Detection of Intact Borrelia garinii in a sural nerve biopsy
Thomas Schneider (St. Gallen | CH)
Mononeuropathy multiplex is a rare clinical manifestation of neuroborreliosis that is characterized by a multifocal axonal damage and painful sensations in the affected limb. The mechanism underlying these neuropathies remains still unclear, although interactions between anti‐Borrelia antibodies and several peripheral nerve constituent molecules raise intriguing possibilities. Here, we present a patient in whom Borreia garinii was immunohistochemically detected along the sural nerve.
2 Clinical Case
A 40-year-old male presented with a six-month history of B-symptoms and neuropathic pain of the right foot sole as well as tingling sensations of the back of his right foot. Neurologic examination revealed paretic flexors and extensors but also a paretic in-/eversion of his right foot, a reduced ankle jerk reflex, allodynia and a loss of touch sensations. Electrophysiologic studies yielded a predominantly axonal damage of the right peroneal, tibial, saphenous and sural nerve. MRI demonstrated inflammatory changes of the right ischiatic nerve. When CSF was investigated, lymphocytosis (126 cells/l), increased protein level (2.0 g/l) and intrathecal synthesis of IgM immunoglobulins were detected. Additional CSF analyses showed elevated CSF-serum indices for both, IgM as well as IgG, and to a lesser extent also increased HSV- and VZV-IgG indices. A biopsy of the affected right sural nerve showed extensive lymphocytic infiltrates and loosely distributed helical structures. Additional immunohistochemical investigations allowed to identify them as spirochetes. Using PCR of nerve tissue, these spirochetes could be assigned to borrelia garinii. Since a immunodeficiency was assumed as the underlying cause of this disease, a screening for malignancies and HIV was performed but have failed to identify a low immunity.
To the best of our knowledge, this is the first proof that B. garinii can infiltrate and persist in peripheral nerves in immunocompetent patients. Hence, local infection seems to be directly causal for nerve damage by triggering an excessive local immune response.
Disrupting myelin-specific Th17 cell trafficking to the gut dampens experimental autoimmune encephalomyelitis
Caroline Pot (Lausanne | CH)
Multiple sclerosis (MS) is a common autoimmune disease of the central nervous system (CNS). While an association between MS and inflammatory bowel diseases is observed, the link connecting intestinal immune responses and neuroinflammation remains unclear.
The aim of this study was to investigate the role of immune cell trafficking to the large intestine during experimental autoimmune encephalomyelitis (EAE), a murine model of MS, to assess their importance during neuroinflammation.
Active and adoptive transfer model of murine experimental autoimmune encephalomyelitis (EAE) were used. Immune cells isolated from the lamina propria of the large intestine were analyzed by flow cytometry and specific myelin reactive CD4+ T cells in the intestinal compartment were further evaluated ex vivo. Gene expression profiles of inflammatory markers were performed by RT-qPCR. Whole mount colonic analysis was performed to assess the localization of Th17 cells within the colon during EAE. Gut microbiota composition was evaluated by 16S rRNA gene sequencing.
We observed that encephalitogenic Th17 cells infiltrate the colonic lamina propria before neurological symptom development using two murine MS models, the active and adoptive experimental autoimmune encephalomyelitis (EAE). Targeting specifically Th17 intestinal homing by blocking integrin α4β7-MAdCAM-1 pathway not only impaired T cell migration to the large intestine but further dampened EAE severity. Mechanistically myelin-specific Th17 cell proliferated in the colon and affected the gut microbiota composition. Finally, the beneficial effect of blocking the integrin α4β7-MAdCAM-1 pathway on EAE was interdependent of the gut microbiota.
Those results show that disrupting myelin-specific Th17 cell trafficking to the large intestine is sufficient to harness neuroinflammation and suggest that the gut environment and microbiota promote the activation of encephalitogenic Th17 cell. Blocking the migration of pro-inflammatory CD4+ T cells in the intestinal compartment alters the EAE disease course pointing towards a contribution of the gut-brain axis in EAE development. Although the link between gut immunity and MS has yet to be further clarified, a better understanding of how immune cells are generated and regulated in the intestine during neuroinflammation could support innovative approaches to dampen neuroinflammation by targeting the gut-brain axis.
