Autoimmune Neuromuscular Disorders Associated With Neural Antibodies.

OBJECTIVE: This article reviews autoimmune neuromuscular disorders and includes an overview of the diagnostic approach, especially the role of antibody testing in a variety of neuropathies and some other neuromuscular disorders. LATEST DEVELOPMENTS: In the past few decades, multiple antibody biomarkers associated with immune-mediated neuromuscular disorders have been reported. These biomarkers are not only useful for better understanding of disease pathogenesis and allowing more timely diagnosis but may also aid in the selection of an optimal treatment strategy. ESSENTIAL POINTS: Recognition of autoimmune neuromuscular conditions encountered in inpatient or outpatient neurologic practice is very important because many of these disorders are reversible with prompt diagnosis and early treatment. Antibodies are often helpful in making this diagnosis. However, the clinical phenotype and electrodiagnostic testing should be taken into account when ordering antibody tests or panels and interpreting the subsequent results. Similar to other laboratory investigations, understanding the potential utility and limitations of antibody testing in each clinical setting is critical for practicing neurologists.

mRNA intramuscular vaccination produces a robust IgG antibody response in advanced neuromuscular disease.

SARS-CoV-2 vaccines protect against symptomatic and severe COVID-19. The BNT162b2/Pfizer and mRNA-1273/Moderna vaccines represent new vaccine technology relying on administration of mRNA encoding SARS-CoV-2 viral spike protein encased in lipid nanoparticles. The vaccines are administered as two doses into muscle, which elicits a strong response, typically within 14 days after the second dose. Neuromuscular diseases are characterized by the progressive loss of muscle and are often treated with chronic glucocorticoid steroids, both of which may contribute to a blunted immune response to vaccination. Here, we measured IgG antibody content and neutralizing antibody response after mRNA COVID-19 vaccination in non-ambulatory neuromuscular disease patients. After two doses of mRNA COVID-19 vaccine, median anti-receptor binding domain IgG and percent surrogate viral neutralization in non-ambulatory neuromuscular disease samples were significantly elevated similar to healthy vaccinated controls. As in healthy controls, COVID-19 vaccines produce greater antibody levels compared to those with a history of outpatient COVID-19 infection. This data documents that non-ambulatory neuromuscular disease patients respond well to two doses of mRNA COVID-19 vaccine despite low muscle mass and even chronic steroid use.

Absence of significant clinical benefit for a systematic routine creatine phosphokinase measurement in asymptomatic patients treated with anti-programmed death protein (ligand) 1 immune checkpoint inhibitor to screen cardiac or neuromuscular immune-related toxicities.

AIM: Despite unprecedented results of anti-programmed death protein (ligand) 1 (PD-(L)1) immune checkpoint inhibitor in the oncology's armamentarium, immune-related adverse events (irAEs) represent a therapeutic hurdle. Currently, there is no consensual recommendation on a routinely monitored biomarker to early detect irAE. Biological markers such as serum creatine phosphokinase (CPK) are commonly used to measure muscular tissue injury. The potential of routine serum CPK monitoring to predict cardiac or neuromuscular irAE in patients treated with immunotherapy remains unknown. METHODS: In this retrospective study between January 2016 and December 2018 at Gustave Roussy Cancer Campus, 1151 cancer patients treated with anti-PD-(L)1 immunotherapy were systematically monitored with serum CPK measurements before each immunotherapy cycle. We considered significant CPK increases according to Common Terminology Criteria for Adverse Events v5.0 (CTCAEV5) of grade ≥2 severity. Comparisons were performed in patients with immune-related CPK (ir-CPK) elevations symptomatic versus asymptomatic. RESULTS: Overall, 53 of 1151 (4.6%) patients showed a CPK increase. Elevations of CPK were deemed to be immunotherapy-related in 31 of 1151 (2.7%) patients. Among them, 12 of 31 (38.7%) patients experienced symptomatic cardiac or neuromuscular irAE, whereas the other 19 of 31 (61.3%) patients remained asymptomatic. In patients with symptomatic irAE, the mean ir-CPK level was higher compared with asymptomatic patients (1271 versus 771 UI/L, P value = 0.02). In the asymptomatic group, all patients experienced a spontaneous resolution of the ir-CPK increase, and none required medical intervention. CONCLUSION: Most patients with immune-related CPK increase remained asymptomatic. The CPK serum increase did not alter the clinical management of asymptomatic patients. The results of this study did not support a significant clinical interest for a systematic routine CPK monitoring in patients amenable to anti-PD-(L)1 immunotherapy.

