Project description:BackgroundAdult opsoclonus-myoclonus (OM), a disorder of eye movements accompanied by myoclonus affecting the trunk, limbs, or head, is commonly associated with an underlying malignancy or precipitated by viral infection.MethodsWe present the first two reports of post-streptococcal OM associated with antibodies against a 56 kDa protein. Two young girls presented with opsoclonus and myoclonus following a febrile illness and pharyngitis. Protein purification techniques were employed. Amino acid sequences of human neuroleukin (NLK) and streptococcal proteins were compared using the protein-protein BLAST application.ResultsThe antigen was identified as NLK (glucose-6-phosphate isomerase, GPI). GPI is present on the cell surface of streptococcus making the protein a candidate target for molecular mimicry.ConclusionsWe have identified NLK as an antigenic target in two patients with post-streptococcal OM. The pathogenicity of the antibodies is uncertain. The potential role of anti-neuroleukin antibodies in the pathogenesis of OM is discussed. We propose that OM may represent a further syndrome in the growing spectrum of post-streptococcal neurological disorders. The role of streptococcus in OM and the frequency with which anti-NLK responses occur in both post-infectious and paraneoplastic OM should be investigated further.
Project description:ImportanceThis observational study describes the efficacy and safety of rituximab in 5 patients with voltage-gated potassium channel (VGKC)-complex/leucine-rich, glioma-inactivated 1 (LGI1) antibody-associated encephalopathy. Rituximab is a monoclonal antibody that targets CD20 and is used to treat other neurologic and nonneurologic diseases.ObservationsThis case series reports sequential seizure frequencies, modified Rankin Scale scores, and VGKC-complex antibody titers in 5 adult patients (median age, 65 years; range, 48-73 years) treated with rituximab. Median time from symptom onset to rituximab initiation was 414 days (range, 312-851 days). One patient showed a rapid clinical improvement after treatment with rituximab alone and experienced a rituximab-responsive clinical relapse. Another showed possible improvement on neuropsychometric memory indexes after rituximab therapy. In contrast, all patients showed robust responses to treatment with glucocorticoids, intravenous immunoglobulins, and/or plasma exchange at some point in their illness. Treatment with glucocorticoids-less so with intravenous immunoglobulins and plasma exchange-was associated with the most marked reductions in VGKC-complex antibodies. The only patient who did not receive glucocorticoids showed the poorest clinical and serologic responses.Conclusions and relevanceRituximab was well tolerated in this predominantly older adult patient population and may be an effective option for some patients with LGI1 antibody-associated encephalopathy. Glucocorticoid therapy appears particularly efficacious. Earlier rituximab administration and randomized trials are required to formally assess efficacy.
Project description:BackgroundLeucine-rich glioma-inactivated (LGI) proteins play a critical role in synaptic transmission. Dysfunction of these genes and encoded proteins is associated with neurological disorders such as genetic epilepsy or autoimmune limbic encephalitis in animals and human. Familial spontaneous epileptic cats (FSECs) are the only feline strain and animal model of familial temporal lobe epilepsy. The seizure semiology of FSECs comprises recurrent limbic seizures with or without evolution into generalized epileptic seizures, while cats with antibodies against voltage-gated potassium channel complexed/LGI1 show limbic encephalitis and recurrent limbic seizures. However, it remains unclear whether the genetics underlying FSECs are associated with LGI family genes. In the present study, we cloned and characterized the feline LGI1-4 genes and examined their association with FSECs. Conventional PCR techniques were performed for cloning and mutational analysis. Characterization was predicted using bioinformatics software.ResultsThe cDNAs of feline LGI1-4 contained 1674-bp, 1650-bp, 1647-bp, and 1617-bp open reading frames, respectively, and encoded proteins comprising 557, 549, 548, and 538 amino acid residues, respectively. The feline LGI1-4 putative protein sequences showed high homology with Homo sapiens, Canis familiaris, Bos taurus, Sus scrofa, and Equus caballus (92%-100%). Mutational analysis in 8 FSECs and 8 controls for LGI family genes revealed 3 non-synonymous and 14 synonymous single nucleotide polymorphisms in the coding region. Only one non-synonymous single nucleotide polymorphism in LGI4 was found in 3 out of 8 FSECs. Using three separate computational tools, this mutation was not predicted to be disease causing. No co-segregation of the disease was found with any variant.ConclusionsWe cloned the cDNAs of the four feline LGI genes, analyzed the amino acid sequences, and revealed that epilepsy in FSEC is not a monogenic disorder associated with LGI genes.
