Timing of MOG-IgG Testing Is Key to 2023 MOGAD Diagnostic Criteria

BACKGROUND AND OBJECTIVES

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is a recently identified autoimmune demyelinating disorder of the CNS affecting both adults and children. Diagnostic criteria for MOGAD have recently been published. We aimed to validate the 2023 MOGAD diagnostic criteria in a real-world cohort of patients with atypical CNS inflammation.

METHODS

All patients referred to the National neuromyelitis optica spectrum disorder (NMOSD) specialized service at The Walton Center NHS Foundation Trust between 2012 and 2023 with an atypical demyelinating syndrome were evaluated. We systematically applied the 2023 MOGAD diagnostic criteria and previous 2018 International Diagnostic Recommendations for MOG encephalomyelitis to our retrospective cohort.

RESULTS

474 patients were screened and 66 were excluded for lack of clinical information. Preexisting diagnoses within our cohort included the following: MOGAD, n = 127; AQP4-IgG NMOSD, n = 125; seronegative NMOSD, n = 33; multiple sclerosis (MS), n = 10; and other diagnoses, n = 113. Of patients with preexisting MOGAD, 97% (123/127) fulfilled the 2023 MOGAD diagnostic criteria. Three patients with a low-positive MOG-IgG did not meet supportive features though 2/3 had insufficient investigations. Alternative diagnoses could not be excluded in 1 patient with MS-MOGAD overlap. No patients with a non-MOGAD diagnosis were found to fulfill the 2023 diagnostic criteria. The sensitivity and specificity of the 2023 MOGAD diagnostic criteria were 97% and 100% with no false positives, improving on 2018 International Diagnostic Recommendations for MOG encephalomyelitis. Low-positive MOG-IgG results were more often associated with a longer time from disease onset to sampling (p < 0.001). In addition, in patients with a MOG-IgG1 test within 6 months of clinical onset, approximately 25% can become low positive by 6 months. Of patients with preexisting MOGAD, 9% (12/127) had insufficient investigations and examinations to fully evaluate additional supportive features. However, in those who were completely evaluated, supportive features were fulfilled in 97% (111/115).

DISCUSSION

The 2023 MOGAD diagnostic criteria were highly sensitive and specific and closely align with historically established cases of MOGAD. However, because additional supportive features are stipulated for patients with a low-positive MOG-IgG result, missed diagnoses may occur due to delayed testing or insufficient investigations.

Differential role of NSs genes in the neurovirulence of two genogroups of Akabane virus causing postnatal encephalomyelitis

Akabane virus (AKAV) is a member of the genus Orthobunyavirus, family Peribunyaviridae. In addition to AKAV strains that cause fetal Akabane disease, which is characterized by abortion in ruminants, some AKAV strains cause postnatal infection characterized by nonsuppurative encephalomyelitis in ruminants. Here, we focused on the NSs protein, a virulence factor for most viruses belonging to the genus Orthobunyavirus, and we hypothesized that this protein would act as a neurovirulence factor in AKAV strains causing postnatal encephalomyelitis. We generated AKAV strains that were unable to produce the NSs protein, derived from two different genogroups, genogroups I and II, and then examined the role of their NSs proteins by inoculating mice intracerebrally with these modified viruses. Our results revealed that the neurovirulence of genogroup II strains is dependent on the NSs protein, whereas that of genogroup I strains is independent of this protein. Notably, infection of primary cultured bovine cells with these viruses suggested that the NSs proteins of both genogroups suppress innate immune-related gene expression with equal efficiency. These results indicate differences in the determinants of virulence of orthobunyaviruses.

The Impact of Innate Components on Viral Pathogenesis in the Neurotropic Coronavirus Encephalomyelitis Mouse Model

Recognition of viruses invading the central nervous system (CNS) by pattern recognition receptors (PRRs) is crucial to elicit early innate responses that stem dissemination. These innate responses comprise both type I interferon (IFN-I)-mediated defenses as well as signals recruiting leukocytes to control the infection. Focusing on insights from the neurotropic mouse CoV model, this review discusses how early IFN-I, fibroblast, and myeloid signals can influence protective anti-viral adaptive responses. Emphasis is placed on three main areas: the importance of coordinating the distinct capacities of resident CNS cells to induce and respond to IFN-I, the effects of select IFN-stimulated genes (ISGs) on host immune responses versus viral control, and the contribution of fibroblast activation and myeloid cells in aiding the access of T cells to the parenchyma. By unraveling how the dysregulation of early innate components influences adaptive immunity and viral control, this review illustrates the combined effort of resident CNS cells to achieve viral control.

CTRP4/interleukin-6 receptor signaling ameliorates autoimmune encephalomyelitis by suppressing Th17 cell differentiation

C1q/TNF-related protein 4 (CTRP4) is generally thought to be released extracellularly and plays a critical role in energy metabolism and protecting against sepsis. However, its physiological functions in autoimmune diseases have not been thoroughly explored. In this study, we demonstrate that Th17 cell-associated experimental autoimmune encephalomyelitis was greatly exacerbated in Ctrp4-/- mice compared with WT mice due to increased Th17 cell infiltration. The absence of Ctrp4 promoted the differentiation of naive CD4+ T cells into Th17 cells in vitro. Mechanistically, CTRP4 interfered with the interaction between IL-6 and the IL-6 receptor (IL-6R) by directly competing to bind with IL-6R, leading to suppression of IL-6-induced activation of the STAT3 pathway. Furthermore, the administration of recombinant CTRP4 protein ameliorated disease symptoms. In conclusion, our results indicate that CTRP4, as an endogenous regulator of the IL-6 receptor-signaling pathway, may be a potential therapeutic intervention for Th17-driven autoimmune diseases.