Influenza vaccination in autoimmune neuromuscular diseases: A survey of current practices and perceptions.

INTRODUCTION: Recommendations for receiving the influenza vaccination in patients with autoimmune neuromuscular disorders, such as myasthenia gravis (MG), chronic inflammatory demyelinating polyneuropathy (CIDP), or Guillain-Barré syndrome (GBS), may vary among neurology practitioners. This survey examined the current practices and perceptions of neurologists regarding the influenza vaccination in these patients. METHODS: We performed an Internet-based survey among neurologists across the United States through online forums for neurologists. RESULTS: Across practice settings, 184 neurologists followed 6465 MG, 2313 CIDP, and 1907 GBS patients. Among the respondents, 82.6%, 58.8%, and 42.3% reported that they recommend the influenza vaccine for all patients with MG, CIDP, and GBS, respectively. Respondents practicing for more than 10 y were more conservative in recommending the influenza vaccine for all patients with MG. A history of exacerbation following the influenza vaccine was regarded as the most important factor influencing vaccine recommendation for MG and CIDP. DISCUSSION: Influenza vaccination recommendation practices varied between surveyed neurologists, despite existing guidelines. Clearer professional society recommendations and education are an unmet need based on this apparent knowledge gap.

Doctor-Should I get the COVID-19 vaccine? Infection and immunization in individuals with neuromuscular disorders.

The clinical course of neuromuscular disorders (NMDs) can be affected by infections, both in immunocompetent individuals, and in those with reduced immunocompetence due to immunosuppressive/immunomodulating therapies. Infections and immunizations may also trigger NMDs. There is a potential for reduced efficacy of immunizations in patients with reduced immunocompetence. The recent vaccination program for coronavirus disease-2019 (COVID-19) raises several questions regarding the safety and efficacy of this vaccine in individuals with NMDs. In this Practice Topic article, we address the role of vaccine-preventable infections in NMDs and the safety and efficacy of immunization in individuals with NMDs, with emphasis on vaccination against COVID-19.

Neurologic autoimmunity and immune checkpoint inhibitors: Autoantibody profiles and outcomes.

OBJECTIVE: To describe neural autoantibody profiles and outcomes in patients with neurologic autoimmunity associated with immune checkpoint inhibitor (ICI) cancer immunotherapy. METHODS: In this retrospective descriptive study, 63 patients with ICI-related neurologic autoimmunity were included: 39 seen at the Mayo Clinic Neurology Department (clinical cohort) and 24 whose serum/CSF was referred to the Mayo Clinic Neuroimmunology Laboratory for autoantibody testing. Serum/CSF samples were tested for neural-specific autoantibodies. Predictors of unfavorable outcome (residual adverse event severity grade ≥3) were explored (logistic regression). RESULTS: Median age at neurologic symptom onset was 65 years (range 31-86); 40% were female. Neurologic manifestations were CNS-restricted (n = 26), neuromuscular (n = 30), combined (n = 5), or isolated retinopathy (n = 2). Neural-specific autoantibodies were common in patients with CNS involvement (7/13 [54%] in the unbiased clinical cohort) and included known or unidentified neural-restricted specificities. Only 11/31 patients with CNS manifestations had neuroendocrine malignancies typically associated with paraneoplastic autoimmunity. Small-cell lung cancer (SCLC)-predictive antibodies were seen in 3 patients with non-neuroendocrine tumors (neuronal intermediate filament immunoglobulin G [IgG] and antineuronal nuclear antibody 1 with melanoma; amphiphysin IgG with non-SCLC). A median of 10 months from onset (range, 0.5-46), 14/39 in the clinical cohort (36%) had unfavorable outcomes; their characteristics were age ≥70 years, female, CNS involvement, lung cancer, higher initial severity grade, and lack of systemic autoimmunity. By multivariate analysis, only age remained independently associated with poor outcome (p = 0.01). Four of 5 patients with preexistent neurologic autoimmunity experienced irreversible worsening after ICI. CONCLUSIONS: Neural-specific autoantibodies are not uncommon in patients with ICI-related CNS neurologic autoimmunity. Outcomes mostly depend on the pre-ICI treatment characteristics and clinical phenotype.

