, multicenter study assessed the performance of a DL-based model for MS lesion segmentation and compared it to alternative DL- and non-DL-based methods. Models were tested on internal (n = 20) and external (n = 18) datasets from Latin America, and on an external dataset from Europe (n = 49). We also examined robustness by rescanning six patients (n = 6) from our MS clinical cohort. Moreover, we studied inter-human annotator agreement and discussed our findings in light of these results. Performance and robustness were assessed using intraclass correlation coefficient (ICC), Dice coefficient (DC), and coefficient of variation (CV).

RESULTS

Inter-human ICC ranged from 0.89 to 0.95, while spatial agreement among annotators showed a median DC of 0.63. Using expert manual segmentations as ground truth, our DL model achieved a median DC of 0.73 on the internal, 0.66 on the external, and 0.70 on the challenge datasets. The performance of our DL model exceeded that of the alternative algorithms on all datasets. In the robustness experiment, our DL model also achieved higher DC (ranging from 0.82 to 0.90) and lower CV (ranging from 0.7 to 7.9%) when compared to the alternative methods.

CONCLUSION

Our DL-based model outperformed alternative methods for brain MS lesion segmentation. The model also proved to generalize well on unseen data and has a robust performance and low processing times both on real-world and challenge-based data.

CLINICAL RELEVANCE STATEMENT

Our DL-based model demonstrated superior performance in accurately segmenting brain MS lesions compared to alternative methods, indicating its potential for clinical application with improved accuracy, robustness, and efficiency.

KEY POINTS

• Automated lesion load quantification in MS patients is valuable; however, more accurate methods are still necessary. • A novel deep learning model outperformed alternative MS lesion segmentation methods on multisite datasets. • Deep learning models are particularly suitable for MS lesion segmentation in clinical scenarios.

Latin American consensus recommendations on the risk of infections in people with multiple sclerosis treated with disease modifying drugs

INTRODUCTION

The emergence of several therapeutic options in multiple sclerosis (MS), which significantly modify the immune system functioning, has led to the need for the consideration of additional factors, such as risk of infections, in the decision-making process. The aim of these consensus recommendations was to discuss and perform a practical guide to Latin American neurologists on the risk of infections at diagnosis, follow-up and prior to initiation of DMDs.

METHODS

A panel of Latin American neurologists, experts in demyelinating diseases and dedicated to management and care of MS patients, gathered during 2021 and 2022 to make consensus recommendations on the risk of infections in PwMS treated with DMDs in Latin America. The RAND/UCLA methodology was developed to synthesize the scientific evidence and expert opinions on health care topics and was used for reaching a formal agreement.

RESULTS

Recommendations were established based on relevant published evidence and expert opinion, focusing on: 1- baseline infection disease and vaccination status; 2- opportunistic infections; 3- progressive multifocal leukoencephalopathy; 4- genitourinary system infections; 5- respiratory tract infections; 6- digestive system infections, 7-others local infections and 8- COVID-19.

CONCLUSION

The recommendations of this consensus seek to optimize the care, management and treatment of PwMS in Latin America. The standardized evidence-based care of pwMS infections will allow better outcomes.

Towards imaging criteria that best differentiate MS from NMOSD and MOGAD: Large multi-ethnic population and different clinical scenarios

BACKGROUND

The "1/3″ brain magnetic resonance imaging (MRI) criteria including 1) a lesion adjacent to the lateral ventricle and in the inferior temporal lobe, or 2) a juxtacortical lesion, or 3) a Dawson finger-type lesion were shown to distinguish multiple sclerosis (MS) from antibody-mediated conditions. In this large multicentre study, we aimed to assess how the criteria perform 1) in different onset phenotypes, 2) distinct ethnic groups, 3) when the absence of myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated disease (MOGAD)-typical fluffy infratentorial (FIT) lesions and longitudinally extensive transverse myelitis (LETM) lesions are added as features ("2/4″ and 3/5″ criteria, respectively).

METHODS

577 patients with MS (n = 332), aquaporin-4 antibody (AQP4-Ab) neuromyelitis optica spectrum disorder (NMOSD) (n = 196) and MOGAD (n = 49) were recruited from 6 international centres (Buenos Aires, Sao Paolo, Maracaibo, Goyang, Oxford and Milan). Imaging scans were obtained at disease onset or relapse.

RESULTS

Adding the absence of FIT lesions increased the specificity of the "1/3″ criteria vs. AQP4-Ab NMOSD from 84.7% to 87.2% and vs. MOGAD from 85.7% to 93.9% without compromising their sensitivity (86%). In particular, for those presenting with brain/brainstem attacks "2/4″ had significantly higher specificity than "1/3″ (85% vs. 80% against AQP4-Ab NMOSD, 88.9% vs. 72.2% against MOGAD). Positive predictive values of the "1/3″ criteria for MS were lowest for Asian patients (84.8 vs. 99.1% for White) but were significantly increased by adding further criteria (94.1% for "3/5″).

CONCLUSION

The "1/3″ criteria perform well in discriminating MS from NMOSD and MOGAD regardless of ethnic background and clinical scenario. Adding the absence of FIT lesions increases the specificity in those presenting with brain/brainstem symptoms.

The risk of infections for multiple sclerosis and neuromyelitis optica spectrum disorder disease-modifying treatments: Eighth European Committee for Treatment and Research in Multiple Sclerosis Focused Workshop Review. April 2021

Over the recent years, the treatment of multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) has evolved very rapidly and a large number of disease-modifying treatments (DMTs) are now available. However, most DMTs are associated with adverse events, the most frequent of which being infections. Consideration of all DMT-associated risks facilitates development of risk mitigation strategies. An international focused workshop with expert-led discussions was sponsored by the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) and was held in April 2021 to review our current knowledge about the risk of infections associated with the use of DMTs for people with MS and NMOSD and corresponding risk mitigation strategies. The workshop addressed DMT-associated infections in specific populations, such as children and pregnant women with MS, or people with MS who have other comorbidities or live in regions with an exceptionally high infection burden. Finally, we reviewed the topic of DMT-associated infectious risks in the context of the current SARS-CoV-2 pandemic. Herein, we summarize available evidence and identify gaps in knowledge which justify further research.

The frequency and characteristics of multiple sclerosis misdiagnosis in Latin America: A referral center study in Buenos Aires, Argentina

OBJECTIVE

Most contemporary data concerning the frequency and causes of multiple sclerosis (MS) misdiagnosis are from North America and Europe with different healthcare system structure and resources than countries in Latin America. We sought to determine the frequency, and potential contributors to MS misdiagnosis in patients evaluated at an MS referral center in Argentina.

METHODS

The study was a retrospective medical record review. We included patients evaluated at the MS Clinic at Fleni between April 2013 and March 2021. Diagnoses prior to consultation, final diagnoses after consultation, demographic, clinical and paraclinical data, and treatment were extracted and classified.