Detection of novel CNS-specific antibodies using hiPSC-derived astrocytes and neurons: a pilot study on autoimmune-mediated neurological syndromes
Amandine Mathias (Lausanne | CH)
Aims: The last 10 years have seen a thrilling rise in the discovery of CNS-reactive auto-antibodies (Abs) involved in neurological disorders such as paraneoplastic syndromes (PNS), autoimmune encephalitis (AIE), neuromyelitis optica (NMO) or systemic lupus erythematosous (SLE). 7-11% of the patients developing auto-immune limbic encephalitis remain seronegative for all currently known neural antigens (Ag). This observation emphasizes the need for the development of new assays able to unravel the presence of yet unknown CNS-reactive Abs. We developed an innovative cell-based assay (CBA) using human-induced pluripotent stem cell (hiPSC)-derived neurons and astrocytes as a source of CNS Ag. We evaluated their capacity to detect auto-Abs in serum and cerebrospinal fluid (CSF) of patients with CNS diseases, the latter being likely due to auto-immune mechanisms but with negative routine antibody panel.
Methods: 96-well plated hiPSC-derived astrocytes and neurons were incubated with paired serum/CSF of 109 patients suffering from inflammatory neurological diseases (IND) and 19 patients with non-inflammatory neurological diseases (NIND). IgG bound to CNS cells were detected using a combination of fluorescently labelled Ab. IgG-associated fluorescence intensity (FI) measure was semi-automated using a fluorescence plate reader. Serum or CSF were defined as positive using a ROUT test with a FDR at 2% on quantified FI. Each CBA well was also observed by fluorescence microscopy. To cross-validate the presence of CNS-reactive Ab, IgG reactivity was tested by flow cytometry using hiPSC-derived astrocytes and neurons exposed to the serum/CSF.
Results: Using our hiPSC-derived CBA, 20 patients (18 IND, 2 NIND) appeared positive on hiPSC-derived astrocytes/neurons including 5 patients previously diagnosed with auto-reactive Ab (3 NMO patients, one PNS and one SLE patient) and 15 with not-yet reported auto-reactive Ab. These results were confirmed by fluorescence microscopy and flow cytometry.
Conclusions: Our hiPSC-based CBA may allow discovering new CNS-reactive Abs. Such a potent tool opens new perspectives in understanding the mechanisms leading to autoimmune mediated neurological syndromes and may lead to improved diagnostic and therapeutic measures in patients with CNS autoimmune conditions.
Comparison of recent pivotal recommendations for the diagnosis and treatment of late onset Pompe disease using diagnostic nodes
Thomas Hundsberger (St. Gallen | CH)
Pompe disease is a rare autosomal-recessive disorder characterised by limb girdle myopathy and respiratory weakness in the late onset form (LOPD) and cardiomyopathy only in the early onset form. Various mutations in the acid alpha-glucosidase gene lead to toxic lysosomal and extra-lysosomal glycogen accumulation in all organs due to ineffective glycogen clearance by the encoded enzyme. Only one randomized trial demonstrated beneficial effects of respiratory function and meters walked in the 6-minute walking test with enzyme replacement therapy (ERT). These results were confirmed in several retrospective and prospective observations and in meta-analyses. Due to a potential life-long therapy, moderate efficacy and high treatment costs time of ERT initiation and cessation is an ongoing matter of debate. So far, several national and international recommendations have been published with different criteria concerning diagnosis, initiation and cessation of ERT in LOPD. We therefore formally analysed recent published recommendations and consensus statements of LOPD using diagnostic nodes (DODES) as a special software tool. With DODES, an objective analysis becomes possible if the content of the recommendations is represented as algorithms using cross-compatible elements. This analysis formally disclosed both, areas of great heterogeneity and concordance for the diagnosis and management of LOPD and paved the way for a Pompe disease burden scale focussing on ERT initiation. According to this investigation further clinical research should concentrate on ERT in pre-symptomatic and severely affected LOPD patients and on cessation criteria for ERT as these issues are areas of international uncertainty and discordance.