Bioinformatics Analysis of Gut Microbiota and CNS Transcriptome in Virus-Induced Acute Myelitis and Chronic Inflammatory Demyelination; Potential Association of Distinct Bacteria With CNS IgA Upregulation.

Virus infections have been associated with acute and chronic inflammatory central nervous system (CNS) diseases, e.g., acute flaccid myelitis (AFM) and multiple sclerosis (MS), where animal models support the pathogenic roles of viruses. In the spinal cord, Theiler's murine encephalomyelitis virus (TMEV) induces an AFM-like disease with gray matter inflammation during the acute phase, 1 week post infection (p.i.), and an MS-like disease with white matter inflammation during the chronic phase, 1 month p.i. Although gut microbiota has been proposed to affect immune responses contributing to pathological conditions in remote organs, including the brain pathophysiology, its precise role in neuroinflammatory diseases is unclear. We infected SJL/J mice with TMEV; harvested feces and spinal cords on days 4 (before onset), 7 (acute phase), and 35 (chronic phase) p.i.; and examined fecal microbiota by 16S rRNA sequencing and CNS transcriptome by RNA sequencing. Although TMEV infection neither decreased microbial diversity nor changed overall microbiome patterns, it increased abundance of individual bacterial genera Marvinbryantia on days 7 and 35 p.i. and Coprococcus on day 35 p.i., whose pattern-matching with CNS transcriptome showed strong correlations: Marvinbryantia with eight T-cell receptor (TCR) genes on day 7 and with seven immunoglobulin (Ig) genes on day 35 p.i.; and Coprococcus with gene expressions of not only TCRs and IgG/IgA, but also major histocompatibility complex (MHC) and complements. The high gene expression of IgA, a component of mucosal immunity, in the CNS was unexpected. However, we observed substantial IgA positive cells and deposition in the CNS, as well as a strong correlation between CNS IgA gene expression and serum anti-TMEV IgA titers. Here, changes in a small number of distinct gut bacteria, but not overall gut microbiota, could affect acute and chronic immune responses, causing AFM- and MS-like lesions in the CNS. Alternatively, activated immune responses would alter the composition of gut microbiota.

Human antibodies neutralize enterovirus D68 and protect against infection and paralytic disease.

Enterovirus D68 (EV-D68) causes outbreaks of respiratory illness, and there is increasing evidence that it causes outbreaks of acute flaccid myelitis (AFM). There are no licensed therapies to prevent or treat EV-D68 infection or AFM disease. We isolated a panel of EV-D68-reactive human monoclonal antibodies that recognize diverse antigenic variants from participants with prior infection. One potently neutralizing cross-reactive antibody, EV68-228, protected mice from respiratory and neurologic disease when given either before or after infection. Cryo-electron microscopy studies revealed that EV68-228 and another potently neutralizing antibody (EV68-159) bound around the fivefold or threefold axes of symmetry on virion particles, respectively. The structures suggest diverse mechanisms of action by these antibodies. The high potency and effectiveness observed in vivo suggest that antibodies are a mechanistic correlate of protection against AFM disease and are candidates for clinical use in humans with EV-D68 infection.