Project description:Background:Leucine-rich glioma-inactivated 1 (LGI1) encephalitis is a rare entity. Its typical features are seizures, faciobrachial dystonic seizures (FBDS), cognitive impairment, and personality changes. Case report:We report the case of a 66-year-old man with an unusual presentation, consisting of two types of FBDS, one starting in the foot and the other consisting of asynchronous myoclonic and dystonic jerks of the face triggered by noise and chin stimulation. The patient displayed no personality changes or cognitive impairment. Discussion:LGI1 encephalitis is a heterogeneous disease. Many different forms of FBDS may be observed, and these seizures can be the only symptom. This type of encephalitis should be suspected in presenting very frequent episodic events with dystonic features, regardless of the part of the body affected.
Project description:ObjectiveTo characterize seizure semiology and the utility of antiepileptic drug (AED) therapy in leucine-rich glioma inactivated-1 ( LGI1-Ab) autoimmune epilepsy (AE).MethodsPatients with voltage-gated potassium channel complex (VGKCc) titers higher than 0.02 nmol/L who were evaluated between May 2008 and June 2016 at the 3 Mayo Clinic sites (Arizona, Florida, or Minnesota) were identified. We then performed a retrospective review of those who were LGI1-Ab positive and were treated for seizures.ResultsA total of 1,095 patients with VGKCc titers higher than 0.02 nmol/L were identified, in which 77 were LGI1 positive. Of these, 56 patients with seizures were included in the analysis. Mean age at symptom onset was 62.9 years; 66% (n = 37) were male. The most common seizure semiology was focal faciobrachial dystonic seizures with preserved awareness (FBDS) (n = 35, 63%), followed by focal with impaired awareness (FIA) (n = 29, 52%), generalized tonic-clonic (GTCs) (n = 28, 50%), and focal non-motor seizures with preserved awareness (n = 28, 50%). The majority had more than one seizure type (n = 49, 88%; median = 2.5). Thirty-eight patients (68%) became seizure free: 29 (76%) with immunotherapy, 3 (5%) with AEDs alone, 2 (3%) with AEDs before any immunotherapy, and 4 (7%) with AEDs after immunotherapy. Levetiracetam (n = 47, 84%) and valproic acid (n = 21, 38%) were the most commonly used AEDs, but neither were associated with seizure freedom. Sodium channel blocking (NCB) AEDs were associated with seizure freedom in 4 patients compared to none treated with non-NCB AEDs. Regardless of class, AEDs prior to or apart from immunotherapy were associated with seizure freedom in only five patients (9%). In patients with FBDS, seizure freedom was more often associated with immunotherapy than AEDs (20/30 vs. 3/34, p = 0.001).SignificanceAlthough FBDS are the most characteristic seizure type seen in LGI1-Ab AE, other seizure types including FIA and GTCs also occur. Immunotherapy was the treatment most frequently associated with seizure freedom in LGI1-Ab AE. In general, AEDs seemed to confer a very low chance for seizure freedom, although AEDs with NCB-blocking properties were associated with seizure freedom in a limited number. Levetiracetam in particular appears to be ineffective in this patient population.
Project description:BackgroundLeucine-rich glioma inactivated 3 (LGI3) is a secreted protein member of LGI family. We previously reported that LGI3 was expressed in brain, adipose tissues and skin, where it played roles as a multifunctional cytokine. We postulated that LGI3 may be involved in cytokine network in cancers.AimThis study aimed to analyze differentially expressed genes in glioma tissues and glioma cohort data to investigate the prognostic role of LGI3 and its receptors.Materials and methodsExpression microarray data from Gene Expression Omnibus and glioma cohort data were analyzed using bioinformatic tools for statistical analysis, protein-protein interactions, functional enrichment and pathway analyses and prognostic association analysis.ResultsWe found that LGI3 and its receptors, ADAM22 and ADAM23, were significantly downregulated in glioma tissues. Eleven upregulated genes and two downregulated genes in glioma tissues were found to be the previously reported LGI3-regulated genes. Protein-protein interaction network analysis showed that 85% of the LGI3-regulated and glioma-altered genes formed a cluster of interaction network. Functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses revealed the association of these genes with hypoxia responses, p53 and Akt signaling and various cancer-related pathways including glioma. Analysis of expression microarray data of glioma cohorts demonstrated that low expression levels of LGI3, ADAM22 and ADAM23 were significantly associated with poor prognosis of glioma.ConclusionThese results propose that LGI3 and its receptors may play a prognostic role in glioma.