RESULTS

Seven hundred thirty-six patients were identified. Five hundred seventy-two presented with an established diagnosis of MS and after evaluation, misdiagnosis was identified in 89 (16%). Women were at 83% greater risk of misdiagnosis (p = 0.034). The most frequent alternative diagnoses were cerebrovascular disease, radiological isolated syndrome (RIS), and headache. Seventy-four (83%) of misdiagnosed patients presented with a syndrome atypical for demyelination, 62 (70%) had an atypical brain magnetic resonance imaging (MRI), and 54 (61%) were prescribed disease-modifying therapy.

CONCLUSION

Sixteen percent of patients with established MS were subsequently found to have been misdiagnosed. Women were at higher risk for misdiagnosis. Expert application of the McDonald criteria may prevent misdiagnosis and its associated morbidity and healthcare system cost.

The Immune Response in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic autoimmune, inflammatory, and neurodegenerative disease that affects the central nervous system (CNS). MS is characterized by immune dysregulation, which results in the infiltration of the CNS by immune cells, triggering demyelination, axonal damage, and neurodegeneration. Although the exact causes of MS are not fully understood, genetic and environmental factors are thought to control MS onset and progression. In this article, we review the main immunological mechanisms involved in MS pathogenesis. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease, Volume 17 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Obesity and the risk of Multiple Sclerosis. The role of Leptin

OBJECTIVE

To investigate the effects of leptin on different T-cell populations, in order to gain more insight into the link between leptin and obesity.

METHODS

Three hundred and nine RRMS patients and 322 controls participated in a cross-sectional survey, to confirm whether excess weight/obesity in adolescence or early adulthood increased the risk of MS. Serum leptin levels were determined by ELISA. MBP_83-102 , and MOG_63-87 peptide-specific T cells lines were expanded from peripheral blood mononuclear cells. Leptin receptor expression was measured by RT-PCR and flow cytometry. Bcl-2, p-STAT3, pERK1/2, and p27^kip1 expression were assayed using ELISA, and apoptosis induction was determined by Annexin V detection. Cytokines were assessed by ELISPOT and ELISA, and regulatory T cells (Tregs) by flow cytometry.

RESULTS

Logistic regression analysis, showed excess weight at age 15, and obesity at 20 years of age increased MS risk (OR = 2.16, P = 0.01 and OR = 3.9, P = 0.01). Leptin levels correlated with BMI in both groups. The addition of Leptin increased autoreactive T-cell proliferation, reduced apoptosis induction, and promoted proinflammatory cytokine secretion. Obese patients produced more proinflammatory cytokines compared to overweight/normal/underweight subjects. Inverse correlation was found between leptin levels and circulating Treg cells (r = -0.97, P < 0.0001). Leptin inhibited Treg proliferation. Effects of leptin on CD4⁺ CD25^- effector T cells were mediated by increased STAT3 and ERK1/2 phosphorylation, and down modulation of the cell cycle inhibitor P27^kip1 . In contrast, leptin effects on Tregs resulted from decreased phosphorylation of ERK1/2 and upregulation of p27^kip1 .

INTERPRETATION

Leptin promotes autoreactive T-cell proliferation and proinflammatory cytokine secretion, but inhibits Treg-cell proliferation.

COVID-19 pneumonia accurately detected on chest radiographs with artificial intelligence

Purpose

To investigate the diagnostic performance of an Artificial Intelligence (AI) system for detection of COVID-19 in chest radiographs (CXR), and compare results to those of physicians working alone, or with AI support.

Materials and methods

An AI system was fine-tuned to discriminate confirmed COVID-19 pneumonia, from other viral and bacterial pneumonia and non-pneumonia patients and used to review 302 CXR images from adult patients retrospectively sourced from nine different databases. Fifty-four physicians blind to diagnosis, were invited to interpret images under identical conditions in a test set, and randomly assigned either to receive or not receive support from the AI system. Comparisons were then made between diagnostic performance of physicians working with and without AI support. AI system performance was evaluated using the area under the receiver operating characteristic (AUROC), and sensitivity and specificity of physician performance compared to that of the AI system.

Results

Discrimination by the AI system of COVID-19 pneumonia showed an AUROC curve of 0.96 in the validation and 0.83 in the external test set, respectively. The AI system outperformed physicians in the AUROC overall (70% increase in sensitivity and 1% increase in specificity, p < 0.0001). When working with AI support, physicians increased their diagnostic sensitivity from 47% to 61% (p < 0.001), although specificity decreased from 79% to 75% (p = 0.007).

Conclusions

Our results suggest interpreting chest radiographs (CXR) supported by AI, increases physician diagnostic sensitivity for COVID-19 detection. This approach involving a human-machine partnership may help expedite triaging efforts and improve resource allocation in the current crisis.

Brain volumes quantification from MRI in healthy controls: Assessing correlation, agreement and robustness of a convolutional neural network-based software against FreeSurfer, CAT12 and FSL

BACKGROUND AND PURPOSE

There are instances in which an estimate of the brain volume should be obtained from MRI in clinical practice. Our objective is to calculate cross-sectional robustness of a convolutional neural network (CNN) based software (Entelai Pic) for brain volume estimation and compare it to traditional software such as FreeSurfer, CAT12 and FSL in healthy controls (HC).

MATERIALS AND METHODS

Sixteen HC were scanned four times, two different days on two different MRI scanners (1.5 T and 3 T). Volumetric T1-weighted images were acquired and post-processed with FreeSurfer v6.0.0, Entelai Pic v2, CAT12 v12.5 and FSL v5.0.9. Whole-brain, grey matter (GM), white matter (WM) and cerebrospinal fluid (CSF) volumes were calculated. Correlation and agreement between methods was assessed using intraclass correlation coefficient (ICC) and Bland Altman plots. Robustness was assessed using the coefficient of variation (CV).

RESULTS

Whole-brain volume estimation had better correlation between FreeSurfer and Entelai Pic (ICC (95% CI) 0.96 (0.94-0.97)) than FreeSurfer and CAT12 (0.92 (0.88-0.96)) and FSL (0.87 (0.79-0.91)). WM, GM and CSF showed a similar trend. Compared to FreeSurfer, Entelai Pic provided similarly robust segmentations of brain volumes both on same-scanner (mean CV 1.07, range 0.20-3.13% vs. mean CV 1.05, range 0.21-3.20%, p = 0.86) and on different-scanner variables (mean CV 3.84, range 2.49-5.91% vs. mean CV 3.84, range 2.62-5.13%, p = 0.96). Mean post-processing times were 480, 5, 40 and 5 min for FreeSurfer, Entelai Pic, CAT12 and FSL respectively.

CONCLUSION

Based on robustness and processing times, our CNN-based model is suitable for cross-sectional volumetry on clinical practice.

Intravenous Chlorpromazine as Potentially Useful Treatment for Chronic Headache Disorders

OBJECTIVE

The aim of this study was to describe a group of patients with chronic headache disorders (CH) and medication overuse headache (MOH) treated with intravenous chlorpromazine (IVC). We hypothesized that IVC is an effective and safe addition to well-known treatment strategies for CH and MOH management.

