Risk Factors Of Long-term Poor Prognosis And Drug Resistance In Tuberculous Meningitis And Its Early Diagnosis

Background:Tuberculous meningitis(TBM)is an infectious disease of the central nervous system caused by Mycobacterium tuberculosis(MTB),which is characterized by meningeal irritation and hypertension caused by tuberculous inflammation,brain edema and hydrocephalus and has the characteristics of high mortality and disability.Meta analysis showed that the mortality risk of TBM was 24.7%,the mortality rate of adult patients with advanced HIV was more than 50%,and the risk of neurological sequelae of survivors was as high as 51%.In recent years,the incidence rate of tuberculous meningitis has been increasing due to population mobility,increased incidence rate of HIV and increased drug resistance tuberculosis cases.Because of its atypical manifestations,early diagnosis is difficult,misdiagnosis rate is high,mortality and disability rate of severe patients are still at a high level.Early diagnosis,combined application of anti tuberculosis drugs which can easily penetrate the blood-brain barrier,active and effective treatment of intracranial hypertension,to reduce sequelae and prevent recurrence,are the main treatment principles of TBM.Clinically,the onset of TBM in most patients is slow,occasionally acute.The correct diagnosis of TBM depends on the full understanding of the pathophysiological process and characteristics of tuberculous meningitis,the correct evaluation of its clinical manifestations,laboratory and imaging examination,and the evidence collection of tuberculous lesions outside the central nervous system.Because subclinical infection is widespread,tuberculin test has little diagnostic significance for adults,and CSF cell count,glucose levels,chloride levels and protein levels are usually similar to other meningitis.In addition,unreasonable or inappropriate treatment makes the clinical manifestations and CSF changes atypical,which increases the difficulty of diagnosis.Considering that the diagnosis mode of TBM is imperfect,it needs new decision reference for early diagnosis of TBM.The main reason for the difficulty in TBM diagnosis is that the symptoms and signs are non-specific,and the number of tuberculosis bacteria in cerebrospinal fluid,which is an important diagnostic specimen,is very small,and it is difficult to make early differential diagnosis.Fever,headache,vomiting,mental state changes and meningeal stimulation are the most common initial symptoms of TBM patients,but these symptoms can occur in a variety of diseases and lack disease specificity.WHO recommends quadruple regimen for the treatment of TBM,but the ability of antituberculous drugs to penetrate the blood cerebrospinal fluid barrier and kill Mycobacterium tuberculosis are different.There are also significant differences in patients' individualized meningitis inflammatory response and the compression effect of severe patients such as hydrocephalus and cerebral tuberculoma.Therefore,the prognosis of TBM varies greatly among individuals,and further understanding of the pathophysiology,clinical characteristics and other factors of TBM is needed.Children under 4 years old,the elderly and people with HIV are susceptible to TBM.A number of studies have conducted in-depth research on the clinical characteristics of TBM in children,HIV combined with TBM and elderly TBM,which has played a positive role in improving the diagnosis level and treatment strategy of corresponding types of TBM.Although TBM is generally considered to be opportunistic infection in ??patients,the incidence of TBM can also be observed in non HIV individuals with normal immune function.Foreign studies have shown that long-term and extensive use of corticosteroids and diseases of liver and biliary organs are common factors of TBM.but some patients without underlying diseases will also suffer from TBM.The middle-aged and young population is an important part of TBM patients,but there are few reports on the clinical characteristics and long-term prognostic factors of TBM patients in this population.The emergence of drug resistance poses an urgent challenge to TB control worldwide.In 2018,an estimated 500000 TB cases(out of 10 million TB cases)worldwide are resistant to rifampicin.Rifampicin is one of the key drugs in first-line anti-tuberculosis treatment.Once drug resistance occurs,expensive second-line anti-tuberculosis drugs need to be applied.Patients with drug resistance have longer treatment time and more toxic and side effects occur during treatment,and the average treatment success rate is only 56%.Although significant progress has been made in the development of simplified prevention programs for drug-resistant TB in recent years,the prevention and treatment of drug-resistant TB become complicated because there is no method to detect latent TB infection(LTBI)to determine the drug sensitivity of infected strains.Between 