Small vessel disease is associated with an unfavorable outcome in stroke patients on oral anticoagulation
Nils Peters (Basel / Schweiz | CH)
Cerebral small vessel disease (SVD) is an important cause for both ischemic stroke (IS) and intracranial hemorrhage (ICH). To date, knowledge on the impact of SVD on the clinical course in stroke patients treated with oral anticoagulation (OAC) for atrial fibrillation (AF) is limited.
Registry-based prospective study of 320 patients (aged 78.2±9.2years) treated with anticoagulation following AF-stroke. Patients underwent standardized magnetic-resonance-imaging assessing measures of SVD, including cerebral microbleeds (CMBs) and white matter lesions (WMLs). Median follow-up was 754 days. Using adjusted logistic and Cox regression we assessed the association of imaging measures with clinical outcome including recurrent IS, ICH and death and assessed disability.
Recurrent IS was more common than ICH (22 versus 8, respectively). CMBs were related to an increased risk of the composite endpoint (IS, ICH, death: OR 2.05, 95%CI 1.27-3.31; p=0.003), as were WMLs (OR 2.00, 95%CI 1.23-3.27, p=0.005). This was also true in time-to-event analysis (CMBs: HR 9.17, 95%CI 1.39-3.52; p < 0.001; WMLs: HR 7.05, 95%CI 1.20-3.17; p=0.007). Both measures were associated with an increased risk for recurrent IS (CMBs: HR 4.4, 95%CI 1.07-18.2; p=0.04; WMLs: HR 5.27, 95%CI 1.08-25.79, p=0.04) and ICH (CMBs: HR 2.43, 95%CI 1.04-5.69 ; p=0.04; WMLs: HR 2.57, 95%CI 1.11-5.98, p=0.03). Furthermore, confluent WMLs were associated with increased disability (OR 4.03; 95%CI 2.16-7.52; p < 0.001) and mortality (HR 1.81, 95%CI 1.04-3.14, p=0.04).
In AF-stroke patients treated with oral anticoagulation, SVD is associated with an unfavorable outcome. The presence of microbleeds indicated a risk higher for recurrent ischemic stroke than for intracranial hemorrhage.
Do we have the appropriate tools for measuring cognitive decline in PD-MCI patients?
Sara Rosenblum (Haifa | IL)
Aims: To explore cognitive, neuropsychological and daily functional-related cognitive deficits among PD patients, diagnosed with mild cognitive impairment (MCI).
Level I diagnostic criteria for PD-MCI includes an abbreviated global cognitive assessment, and Level II requires at least two neuropsychological tests that assess cognitive functioning in 5 domains. PD-MCI is defined when performance is 1 to 2 standard deviations below cut-off norms scores, or significantly decline from estimated premorbid levels. Knowledge about cognitive deficits in the context of daily functioning in this population is scarce.
Methods: The study included 118 participants, ages 40-79, 77 diagnosed with PD who scored 22 to 25 on the global cognitive assessment Montreal Cognitive Assessment (MoCA). A control group included 41 healthy controls (HC) matched for gender, age, and education level, and scored 25 or higher on the MoCA. All participants achieved a score lower than18 on the Beck Depression Inventory (BDI). Level II neuropsychological assessment tools were administered along with self-report questionnaires focused on participant's daily function abilities, such as the Time Organization and Participation Scale (TOPS).
Results: No significant group differences were found for gender, age or education level. Most participants education level in both groups was academic (PD: 60%; HC: 70%).
Analysis revealed a surprisingly low number of participants in the PD-MCI group with cognitive deficit, according to the neuropsychological tests cut-off scores (0-56.4%). The highest rates were identified by the Trail Making Test A (PD: 56.4%; HC: 19.5%), B (PD: 38.5%; HC: 22.0%), and the Rey-Osterrieth Complex Figure Test (copying PD: 25.6%; HC: 4.9%; delayed recall (PD: 24.4%; HC: 12.2%). The profiles exhibited higher mean scores and a different distribution curve to the norm. The TOPS revealed significant differences between the groups indicating deficient ability in timely organization of daily activities and consequent emotional frustration for the PD subjects.
These results support the ongoing discussion of the complexity of capturing PD-MCI, particularly among people with premorbid high education level. Considering the neuropsychological tests results, assessments which reflect these people's real-life daily confrontations are warranted.