INTRODUCTION

Up to 4% of the general population could experience CH. Most cases occur in women, in association with MOH. To date, evidence to support different treatment strategies is lacking. Although IVC is frequently used in the emergency room (ER), documentation on its use as supportive treatment for CH and for withdrawal management of MOH is poor.

METHODS

A retrospective cohort of patients hospitalized to receive treatment for CH in a specialized neurological center in Argentina was analyzed.

RESULTS

A total of 35 CH patients were included. Of the 35 patients, 33 (94%) patients also presented MOH. Patients reported only minor side effects to IVC administration (mainly drowsiness and symptomatic hypotension). Three months after inpatient treatment, the number of ER visits made by these patients decreased from an average of 2.8 in the 3 months prior to hospitalization to 0.7 after it (72%, P = .009). Headache frequency decreased in 20/34 (59%) patients during the same time period. Pain levels had dropped from a mean of 8 points at admission (in the scale of 1-10) to 2 points at discharge. In the first 3 months of follow-up, the average number of days per month in which patients experienced headache decreased from 28.9 to 15.4 days (53.3%, P < .0001).

CONCLUSION

In this particular group of inpatients, there were no significant safety issues with IVC administration and the study might suggest that the efficacy of IVC as an add-on treatment for CH and MOH.

Disease activity impacts disability progression in primary progressive multiple sclerosis

BACKGROUND

Although solid information on the natural history of primary progressive multiple sclerosis (PPMS) is available, evidence regarding impact of disease activity on PPMS progression remains controversial.

OBJECTIVE

To describe the clinical characteristics, presence or absence of MRI activity, and natural history of a PPMS cohort from two referral centers in Argentina and assess whether clinical and/or radiological disease activity correlated with disability worsening.

METHODS

Retrospective study conducted at two MS clinics in Buenos Aires, Argentina, through comparative analysis of patients with and without evidence of disease activity.

RESULTS

Clinical and/or radiologic activity was presented in 56 (31%) of 178 patients. When stratified by age at onset, we found that for every 10 years of increase in age at onset, risk of reaching EDSS scores of 4 and 6 increased by 26% and 31%, respectively (EDSS 4: HR 1.26, CI 95%: 1.06-1.50; EDSS 6: HR 1.31, CI 95%: 1.06-1.62). Patients who presented clinical exacerbations reached EDSS scores of 6, 7 and 8 faster than those without associated exacerbations (p = 0.009, p = 0.016 and p = 0.001, respectively). Likewise, patients who presented gadolinium-enhancing lesions during the course of disease reached EDSS scores of 7 earlier (p = 0.002).

CONCLUSION

Older age at onset and presence of clinical and/or radiological disease activity correlated with accelerated disability progression in this cohort of PPMS patients.

Transient global amnesia: clinical features and prognostic factors suggesting recurrence

OBJECTIVE

The risk of recurrence of new amnesia events in patients having previously experienced transient global amnesia (TGA) ranges between 2.9-23.8%. Our objective was to search for recurrence predictors in TGA patients.

METHODS

Retrospective analysis to identify recurrence predictors in a cohort of 203 TGA patients from a single center in Buenos Aires, Argentina, diagnosed between January 2011 and March 2017 Clinical features and complementary studies (laboratory results, jugular vein Doppler ultrasound and brain MRI) were analyzed. Comparison between patients with recurrent versus single episode TGA was performed, applying a multivariate logistic regression model.

RESULTS

Mean age at presentation was 65 years (20-84); 52% were female. Median time elapsed between symptom onset and ER visit was two hours, with the average episode duration lasting four hours. Mean follow-up was 22 months. Sixty-six percent of patients referred to an identifiable trigger. Jugular reflux was present in 66% of patients; and 22% showed images with hippocampus restriction on diffusion-weighted MRI. Eight percent of patients had TGA recurrence. Patients with recurrent TGA had a more frequent history of migraine than patients without recurrence (37.5% vs. 14%; p = 0.03). None of the other clinical characteristics and complementary studies were predictors of increased risk of recurrence.

CONCLUSIONS

Patients with migraine may have a higher risk of recurrent TGA. None of the other clinical characteristics evaluated allowed us to predict an increased risk of recurrence. Although the complementary studies allowed us to guide the diagnosis, they did not appear to have a significant impact on the prediction of recurrence risk.

Mucosal-Associated Invariant T Cell Features and TCR Repertoire Characteristics During the Course of Multiple Sclerosis

Objective: To investigate the frequency, phenotype, function, and longitudinal repertoire of mucosal-associated invariant T (MAIT) cells in relapsing remitting multiple sclerosis (RRMS) and primary progressive multiple sclerosis (PPMS) patients.

Methods: Forty-five RRMS patients in remission, 20 RRMS patients experiencing exacerbations, 15 PPMS patients, and 30 healthy controls (HCs) were included in the study. MAIT cells were identified phenotypically as CD3⁺ TCRγδ⁻ Vα7.2 + CD161^high. In 15 patients, MAIT cell number and MRI lesions were evaluated every 6 months, for 36 months. MAIT cell TCRVβ repertoire was defined using single-cell cloning and mRNA sequencing.

Results: Circulating MAIT cells were significantly reduced in both RRMS and PPMS patients, particularly during exacerbations, compared to healthy subjects. This decrease was accompanied by pro-inflammatory cytokine production (TNF-α, IFN-γ, IL-17, and GM-CSF). Three months post-exacerbation, peripheral blood MAIT cell percentages increased significantly along with clinical recovery. Likewise, we observed inverse correlation between MRI lesions and peripheral blood MAIT cell numbers. In paired samples, MAIT cell percentage was significantly higher in CSF than in peripheral blood, suggesting MAIT cell migration through the blood–brain barrier. Finally, MAIT cells showed limited TCRVβ repertoires, in both CSF and peripheral blood, which remained stable over time.

Conclusions: MAIT cell levels correlated with MS course both clinically and radiologically, showing marked and sustained oligoclonality. These findings may contribute to a better understanding of pathophysiological phenomena underlying the course of MS, and discovery of MAIT cell inhibitors could pave the way for the development of new therapeutic strategies.

Author Correction: Control of tumor-associated macrophages and T cells in glioblastoma via AHR and CD39

In the version of this article initially published, author Alexandre Prat's surname was misspelled. The error has been corrected in the HTML and PDF versions of the article.

Practice guideline update summary: Vaccine-preventable infections and immunization in multiple sclerosis

Objective

To update the 2002 American Academy of Neurology (AAN) guideline regarding immunization and multiple sclerosis (MS).

Methods

The panel performed a systematic review and classified articles using the AAN system. Recommendations were based on evidence, related evidence, principles of care, and inferences according to the AAN 2011 process manual, as amended.