Peripheral nervous system involvement accompanies central nervous system involvement in anti-glial fibrillary acidic protein (GFAP) antibody-related disease

BACKGROUND

Glial fibrillary acidic protein (GFAP) is expressed by astrocytes in the central nervous system (CNS), but also by immature and regenerative Schwann cells in the peripheral nervous system (PNS). GFAP antibodies (GFAP-Abs) in cerebrospinal fluid (CSF) have been mainly described in patients with meningoencephalomyelitis. We aimed to study PNS symptoms in patients with CSF GFAP-Abs.

METHODS

We retrospectively included all patients tested positive for GFAP-Abs in the CSF by immunohistochemistry and confirmed by cell-based assay expressing human GFAPα since 2017, from two French reference centers.

RESULTS

In a cohort of 103 CSF GFAP-Abs patients, 25 (24%) presented with PNS involvement. Among them, the median age at onset was 48 years and 14/25 (56%) were female. Abnormal electroneuromyography was observed in 11/25 patients (44%), including eight isolated radiculopathies, one radiculopathy associated with polyneuropathy, one radiculopathy associated with sensory neuronopathy, and one demyelinating polyradiculoneuropathy. Cranial nerve involvement was observed in 18/25 patients (72%). All patients except one had an associated CNS involvement. The first manifestation of the disease concerned the PNS in three patients. First-line immunotherapy was administered to 18/24 patients (75%). The last follow-up modified Rankin Scale was ≤ 2 in 19/23 patients (83%). Patients with PNS involvement had significantly more bladder dysfunction than patients with isolated CNS involvement (68 vs 40.3%, p = 0.031).

CONCLUSIONS

PNS involvement in GFAP-Abs autoimmunity is heterogeneous but not rare and is mostly represented by acute or subacute cranial nerve injury and/or lower limb radiculopathy. Rarely, PNS involvement can be the first manifestation revealing the disease.

High-intensity interval training attenuates development of autoimmune encephalomyelitis solely by systemic immunomodulation

The impact of high-intensity interval training (HIIT) on the central nervous system (CNS) in autoimmune neuroinflammation is not known. The aim of this study was to determine the direct effects of HIIT on the CNS and development of experimental autoimmune encephalomyelitis (EAE). Healthy mice were subjected to HIIT by treadmill running and the proteolipid protein (PLP) transfer EAE model was utilized. To examine neuroprotection, PLP-reactive lymph-node cells (LNCs) were transferred to HIIT and sedentary (SED) mice. To examine immunomodulation, PLP-reactive LNCs from HIIT and SED donor mice were transferred to naïve recipients and analyzed in vitro. HIIT in recipient mice did not affect the development of EAE following exposure to PLP-reactive LNCs. HIIT mice exhibited enhanced migration of systemic autoimmune cells into the CNS and increased demyelination. In contrast, EAE severity in recipient mice injected with PLP-reactive LNCs from HIIT donor mice was significantly diminished. The latter positive effect was associated with decreased migration of autoimmune cells into the CNS and inhibition of very late antigen (VLA)-4 expression in LNCs. Thus, the beneficial effect of HIIT on EAE development is attributed solely to systemic immunomodulatory effects, likely because of systemic inhibition of autoreactive cell migration and reduced VLA-4 integrin expression.

Chronic encephalomyelitis virus exhibits cellular tropism and evades pDCs by binding to sialylated integrins as the cell surface receptors

Theiler's murine encephalomyelitis virus (TMEV) causes a chronic demyelinating disease similar to multiple sclerosis in mice. Although sialic acids have been shown to be essential for TMEV attachment to the host, the surface receptor has not been identified. While type I interferons play a pivotal role in the elimination of the chronic infectious Daniel (DA) strain, the role of plasmacytoid dendritic cells (pDCs) is controversial. We herein found that TMEV binds to conventional DCs but not to pDCs. A glycomics analysis showed that the sialylated N-glycan fractions were lower in pDCs than in conventional DCs, indicating that pDCs are not susceptible to TMEV infection due to the low levels of sialic acid. TMEV capsid proteins contain an integrin recognition motif, and dot blot assays showed that the integrin proteins bind to TMEV and that the viral binding was reduced in the desialylated αX β2 . αX β2 protein suppressed TMEV replication in vivo, and TMEV co-localized with integrin αM at the cell membrane and TLR 3 in the cytoplasm, suggesting that αM serves as the viral attachment and entry. These results show that the chronic encephalomyelitis virus utilizes sialylated integrins as cell surface receptors, leading to cellular tropism to evade pDC activation.

Rustrela Virus-Associated Encephalomyelitis ('Staggering Disease') in Cats from Eastern Austria, 1994-2016

Clinical cases of 'staggering disease', a nonsuppurative encephalomyelitis associated with gait abnormalities in cats, have been documented for decades in Sweden. In Austria, an increased incidence was observed in the 1990s. Only recently, rustrela virus (RusV) was identified as the causative agent of this clinicopathologic disease entity. In this retrospective study, we analyzed a total of 23 brain and spinal cord samples from Austrian cats with the pathohistological diagnosis of nonsuppurative encephalomyelitis and clinical signs consistent with staggering disease from 1994 to 2016 using reverse transcription real-time polymerase chain reaction (RT-qPCR) and in situ hybridization. We were able to detect RusV nucleic acids in seven of the examined samples. Borna disease virus 1 (BoDV-1) could be excluded in all cases via immunohistochemistry and RT-qPCR. This study confirms that RusV has been a relevant etiological agent of nonsuppurative encephalomyelitis of cats in a geographically and temporally limited disease cluster in Austria, mainly in the 1990s. The geographic distribution of the positive samples in this study is consistent with earlier reports on 'staggering disease' in Austria. Further studies are necessary to confirm the reservoir host of 'staggering disease' in Austria, as well as investigations on the disappearance of this disease and its possible zoonotic potential.