Project description:ObjectiveA recent study showed glutamate receptor delta 2 antibodies (GluD2-ab) in sera of patients with opsoclonus-myoclonus syndrome (OMS). Inconsistencies between cerebellar immunoreactivity and expression of GluD2 led us to hypothesize that these antibodies are not biomarkers of OMS.MethodsSerum of 45 children with OMS (10 [22%] with neuroblastoma), 158 adults with OMS (53 [34%] with tumors), and 172 controls including 134 patients with several types of neurologic disorders, 18 with neuroblastoma without OMS, and 20 healthy participants were investigated. Antibodies were determined with 3 different techniques: (1) rat brain immunohistochemistry, (2) a live cell-based assay using a standard secondary antibody (2-step CBA), and (3) a similar CBA with a secondary and tertiary antibodies (3-step CBA). Two plasmids were used in the CBA studies. Three commercial GluD2-ab and 2 human sera with GluD2-ab served as controls for expression of GluD2.ResultsThe 3 commercial GluD2-ab showed predominant reactivity with the molecular and Purkinje cell layers (where GluD2 is highly enriched), and were also positive with the indicated CBAs. Substantially milder reactivity with brain tissue and CBA was obtained with the 2 control human sera containing GluD2-ab. None of the 203 patients with OMS and 172 controls showed immunoreactivities consistent with GluD2-abs. Compared with a standard 2-step CBA, the 3-step assay did not improve antibody detection and showed more frequent nonspecific reactivity that was not immunoabsorbed with GluD2.ConclusionWe did not find GluD2-ab in a large cohort of patients with OMS. GluD2-ab should not be considered diagnostic biomarkers of OMS.
Project description:Background: Coronavirus disease-2019 (COVID-19), caused by the severe acute respiratory distress syndrome-coronavirus-2 (SARS-CoV-2), is primarily a respiratory infection but has been recently associated with a variety of neurological symptoms. We present herewith a COVID-19 case manifesting as opsoclonus-myoclonus syndrome (OMS), a rare neurological disorder. Case Presentation: A 63-year-old male diagnosed with COVID-19 infection developed behavioral changes, confusion, and insomnia followed by reduced mobility and abnormal eye movements within 48 h of recovery from respiratory symptoms associated with COVID-19. On examination, he had rapid, chaotic, involuntary saccadic, multidirectional eye movements (opsoclonus), and limb myoclonus together with truncal ataxia. CSF analysis, MRI of the brain, and screening for anti-neuronal and encephalitis related antibodies were negative. Extensive testing revealed no underlying malignancy. The patient was successfully treated with intravenous immunoglobulin (IVIG) with complete resolution of symptoms within 4 weeks of treatment. Conclusion: COVID-19 infection can be associated with the manifestation of opsoclonus myoclonus syndrome, a rare neurological disorder that can be treated with IVIG if not responsive to corticosteroids.
Project description:ObjectiveTo identify neuronal surface antibodies in opsoclonus myoclonus ataxia syndrome (OMAS) using contemporary antigen discovery methodology.MethodsOMAS patient serum immunoglobulin G immunohistochemistry using age-equivalent rat cerebellar tissue was followed by immunoprecipitation, gel electrophoresis, and mass spectrometry. Data are available via ProteomeXchange (identifier PXD009578). This generated a list of potential neuronal surface cerebellar autoantigens. Live cell-based assays were used to confirm membrane-surface antigens and adsorb antigen-specific immunoglobulin Gs. The serologic results were compared to the clinical data.ResultsFour of the 6 OMAS sera tested bound rat cerebellar sections. Two of these sera with similar immunoreactivities were used in immunoprecipitation experiments using cerebellum from postnatal rat pups (P18). Mass spectrometry identified 12 cell-surface proteins, of which glutamate receptor δ2 (GluD2), a predominately cerebellar-expressed protein, was found at a 3-fold-higher concentration than the other 11 proteins. Antibodies to GluD2 were identified in 14/16 (87%) OMAS samples, compared with 5/139 (5%) pediatric and 1/38 (2.6%) adult serum controls (p < 0.0001), and in 2/4 sera from patients with neuroblastoma without neurologic features. Adsorption of positive OMAS sera against GluD2-transfected cells substantially reduced but did not eliminate reactivity toward cerebellar sections.ConclusionAutoantibodies to GluD2 are common in patients with OMAS, bind to surface determinants, and are potentially pathogenic.
Project description:Opsoclonus myoclonus ataxia syndrome (OMAS) is an autoimmune disorder characterized by rapid, random, conjugate eye movements (opsoclonus), myoclonus, and ataxia. Given these symptoms, autoantibodies targeting the cerebellum or brainstem could mediate the disease or be markers of autoimmunity. In a subset of patients with OMAS, we identified such autoantibodies, which bind to non-synaptic puncta on the surface of live cultured cerebellar and brainstem neuronal dendrites. These findings implicate autoimmunity to a neuronal surface antigen in the pathophysiology of OMAS. Identification of the targeted antigen(s) could elucidate the mechanisms underlying OMAS and provide a biomarker for diagnosis and response to therapy.