Major recommendations (Level B except where indicated)

Clinicians should discuss the evidence regarding immunizations in MS with their patients and explore patients' opinions, preferences, and questions. Clinicians should recommend that patients with MS follow all local vaccine standards, unless there are specific contraindications and weigh local vaccine-preventable disease risks when counseling patients. Clinicians should recommend that patients with MS receive the influenza vaccination annually. Clinicians should counsel patients with MS about infection risks associated with specific immunosuppressive/immunomodulating (ISIM) medications and treatment-specific vaccination guidance according to prescribing information (PI) and vaccinate patients with MS as needed at least 4–6 weeks before initiating patients' ISIM therapy. Clinicians must screen for infections according to PI before initiating ISIM medications (Level A) and should treat patients testing positive for latent infections. In high-risk populations, clinicians must screen for latent infections before starting ISIM therapy even when not specifically mentioned in PI (Level A) and should consult specialists regarding treating patients who screen positive for latent infection. Clinicians should recommend against using live-attenuated vaccines in people with MS receiving ISIM therapies. Clinicians should delay vaccinating people with MS who are experiencing a relapse.

Control of tumor-associated macrophages and T cells in glioblastoma via AHR and CD39

Tumor-associated macrophages (TAMs) play an important role in the immune response to cancer, but the mechanisms by which the tumor microenvironment controls TAMs and T cell immunity are not completely understood. Here we report that kynurenine produced by glioblastoma cells activates aryl hydrocarbon receptor (AHR) in TAMs to modulate their function and T cell immunity. AHR promotes CCR2 expression, driving TAM recruitment in response to CCL2. AHR also drives the expression of KLF4 and suppresses NF-κB activation in TAMs. Finally, AHR drives the expression of the ectonucleotidase CD39 in TAMs, which promotes CD8⁺ T cell dysfunction by producing adenosine in cooperation with CD73. In humans, the expression of AHR and CD39 was highest in grade 4 glioma, and high AHR expression was associated with poor prognosis. In summary, AHR and CD39 expressed in TAMs participate in the regulation of the immune response in glioblastoma and constitute potential targets for immunotherapy.

A Population-Based Survey of Stroke Knowledge in Argentina: The SIFHON Study

BACKGROUND AND OBJECTIVES

Information about stroke awareness in Latin America is scant. We conducted a large population survey in Argentina to assess stroke knowledge.

METHODS

We distributed 110,000 multiple-choice anonymous questionnaires using the house distribution system of a bottled water dispensing company. The survey assessed demographic characteristics and stroke knowledge.

RESULTS

A total of 12,710 surveys were returned (12%). Even though 95% of the respondents reported some prior information about stroke, only 37% had adequate knowledge based on prespecified criteria. The Spanish acronym for accidente cerebrovascular, was the most frequently identified name for stroke. Sixty nine percent of respondents were able to identify stroke main risk factors and only 29% knew about transient ischemic attacks. If a hypothetical scenario of stroke was presented, 63% knew the existence of a time-dependent treatment, 25% would call an ambulance, and 50% would go to an emergency room by own means. A lower degree of knowledge was present in young, single, and nonuniversity men.

CONCLUSIONS

This study represents the largest stroke awareness survey in a Spanish-speaking population. There was good recognition of some basic facts of stroke. However, the population had poor knowledge of prevalence and severity of the disease, transient ischemic attacks, and treatment availability.

Headache in Patients with Celiac Disease and Its Response to the Gluten-Free Diet

AIMS

To describe headache characteristics among celiac disease (CD) patients and to analyze the relationship between CD and headache.

METHODS

An online survey analyzing the characteristics of headache and its response to the gluten-free diet (GFD) in celiac patients was published on Argentinean Celiac social networks, open to the public to complete. The results were analyzed using chi-square test or Mann-Whitney test accordingly.

RESULTS

A total of 1,517 subjects completed the survey, and 866 (55.2%) met the inclusion criteria (headache and CD confirmed with positive biopsy). The subjects were predominantly female (94.5%) and had a median age of 39 ± 11.27 years. Tension-type headache was the most prevalent headache type (52%), followed by migraine without (32.5%) and with aura (15.4%), respectively. Of the included participants, 24% reported headache as the main symptom that resulted in the diagnosis of CD. Following initiation of GFD, headache frequency and intensity improved significantly more in participants with migraine than tension-type headache (P = .02 and P = .013, respectively). Compliance to GFD was higher among subjects with severe manifestations (77% vs 66%, P = .05), and compliant individuals showed a 48% improvement in headache frequency (P = .049). An association between food transgressions and headache was better recognized by migraineurs (P = .02).

CONCLUSION

These results suggest that strict compliance to the GFD could improve headache in celiac patients with headache, even in those without gastrointestinal symptoms. This observation could provide an additional factor when convincing patients to follow a GFD, thus reducing the morbidity related to CD.

The role of infections in multiple sclerosis

Several lines of evidence suggest that multiple sclerosis (MS), like other autoimmune diseases, may be triggered by microbial infections. Pathogens associated with development or exacerbation of MS include bacteria, such as Chlamydia pneumoniae, Staphylococcus aureus-produced enterotoxins that function as superantigens, and viruses of the Herpesviridae (Epstein–Barr virus and human herpes virus 6) and human endogenous retrovirus families. However, to date, no single pathogen has been accepted as causal agent. In addition, common upper respiratory, gastrointestinal, and urogenital tract infections have also been associated with MS exacerbations. Although evidence of an infectious etiology as cause of MS in humans remains inconclusive, microbial agents may modulate the neuroimmunological system of genetically susceptible individuals. Decoding the epidemiological contribution of different microorganisms to MS, along with their pathogenic mechanisms, may help develop new treatment strategies and prevent relapses.

Cerebellar Ataxia With Extreme Photophobia Associated With Anti-SOX1 Antibodies

Anti-SOX1 antibodies are associated with diverse neurological syndromes, targeting both the central (paraneoplastic cerebellar degeneration) and peripheral nervous systems (Lambert Eaton myasthenic syndrome, paraneoplastic neuropathy). Although the pathogenic role of these antibodies remains unclear, their strong association with underlying neoplastic disease (mainly small-cell lung cancer) has designated them as onconeural antibodies. Here, we present a case of cerebellar ataxia with marked photophobia, with severe atrophy of the cerebellum and brain stem, associated with anti-SOX1 antibodies without evidence of an underlying malignancy. Although anti-SOX1-associated cerebellar syndrome is infrequent, investigation of these antibodies should be considered as a part of the diagnostic algorithm if more common causes have been ruled out. Extensive brain stem lesions causing disruption of the trigeminal pathway and its connections with the pretectal area might explain the underlying mechanism of the associated photophobia. Early recognition of anti-SOX1 antibodies, exclusion of underlying neoplasm, and prompt initiation of immunotherapy are essential to achieve a better outcome.