Effect of Viral Strain and Host Age on Clinical Disease and Viral Replication in Immunocompetent Mouse Models of Chikungunya Encephalomyelitis

The alphavirus chikungunya virus (CHIKV) represents a reemerging public health threat as mosquito vectors spread and viruses acquire advantageous mutations. Although primarily arthritogenic in nature, CHIKV can produce neurological disease with long-lasting sequelae that are difficult to study in humans. We therefore evaluated immunocompetent mouse strains/stocks for their susceptibility to intracranial infection with three different CHIKV strains, the East/Central/South African (ECSA) lineage strain SL15649 and Asian lineage strains AF15561 and SM2013. In CD-1 mice, neurovirulence was age- and CHIKV strain-specific, with SM2013 inducing less severe disease than SL15649 and AF15561. In 4-6-week-old C57BL/6J mice, SL15649 induced more severe disease and increased viral brain and spinal cord titers compared to Asian lineage strains, further indicating that neurological disease severity is CHIKV-strain-dependent. Proinflammatory cytokine gene expression and CD4+ T cell infiltration in the brain were also increased with SL15649 infection, suggesting that like other encephalitic alphaviruses and with CHIKV-induced arthritis, the immune response contributes to CHIKV-induced neurological disease. Finally, this study helps overcome a current barrier in the alphavirus field by identifying both 4-6-week-old CD-1 and C57BL/6J mice as immunocompetent, neurodevelopmentally appropriate mouse models that can be used to examine CHIKV neuropathogenesis and immunopathogenesis following direct brain infection.

The Postpartum Period Can Worsen Myelin Oligodendrocyte Glycoprotein Antibody-associated Encephalomyelitis

Myelin oligodendrocyte glycoprotein (MOG) antibodies are associated with relapsing inflammatory demyelinating disease. Pregnancy complicates the disease course, potentially leading to either symptom improvement or worsening. A 28-year-old woman with MOG antibody-associated encephalomyelitis had 2 pregnancies; her disease worsened during both postpartum periods despite continuing prednisolone and levetiracetam. The umbilical cord blood was positive for MOG antibodies following her second pregnancy, but neither baby had MOG antibody-associated disease. This is the first case report of MOG antibody-associated demyelinating disease that worsened postpartum despite continuous medication. Furthermore, we observed the placental transfer of MOG antibodies for the first time.

Re-examination of the risk of autoimmune diseases after dengue virus infection: A population-based cohort study

Previous studies suggested that dengue was associated with an increased risk of several autoimmune diseases. However, this association still needs to be explored due to the limitations of these studies. A population-based cohort study was conducted using national health databases in Taiwan and included 63,814 newly diagnosed, laboratory-confirmed dengue patients between 2002 and 2015 and 1:4 controls (n = 255,256) matched by age, sex, area of residence and symptom onset time. Multivariate Cox proportional hazard regression models were used to investigate the risk of autoimmune diseases after dengue infection. Dengue patients had a slightly higher risk of overall autoimmune diseases than non-dengue controls (aHR 1.16; P = 0.0002). Stratified analyses by specific autoimmune diseases showed that only autoimmune encephalomyelitis remained statistically significant after Bonferroni correction for multiple testing (aHR 2.72; P < 0.0001). Sixteen (0.025%) dengue patients and no (0%) controls developed autoimmune encephalomyelitis in the first month of follow-up (HR >9999, P < 0.0001), but the risk between groups was not significantly different thereafter. Contrary to previous studies, our findings showed that dengue was associated with an increased short-term risk of a rare complication, autoimmune encephalomyelitis, but not associated with other autoimmune diseases.

Psychiatric Symptoms in Stiff-Person Syndrome: A Systematic Review and a Report of Two Cases

BACKGROUND

The clinical spectrum of stiff-person syndrome (SPS) encompasses a wide range of signs including psychiatric symptoms (PS).

OBJECTIVE

Our objective was to provide an overview of the spectrum of PS in SPS through a systematic literature search and 2 illustrative case reports.

METHODS

We reported 2 anti-glutamic acid decarboxylase-positive SPS cases that presented with phobic disorder, and we performed a systematic review by following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles published in PubMed, MEDLINE on Ovid, Embase, and via a manual search before October 20, 2020, were selected by 2 independent reviewers. Original studies, case reports, editorials, commentaries, and letters to the editor reporting cases of SPS with PS were all included. Conference abstracts, reviews and book chapters, unavailable articles, and those not reporting SPS cases or PS were excluded. Quantitative summary data were calculated.

RESULTS

In addition to our 2 cases, we identified 237 cases of SPS with PS from 74 additional included publications totaling 239 patients. Anxiety (56%) and depression (45%) were the most common PS in SPS. Mean diagnostic delay was 4.7 years. Among the 3 SPS phenotypes, the classic form was predominant (77%), followed by stiff-limb syndrome (13%) and progressive encephalomyelitis with rigidity and myoclonus (10%). The most frequent etiology of SPS with PS was autoimmune (90%), followed by cryptogenic (7%) and paraneoplastic forms (7%). These patients were mainly treated with immune-mediated therapies and GABAergic drugs.