Impact of dietary factors and circadian rhythms on Fatigue in multiple sclerosis
Tinh-Hai Collet (Lausanne | CH)
Caroline Pot (Lausanne | CH)
Multiple sclerosis (MS) is a chronic inflammatory and autoimmune disease that affects the central nervous system. Fatigue is a common debilitating symptom experienced by patients with MS. However, it is a difficult symptom to treat efficiently. Recent studies suggest that food intake could impact fatigue. When assessing eating habits, researchers have classically focused on food content (i.e. calories and macronutrients intake), but for other diseases such as the metabolic syndrome, a new dimension is being explored, the timing of caloric intake. This increased interest in eating patterns, sometimes dubbed “chrononutrition”, with the underlying idea that the timing of caloric intake over the 24h cycle might interact with the circadian rhythm and have additional effects on metabolism.
The purpose of this pilot study was to assess the association between timing of food intake and fatigue among patients with MS and their caregivers as controls using questionnaires.
We set up a pilot survey of 33 patients with MS and 12 accompanying caregivers as control participants using an MS-specific and validated fatigue questionnaire in French (EMIF-SEP), which is composed of 40 items, as well as a questionnaire specifically addressing dietary timing developed by nutrition epidemiologists (currently in validation).
Out of the 45 participants in the survey, 42 (93%) fully completed the EMIF-SEP and 45 (100%) the dietary rhythm questionnaires. Among the 41 women and 4 men, the mean age (± standard deviation) was 51 years (± 12) for the MS group and 53 years (± 13) in caregivers. MS patients were classified into relapsing-remitting (n = 19), secondary progressive and primary progressive (n = 8) and unspecified MS (n = 3). The mean EMIF-SEP score was 89 points (± 25) for the MS group and 83 (± 24) for the MS caregivers. The mean eating duration per 24h cycle was 12.7 h. (± 2) for the MS group versus 12.5 h. (± 1.6) for the MS caregivers during weekdays and 10.8 hours (± 2.2) and 11.1 (±1) respectively during weekends. Correlations between fatigue score and eating duration will be presented.
This pilot survey indicates that it is feasible to address the timing of caloric intake using a new questionnaire in MS patients and to correlate timing of food intake with fatigue. This study has led to the start of a larger study at the Lausanne University Hospital to evaluate the link between chrononutrition and fatigue in MS.
Acute Ischemic Stroke, Atrial Fibrillation and Early DOAC-Treatment: 30-Day Risk of Recurrent Ischemic Stroke, Intracranial Haemorrhage in a Multi-Centre Individual Patient Data Meta-Analysis
Gian Marco De Marchis (Basel | CH)
Aim: We aimed to investigate recurrent ischaemic stroke (IS) and symptomatic intracranial haemorrhage (ICH) early after a recent cerebral ischaemia in patients with atrial fibrillation (AF) and their time course in relation to the initiation of direct oral anticoagulants (DOACs).
Patient & Methods: International, individual patient data meta-analysis from 8 cohort studies. We included patients with acute IS or TIA, non-valvular AF, and a DOAC within 30 days. We excluded patients with symptomatic intracranial haemorrhage (ICH) within 24 hours of endovascular recanalization therapy (n=2), or not started on a DOAC within 30 days. The endpoints were recurrent IS (re-IS) and ICH within 30 days.
Results: We included 2555 patients (median age: 77 years, IQR 70-84), of which 2460 had IS (96.5%). The median NIHSS was 5 (IQR 2-10). DOAC were started after a median of 5 days (IQR 2-10). Re-IS occurred, after a median of 6 days (IQR 2-15), in 37 patients (1.4%); 16 of these re-IS (43%) occurred prior to DOAC-start. ICH occurred, after a median of 10 days (IQR 7.5-14), in 11 patients (0.4%); 6 of these ICH (55%) occurred after DOAC-start.
Conclusions: Among patients with acute IS and AF, nearly half of the re-IS occurred prior to DOAC-start, i.e. were potentially preventable. The number of ICH potentially attributable to early start of DOAC was very low. Ongoing randomized clinical trials will show whether an earlier DOAC-start can further reduce the risk of re-IS while keeping the risk of ICH low.