Differences between acute-onset chronic inflammatory demyelinating polyneuropathy and acute inflammatory demyelinating polyneuropathy in adult patients

Acute inflammatory demyelinating polyneuropathy (AIDP) and acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) are conditions presenting overlapping clinical features during early stages (first 4 weeks), although the latter may progress after 8 weeks. The aim of this study was to identify predictive factors contributing to their differential diagnosis. Clinical records of adult patients with AIDP or A-CIDP diagnosed at our institution between January 2006 and July 2017 were retrospectively reviewed. Demographic characteristics, clinical manifestations, cerebrospinal-fluid (CSF) findings, treatment and clinical evolution were analyzed. Nerve conduction studies were performed in all patients with at least 12 months follow-up. A total of 91 patients were included (AIDP, n = 77; A-CIDP, n = 14). The median age was 55.5 years in patients with A-CIDP vs 43 years in AIDP (P = .07). The history of diabetes mellitus was more frequent in A-CIDP (29% vs 8%, P = .04). No significant differences between groups were observed with respect to: human immunodeficiency virus (HIV) status, presence of auto-immune disorder or oncologic disease. Cranial, motor and autonomic nerve involvement rates were similar in both groups. Patients in the A-CIDP group showed higher frequency of proprioceptive disturbances (83% vs 28%; P < .001), sensory ataxia (46% vs 16%; P = .01), and the use of combined immunotherapy with corticoids (29% vs 3%; P = .005). There were no significant differences in CSF findings, intensive care unit (ICU) admission, or mortality rates. During the first 8 weeks both entities are practically indistinguishable. Alterations in proprioception could suggest A-CIDP. Searching for markers that allow early differentiation could favor the onset of corticotherapy without delay.

Effects of Systolic Blood Pressure on Brain Integrity in Multiple Sclerosis

Background: In MS patients, hypertension is associated with a delayed diagnosis and an increased risk of progression. Understanding the mechanisms of this association could potentially lead to improved prevention of disease progression. We aimed to establish whether high blood pressure contributes to white-matter injury and brain atrophy in MS.

Methods: Cross-sectional study of 95 patients with RRMS. Estimates of fractional anisotropy, gray-matter volume and lesion load were obtained from 3T MRI. We used fractional anisotropy voxel-based statistics to establish the effect of blood pressure on white matter tracts. Additionally, we used voxel-based morphometry (VBM) to study the effect on gray matter integrity.

Results: Only 29.5% had normal blood pressure levels, with 52.6% suffering from prehypertension and 17.9% with hypertension. Increasing systolic blood pressure was associated with damage to posterior white-matter tracts as well as greater levels of gray matter atrophy, in particular in the frontal cortex. Age-adjusted linear regression indicated that neither lesion volume (β = 0.002, 95%CI: 0.02–0.02; p = 0.85) or lesion number (β = −0.004, 95%CI: 0.03–0.02; p = 0.74) were associated with systolic blood pressure.

Conclusions: Prehypertension and hypertension are frequent in MS. Increased blood pressure is related to white- and gray-matter integrity, both related to MS disability outcomes. These findings suggest attention to the control of blood pressure in MS patients.

Chronic and Subacute Meningitis: Differentiating Neoplastic From Non-Neoplastic Etiologies

Background and Purpose

Although incidence rates vary, infectious, autoimmune, and neoplastic diseases can all cause chronic and subacute meningitis (CSM). We report a Latin-American, single center, CSM case series, analyzing the main clinical characteristics as well as ancillary diagnostic methods differentiating neoplastic from non-neoplastic etiologies.

Methods

Retrospective review of CSM cases from a single center in Buenos Aires, Argentina.

Results

Seventy patients with CSM diagnosis were identified, 49 with neoplastic and 21 with non-neoplastic meningitis. A history of previous cancer was significantly higher in neoplastic cases, whereas prevalence of autoimmune disease and fever was more common in non-neoplastic meningitis. C-reactive protein values were higher in non-neoplastic CSM, as was pleocytosis in cerebrospinal fluid analysis. The most frequent etiologies were breast and lung cancer for neoplastic meningitis cases; and idiopathic, tuberculous, and fungal infection for non-neoplastic cases.

Conclusions

Chronic and subacute meningitis diagnosis is challenging in daily neurological practice. The results we report contribute information from Latin America regarding etiologies of CSM, which can be identified after a comprehensive evaluation in a majority of cases.

Door-to-Needle Time in Acute Stroke Treatment and the "July Effect"

Intravenous thrombolysis improves outcomes in acute ischemic stroke in a time-dependent fashion. As in teaching hospitals, clinical outcomes may worsen due to the arrival of new inexperienced house staff early in the academic year (July effect, JE), we evaluated the impact of the "JE" on the door-to-needle time for intravenous thrombolysis and other stroke outcomes. In this retrospective cohort study, we assessed all acute ischemic strokes treated with intravenous thrombolysis between July 2003 and June 2016. Among 101 patients, there was no detrimental July effect on the door-to-needle time, rate of thrombolysis within 60 minutes of arrival, thrombolysis of stroke mimics, post-thrombolysis intracranial hemorrhages, National Institutes of Health Stroke Scale, and modified Rankin Scale outcomes.

Differential characteristics, stroke recurrence, and predictors of covert atrial fibrillation of embolic strokes of undetermined source

Background and purpose Identifying embolic strokes of undetermined source (ESUS) patients likely to harbor atrial fibrillation may have diagnostic and therapeutic implications. Our aim was to examine differences between ESUS and cardioembolic strokes, to evaluate stroke recurrence rate among ESUS and to identify baseline characteristics of ESUS patients who were later diagnosed with atrial fibrillation. Materials and methods We assessed all ischemic stroke patients admitted between June 2012 and November 2013. ESUS were compared to cardioembolic strokes at discharge. After at least 12-month follow-up, ESUS patients diagnosed with atrial fibrillation were compared to those who remained as ESUS. Results There were 236 ischemic strokes, 32.6% were ESUS. Compared to cardioembolic strokes, ESUS were younger (p < 0.0001), had milder strokes (p < 0.05), less prevalence of hypertension (p < 0.05), peripheral vascular disease (p < 0.05), and previous ischemic stroke (p < 0.05). After follow-up, 15% of ESUS patients had stroke recurrences and 12% evidenced paroxysmal atrial fibrillation. ESUS patients diagnosed with atrial fibrillation in the follow-up were older (p < 0.0001), had higher erythrocyte sedimentation rate (p < 0.05), and were more likely to have ≥2 infarcts in the same arterial territory in the initial magnetic resonance imaging (p < 0.05). Conclusions Older age, small-scattered infarcts on initial magnetic resonance imaging and high erythrocyte sedimentation rate levels appear to identify ESUS patients more likely to be diagnosed of atrial fibrillation during follow-up.

Environmental factors influencing multiple sclerosis in Latin America

It is generally accepted that autoimmune diseases like multiple sclerosis (MS) arise from complex interactions between genetic susceptibility and environmental factors. Genetic variants confer predisposition to develop MS, but cannot be therapeutically modified. On the other hand, several studies have shown that different lifestyle and environmental factors influence disease development, as well as activity levels and progression. Unlike genetic risk factors, these can be modified, with potential for prevention, particularly in high-risk populations. Most studies identifying particular lifestyle and environmental factors have been carried out in Caucasian patients with MS. Little or no data is available on the behavior of these factors in Latin American populations. Ethnic and geographic differences between Latin America and other world regions suggest potential regional variations in MS, at least with respect to some of these factors. Furthermore, particular environmental characteristics observed more frequently in Latin America could explain regional differences in MS prevalence. Site-specific studies exploring influences of local environmental factors are warranted.