Acute flaccid paralysis due to Echovirus 30 in an immunosuppressed transplant recipient.

An Italian 13-year-old boy immunosuppressed due to kidney transplant presented in November 2018 with acute flaccid paralysis with anterior horn cell involvement resembling the clinical, radiological, and laboratory features of poliomyelitis. Enterovirus was molecularly identified in cerebral spinal fluid and stool samples and the sequence analysis of the VP1 gene of enterovirus genome revealed the presence of Echovirus 30 both in CSF and in stool samples. Echovirus 30 is an emerging neurotropic virus able to cause outbreaks of aseptic meningitis and meningoencephalitis all over the world, but acute flaccid paralysis is not a classical manifestation. A 6-month follow-up revealed a poor outcome with severe motor deficits and only slight improvement in disability. Clinicians must be aware of the possible role of Echovirus 30 in acute flaccid paralysis and active surveillance should consider the possible influence of immunosuppression on the symptoms caused by the widening spectrum of enterovirus infections.

Immune checkpoint inhibitors-induced neuromuscular toxicity: From pathogenesis to treatment.

Immune checkpoint inhibitors (ICIs) are increasingly used and are becoming the standard of care in the treatment of various tumor types. Despite the favorable results in terms of oncological outcomes, these treatments have been associated with a variety of immune-related adverse events (irAEs). Neurological irAEs are rare but potentially severe. Neuromuscular disorders represent the most common neurological irAEs following anti-PD-1, anti-PD-L1, and anti-CTLA-4 treatment, and include myositis, myasthenia gravis, and demyelinating polyradiculoneuropathy. Instrumental findings may differ from typical neuromuscular disorders occurring outside ICIs treatment. Despite initial severity, neurological irAEs often respond to immune-modulating therapies. Prompt irAEs diagnosis, ICIs discontinuation, and early treatment with corticosteroids, together with patient education and a multi-disciplinary approach, are important for optimizing clinical outcomes. Intravenous immunoglobulin, plasma exchange, and other immune-modulating treatments should be considered in more severe cases. Consideration of re-challenging with the same immunotherapy drug may be given in some cases, based on clinical picture and initial severity of irAEs.

A survey of known immune epitopes in the enteroviruses strains associated with acute flaccid myelitis.

Enteroviruses are potentially linked to the emergence of Acute Flaccid Myelitis (AFM), a rare but very serious condition that affects the nervous system. AFM has been associated with coxsackievirus A16, enterovirus A71 (EVA71) and enterovirus D68 (EVD68). Little is known about host-pathogen interactions for these viruses, and whether immune responses may have a protective or immunopathological role in disease presentations. Towards addressing this issue, we used the Immune Epitope Database to assess the known inventory of B and T cell epitopes from enteroviruses, focusing on data related to human hosts. The extent of conservation in areas that are targets of B and T cell immune responses were examined. This analysis sheds light on regions of the enterovirus polypeptide that can be probed to induce a specific or cross-reactive B or T cell the immune response to enteroviruses, with a particular focus on coxsackievirus A16, EVA71 and EVD68. In addition, these analyses reveal the current gap-of-knowledge in the T and B cell immune responses that future studies should aim to address.

Myositis and neuromuscular side-effects induced by immune checkpoint inhibitors.

