Evaluation Of Metagenomic Next-generation Sequencing Of Cerebrospinal Fluid For The Early Diagnosis Of Tuberculous Meningitis

Background:Tuberculous meningitis(TBM)is a non-purulent inflammation of the meninges and cerebrospinal membranes caused by Mycobacterium tuberculosis infection.TBM is the most serious form of extrapulmonary tuberculosis with high morbidity and mortality,which causes a serious social burden.Due to the lack of specificity of the clinical manifestations of tuberculous meningitis,and the traditional etiological diagnosis method is time-consuming and low sensitivity,the diagnosis of tuberculous meningitis is always a serious challenge.Furthermore,it seriously affects the treatment and prognosis of tuberculous meningitis,resulting in high mortality and disability.Metagenomic Next-Generation Sequencing(m NGS)is an emerging molecular diagnostics method.It quickly and accurately obtains the genome information of pathogens by sequencing the DNA or RNA in the submitted samples.It is currently widely used in pathogens of central nervous system infection Detection,but less used in tuberculous meningitis.Objective:To evaluate the value of cerebrospinal fluid m NGS in early diagnosis of tuberculous meningitis.Methods:We recruited 16 clinically diagnosed TBM patients admitted to the Henan Provincial People's Hospital between September 2017 and September 2018.The diagnosis of TBM was based on the international TBM diagnosis classification.In addition,we recruited 6 cases of cryptococcal meningitis as m NGS positive control and 1 patient with anti-N-methyl-d-aspartic acid receptor(NMDAR)encephalitis as m NGS negative control.All patients underwent both m NGS and routine test.Simultaneously,the sensitivity and specificity of m NGS and other detection methods for the diagnosis of TBM were calculated,and their diagnostic efficacy was compared.Results:1.Among the TBM patients,10 were male and 6 were female,aged 40.8 ± 18.1,and the duration of symptoms before admission was 10-120 days(average 31.2 days).The most common clinical manifestation was fever 100%(16 / 16),headache 75%(12/16),disturbance of consciousness 75%(12/16),neck stiffness 81.5%(13/16).Meningeal enhancement occurred in 68.75%(11/16),cerebral infarction(brain stem,thalamus,and intracerebroventricular ventricle)in 25%(4/16)and hydrocephalus 6.25%;2.Laboratory examination results of patients with TBM revealed that: elevated intracranial pressure 81.25%(13/16),cerebrospinal fluid leukocytes increased 93.75%(15/16,average of 211.25*106/L),cerebrospinal fluid cytology dominant lymphocytes 62.5%(10/16),cerebrospinal fluid protein elevated 100%(16/16,average 1.86 g / l),cerebrospinal fluid glucose decreased 62.5%(10/16,average 1.92mmol/l),XPERT MTB/RIF positive 18.5%(3/16),AFB positive 0%(0/16),cerebrospinal fluid culture positive 0%(0/16),and peripheral blood T-SPOT.TB positive 56.25%;3.When clinical diagnosis is the gold standard,the sensitivity of m NGS is 62.5%(10/16),the sensitivity of XPERT MTB / RIF is 18.25%(3/16),and the sensitivity of T-SPOT.TB is 50%(8 / 16).Compared with XPERT MTB / RIF and T-SPOT.TB,m NGS has the highest sensitivity.4.When the final clinical diagnosis is the gold standard,the agreement of m NGS and XPERT MTB / RIF technology is poor(Kappa = 0.027,p = 0.165).The positive rate of m NGS diagnosis is 62.5%,which is significantly higher than XPERT MTB / RIF(18.75%)And the difference was statistically significant(Mc Nemar test,P = 0.039).The combination of m NGS technology and XPERT MTB / RIF technology can improve the detection sensitivity to 69.53%;the diagnostic method of m NGS and T-SPOT.TB technology has medium agreement(Kappa = 0.5,p = 0.039).There was no significant difference between the m NGS and T-SPOT.TB(Mc Nemar test,P = 0.625),and the agreement was 74.2%.The combination of m NGS technology and T-SPOT.TB technology can improve the detection sensitivity to 81.25%.5.When using MRN?1,MRN?2,MRN?3,and MRN?5 as diagnostic criteria to determine whether m NGS is positive or not,the diagnostic sensitivity is 62.5%,56.25%,37.5%,and 31.25%,and all the specificity is 100% The negative predictive value was 53.85%,50%,41.18%,and 38.89%.The sensitivity and negative predictive value of diagnosis were the highest when MRN ? 1 was used to define MTB positive.Conclusions: 1.Among 16 TBM patients,the positive rate of MTB detection by m NGS was 62.5%,the positive rate of T-SPOT.TB was 50%,and the positive rate of XPERT MTB / RIF was 18.25%,the combination of m NGS and other detection methods can improve the detection rate of MTB;2.m NGS can be used for the diagnosis of complicated infection of TBM and fungal meningitis.,such as case 10,MTB is an intracellular bacterium,and the bacterial abundance in the cerebrospinal fluid sample is low.When the MTBC MRN ? 1,the MTB can be identified as positive.