Immunologic Effects of Metformin and Pioglitazone Treatment on Metabolic Syndrome and Multiple Sclerosis

IMPORTANCE

Metabolic syndrome (MetS) is thought to influence several autoimmune diseases, including multiple sclerosis (MS). Anti-inflammatory effects of treatments used for MetS, such as metformin hydrochloride and pioglitazone hydrochloride, have been demonstrated, although clinical evidence supporting use of these treatments in MS is lacking.

OBJECTIVES

To determine whether metformin and/or pioglitazone are associated with a reduction in disease activity as measured by brain magnetic resonance imaging in patients with MS and MetS and to evaluate the potential mechanisms underlying this anti-inflammatory effect.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study was conducted from March 1, 2012, to December 30, 2014, at a private MS referral center among 50 obese patients with MS who also developed MetS. Twenty patients received metformin hydrochloride, 850 to 1500 mg/d, and 10 patients received pioglitazone hydrochloride, 15 to 30 mg/d; 20 untreated patients served as controls. Groups were comparable in terms of sex, age, body mass index, Expanded Disability Status Scale score, disease duration, annual relapse rate, and treatment status. Patients were followed up for a mean (SD) of 26.7 (2.7) months (range, 24-33 months).

MAIN OUTCOMES AND MEASURES

Magnetic resonance imaging of the brain was performed at 6-month intervals, and the presence of new or enlarging T2 lesions or gadolinium-enhancing lesions was registered. Serum leptin and adiponectin levels were measured. The production of cytokines by peripheral blood mononuclear cells was assayed, as were regulatory T-cell numbers and function.

RESULTS

Of 50 patients, after 6 months of treatment, 20 patients with MS who were treated with metformin and 10 who received pioglitazone showed a significant decrease in the number of new or enlarging T2 lesions (metformin, 2.5 at study entry to 0.5 at month 24; pioglitazone, 2.3 at study entry to 0.6 at month 24), as well as of gadolinium-enhancing lesions (metformin, 1.8 at study entry to 0.1 at month 24; pioglitazone, 2.2 at study entry to 0.3 at month 24). Compared with controls, both treatments led to a decrease in mean (SD) leptin levels (metformin, 5.5 [2.4] vs 10.5 [3.4] ng/mL, P < .001; pioglitazone, 4.1 [0.8] vs 11.0 [2.6] ng/mL, P < .001) and increase in mean (SD) adiponectin serum levels (metformin, 15.4 [5.5] vs 4.5 [2.4] μg/mL, P < .001; pioglitazone, 12.6 [3.6] vs 4.8 [0.6] μg/mL, P < .001). Mean (SD) number of myelin basic protein peptide-specific cells secreting interferon γ and interleukin (IL)-17 were significantly reduced in patients receiving metformin compared with controls (interferon γ, 30.3 [11.5] vs 82.8 [18.8], P < .001; IL-17, 212.4 [85.5] vs 553.8 [125.9], P < .001). Patients treated with pioglitazone showed significant decreases in the mean (SD) number of myelin basic protein peptide-specific cells secreting IL-6 and tumor necrosis factor compared with controls (IL-6, 361.6 [80.5] vs 1130.7 [149.21], P < .001; tumor necrosis factor, 189.9 [53.4] vs 341.0 [106.0], P < .001). Both metformin and pioglitazone resulted in a significant increase in the number and regulatory functions of CD4+CD25+FoxP3+ regulatory T cells compared with controls (metformin, 6.7 [1.5] vs 2.1 [1.0], P = .001; pioglitazone, 6.9 [0.8] vs 3.0 [0.8], P = .001).

CONCLUSIONS AND RELEVANCE

Treatment with metformin and pioglitazone has beneficial anti-inflammatory effects in patients with MS and MetS and should be further explored.

Age may contribute to the increased frequency of axonal Guillain-Barré syndrome

INTRODUCTION

The frequency of axonal Guillain-Barré syndrome (GBS) varies among countries. Previous studies supporting the high frequency of axonal GBS in South America have been carried out with pediatric populations. We seek to determine the frequency of axonal GBS in both children and adults in South America.

METHODS

This is a retrospective cohort analysis of patients who were diagnosed with GBS between January 2006 and December 2013 in a neurological center in Buenos Aires, Argentina. Adults and children with a diagnosis of GBS were included and classified by applying Ho and colleagues' criteria¹ for axonal GBS.

RESULTS

The study included 105 patients with GBS. Among 58 adults, only 5 individuals were classified as axonal GBS compared with 16 of 47 children. The frequency of axonal GBS was significantly higher in children than in adults (34% vs. 8.6%, P = 0.0001).

DISCUSSION

As shown in a cohort of South American patients, age may impact the frequency of axonal GBS. Muscle Nerve 56: 1311-1313, 2017.

Headache and Treatment of Unruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE

The relationship between unruptured intracranial aneurysms (UIAs) and chronic headache and the impact of aneurysm treatment on headache outcome are controversial. The aim of this study was to determine clinical features of a supposedly primary headache in patients with UIA. We also assessed changes in headache characteristics after UIA treatment.

METHODS

We examined clinical and imaging data of patients in whom a UIA was diagnosed during diagnostic workup of a suspected primary headache. Medical records were reviewed and personal telephone follow-ups were performed after UIA treatment to assess changes in the frequency and intensity of the headache.

RESULTS

Forty-two patients (76%) reported a substantial improvement in headache frequency and intensity after UIA treatment. Forty-five patients (81%) reported a decrease in headache frequency from a median of 8 days/month before treatment to 1 day/month after treatment (95% confidence interval [CI] 81-83, P < .001). The average intensity in an analog pain scale was 7.7 ± 1.6 before treatment and 5.6 ± 2.4 after treatment (P < .001). Higher headache frequency was associated with a greater odd of improvement after treatment (odds ratio 1.12, 95% CI 1.0-1.26, P = .03). No associations were found between the type of headache, type of treatment (endovascular versus surgical), number, size, or localization of the aneurysms and the response to treatment.

CONCLUSIONS

The treatment of UIA had a robust beneficial effect on previous headache. Although a "placebo" effect of aneurysm treatment cannot be ruled out, these results suggest a potential association between UIA and certain chronic headaches usually considered to be primary.

Abstract TP199: Stroke Awareness in Argentina, the Sifhon Population Survey

Introduction: Stroke awareness in Latin America is scant. We conducted a large population survey in 13 provinces in Argentina to assess knowledge of cerebrovascular disease.

Methods: We distributed 110,000 multiple-choice anonymous questionnaires using the house distribution system of a bottled water dispensing company, assessing information regards age, gender, educational level, general stroke information, attitude towards symptoms and treatment. Percentages of each choice were recorded for every question and a multivariate analysis was performed.