Tacrolimus in a patient with anti-HMGCR antibody-associated necrotizing autoimmune myopathy
Amrei Beuttler (St. Gallen | CH)
Statins are among the most frequently prescribed drugs for the treatment of dyslipidemia and for risk reduction in cardiovascular disease. However, they can cause a wide spectrum of muscular adverse effects, from asymptomatic elevations of creatin kinase (CK) and myalgia to toxic necrotizing myopathy. While these effects are usually self-limiting upon discontinuation of the offending medication, in some instances statins trigger a severe autoimmune myopathy with antibodies that recognise 3-Hydroxy-2-methylglutaryl-coenzyme A reductase (HMGCR) that does not resolve when statin therapy is stopped. Recognition of statin-associated autoimmune myopathy is important as patients require immunosuppressive therapy to prevent progressive weakness.
We present the case of a patient with statin-associated autoimmune myopathy that demonstrates the challenging management of this entity. The patient was initially treated with intravenous immunoglobulin (IVIg), which resulted in clinical improvement. However, CK levels remained above 6000 IU/L, requiring escalation of therapy. Add-on steroids coincided with aggravation of weakness. Despite an increase in the dose and frequency of IVIg, she experienced recurrent relapses. Rituximab was not effective, and the use of other immune-modulating agents, such as methotrexate and cyclophosphamide, was limited due to the presence of various comorbidities (liver disease, history of breast cancer). Therefore, tacrolimus was started as rescue therapy in combination with IVIg and steroids, which permitted clinical remission. The patient has remained stable with maintenance therapy consisting of tacrolimus and very-low-dose prednisone.
Statin-associated autoimmune myopathy is responsive to immunosuppressive therapy, however, as this case report illustrates, achieving clinical remission may be difficult and require the use of multiple immunotherapeutic agents. To our knowledge, this is the first report describing the successful use of tacrolimus in treating anti-HMGCR antibody-associated necrotizing autoimmune myopathy. Tacrolimus may be effective for treatment and prevention of relapses in patients with statin-associated autoimmune myopathy.
80Hz vs. 130Hz: Differential effect STN DBS frequency on Oculomotor vs. Stroop task performance: an exploratory, double blind study
André Zacharia (Geneva | CH)
Objectives: Deep Brain Stimulation of the subthalamic nucleus (STN-DBS) is an effective treatment for patients with advanced Parkinson’s disease (PD). The role of the frequency of stimulation is not fully understood. We compared the effect of 80 Hz and 130 Hz on functions mediated by the associative and oculomotor fronto-striatal loops by assessing several oculomotor tasks and a cognitive test (the Stroop test), in a randomised double blind design.
Methods: After overnight withdrawal of dopaminergic medication, 20 patients received 80Hz and 130 Hz stimulation in a randomised order during 24 hours. The amplitude of stimulation was adjusted to keep the energy delivered stable. The assessments included: Unified PD Rating Scale motor score (UPDRS-III), pro-saccade (S) and anti-saccades (AS) task and Stroop test. Horizontal eye movements were collected using an eye-tracking system consisting of an infrared camera and padded helmet (Mobile EBTH, e(ye)BRAIN. 24 horizontal saccades across 3 visual angles (5°,10°,20°) were registered for both S and AS.
Results: Motor scores were similar between the two frequencies, tremor did not deteriorate. The saccade latencies and gain were similar for the two frequencies of stimulation during the S task. However, for AS, the error rate (10.2±6.3 vs. 12.2±5.73, p=0.02) and the latencies (326.0±101.6 ms vs. 381±135 ms, p= 0.03) were higher at 80Hz. The Stroop test revealed less errors in the more complex task at 80Hz (2.5±3.1 vs. 1.1±1.4 p=0.02).
Conclusions: The acute change of frequencies did not affect the clinical benefit measured with UPDRS III. However, antisaccade performance was superior at 130Hz stimulation, while performance on the complex Stroop task was comparatively better at 80Hz. This discrepancy might be related to interference with neural circuits differentially involved in lower-order oculomotor function versus higher-order cognitive tasks.