AIM: To characterise clinical presentation, laboratory and histopathologic characteristics and assess the treatment and outcome of neuromuscular side-effects of checkpoint therapy. METHODS: The side-effect registry and the institutional database from ten skin cancer centres were queried for reports on myositis and neuromuscular side-effects induced by checkpoint inhibitors. In total, 38 patients treated with ipilimumab, tremelimumab, nivolumab and pembrolizumab for metastatic skin cancer were evaluated and characterised. RESULTS: Myositis was the most frequent neuromuscular adverse event. In 32% of cases, myositis was complicated by concomitant myocarditis. Furthermore, cases of isolated myocarditis, myasthenia gravis, polymyalgia rheumatica, radiculoneuropathy and asymptomatic creatine kinase elevation were reported. The onset of side-effects ranged from the first week of treatment to 115 weeks after the start of therapy. Most of the cases were severe (49% grade III-IV Common Terminology Criteria for Adverse Events), and there were two fatalities (5%) due to myositis and myositis with concomitant myocarditis. Only half of the cases (50%) completely resolved, whereas the rest was either ongoing or had sequelae. Steroids were given in 80% of the resolved cases and in 40% of the unresolved cases. CONCLUSION: Immune-mediated neuromuscular side-effects of checkpoint inhibitors greatly vary in presentation and differ from their idiopathic counterparts. These side-effects can be life threatening and may result in permanent sequelae. Occurrence of these side-effects must be taken into consideration for patient information, especially when considering adjuvant immunotherapy with anti-programmed cell-death protein 1 (PD-1) antibodies and monitoring, which should include regular surveillance of creatine kinase.

Peripheral Nerve Hyperexcitability Syndromes.

PURPOSE OF REVIEW: This article provides a review of the clinical phenotypes and evaluation of peripheral nerve hyperexcitability syndromes. These rare diagnoses include cramp-fasciculation syndrome, Isaacs syndrome, and Morvan syndrome. Recent investigations have led to an understanding of the autoimmune underpinnings of these conditions and their specific associated antibodies. As the presentation of peripheral nerve hyperexcitability syndromes includes muscle stiffness, twitches, and spasms, which are also shared with certain central nervous system and myopathic conditions, the differential diagnosis of peripheral nerve hyperexcitability syndromes is reviewed. RECENT FINDINGS: Peripheral nerve hyperexcitability syndromes share clinical and electrodiagnostic evidence of motor nerve instability; however, their clinical presentations are varied. Case reviews have helped us understand the spectrum of symptoms associated with the three peripheral nerve hyperexcitability syndromes reviewed here: cramp-fasciculation syndrome, Isaacs syndrome, and Morvan syndrome. More recently, research has focused on understanding the voltage-gated potassium channel complex antibodies as well as neoplasms associated with these conditions. SUMMARY: The diagnosis of peripheral nerve hyperexcitability syndromes requires a high index of suspicion, support from the physical examination, familiarity with the spectrum of symptoms associated with peripheral nerve hyperexcitability syndromes, and recognition of diagnostic EMG features. Voltage-gated potassium channel complex antibodies are associated with these conditions. Optimum treatment and autoimmune pathogenesis remain areas of active research.

Neuronal autoantibodies: differentiating clinically relevant and clinically irrelevant results.

The aim of this study is to compare the rates of clinically relevant and clinically irrelevant neuronal autoantibodies among patients presenting with new neurological symptoms. We reviewed 401 neurological patients who were tested for the Mayo-Clinic paraneoplastic panel from January 2014 to December 2014 at the Johns Hopkins Hospital. We divided antibody-positive patients into two groups: clinically relevant (CR), in which a recognizable autoimmune or paraneoplastic syndrome was confirmed, and clinically irrelevant (CI), in which an autoimmune/paraneoplastic etiology was initially suspected but an alternative diagnosis was eventually found. We used Fisher's exact test for categorical variables and Mann-Whitney U test for continuous variables to identify differences between the two groups. Fifty-three patients tested positive for one or more neuronal autoantibodies. There were 17 CR (65% females, mean age 56 years), 33 CI, and 3 indeterminate patients. Compared to CI patients, CR patients were more likely to present with movement disorders or stiff person syndrome, have inflammatory CSF markers, cancer or smoking history, concomitant hyponatremia, and classical onconeuronal antibodies. CI patients were more likely to have a neuromuscular presentation, a chronic course, and antibodies against synaptic antigens. By combining the most robust differentiating factors, we developed a simple scale that predicted clinical relevance with an odds ratio of 50.3 (CI 8.2-309.9, P < 0.0001) if the score was ≥ 2. Up to 62% of neuronal autoantibody-positive patients are ultimately found to have an alternative diagnosis. Several clinical and laboratory factors can differentiate CR from CI patients to aid in interpretation of positive results.