2016 and 201 7,six of the 30 countries with a high MDR-TB burden reported increases of more than 30 per cent in the number of MDR-TB cases.It is estimated that there will be 484000 MDR/RR-TB cases worldwide in 2018.In 2019,3.3%of new TB cases and 17.7%of previously treated cases are related to MDR-TB.In China,7.1%of new cases and 23%of previously treated cases were MDR-TB,exceeding the global average.Some studies have shown that the recent spread of MDR-TB strains and XDR-TB strains has become more and more severe,and that the mode of transmission predominates,not the improper use of antibiotics causing the emergence of resistance,which highlights the importance of DR-TB control.As researchers from different countries agree,controlling the prevalence of DR-TB plays an important role in global TB control and public health.Foreign studies show that the average cost of MDR-TB in 2017 was US $7,141,which was almost six times higher than that of drug-sensitive TB,causing huge losses to patients and health workers.As TB treatment moves from standardized treatment to more individualized treatment,information about drug resistance patterns in populations becomes more and more important.Under the background of high incidence of tuberculosis in China,it is very important to pay attention to the drug resistance of MTB and provide decision-making basis for clinical rational drug use.At present,the gold standard for TBM diagnosis is the detection of MTB in cerebrospinal fluid,but the positive rate of acid-fast staining on cerebrospinal fluid smear is only 10%,while the culture of MTB takes a long time,usually more than 2 weeks,and the positive rate of culture is only 20%-30%,which is of limited value for early clinical diagnosis.In recent years,there have been a variety of new diagnostic techniques for tuberculosis,and molecular diagnostic technology is an important breakthrough in recent years,which is represented by Xpert MTB/RIF detection kit.However,both the traditional cerebrospinal fluid MTB culture method and the new Xpert MTB/RIF assay still have a low sensitivity in the diagnosis of TBM.Along with the development of modern science and technology,High throughput sequencing has been successfully applied to the tumor,diabetes,prenatal diagnosis,clinical pathogens detection and other fields,the second generation sequencing(next-generation sequencing,NGS)is a new kind of high-throughput sequencing method,it can quickly sequence the bases of DNA or RNA samples,this technique has been reported for the diagnosis of bacteria,fungi and viruses and other pathogens,In particular,this technique has been reported for the diagnosis of central nervous system infections;however,the diagnostic value of this technique for TBM remains unclear.Objective:The first part:To investigate the clinical characteristics and risk factors for long-term adverse prognosis of young and middle-aged patients with TBM.The second part:To investigate the clinical characteristics of drug-resistant TBM patients and to analyze the risk factors for drug resistance.The third part:To evaluate the value of second-generation sequencing technology in early diagnosis of TBM.Methods:The first part:The data of young and middle-aged TBM patients hospitalized in Shandong Provincial Chest Hospital from January 2009 to December 2013 were retrospectively analyzed.The clinical data of the patients were recorded and the functional prognosis of the patients was analyzed after 5 years of follow-up.First,the chi-square test or t test was performed on the clinical data according to the prognosis,which had statistical significance(P<0.05),and then univariate and multivariate logistic regression was used to analyze independent risk factors for long-term poor outcomesThe second part:Data of patients with culture positive tuberculous meningitis hospitalized from January 2009 to December 2016 were collected for retrospective study,and clinical,laboratory data and demographic characteristics of patients were collected.In order to identify the clinical features of drug-resistant tuberculous meningitis and identify the risk factors for drug resistance,univariate comparison and multivariate logistic regression analysis were used.The third part:A total of 50 patients with clinically suspected tuberculous meningitis who were treated at Shandong Provincial Chest Hospital from February 2,2018 to August 2,2018 were prospectively included,and their diagnosis and treatment outcomes were followed up.The submitted cerebrospinal fluid specimens were all subjected to next-generation sequencing,and the obtained original sequence was compared with the pathogenic microorganism database to get the final result.The next-generation sequencing results showed positive when detecting the unique alignment sequence of the Mycobacterium tuberculosis complex,and negative when no unique alignment sequence was detected.Confirmed tuberculous meningitis patients were those