Resumo O vírus herpes simples (HSV) é um dos agentes causadores de uma doença grave no sistema nervoso central (SNC) em humanos. A detecção de anticorpos específicos no líquido cefalorraquidiano (LCR) pode contribuir para o diagnóstico neurológico retrospectivo. Entretanto, os testes imunológicos comerciais são para uso em amostras de soro. Objetivo: Adaptar um kit comercial sorológico anti-HSV IgG para ser utilizado no de LCR. Metodos: Quarenta amostras de LCR de 38 pacientes com suspeita de infecção por HSV no SNC foram diluídas pesquisa de anticorpos anti-HSV IgG pelo método imunoenzimático (EIA). Além disso, as mesmas amostras também foram analisadas por reação em cadeia da polimerase (PCR). Resultados: A sensibilidade do teste EIA para o HSV consistiu em 5% (diluição 1:40) e 65% (diluição 1:2) no LCR, e o PCR do DNA do HSV, 15%. A análise combinada de EIA (diluição 1:2) e PCR aumentou a sensibilidade para 72,5%. Houve associação entre presença do LCR inflamatório e PCR positiva para HSV. Conclusões: Demonstramos a importância na adaptação previa do teste sorológico anti-HSV IgG EIA para ensaios do no LCR, a fim de aumentar a acuracia da análise, considerando a baixa concentração de anticorpos específicos no LCR.

Abstract Herpes simplex virus (HSV) is a cause of a severe disease of the central nervous system (CNS) in humans. The demonstration of specific antibodies in the cerebrospinal fluid (CSF) may contribute to the retrospective neurological diagnosis. However, the commercial immunological tests for HSV infection are for use in serum samples. Objective: The aim of the present study was to adapt a commercial kit anti-HSV IgG used for serum samples to be performed with a CSF sample. Methods: Forty CSF specimens from 38 patients with suspected CNS HSV infection were serially diluted for detecting anti-HSV IgG by enzyme immunoassay (EIA). The same samples were also analyzed with the polymerase chain reaction (PCR). Results: The sensitivity of EIA test for HSV was 5% (dilution 1:40) and 65% (dilution 1:2) in CSF, and HSV DNA PCR was 15%. The combined analysis of EIA (dilution 1:2) and PCR increased the sensitivity up to 72.5%. The inflammatory CSF was associated with positive HSV PCR. Conclusions: We demonstrated the importance to adapt serological anti-HSV IgG EIA test for CSF assays to increase the accuracy of the analysis, considering the low concentration of specific antibodies in CSF.

Abstract Recent reports indicate that besides respiratory and systemic symptoms among coronavirus disease (COVID-19) patients, the disease has a wide spectrum of neurological manifestations (encephalitis, meningitis, myelitis, acute disseminated encephalomyelitis, metabolic and acute hemorrhagic necrotizing encephalopathy, cerebrovascular diseases, Guillain-Barré syndrome, polyneuritis cranialis, dysautonomia, and myopathies). The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can spread from the respiratory system to the central nervous system, using transneuronal and hematogenous mechanisms. Although not every COVID-19 patient will test positive for the virus in the cerebrospinal fluid exam, the appearance of neurological symptoms associated with SARS-CoV-2 infection reveals the importance of understanding the neurologic manifestations and capacity for neural invasion associated with the pathogen. These aspects are relevant for correct diagnosis and treatment, and for the potential development of vaccines. This review highlights the latest evidence of SARS-CoV-2 infection with a focus on neurological involvement and potential neuropathogenesis mechanisms.