Results: A total of 12,710 surveys were returned, age 51±17 years, 69% women. Almost 95% reported prior knowledge of the disease, 50% through public media, 37% through a relative/friend that had a stroke and 8% through their family doctor. The Spanish acronym for accidente cerebrovascular , ACV, was the most frequently identified name for stroke (79%), the Spanish equivalent to cerebral attack was used by 7% and 0,4% used the term “ictus”. Only 29% knew about TIA but 69% identified stroke risk factors. Although 73% recognized their signs and symptoms, 11% misinterpreted them as a heart attack and 34% ignored that stroke can present with severe headache. Although 73% considered the disease potentially disabling/fatal, 40% ignored its frequency. If symptoms, 25% would call 911 and 50% would go to an emergency room by own means. Only 63% knew the existence of a specific treatment. Lowest degree of knowledge was seen in young, single, non-university men.

Conclusion: This study represents the largest general public stroke awareness survey in Spanish speaking populations. Respondents showed excellent recognition of risk factors, warning signs and need of a rapid response. The population had little knowledge of prevalence, severity, TIA, and acute treatment. Public media appear to have an essential role in education.

Perception of stroke symptoms and utilization of emergency medical services

Methods

Review of hospital records and structured telephone interviews of 100 consecutive stroke patients. Forward stepwise logistic regression was used for the statistical analysis.

Results

Seventy patients (75%) arrived at the hospital 4.5 hours after stroke symptoms onset. The use of EMS did not improve arrival times. Most patients who recognized their symptoms did not use EMS (p < 0.02). Nineteen patients (20%) were initially misdiagnosed. Eighteen of them were first assessed by non-neurologist physicians (p < 0.001).

Conclusions

Our population showed a low level of stroke awareness. The use of EMS did not improve arrival times at the hospital and the non-utilization of the EMS was associated with the recognition of stroke symptoms. There was a concerning rate of misdiagnosis, mostly by non-neurologist medical providers.

Melatonin Contributes to the Seasonality of Multiple Sclerosis Relapses

Seasonal changes in disease activity have been observed in multiple sclerosis, an autoimmune disorder that affects the CNS. These epidemiological observations suggest that environmental factors influence the disease course. Here, we report that melatonin levels, whose production is modulated by seasonal variations in night length, negatively correlate with multiple sclerosis activity in humans. Treatment with melatonin ameliorates disease in an experimental model of multiple sclerosis and directly interferes with the differentiation of human and mouse T cells. Melatonin induces the expression of the repressor transcription factor Nfil3, blocking the differentiation of pathogenic Th17 cells and boosts the generation of protective Tr1 cells via Erk1/2 and the transactivation of the IL-10 promoter by ROR-α. These results suggest that melatonin is another example of how environmental-driven cues can impact T cell differentiation and have implications for autoimmune disorders such as multiple sclerosis.

The Role of Astrocytes in Multiple Sclerosis Progression

Multiple sclerosis (MS) is an inflammatory disorder causing central nervous system (CNS) demyelination and axonal injury. Although its etiology remains elusive, several lines of evidence support the concept that autoimmunity plays a major role in disease pathogenesis. The course of MS is highly variable; nevertheless, the majority of patients initially present a relapsing–remitting clinical course. After 10–15 years of disease, this pattern becomes progressive in up to 50% of untreated patients, during which time clinical symptoms slowly cause constant deterioration over a period of many years. In about 15% of MS patients, however, disease progression is relentless from disease onset. Published evidence supports the concept that progressive MS reflects a poorly understood mechanism of insidious axonal degeneration and neuronal loss. Recently, the type of microglial cell and of astrocyte activation and proliferation observed has suggested contribution of resident CNS cells may play a critical role in disease progression. Astrocytes could contribute to this process through several mechanisms: (a) as part of the innate immune system, (b) as a source of cytotoxic factors, (c) inhibiting remyelination and axonal regeneration by forming a glial scar, and (d) contributing to axonal mitochondrial dysfunction. Furthermore, regulatory mechanisms mediated by astrocytes can be affected by aging. Notably, astrocytes might also limit the detrimental effects of pro-inflammatory factors, while providing support and protection for oligodendrocytes and neurons. Because of the dichotomy observed in astrocytic effects, the design of therapeutic strategies targeting astrocytes becomes a challenging endeavor. Better knowledge of molecular and functional properties of astrocytes, therefore, should promote understanding of their specific role in MS pathophysiology, and consequently lead to development of novel and more successful therapeutic approaches.

Sodium intake is associated with increased disease activity in multiple sclerosis

BACKGROUND

Recently, salt has been shown to modulate the differentiation of human and mouse Th17 cells and mice that were fed a high-sodium diet were described to develop more aggressive courses of experimental autoimmune encephalomyelitis. However, the role of sodium intake in multiple sclerosis (MS) has not been addressed. We aimed to investigate the relationship between salt consumption and clinical and radiological disease activity in MS.

METHODS

We conducted an observational study in which sodium intake was estimated from sodium excretion in urine samples from a cohort of 70 relapsing-remitting patients with MS who were followed for 2 years. The effect of sodium intake in MS disease activity was estimated using regression analysis. We then replicated our findings in a separate group of 52 patients with MS.

RESULTS

We found a positive correlation between exacerbation rates and sodium intake in a multivariate model adjusted for age, gender, disease duration, smoking status, vitamin D levels, body mass index and treatment. We found an exacerbation rate that was 2.75-fold (95% CI 1.3 to 5.8) or 3.95-fold (95% CI 1.4 to 11.2) higher in patients with medium or high sodium intakes compared with the low-intake group. Additionally, individuals with high-sodium intake had a 3.4-fold greater chance of developing a new lesion on the MRI and on average had eight more T2 lesions on MRI. A similar relationship was found in the independent replication group.

CONCLUSIONS

Our results suggest that a higher sodium intake is associated with increased clinical and radiological disease activity in patients with MS.

Decision-making impairment in patients with multiple sclerosis: a case-control study

OBJECTIVES

To assess decision-making under explicit risk conditions in relapsing-remitting multiple sclerosis patients and its relationship to decisions made under conditions of ambiguity. To assess cognitive functions related to decision-making performance in patients with multiple sclerosis (MS).

SETTING

MS center in Buenos Aires, Argentina.

PARTICIPANTS

27 patients with relapsing-remitting multiple sclerosis and 27 sex-matched, age-matched and education-matched healthy controls.

INTERVENTION

Neuropsychological assessment and decision-making evaluation using the Game of Dice Task and the Iowa Gambling Task.

OUTCOMES

Game of Dice Task and the Iowa Gambling Task scores.

RESULTS

Patients with MS showed significantly poorer performance on the Game of Dice Task, choosing disadvantageous dice more often (p=0.019), as well as significantly lower overall scores in the Iowa Gambling Task (p=0.007). Block analysis showed that patients with MS and controls had scores that were comparable for blocks 1 and 2 (p=0.15 and p=0.24, respectively). Conversely, patients with MS scored poorly on blocks 4 (p=0.003) and 5 (p=0.023), the last two of the test, corresponding to decision-making under conditions of risk. Finally, the Game of Dice Task performance together with the last three blocks of the Iowa Gambling Task were correlated with visuospatial learning, processing speed and working memory but not with executive functioning.

CONCLUSIONS

Patients with MS showed deficits in decision-making under risk conditions, which might be related to deficits in visuospatial learning, processing speed and working memory.