CONCLUSIONS

Our review revealed that the most common PS of SPS are anxiety and depression occurring mostly in autoimmune and classic forms, allowing a clearer understanding of this entity, which may lead to earlier diagnosis and better outcome.

Paraneoplastic neurological syndromes associated with renal or bladder cancer: case series and PRISMA-IPD systematic review

BACKGROUND

The link between paraneoplastic neurological syndromes (PNS) and renal cell and bladder cancer (RCC/BC) is rare and uncertain. Our aim was to clinically evaluate, in light of the updated PNS criteria, these uncommon associations.

METHODS

Retrospective nationwide cohort chart review study and systematic review of the literature.

RESULTS

After excluding 5 patients due to the diagnosis of another co-occurrent malignancy, 10/18 patients with RCC and 8/18 patients with BC were identified. A total of 31 cases were previously published, yielding an overall series of 27/49 RCC and 22/49 BC patients. There was a predominance of cerebellar syndromes in both cancers (10/27, 37% for RCC; 9/22, 41% for BC), followed by encephalitis in 9/27 (33%) patients with RCC and encephalomyelitis/sensory neuronopathy in 5/22 (23%) patients with BC. The detection of high-risk Abs was more frequent among BC patients (16/19, 84% vs. 3/13, 23% in RCC, p = 0.0009), Ri antibodies being the most frequent thereof. After applying the updated PNS criteria, patients with BC met highest degrees (possible, probable, and definite) of certainty for PNS diagnosis (20/22, 91% vs. 16/27, 59% in RCC, p = 0.021).

CONCLUSION

A second neoplasm should always be ruled out before establishing the diagnosis of PNS in patients with RCC or BC. However, while this association remains dubious for most patients with RCC, a casual role is more probable in patients with BC and high-risk antibodies presenting with cerebellar ataxia, brainstem encephalitis or encephalomyelitis/sensory neuronopathy.

Treatment of Sindbis Virus-Infected Neurons with Antibody to E2 Alters Synthesis of Complete and nsP1-Expressing Defective Viral RNAs

Alphaviruses are positive-sense RNA viruses that are important causes of viral encephalomyelitis. Sindbis virus (SINV), the prototype alphavirus, preferentially infects neurons in mice and is a model system for studying mechanisms of viral clearance from the nervous system. Antibody specific to the SINV E2 glycoprotein plays an important role in SINV clearance, and this effect is reproduced in cultures of infected mature neurons. To determine how anti-E2 antibody affects SINV RNA synthesis, Oxford Nanopore Technologies direct long-read RNA sequencing was used to sequence viral RNAs following antibody treatment of infected neurons. Differentiated AP-7 rat olfactory neuronal cells, an in vitro model for mature neurons, were infected with SINV and treated with anti-E2 antibody. Whole-cell RNA lysates were collected for sequencing of poly(A)-selected RNA 24, 48, and 72 h after infection. Three primary species of viral RNA were produced: genomic, subgenomic, and defective viral genomes (DVGs) encoding the RNA capping protein nsP1. Antibody treatment resulted in overall lower production of SINV RNA, decreased synthesis of subgenomic RNA relative to genomic RNA, and suppressed production of the nsP1 DVG. The nsP1 DVG was packaged into virus particles and could be translated. Because antibody-treated cells released a higher proportion of virions with noncapped genomes and transient transfection to express the nsP1 DVG improved viral RNA capping in antibody-treated cells, we postulate that one mechanism by which antibody inhibits SINV replication in neurons is to suppress DVG synthesis and thus decrease production of infectious virions containing capped genomes. IMPORTANCE Alphaviruses are important causes of viral encephalomyelitis without approved treatments or vaccines. Antibody to the Sindbis virus (SINV) E2 glycoprotein is required for immune-mediated noncytolytic virus clearance from neurons. We used direct RNA nanopore sequencing to evaluate how anti-E2 antibody affects SINV replication at the RNA level. Antibody altered the viral RNAs produced by decreasing the proportion of subgenomic relative to genomic RNA and suppressing production of a previously unrecognized defective viral genome (DVG) encoding nsP1, the viral RNA capping enzyme. Antibody-treated neurons released a lower proportion of SINV particles with capped genomes necessary for translation and infection. Decreased nsP1 DVG production in antibody-treated neurons led to lower expression of nsP1 protein, decreased genome capping efficiency, and release of fewer infectious virus particles. Capping was increased with exogenous expression of the nsP1 DVG. These studies identify a novel alphavirus DVG function and new mechanism for antibody-mediated control of virus replication.

Astrocytoma with myelin oligodendrocyte glycoprotein antibody associated encephalomyelitis: A case report

BACKGROUND

Demyelination is similar with malignancy in clinical symptoms. Magnetic resonance imaging (MRI) is an important auxiliary examination in the diagnosis of demyelinating diseases and malignancy. Since MRI and symptoms can be difficult to distinguish demyelination from malignancy, other auxiliary examinations, such as demyelinating disease-specific antibodies, play an important role in distinguishing them. Previous studies have reported demyelinating disease-specific antibodies in patients with malignancy. What's more, it is more difficult to confirm the diagnosis when the malignant tumor co-occurs with demyelinating diseases, which has never been reported in previous studies. We report the diagnosis of myelin oligodendrocyte glycoprotein antibody associated encephalomyelitis (MOG-EM) in a patient who had astrocytoma for several years.

