Molecular mimicry between Zika virus and central nervous system inflammatory demyelinating disorders: the role of NS5 Zika virus epitope and PLP autoantigens.

BACKGROUND: Evidence indicates a strong link between Zika virus (ZikV) and neurological complications. Acute myelitis, optic neuritis, polyneuropathy, and encephalomyelitis that mimic inflammatory idiopathic demyelination disorders (IIDD) after ZikV infection have been reported in Brazil. OBJECTIVE: The present study aims to investigate the possible occurrence of molecular mimicry between ZikV antigens and Multiple Sclerosis (MS) autoantigens, the most frequent IIDD of the central nervous system (CNS). METHODS: A retrospective cohort study with 305 patients admitted due to suspected arbovirus infection in Rio de Janeiro was performed, all subjects were submitted to neurological examination, and a biological sample was collected for serologic and molecular diagnostic. Bioinformatics tools were used to analyze the peptides shared between ZikV antigens and MS autoantigens. RESULTS: Of 305 patients, twenty-six were positive for ZikV and 4 presented IDD patterns found in MS cases. Sequence homology comparisons by bioinformatics approach between NS5 ZikV and PLP MS protein revealed a homology of 5/6 consecutive amino acids (CSSVPV/CSAVPV) with 83% identity, deducing a molecular mimicry. Analysis of the 3D structures revealed a similar conformation with alpha helix presentation. CONCLUSIONS: Molecular mimicry between NS5 Zika virus antigen and PLP MS autoantigens emerge as a possible mechanism for IDD spectrum in genetically susceptible individuals.

ANTECEDENTES: Evidências indicam uma forte ligação entre o vírus Zika (ZikV) e complicações neurológicas. Mielite aguda, neurite óptica, polineuropatia e encefalomielite que mimetizam distúrbios inflamatórios de desmielinização idiopáticos (DDII) após infecção por ZikV têm sido relatadas no Brasil. OBEJTIVO: O presente estudo tem como objetivo investigar a possível ocorrência de mimetismo molecular entre antígenos do ZikV e autoantígenos da Esclerose Múltipla (EM), a DDII mais frequente do sistema nervoso central (SNC). MéTODOS: Foi realizado um estudo de coorte retrospectivo com 305 pacientes internados por suspeita de infecção por arbovírus no Rio de Janeiro, todos os indivíduos foram submetidos a exame neurológico e coleta de amostra biológica para diagnóstico sorológico e molecular. Ferramentas de bioinformática foram usadas para analisar os peptídeos compartilhados entre antígenos do ZikV e autoantígenos da EM. RESULTADOS: Dos 305 pacientes, vinte e seis foram positivos para ZikV e 4 apresentaram padrão IDD encontrado em casos de EM. As comparações de homologia de sequência por abordagem de bioinformática entre a proteína NS5 ZikV e PLP EM revelaram uma homologia de 5/6 aminoácidos consecutivos (CSSVPV/CSAVPV) com 83% de identidade, deduzindo um mimetismo molecular. A análise das estruturas 3D revelou uma conformação semelhante com apresentação em alfa-hélice. CONCLUSõES: O mimetismo molecular entre o antígeno NS5 do vírus Zika e o autoantígeno PLP da EM surge como um possível mecanismo para o espectro IDD em indivíduos geneticamente suscetíveis.

Molecular mimicry between Zika virus and central nervous system inflammatory demyelinating disorders: the role of NS5 Zika virus epitope and PLP autoantigens / Mimetismo molecular entre o vírus Zika e os distúrbios inflamatórios desmielinizantes do sistema nervoso central: o papel do epítopo NS5 do vírus Zika e dos autoantígenos PLP