[Immunopathology of multiple sclerosis]

Multiple sclerosis is an inflammatory demyelinating disease affecting the central nervous system and considered one of the leading causes of disability in young adults. The precise cause of multiple sclerosis is unknown, although the current evidence points towards a combination of genetic and environmental factors leading to an autoimmune response that promotes neuronal degeneration. In this review, we will describe the association between the immune response and neurodegeneration in multiple sclerosis.

Parasite infections in multiple sclerosis modulate immune responses through a retinoic acid-dependent pathway

We recently demonstrated better outcomes in helminth-infected multiple sclerosis (MS) patients, compared with uninfected ones. The present study evaluates the role of TLR2 and retinoic acid (RA) in parasite-driven protection in MS patients. RA serum levels were significantly higher in helminth-infected MS patients than in uninfected MS subjects or healthy controls. Genes involved in RA biosynthesis and metabolism, such as Adh1 and Raldh2, as well as RA receptors and IL-10, were induced in dendritic cells (DCs) via TLR2-dependent ERK signaling. This programmed DCs to induce FOXP3(+) T regulatory cells and suppressed production of proinflammatory cytokines (IL-6, IL-12, IL-23, and TNF-α) via induction of suppressor of cytokine signaling 3 (SOCS3), an effect mediated by soluble egg Ag (SEA) obtained from Schistosoma mansoni, and by RA. SEA-activated DCs also inhibited IL-17 and IFN-γ production through autoreactive T cells. These inhibitory effects were abrogated when SOCS3 gene expression was silenced, indicating that SEA-mediated signaling inhibited production of these cytokines by T cells, through a SOCS3-dependent pathway. Overall, helminth-related immunomodulation observed in MS patients was mediated by TLR2- and RA-dependent pathways, through two different mechanisms, as follows: 1) induction of IL-10 and FOXP3(+) T regulatory cells, and 2) suppression of proinflammatory cytokine production mediated by SOCS3.

Does helminth activation of toll-like receptors modulate immune response in multiple sclerosis patients?

Multiple sclerosis (MS) is an inflammatory autoimmune demyelinating disease affecting the Central Nervous System (CNS), in which Th1 and Th17 cells appear to recognize and react against certain myelin sheath components. Epidemiological evidence has accumulated indicating steady increase in autoimmune disease incidence in developed countries. Reduced infectious disease prevalence in particular has been proposed as the cause. In agreement with this hypothesis, we recently demonstrated significantly better clinical and radiological outcome in helminth-infected MS patients, compared to uninfected ones. Parasite-driven protection was associated with regulatory T cell induction and anti-inflammatory cytokine secretion, including increased TGF-β and IL-10 levels. Interestingly, surface expression of TLR2, on both B cells and dendritic cells (DC) was significantly higher in infected MS patients. Moreover, stimulation of myelin-specific T cell lines with a TLR2 agonist induced inhibition of T cell proliferation, suppression of IFN-γ, IL-12, and IL-17 secretion, as well as increase in IL-10 production, suggesting the functional responses observed correlate with TLR2 expression patterns. Furthermore, parasite antigens were able to induce TLR2 expression on both B cells and DCs. All functional effects mediated by TLR2 were abrogated when MyD88 gene expression was silenced; indicating helminth-mediated signaling induced changes in cytokine secretion in a MyD88-dependent manner. In addition, helminth antigens significantly enhanced co-stimulatory molecule expression, effects not mediated by MyD88. Parasite antigens acting on MyD88 induced significant ERK kinase phosphorylation in DC. Addition of the ERK inhibitor U0126 was associated with dose-dependent IL-10 inhibition and reciprocal enhancement in IL-12, both correlating with ERK inhibition. Finally, cytokine effects and changes observed in co-stimulatory DC molecules after helminth antigen exposure were lost when TLR2 was silenced. Overall, the data described indicate that helminth molecules exert potent regulatory effects on both DCs and B cells from MS patients through TLR2 regulation.

Intensive insulin therapy in brain injury: a meta-analysis

Many studies have addressed the question of whether intensive insulin therapy (IIT) provides better outcomes for brain-injured patients than does conventional insulin therapy (CIT), with conflicting results. We performed a systematic review and meta-analysis of the literature to estimate the effect of IIT on patients with brain injury. We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and citations of key articles and selected "all randomized controlled trials" (RCTs) comparing the effect of IIT to CIT among adult patients with acute brain injury (traumatic brain injury, stroke, subarachnoid hemorrhage, and encephalitis). Of the 2807 studies, we identified 9 RCTs with a total of 1160 patients for analysis. IIT did not appear to decrease the risk of in-hospital or late mortality (RR=1.04, 95% CI=0.75, 1.43 and RR=1.07, 95%CI=0.91, 1.27 respectively). No significant heterogeneity was found (I(2)=0.0%). IIT also did not have a protective effect on long-term neurological outcomes (LTNO) (RR=1.10, 95% CI=0.96, 1.27). IIT, however, did decrease the rate of infections (RR=0.76, 95% CI=0.58, 0.98). Heterogeneity was present (I(2)=64%), which was eliminated upon sensitivity analysis bringing the RR to 0.66 (95% CI=0.55, 0.80, I(2)=0%). IIT increased the rate of hypoglycemic episodes (RR=1.72, 95% CI=1.20, 2.46) however there was intractable heterogeneity present (I(2)=89%), which did not resolve upon sensitivity analysis. We found no evidence of publication bias by Egger's test (p=0.50). To conclude, IIT has no mortality or LTNO benefit to patients with brain injury, but is beneficial at decreasing infection rates.

Antigen microarrays identify CNS-produced autoantibodies in RRMS

OBJECTIVE

Multiple sclerosis (MS) is characterized by the local production of antibodies in the CNS and the presence of oligoclonal bands in the CSF. Antigen arrays allow the study of antibody reactivity against a large number of antigens using small volumes of fluid with greater sensitivity than ELISA. We investigated whether there were unique autoantibodies in the CSF of patients with MS as measured by antigen arrays and whether these antibodies differed from those in serum.

METHODS

We used antigen arrays to analyze the reactivity of antibodies in matched serum and CSF samples of 20 patients with untreated relapsing-remitting MS (RRMS), 26 methylprednisolone-treated patients with RRMS, and 20 control patients with other noninflammatory neurologic conditions (ONDs) against 334 different antigens including heat shock proteins, lipids, and myelin antigens.

RESULTS

We found different antibody signatures in matched CSF and serum samples The targets of these antibodies included epitopes of the myelin antigens CNP, MBP, MOBP, MOG, and PLP (59%), HSP60 and HSP70 (38%), and the 68-kD neurofilament (3%). The antibody response in patients with MS was heterogeneous; CSF antibodies in individual patients reacted with different autoantigens. These autoantibodies were locally synthesized in the CNS and were of the immunoglobulin G class. Finally, we found that treatment with steroids decreased autoantibody reactivity, epitope spreading, and intrathecal autoantibody synthesis.

CONCLUSIONS

These studies provide a new avenue to investigate the local antibody response in the CNS, which may serve as a biomarker to monitor both disease progression and response to therapy in MS.