CASE PRESENTATION

Patient's concerns and diagnoses: our case report records a 49-year-old woman with astrocytoma for more than 4 years, who recently developed the symptoms of MOG-EM, including dizziness, vomiting, and vision loss. This astrocytoma patient was diagnosed with MOG-EM according to comprehensive evidence, including MRI, visual evoked potential (VEP), serum myelin oligodendrocyte glycoprotein antibody (MOG-IgG), and therapeutic effect. Interventions and outcomes: this patient was diagnosed with astrocytoma by surgical biopsy 4 years earlier. This patient has been treated with tumor resection, postoperative radiation treatment and chemotherapy. After treatment, the patient was left with right limb weakness while other symptoms were improved. Recently, the intravenous steroid agent was used to treat this patient after being diagnosed with MOG-EM. Dizziness, vomiting, and vision loss have gone into remission. This patient did not relapse in 7 months after discharge. This patient is still being followed up at the outpatient clinic. And the patient will next be treated with azathioprine.

CONCLUSIONS

In previous studies, polyclonal antibody has been found in cancer patients, such as aquaporin-4 and MOG-IgG in astrocytoma patients. But the case of our study finds that astrocytoma can coexist with MOG-EM. Therefore, MOG-EM should not be excluded easily in astrocytoma patients when the relative antibody of encephalomyelitis is positive. What's more, it reminds us that the pathogenesis of MOG-EM might be related to astrocytoma.

Effect of IL-10 Deficiency on TGFβ Expression during Fatal Alphavirus Encephalomyelitis in C57Bl/6 Mice

Sindbis virus (SINV) causes viral encephalitis in mice with strain-dependent virulence. Fatal encephalomyelitis in C57Bl/6 mice infected with a neuroadapted strain of SINV (NSV) is an immunopathogenic process that involves Th17 cells modulated by the regulatory cytokine IL-10. To further characterize the pathogenic immune response to NSV, we analyzed the regulation of transforming growth factor (TGF)-b in both wild-type (WT) and IL-10-deficient mice. NSV infection upregulated the expression of TGFb1 and TGFb3 in the central nervous system (CNS). In the absence of IL-10, levels of brain Tgfb1 mRNA and brain and spinal cord mature active TGFβ1 and TGFβ3 proteins were higher than in WT mice. Compared to WT mice, IL-10-deficient mice had more TGFβ1-expressing type 3 innate lymphoid cells (ILC3s) and CD4+ T cells infiltrating the CNS, but similar numbers in the cervical lymph nodes. Expression of glycoprotein A repetitions predominant protein (GARP) that binds pro-TGFb on the surface of regulatory T cells was decreased on CNS cells from IL-10-deficient mice. Higher CNS TGFb was accompanied by more expression of TGFbRII receptor, activation of SMAD transcription factors, increased PCKα mRNA, and more RORγt-positive and IL-17A-expressing cells. These results suggest a compensatory role for TGFβ in the absence of IL-10 that fosters Th17-related immunopathology and more rapid death after NSV infection.

β2 Integrins on Dendritic Cells Modulate Cytokine Signaling and Inflammation-Associated Gene Expression, and Are Required for Induction of Autoimmune Encephalomyelitis

Heterodimeric β2 integrin surface receptors (CD11a-d/CD18) are specifically expressed by leukocytes that contribute to pathogen uptake, cell migration, immunological synapse formation and cell signaling. In humans, the loss of CD18 expression results in leukocyte adhesion deficiency syndrome (LAD-)1, largely characterized by recurrent severe infections. All available mouse models display the constitutive and ubiquitous knockout of either α or the common β2 (CD18) subunit, which hampers the analysis of the cell type-specific role of β2 integrins in vivo. To overcome this limitation, we generated a CD18 gene floxed mouse strain. Offspring generated from crossing with CD11c-Cre mice displayed the efficient knockdown of β2 integrins, specifically in dendritic cells (DCs). Stimulated β2-integrin-deficient splenic DCs showed enhanced cytokine production and the concomitantly elevated activity of signal transducers and activators of transcription (STAT) 1, 3 and 5, as well as the impaired expression of suppressor of cytokine signaling (SOCS) 2–6 as assessed in bone marrow-derived (BM) DCs. Paradoxically, these BMDCs also showed the attenuated expression of genes involved in inflammatory signaling. In line, in experimental autoimmune encephalomyelitis mice with a conditional DC-specific β2 integrin knockdown presented with a delayed onset and milder course of disease, associated with lower frequencies of T helper cell populations (Th)1/Th17 in the inflamed spinal cord. Altogether, our mouse model may prove to be a valuable tool to study the leukocyte-specific functions of β2 integrins in vivo.

Astrocyte depletion alters extracellular matrix composition in the demyelinating phase of Theiler's murine encephalomyelitis

Astrocytes produce extracellular matrix (ECM) glycoproteins contributing to the blood-brain barrier and regulating the immune response in the central nervous system (CNS). The aim of this study was to investigate the impact of astrocyte depletion upon the clinical outcome and the composition of ECM glycoproteins in a virus-induced animal model of demyelination. Glial fibrillary acidic protein (GFAP)-thymidine-kinase transgenic SJL (GFAP-knockout) and wildtype mice were infected with Theiler’s murine encephalomyelitis virus (TMEV). Astrocyte depletion was induced during the progressive, demyelinating disease phase by ganciclovir administration once daily between 56 and 77 days post infection (dpi). At 77 dpi GFAP-knockout mice showed a significant deterioration of clinical signs associated with a reduction of azan and picrosirius red stained ECM-molecules in the thoracic spinal cord. Basement-membrane-associated ECM-molecules including laminin, entactin/nidogen-1 and Kir4.1 as well as non-basement membrane-associated ECM-molecules like collagen I, decorin, tenascin-R and CD44 were significantly reduced in the spinal cord of GFAP-knockout mice. The reduction of the investigated ECM-molecules demonstrates that astrocytes play a key role in the production of ECM-molecules. The present findings indicate that the detected loss of Kir4.1 and CD44 as well as the disruption of the integrity of perineuronal nets led to the deterioration of clinical signs in GFAP-knockout mice.