First ever treatment in Multiple Sclerosis : Fingolimod vs dimethyl fumarate The Lausanne real life experience
Vasiliki Pantazou (Lausanne | CH)
Background: Because patients with Multiple Sclerosis (MS) are now treated as early as possible after disease onset, the current MS treated population is much different from the patients included in the randomized clinical trials for disease modifying drugs: younger age, shorter disease duration, lower clinical and radiological disease activity.
Objective: To study the efficacy and tolerance of fingolimod (FGL) and dimethyl-fumarate (DMF) in early treated, treatment-naive patients with relapsing-remitting MS.
Methods: From the Lausanne observational MS registry of 1616 patients, we retrospectively collected clinical and radiological data of the 82 patients fulfilling the following inclusion criteria: (i) first line treatment with FGL or DMF, (ii) initiation of treatment within 36 months after disease onset, (iii) minimal treatment duration of 12 m.
Results: There were 61 patients on FGL and 21 on DMF. Mean disease duration prior to treatment initiation was 14 m. Demographics and MRI characteristics at baseline were not significantly different in both groups, but patients on FGL had higher pre-treatment clinical activity (mean relapses 1.97, SD 0.98 vs 1.43, SD 1.17, p=0.04). Almost 20% of the patients in both groups had highly active disease ( ≥ 2 relapses/year prior to treatment initiation and ≥ 1 Gd-enhancing T1 lesion at treatment onset). At last follow-up (median 43 m, range 16-133), 53.3 % of FGL and 66.7 % of DMF patients reached NEDA 3 status (p=0.258), and median EDSS score remained stable in both groups. Both treatments significantly decreased the occurrence of new T1 Gd-enhancing lesions (FGL median number of lesions at onset 1.0, range 0-26, at last follow up 0, range 0-2, RR 0.31, 95 % CI 0.168 – 0.577, p < 0.001, DMF at onset 1.0, range 0-8, at last follow up 0, range 0-5, RR 0.18, 95 % CI 0.061 – 0.52, p < 0.001). Retention tended to be better in the DMF group (81 % of the DMF patients versus 62.3% on FGL, p=0.2). The main reason for discontinuation was disease activity. No severe side effects occurred on both treatments.
Discussion : Our findings support both efficacy and tolerance of FGL and DMF in early treated, treatment naive MS patients. In Lausanne, FGL was more frequently prescribed than DMF (ratio 3:1), especially in patients with evidence of higher clinical disease activity. Despite the higher pre-treatment clinical activity in the FGL group, the majority of patients were free of disease activity at last follow-up.
Transcriptomic analysis of reactive human iPSC-derived astrocytes induced by neuroinflammatory cytokines
Sylvain Perriot (Epalinges | CH)
Astrocytes occupy a central place in neuroinflammatory diseases, such as multiple sclerosis (MS). Recent studies in mice have identified two clear states of astrocyte reactivity, A1 and A2, respectively induced by neuroinflammation and transient ischemia. However, due to the difficulty in obtaining human astrocytes, validity of these data in a human context remains to be established.
Here, we aimed at better characterizing human astrocyte reactivity in different neuroinflammatory conditions. To address this issue, we took advantage of our recently published serum-free technique to obtain resting astrocytes from human induced pluripotent stem cells (hiPSCs).
We generated hiPSC-derived astrocytes from healthy donors and MS patients and stimulated them with major neuroinflammatory cytokines (IL-6, IL-1β and/or TNFα) to assess their transcriptomic profile in response to these stimuli.
Transcriptomic analysis of reactive astrocytes showed first that each of these three cytokines leads to the modulation of a specific set of genes, triggering a unique activation profile of astrocytes. Second, gene ontology analysis revealed that IL-6 triggered the upregulation of genes mainly involved in cell adhesion, CNS development and ion transport while IL-1β and TNFα led to the upregulation of genes mainly involved in the inflammatory response, interferon signaling and defense against viruses.
In conclusion, our study reveals specific activation states of astrocytes in response to neuroinflammatory cues, suggesting distinct functionalities in different inflammatory contexts. As each neuroinflammatory disease is associated to a different inflammatory CNS milieu, our data call for a more precise characterization of reactive astrocytes in a given disease to decipher their role in such conditions. Better understanding of these reactive states would lead to a better understanding of astrocyte roles in neuroinflammatory diseases and may allow identifying new therapeutic targets.