Intracellular and non-neuronal targets of voltage-gated potassium channel complex antibodies.

OBJECTIVES: Autoantibodies against the extracellular domains of the voltage-gated potassium channel (VGKC) complex proteins, leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-2 (CASPR2), are found in patients with limbic encephalitis, faciobrachial dystonic seizures, Morvan's syndrome and neuromyotonia. However, in routine testing, VGKC complex antibodies without LGI1 or CASPR2 reactivities (double-negative) are more common than LGI1 or CASPR2 specificities. Therefore, the target(s) and clinical associations of double-negative antibodies need to be determined. METHODS: Sera (n=1131) from several clinically defined cohorts were tested for IgG radioimmunoprecipitation of radioiodinated α-dendrotoxin (125I-αDTX)-labelled VGKC complexes from mammalian brain extracts. Positive samples were systematically tested for live hippocampal neuron reactivity, IgG precipitation of 125I-αDTX and 125I-αDTX-labelled Kv1 subunits, and by cell-based assays which expressed Kv1 subunits, LGI1 and CASPR2. RESULTS: VGKC complex antibodies were found in 162 of 1131 (14%) sera. 90 of these (56%) had antibodies targeting the extracellular domains of LGI1 or CASPR2. Of the remaining 72 double-negative sera, 10 (14%) immunoprecipitated 125I-αDTX itself, and 27 (38%) bound to solubilised co-expressed Kv1.1/1.2/1.6 subunits and/or Kv1.2 subunits alone, at levels proportionate to VGKC complex antibody levels (r=0.57, p=0.0017). The sera with LGI1 and CASPR2 antibodies immunoprecipitated neither preparation. None of the 27 Kv1-precipitating samples bound live hippocampal neurons or Kv1 extracellular domains, but 16 (59%) bound to permeabilised Kv1-expressing human embryonic kidney 293T cells. These intracellular Kv1 antibodies mainly associated with non-immune disease aetiologies, poor longitudinal clinical-serological correlations and a limited immunotherapy response. CONCLUSIONS: Double-negative VGKC complex antibodies are often directed against cytosolic epitopes of Kv1 subunits and occasionally against non-mammalian αDTX. These antibodies should no longer be classified as neuronal-surface antibodies. They consequently lack pathogenic potential and do not in themselves support the use of immunotherapies.

Childhood-Onset Multifocal Motor Neuropathy With Immunoglobulin M Antibodies to Gangliosides GM1 and GM2: A Case Report and Review of the Literature.

Multifocal motor neuropathy is a rare immune-mediated neuropathy characterized by progressive asymmetric weakness and atrophy without sensory abnormalities. Although disease onset is usually in adulthood, a few childhood-onset cases have been reported. Here, we report the case of an 8-year-old boy with multifocal motor neuropathy who presented with a slowly progressive left and distal upper limb weakness without sensory loss. The initial high-dose intravenous immunoglobulin treatment significantly improved left upper limb muscle weakness. Continued monthly intravenous immunoglobulin treatment gradually improved muscle strength for several months initially. While the muscle strength decreased slightly after 8 months of therapy, it was better than that before intravenous immunoglobulin treatment. One year and eight months after the initiation of treatment, serum testing for IgM antibodies to gangliosides, GM1 and GM2, was negative. This is the first pediatric report of the serum IgM autoantibodies positive to GM1 and GM2. The clinical course is similar to that of partial intravenous immunoglobulin responders among patients with adulthood-onset multifocal motor neuropathy. Since the symptoms plateaued after the initial intravenous immunoglobulin therapy, prognosis appears to be determined by the patient's initial response to intravenous immunoglobulin treatment.