Identification of Anti-Collapsin Response Mediator Protein 2 Antibodies in Patients With Encephalitis or Encephalomyelitis

Background and Purpose

An increasing number of autoimmune encephalitis (AE)-associated autoantibodies have been successfully characterized. However, many cases of AE remain unexplained on account of unknown antibodies. The aim of the present study was to identify a novel antibody against collapsin response mediator protein 2 (CRMP2) in suspected AE patients.

Methods

A patient’s serum and cerebrospinal fluid samples tested negative for known AE antibodies; however, strong immunolabel signals were observed in the neuronal cytoplasm of the cortex, hippocampus, and Purkinje cells on rat brain sections. Immunoprecipitation from the rat brain protein lysate, followed by mass spectrometry analysis, was used to identify the targeting antigen. Western blotting and cell-based assay with antigen-overexpressing HEK293T cells were used for antibody specificity, epitope, IgG subtype determination, and retrospective study.

Results

An antibody against CRMP2, a synaptic protein involved in axon guidance, was identified. The immunostains of the patient’s samples on rat brain sections were eliminated by pre-absorption with HEK293T cells overexpressing CRMP2. The samples specifically immunoreacted with CRMP2, but not with CRMP1, CRMP3, CRMP4, and CRMP5. The C-terminus of CRMP2 with 536 amino acids contained the epitope for antibody binding. The subtype analysis showed that the anti-CRMP2 antibody was IgG4. Furthermore, a screening of 46 patients with neurological disoders and neuro-cytoplasm immunostainings on rat brain sections resulted in the identification of anti-CRMP2 antibodies in a case of encephalomyelitis. The two patients responded well to immunotherapies.

Conclusions

This study discovered that a novel anti-CRMP2 antibody was associated with suspected AE and thus should be included in the testing list for AE.

Bickerstaff brainstem encephalitis: clinical, neurophysiological, laboratory and postmortem findings of a case presenting as encephalomyelitis

Our patient was admitted to hospital with a 1-week history of an upper respiratory tract infection and a rapidly progressive encephalopathy dominated by brainstem features and widespread areflexia. Her antiganglioside antibodies and electroencephalography were consistent with Bickerstaff brainstem encephalitis (BBE), and her postmortem examination revealed a predominantly florid brainstem encephalitis and myelitis. Her sputum and throat swabs isolated Haemophilus influenzae and Fusobacterium, respectively, the former being the most probable trigger of BBE. Our patient's death, despite the otherwise good prognosis of the disorder, may reflect the severity of the pathological changes at postmortem or the association of comorbid disorders such as sepsis-associated encephalopathy. Her poor outcome may also be an indication to treat rapidly progressive cases of BBE with more than one immune modulating drug.

Iliopsoas Hematomas in a Patient with Progressive Encephalomyelitis with Rigidity and Myoclonus

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare and severe syndrome characterized by rigidity of the limb and truncal muscles, brainstem signs, myoclonus, and hyperekplexia. Iliopsoas hematoma is a serious complication of bleeding disorders that occurs most commonly in patients with hemophilia and also in association with anti-coagulant drug treatment. We herein present a case of PERM complicated with bilateral iliopsoas hematomas. His neurological symptoms improved after immunotherapy, and thereafter the iliopsoas hematomas disappeared. Neurologists should consider iliopsoas hematomas as a serious potential complication of PERM.

[Stiff-Person Syndrome]

Stiff-person syndrome (SPS) is a neurological disorder characterized by fluctuating muscle rigidity and painful spasms that occur spontaneously or are triggered by diverse stimuli. Partial or segmental forms of the disorder, such as stiff-limb syndrome (SLS) and the more severe disease called progressive encephalomyelitis with rigidity and myoclonus (PERM), are usually considered within the spectrum of SPS. SPS responds to immunotherapies, and several autoantigens have been identified. Most patients with SPS have high titers of antibodies against glutamic acid decarboxylase (GAD), the enzyme that limits the rate of the synthesis of γ-aminobutyric acid (GABA), and up to 15% have antibodies against the glycine receptor α-subunit.

[Treatment of antibody-mediated encephalomyelitis : Strategies for the treatment of neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease]

BACKGROUND

Antibody-mediated encephalomyelitis, such as neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and glial fibrillary acidic protein (GFAP) antibody-associated astrocytopathy belong to a group of newly described autoimmune diseases.

AIM

Presentation of the treatment of antibody-mediated encephalomyelitis with a focus on NMOSD and MOGAD.

METHODS

Selective literature search in PubMed taking the consultation version of the S2k guidelines of the German Society of Neurology (DGN) on the diagnosis and treatment of multiple sclerosis (MS), NMOSD and MOG IgG-associated diseases into account.

RESULTS

Acute relapses are treated with high-dose steroid pulse therapy or apheresis therapy (plasma exchange or immunoadsorption). It is crucial to start treatment as quickly as possible and apheresis therapy can also be used as first-line treatment under certain conditions. For prophylactic immunotherapy, steroids, classical immunosuppressants and monoclonal antibodies with specific mechanisms of action are used. Eculizumab, inebilizumab and satralizumab are the first drugs approved for NMOSD. Symptomatic treatment and neurorehabilitation are important complementary measures.