Abstract Background Evidence indicates a strong link between Zika virus (ZikV) and neurological complications. Acute myelitis, optic neuritis, polyneuropathy, and encephalomyelitis that mimic inflammatory idiopathic demyelination disorders (HDD) after ZikV infection have been reported in Brazil. Objective The present study aims to investigate the possible occurrence of molecular mimicry between ZikV antigens and Multiple Sclerosis (MS) autoantigens, the most frequent HDD of the central nervous system (CNS). Methods A retrospective cohort study with 305 patients admitted due to suspected arbovirus infection in Rio de Janeiro was performed, all subjects were submitted to neurological examination, and a biological sample was collected for serologic and molecular diagnostic. Bioinformatics tools were used to analyze the peptides shared between ZikV antigens and MS autoantigens. Results Of 305 patients, twenty-six were positive for ZikV and 4 presented IDD patterns found in MS cases. Sequence homology comparisons by bioinformatics approach between NS5 ZikV and PLP MS protein revealed a homology of 5/6 consecutive amino acids (CSSVPV/CSAVPV) with 83% identity, deducing a molecular mimicry. Analysis of the 3D structures revealed a similar conformation with alpha helix presentation. Conclusions Molecular mimicry between NS5 Zika virus antigen and PLP MS autoantigens emerge as a possible mechanism for IDD spectrum in genetically susceptible individuals.

Resumo Antecedentes Evidências indicam uma forte ligação entre o vírus Zika (ZikV) e complicações neurológicas. Mielite aguda, neurite óptica, polineuropatia e encefalomielite que mimetizam distúrbios inflamatórios de desmielinização idiopáticos (DDII) após infecção por ZikV têm sido relatadas no Brasil. Obejtivo O presente estudo tem como objetivo investigar a possível ocorrência de mimetismo molecular entre antígenos do ZikV e autoantígenos da Esclerose Múltipla (EM), a DDII mais frequente do sistema nervoso central (SNC). Métodos Foi realizado um estudo de coorte retrospectivo com 305 pacientes internados por suspeita de infecção por arbovirus no Rio de Janeiro, todos os indivíduos foram submetidos a exame neurológico e coleta de amostra biológica para diagnóstico sorológico e molecular. Ferramentas de bioinformática foram usadas para analisar os peptídeos compartilhados entre antígenos do ZikV e autoantígenos da EM. Resultados Dos 305 pacientes, vinte e seis foram positivos para ZikV e 4 apresentaram padrão IDD encontrado em casos de EM. As comparações de homologia de sequência por abordagem de bioinformática entre a proteína NS5 ZikV e PLP EM revelaram uma homologia de 5/6 aminoácidos consecutivos (CSSVPV/CSAVPV) com 83% de identidade, deduzindo um mimetismo molecular. A análise das estruturas 3D revelou uma conformação semelhante com apresentação em alfa-hélice. Conclusões O mimetismo molecular entre o antígeno NS5 do vírus Zika e o autoantígeno PLP da EM surge como um possível mecanismo para o espectro IDD em indivíduos geneticamente suscetíveis.

Exome-Wide Search for Genes Associated With Central Nervous System Inflammatory Demyelinating Diseases Following CHIKV Infection: The Tip of the Iceberg.

Chikungunya virus (CHIKV) is a re-emergent arbovirus that causes a disease characterized primarily by fever, rash and severe persistent polyarthralgia, although <1% of cases develop severe neurological manifestations such as inflammatory demyelinating diseases (IDD) of the central nervous system (CNS) like acute disseminated encephalomyelitis (ADEM) and extensive transverse myelitis. Genetic factors associated with host response and disease severity are still poorly understood. In this study, we performed whole-exome sequencing (WES) to identify HLA alleles, genes and cellular pathways associated with CNS IDD clinical phenotype outcomes following CHIKV infection. The cohort includes 345 patients of which 160 were confirmed for CHIKV. Six cases presented neurological manifestation mimetizing CNS IDD. WES data analysis was performed for 12 patients, including the CNS IDD cases and 6 CHIKV patients without any neurological manifestation. We identified 29 candidate genes harboring rare, pathogenic, or probably pathogenic variants in all exomes analyzed. HLA alleles were also determined and patients who developed CNS IDD shared a common signature with diseases such as Multiple sclerosis (MS) and Neuromyelitis Optica Spectrum Disorders (NMOSD). When these genes were included in Gene Ontology analyses, pathways associated with CNS IDD syndromes were retrieved, suggesting that CHIKV-induced CNS outcomesmay share a genetic background with other neurological disorders. To our knowledge, this study was the first genome-wide investigation of genetic risk factors for CNS phenotypes in CHIKV infection. Our data suggest that HLA-DRB1 alleles associated with demyelinating diseases may also confer risk of CNS IDD outcomes in patients with CHIKV infection.