Disease specificity of autoantibodies to cytosolic 5'-nucleotidase 1A in sporadic inclusion body myositis versus known autoimmune diseases.

OBJECTIVES: The diagnosis of inclusion body myositis (IBM) can be challenging as it can be difficult to clinically distinguish from other forms of myositis, particularly polymyositis (PM). Recent studies have shown frequent presence of autoantibodies directed against cytosolic 5'-nucleotidase 1A (cN-1A) in patients with IBM. We therefore, examined the autoantigenicity and disease specificity of major epitopes of cN-1A in patients with sporadic IBM compared with healthy and disease controls. METHODS: Serum samples obtained from patients with IBM (n=238), PM and dermatomyositis (DM) (n=185), other autoimmune diseases (n=246), other neuromuscular diseases (n=93) and healthy controls (n=35) were analysed for the presence of autoantibodies using immunodominant cN-1A peptide ELISAs. RESULTS: Autoantibodies directed against major epitopes of cN-1A were frequent in patients with IBM (37%) but not in PM, DM or non-autoimmune neuromuscular diseases (<5%). Anti-cN-1A reactivity was also observed in some other autoimmune diseases, particularly Sjögren's syndrome (SjS; 36%) and systemic lupus erythematosus (SLE; 20%). CONCLUSIONS: In summary, we found frequent anti-cN-1A autoantibodies in sera from patients with IBM. Heterogeneity in reactivity with the three immunodominant epitopes indicates that serological assays should not be limited to a distinct epitope region. The similar reactivities observed for SjS and SLE demonstrate the need to further investigate whether distinct IBM-specific epitopes exist.

CROSSTALK BETWEEN VITAMIN B AND IMMUNITY.

Vitamin B1 (thiamin) is considered to be the oldest vitamin and in 1936 R.R. Williams and colleagues determined its chemical structure and were able to synthesize this vitamin. Vitamin B1 influences pro-apoptotic proteins, mitochondrial membrane potential, cytochrome C release, protein kinases, p38-MAPK, suppresses oxidative stress-induced NF-kappaB and has anti-inflammatory properties. Deficiency of vitamin B1 may cause beriberi, dysfunction of the nervous system, neuroinflammation, T cell infiltration, chemokine CCL2 activation, over expression of proinflammatory cytokines, such as IL-1, TNF, IL-6, and arachidonic acid products, and induces expression of CD40 by the microglia and CD40L by astrocytes which provoke the death of neurons. Here we report the relationship between vitamin B complex and immunity.

IgG4-Related Neuromyopathy Associated With Recurrent Pleural Effusion.

OBJECTIVE: Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized idiopathic systemic disorder associated with elevated serum IgG4 level and tissue infiltration by IgG4-positive plasma cells. Multiple neurological manifestations, including peripheral neuropathy, have been described in IgG4-RD. Our objective is to discuss a case report and review of the literature, which would expand the spectrum of IgG4-RD. METHODS: We describe the clinical features and biopsy findings in a patient with IgG4-RD who presented with features suggestive of neuromyopathy in the setting of recurrent pleural effusion and weight loss. RESULTS: Electrodiagnostic findings were suggestive of an irritable myopathy and polyradiculoneuropathy with primary demyelination and secondary axonal degeneration. Pleural biopsy and laboratory studies confirmed the diagnosis. Improvement was sustained with steroid therapy. CONCLUSIONS: We describe the first case, to our knowledge, of IgG4-related neuromyopathy associated with recurrent pleural effusion. Our case expands the clinical spectrum of IgG4-RD. Neurologists should be aware of this treatable disorder and in the appropriate clinical context consider it in the differential diagnosis of neuromyopathy.