CONCLUSION

Treatment of antibody-mediated encephalomyelitis differs from treatment of multiple sclerosis and requires specific measures.

Efficacy of postoperative radiotherapy combined with taxol+carboplatin chemotherapy regimens in the treatment of high-risk early-stage endometrial cancer

PURPOSE

To compare the efficacy and safety of postoperative extrapelvic irradiation intensity-modulated radiotherapy (IMRT)+concurrent chemotherapy and vaginal brachytherapy (VBT)+concurrent chemotherapy in the treatment of patients with high-risk early-stage endometrial cancer, and analyze the influencing factors for the prognosis of patients.

METHODS

A total of 126 patients with high-risk stage Ic-IIa endometrial cancer were divided into extrapelvic irradiation IMRT + concurrent taxol+carboplatin (TC) chemotherapy group (IMRT group, n=63) and VBT + concurrent TC chemotherapy group (VBT group, n=63). Then, the efficacy and the incidence rate of adverse reactions were compared between the two groups of patients. Additionally, the possible influencing factors for the prognosis of patients were analyzed.

RESULTS

In the Functional Assessment of Cancer Therapy-General Version 4 (FACT-G-V4) scale for the quality of life of patients, the scores of physiological status, social/family status, emotional status and functional status were dramatically higher in the VBT group than in the IMRT group at 3 months after treatment. The 5-year overall survival (OS) and progression-free survival (PFS) rates were 87.3% and 73.0% in the IMRT group and 82.5% and 66.7% in the VBT group, respectively. Furthermore, advanced age, lower uterine segment involvement and anemia before treatment were independent risk factors for tumor progression in patients with endometrial cancer.

CONCLUSIONS

For patients with high-risk early-stage endometrial cancer, postoperative VBT + concurrent TC chemotherapy has similar efficacy to postoperative extrapelvic irradiation IMRT + concurrent TC chemotherapy, but patients receiving the former have fewer adverse reactions and high quality of life. Advanced age, lower uterine segment involvement and anemia before treatment are independent risk factors affecting tumor progression in such patients.

Clinical features and management of coexisting anti-N-methyl-D-aspartate receptor encephalitis and myelin oligodendrocyte glycoprotein antibody-associated encephalomyelitis: a case report and review of the literature

BACKGROUND

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an autoimmune encephalitis caused by antibodies targeting the GluN1 subunit of NMDA receptors. Myelin oligodendrocyte glycoprotein (MOG) antibody disorders are now widely accepted as peculiar neuroimmunological diseases with specific clinical and pathological features. Some rare cases of overlapping anti-NMDA receptor encephalitis and MOG antibody-associated diseases have been reported, presenting complex clinical symptoms that make the disease more difficult to recognize.

METHOD

In accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, the terms "NMDAR" and "MOG," "NMDAR" and "demyelination," and "MOG" and "encephalitis" were searched in PubMed. Clinical cases with dual-positive anti-NMDA cerebrospinal fluid receptors and MOG serum antibodies during the disease course were included in this study.

RESULTS

A total of 25 patients were analyzed in this study. The age at onset ranged from 3 to 54 years. The median number of relapses was 2.8. Administration of intravenous methylprednisolone and immunoglobulin was the most widely used treatment strategy (19/25 patients). Second-line treatments such as administration of mycophenolate mofetil, rituximab, interferon-β, azathioprine, cyclophosphamide, and temozolomide were also reported, followed by good outcomes.

CONCLUSIONS

The rates of coexisting anti-NMDA receptor encephalitis and MOG antibody-associated encephalomyelitis may be underestimated. Clinical symptoms such as seizures and cognitive decline accompanied by atypical central nervous system demyelination serve as warning signs of possible coexisting anti-NMDA receptor encephalitis and MOG antibody-associated encephalomyelitis. These patients could achieve good outcomes under proper immunotherapies.

Gut microbiome signature of Viliuisk encephalomyelitis in Yakuts includes an increase in microbes linked to lean body mass and eating behaviour

BACKGROUND

Viliuisk encephalomyelitis (VE) is a rare endemic neurodegenerative disease occurring in the Yakut population of Northeastern Siberia. The main clinical features of VE are spasticity, dysarthria, dementia, central paresis and paralysis, and cortical atrophy observed via MRI. Many hypotheses have been proposed regarding its etiology, including infectious agents, genetics, environmental factors, and immunopathology. Each of these hypotheses has been supported to some extent by epidemiological and experimental data. Nevertheless, none of them has been decisively proven. Gut microbiome is one of the factors that might be involved in VE pathogenesis.

RESULTS

Here we performed a pilot survey of the stool microbiomes of Yakut subjects with VE (n = 6) and without VE (n = 11). 16S rRNA sequencing showed that in comparison with the control group, the Yakuts with VE had increased proportions of Methanobrevibacter and Christensenella, which are reported to be linked to body mass index, metabolism, dietary habits and potentially to neurodegenerative disorders. The identified associations suggest that the microbiome may be involved in VE. Overall, the Yakut microbiome was quite specific in comparison with other populations, such as metropolitan Russians and native inhabitants of the Canadian Arctic.

CONCLUSIONS

Describing the gut microbiome of indigenous human populations will help to elucidate the impact of dietary and environmental factors on microbial community structure and identify risks linked to the lifestyles of such groups as well as endemic diseases.