Syncope in patients with drug-resistant epilepsy without apparent cardiovascular disease.

Epilepsy and syncope are clinical conditions with high prevalence rates in the general population, and the differential diagnosis between them is difficult. Objective To assess the frequency of syncope in patients diagnosed with drug-resistant epilepsy (DRE) without appa-rent heart disease, to investigate the relationship between clinical and electroencephalographic (EEG) changes, and to verify the role of the inclination test (IT). Method An open, prospective study from 2004 to 2006, including 35 consecutive patients from the Epilepsy Program of Hospital Universitário Clementino Fraga Filho who were diagnosed with DRE without apparent heart disease. Results The frequency of syncope was 25.7% (n=9), with a significant prevalence in women. Vasovagal syncope (VVS) was the most frequent diagnosis. Conclusion We found a significant association between syncope and the presence of autonomic symptoms (p=0.005). The IT plays an important role in the differential diagnosis of patients with DRE presenting with autonomic symptoms, regardless of EEG results and brain magnetic resonance imaging (MRI) abnormalities.

Syncope in patients with drug-resistant epilepsy without apparent cardiovascular disease / Sincope em pacientes com epilepsia farmaco resistente sem doenca cardiovascular aparente

Epilepsy and syncope are clinical conditions with high prevalence rates in the general population, and the differential diagnosis between them is difficult. Objective To assess the frequency of syncope in patients diagnosed with drug-resistant epilepsy (DRE) without appa­rent heart disease, to investigate the relationship between clinical and electroencephalographic (EEG) changes, and to verify the role of the inclination test (IT). Method An open, prospective study from 2004 to 2006, including 35 consecutive patients from the Epilepsy Program of Hospital Universitário Clementino Fraga Filho who were diagnosed with DRE without apparent heart disease. Results The frequency of syncope was 25.7% (n=9), with a significant prevalence in women. Vasovagal syncope (VVS) was the most frequent diagnosis. Conclusion We found a significant association between syncope and the presence of autonomic symptoms (p=0.005). The IT plays an important role in the differential diagnosis of patients with DRE presenting with autonomic symptoms, regardless of EEG results and brain magnetic resonance imaging (MRI) abnormalities. .

Epilepsia e síncope são condições clínicas com alta prevalência na população geral e, às vezes, o diagnóstico diferencial entre elas é difícil. Objetivo Investigar a frequência de síncope em pacientes diagnosticados com epilepsia fármaco resistente (EFR), sem doença cardíaca aparente; investigar a relação entre alterações clínicas e eletrencefalográficas; verificar o papel do teste de inclinação (TI). Método Estudo aberto prospectivo, realizado de 2004 a 2006, incluindo 35 pacientes consecutivos do Programa de Epilepsias do Hospital Universitário Clementino Fraga Filho, diagnosticados com EFR, sem doença cardíaca aparente. Resultados A frequência de síncope foi de 25,7% (n=9), com prevalência significativa em mulheres. Síncope vasovagal (SVV) foi o diagnóstico mais frequente. Conclusão Encontramos uma significativa associação entre síncope e a presença de sintomas autonômicos (p=0,005). O TI tem importante papel no diagnóstico diferencial de pacientes com diagnóstico de EFR que apresentam sintomas autonômicos, a despeito de alterações eletrencefalográficas e de ressonância magnética do crânio. .