| Background and Objectives:Viral encephalitis / meningitis is one of the most common infectious diseases of the central nervous system(CNS)in the world.This disease is commonly caused by the virus invading the central nervous system by blood circulation or neural circuit diffusion,.It usually takes place in the elderly,young children and the people with the low immunity,and have the high mortality and disability rate.In recent years,as the number of people with HIV,tumor and other diseases increases or the climate changes,the incidence of viral encephalitis / meningitis is gradually increasing.However,the isolation and identification of the virus should take a long time and the high operation intensity,and the detection rate is low.Serological test should take 2-4 weeks to get the highest positive rate and may produce the false positive result.Although PCR and Sanger sequencing can accurately detect viral pathogens,they are limited by the nucleic acid fragments that primers can bind.Therefore,clinicians urgently need a new diagnostic method.Our study was to evaluate the value of Next-generation Sequencing(NGS)in pathogen diagnosis of viral encephalitis / meningitisMethods:Through the inclusion and exclusion criteria,we selected 18 patients who were hospitalized in the Department of Neurology of Henan people’s Hospital from November 2018 to July 2020.All patients were finally diagnosed with viral encephalitis / meningitis.In addition,5 patients with anti-N-methyl-d-aspartate receptor(NMDAR)encephalitis were selected as the negative control group.We recorded the medical history,clinical signs and the examination results of all patients and collected their CSF samples sequenced by BGISEQ-500 platform.The low quality sequence and host background related information were removed from the sequencing results to get the high quality data and the high quality data was compared with the microbiological database to obtain the sequencing analysis results.Besides,we collected the results of antibody tests in blood and cerebrospinal fluid,and calculated their sensitivity,specificity,positive predictive value,negative predictive value and Youden index.Fianlly,we used the Mc Nemar test and Kappa test to detect the difference between these methods.Results:1.Among the 18 patients with probable viral encephalitis / meningitis,11 patients were males and 7 patients were females,aged from 16 to 79 years(mean47.78 years).They all have fever and headache 2 of them have the history of use of immunosuppressant and 1 of them has the history of chemotherapy for lung cancer.6lg M antibodies were detected positive,including 1 Cytomegalovirus lg M,2 VZV lg M,1 HSV type I lg M in the blood and 2 VZV lg M in cerebrospinal fluid.Under the condition of virus genome sequence greater than 1,9 patients were detected the positive results by NGS,including 1 HSV type I DNA,1 cytomegalovirus DNA,1Human herpesvirus type 6 DNA and 5 VZV DNA.In addition,among 5 patients with NMDA encephalitis,VZV sequence was detected in 1 patient,which was proved to be the fasle positive result.2.The clinical diagnosis of highly probable viral encephalitis / meningitis was regarded as the gold standard,including that the white blood cell count in cerebrospinal fluid is ≥ 5 × 106 / L,clinical antiviral therapy is effective and there is no other clinical evidence of microbial etiology.The sensitivity of CSF antibody detection,blood antibody detection clinical overall antibody detection and NGS were 11.11%(2/18),22.22%(4/18),33.33 %(6/18)and 50.00%(9/18).The specificity of CSF antibody detection,blood antibody detection clinical overall antibody detection and NGS were 100%,100%,100$,100% and 80.00%(4/5).The positive predictive value of CSF antibody detection,blood antibody detection clinical overall antibody detection and NGS were 100%,100%,100%,100% and 90.00%(9/10).The negative predictive value of CSF antibody detection,blood antibody detection,clinical overall antibody detection and NGS were 23.81%(5/21),26.32%(5/19),29.41%(5/17),30.77%(4/13).The Youden index of CSF antibody detection,blood antibody detection,clinical overall antibody detection and NGS were 0.11,0.22,0.33,0.30.3.Mc Nemar test indicated there had no difference(P=0.125 > 0.05)in the pathogens detection rate of CSF between m NGS and blood antibody detection.But there is the poor consistency because the Kappa value is 0.222< 0.4..4.Mc Nemar test indicated there had the difference(P=0.039<0.05)between m NGS and CSF antibody in the detection of the viral encephalitis / meningitis.The sensitivity of NGS in the pathogens detection rate is higher than the CSF antibody detection.5.Mc Nemar test indicated there had no difference(P=0.423 > 0.05)between m NGS and clinical overall antibody in the detection of the viral encephalitis /meningitis.But there is the poor consistency because the Kappa value is < 0.4.The combination of NGS and clinical antibody detection can increase the positive rate of viral encephalitis / meningitis diagnosis to 61.11%Conclusion:1.NGS can assist in the diagnosis of viral encephalitis / meningitis.2.There was no significant difference between the positive rate of NGS and clinical antibody in the diagnosis of viral encephalitis / meningitis.But there is the poor consistency.If NGS is combined with clinical antibody detection,it can improve the positive rate of viral encephalitis / meningitis diagnosis.3.NGS may produce false positive results and interfere with the diagnosis of clinicians.Therefore,it is necessary to comprehensively analysis the results of NGS combined with clinical systerms. |
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