Reelin depletion protects against autoimmune encephalomyelitis by decreasing vascular adhesion of leukocytes

Neuroinflammation as a result of immune cell recruitment into the central nervous system (CNS) is a key pathogenic mechanism of multiple sclerosis (MS). However, current anti-inflammatory interventions depleting immune cells or directly targeting their trafficking into the CNS can have serious side effects, highlighting a need for better immunomodulatory strategies. We detected increased Reelin concentrations in the serum of patients with MS, resulting in increased endothelial permeability to leukocytes through increased nuclear factor κB-mediated expression of vascular adhesion molecules. We thus investigated the prophylactic and therapeutic potential of Reelin immunodepletion in experimental autoimmune encephalomyelitis (EAE) and further validated the results in Reelin knockout mice. Removal of plasma Reelin by either approach protected against neuroinflammation and largely abolished the neurological consequences by reducing endothelial permeability and immune cell accumulation in the CNS. Our findings suggest Reelin depletion as a therapeutic approach with an inherent good safety margin for the treatment of MS and other diseases where leukocyte extravasation is a major driver of pathogenicity.

Tempol ameliorates murine viral encephalomyelitis by preserving the blood-brain barrier, reducing viral load, and lessening inflammation

Multiple sclerosis (MS) is a progressive inflammatory and/or demyelinating disease of the human central nervous system (CNS). Most of the knowledge about the pathogenesis of MS has been derived from murine models, such as experimental autoimmune encephalomyelitis and viral encephalomyelitis. Here, we infected female C57BL/6 mice with a neurotropic strain of the mouse hepatitis virus (MHV-59A) to evaluate whether treatment with the multifunctional antioxidant tempol (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy) affects the ensuing encephalomyelitis. In untreated animals, neurological symptoms developed quickly: 90% of infected mice died 10 days after virus inoculation and the few survivors presented neurological deficits. Treatment with tempol (24 mg/kg, ip, two doses on the first day and daily doses for 7 days plus 2 mM tempol in the drinking water ad libitum) profoundly altered the disease outcome: neurological symptoms were attenuated, mouse survival increased up to 70%, and half of the survivors behaved as normal mice. Not surprisingly, tempol substantially preserved the integrity of the CNS, including the blood-brain barrier. Furthermore, treatment with tempol decreased CNS viral titers, macrophage and T lymphocyte infiltration, and levels of markers of inflammation, such as expression of inducible nitric oxide synthase, transcription of tumor necrosis factor-alpha and interferon-gamma, and protein nitration. The results indicate that tempol ameliorates murine viral encephalomyelitis by altering the redox status of the infectious environment that contributes to an attenuated CNS inflammatory response. Overall, our study supports the development of therapeutic strategies based on nitroxides to manage neuroinflammatory diseases, including MS.

The inactivation of biologically active proteins, and the virus of western equine encephalomyelitis by periodic acid

The action of periodic acid on two biologically active proteins, crystalline ribonuclease and pneumococcus Type III immune globulin, and on the virus of Western equine encephalomyelitis has been studied. The biological activity of the two proteins and the pathogenic action of the virus were destroyed by the reagent; the specific antigenicity of the immune globulin was retained, however, but that of the equine virus was lost. The bearing of these reactions on the chemical alteration of the respective substances has been discussed.

Studies on acute disseminated encephalomyelitis produced experimentally in rhesus monkeys

The factor in brain tissue which induces acute disseminated encephalomyelitis, when injected into rhesus monkeys as an emulsion with adjuvants, has been found in human, monkey, rabbit, and chicken brain but is absent from frog and fish brain. It is unaffected by fixation of the brain in formalin, by boiling, and by treatment with ultrasound. It is present in the spinal cord of 3 day old rabbits but does not appear in the rabbit cerebrum until about the 12th day of life; in this respect it parallels the laying down of myelin. Attempts to produce the encephalomyelitis passively with large quantities of serum or of cell exudates, and suspensions of cells from spleen and lymph node from monkeys with encephalomyelitis, were unsuccessful.

A murine virus (JHM) causing disseminated encephalomyelitis with extensive destruction of myelin

The isolation of a murine virus causing disseminated encephalomyelitis accompanied by extensive destruction of myelin in the central nervous system, and focal necrosis of the liver has been described. Young mice can be infected by a number of parenteral routes. Both encephalitic and paralytic signs can be observed. After intracerebral inoculation the virus has been isolated from brain, spinal cord, liver, lung, spleen, and kidney, but not from blood or from intestinal walls and contents. Hamsters, cotton rats, and Hisaw rats can be infected by the intracerebral route. Guinea pigs and rabbits appear to be insusceptible. Attempts to infect chick embryos have so far met with failure. Under proper conditions the agent can pass through the usual bacterial filters. No inclusion bodies have been seen. No serological relationship to other neurotropic viruses has been demonstrated as yet.

Experimental disseminated encephalomyelitis in white mice

Disseminated encephalomyelitis was readily induced in mice of the Swiss strain by means of repeated intramuscular and subcutaneous injections of apparently normal mouse brain mixed with an adjuvant. The latter consisted of autoclaved virulent tubercle bacilli and heavy liquid petrolatum, a modification of the Freund adjuvant. The syndrome and the histopathological picture of the induced malady were essentially similar to those in monkeys, rabbits, and guinea pigs, previously reported by others. Certain exceptional characteristics of the affection, as occurring in mice, suggest that they may be the animals of choice for its study as well as for that of other encephalitides. Not only were the signs indicative of marked involvement of the central nervous system but also of the respiratory mechanism, and only a few injections of mouse brain-adjuvant mixture were required to evoke the neurological symptom complex in almost every animal.