diagnosed with at least one of the four items:cerebrospinal fluid Mycobacterium tuberculosis culture positive,smear positive,Xpert MTB/RIF test positive and Mycobacterium tuberculosis nucleic acid test positive;clinically diagnosed tuberculous meningitis patients were those with clinically suspected tuberculous meningitis and effective anti-tuberculosis treatment;non-tuberculous meningitis patients were those with other etiological evidence or clinical exclusion of tuberculous meningitis.The sensitivity and specificity of next-generation sequencing in the early diagnosis of tuberculous meningitis were analyzed.Results:The first part:A total of 600 patients were selected,including 339 males and 261 females,with an average age of(36±19)years;the poor prognosis rate was 42.17%(253/600).Univariate analysis showed that There was a significant difference in age(t=-3.723,P<0.05).stage(z=-4.789,P=0.000).change of consciousness(?2=10.198,P=0.001),cognitive impairment(?2=7.813,P=0.000),cranial nerve palsy(?2=5.911,P=0.041),abnormal peripheral nerve function(?2=14.179,P=0.017),meningeal irritation(?2=6.951,P=0.008),cerebrospinal fluid(CSF)in patients with different prognosis There were significant differences in WBC(z=-4.835,P=0.01 5),hydrocephalus(?2=11.564,P=0.001).cerebral infarction(?2=7.142,P=0.017)and drug-resistant tuberculosis(?2=0.217,P=0.004)between different prognosis.Multivariate logistic regression analysis showed that patients' age[or 1.059,95%CI 1.025,1.087),P=0.000],consciousness change[or=3.545,95%CI(1.069.10.685),P=0.037].MRC Stage ?[or = 23.985,95%CI(3.878,40.129),P=0.000],hydrocephalus[or=2.917,95%CI(1.049.8.613),P=0.023],cerebral infarction[or=3.178,95%CI(0.981,8.173),P=0.019],drug-resistant tuberculosis[or=11.672,95%CI(1.681,30.112),P=0.001]were risk factors for poor prognosis.The second part:A total of 164 patients with positive culture of tuberculous bacteria were screened in this study,including 41 cases(25%)of drug-resistant tuberculous meningitis.Drug resistant tuberculous meningitis had higher mortality than drug sensitive tuberculous meningitis(46.3%vs 8.9%,P<0.001).Length of stay(OR 1.059,95%CI 1.025.1087),vomiting(OR 3.545,95%CI 1.069,10.685),cerebrospinal fluid Ada(OR 3.178,95%CI 0.981,8.173).cerebrospinal fluid neutrophil cytology(OR 11.672,95%CI 1.681,30.112).previous history of tuberculosis(OR 23.985,95%CI 3.878.40.129),combined with tuberculosis of other organs(OR 8.161,95%CI 1.235,95%CI 1.087),269).age(OR 5.471.95%CI 1.051.8.954)and brain pressure(OR 2.917,95%CI 1.049,8.613)were independent risk factors for drug-resistant tuberculous meningitis.The third part:Of the 22 confirmed tuberculous meningitis patients.13 were positive for Xpert MTB/RIF test,6 were positive for culture,and 5 were positive for Mycobacterium tuberculosis nucleic acid PCR.There were 12 clinically diagnosed tuberculous meningitis and 16 non-tuberculous meningitis patients.Among the confirmed and clinically diagnosed patients,20 cases of Mycobacterium tuberculosis complex series were detected by next-generation sequencing technology,with a sensitivity of 58.8%(20/34)and a specificity of 100%(16/16).Among the confirmed patients,the sensitivity of next-generation sequencing was 63.6%(14/22).In the 50 specimens that were simultaneously submitted for Mycobacterium tuberculosis culture,Xpert MTB/RIF test and next-generation sequencing,the specificity of the three methods was 100%(16/16)with clinical diagnosis as the standard.The sensitivity of traditional method.Xpert MTB/RIF test and next-generation sequencing were 29.4%(10/34).38.2(13/24)and 58.8(20/34),respectively.The sensitivity differences between the first two detection methods and next-generation sequencing were statistically significant(McNemar test:?2=8.333,p=0.013,?2=8.333,p=0.065).The sensitivity of the combined detection of traditional method and next-generation sequencing was as high as 82.4%(28/34).Conclusion:The first part:Age.MRC stage ?,change of consciousness,hydrocephalus,cerebral infarction and drug-resistant tuberculosis were independent risk factors for long-term poor prognosis of tuberculous meningitis.The second part:Drug resistant tuberculous meningitis has a higher risk of death and worse prognosis than drug sensitive tuberculous meningitis,and its potential mechanism needs further study.Male,unmarried,length of hospital stay,vomiting,cerebrospinal fluid ADA,cerebrospinal fluid neutrophil cytology dominant,previous history of tuberculosis,combined with other organ tuberculosis were independent risk factors of drug-resistant tuberculous meningitis.The third part:Next-generation sequencing technology could quickly detect the Mycobacterium tuberculosis complex in the cerebrospinal fluid,with significant sensitivity and specificity,and could be used as an early diagnosis index for tuberculous meningitis.Next-generation sequencing combined with traditional detection method could increase the detection rate.