The Diagnostic Value Of CSF Parameters Was Evaluated In Patients With Tuberculous Meningitis

Objective: To analyze the value of Cerebrospinal fluid(CSF)biochemistry and adenosine deamimse(ADA)in early diagnosis of tuberculous meningitis,the CSF parameters and ADA levels of patients with central nervous system infection and continual CSF ADA levels of patients with tuberculous meningitis were measured and compared with the Viral meningitis CSF parameters.Methods: Hospitalized cases were enrolled from January 2015 to November 2018 in tuberculosis department of The Eighth Medical Center of PLA General Hospital.We collected the medical records of TBM,and screened out of 74 cases according to the Thwaites diagnostic and Primary and retreatment of tuberculosis criteria;the “Definite TBM” and “probable TBM” “Primary TBM” and “retreatment TBM” as the case group(TBM group).The cut-off value,sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV),positive likelihood ratio and negative likelihood ratio of ADA and CSF parameters(CSF protein,glucose,)were studied by receiver operating characteristic(ROC)curves.Results:1.Clinical data analysis results: A total of 74 patients with TBM were diagnosed in this study(22 confirmed,52 possible;56 newly treated,18 retreated),including 44 males and30 females,with an average age of 15-67 years(38.22 ± 14.88)years old.There were 54 cases in the VM group,including 29 males and 16 females,aged 14-69 years,with an average of(39.62 ± 16.93)years.There was no significant difference in age and gender between the two groups.2.TBM group(diagnosed group and possible group)compared with VM group: CSF protein(1.09 ± 0.23 g / l),glucose(2.30 ± 1.18 mmol),chloride(116.09 ± 7.79 mmol/ l)and ADA(7.38 ± 1.36 U / l)in TBM group was compared with protein(0.77 ± 0.47 g/ L).ADA(3.11 ± 2.95 u / l),sugar(3.02±1.45 mmol/L)and chloride(121.93 ± 5.40 mmol/ L)in VM group.The levels of ADA and protein showed an upward trend.the levels of chloride and glucose showed a downward trend.all indicators were statistically significant(P<0.05).3.Comparison between the newly treated TBM group and the retreated TBM group: 18 patients with newly treated TBM used effective anti-tuberculosis treatment for at least half a year.The contents of protein(0.89±0.64g/L vs.2.09±1.56g/L),ADA(3.54±3.67u/l vs.12.3±9.04 u/l)and chloride(121.74±5.39 mmol/L vs.114.33±7.56 mmol/L)in CSF gradually approached the normal level.This is statistically significant compared with the detection results of protein,chloride and ADA in CSF of retreated patients(P<0.05).However,there was no statistically significant difference in the content of glucose(2.76±1.38 vs.2.36±1.26mmol/L)in CSF(P=0.002,P<0.05).4.Using the critical values of protein content(> 50 mg / ml),glucose content(<50mg / dl),ADA content(> 10 u / l)detect the diagnostic effectiveness of TBM: the results show that the area under the curve of ADA is 0.92 in CSF,sensitivity 86.36%,specific Degree88.89%,PPV 76%,NPV 94%,positive likelihood ratio 7.77,negative likelihood ratio 0.15;CSF protein AUC 0.852,sensitivity 95.45%,specificity 48.14%,PPV 43%,NPV 96%,positive likelihood Ratio 1.84,negative likelihood ratio 0.09;CSF glucose AUC 0.294,sensitivity 77.27%,specificity 64.81%,PPV 47%,NPV 87%,positive likelihood ratio 2.20,negative likelihood ratio 0.35.5.With effective anti-tuberculosis treatment,the content of ADA in cerebrospinal fluid showed a downward trend.Within 3 weeks,the differences in ADA content between the TBM and VM groups were statistically significant(P <0.05).However,the ADA level at week 4(4.11 ± 4.33 u / L vs.3.11 ± 2.95 u / L)was not statistically different between the TBM and VM groups(P = 0.238,P> 0.05).Conclusions: Protein、glucose、chloride and ADA level were predictor for early diagnosis of TBM,which was a fast,cheap and practical method.When the protein content(>50mg/ml),glucose content(<50mg/dl),ADA content(>10u/l)are used as the critical values,the diagnosis of TBM has high accuracy,and ADA in CSF is the best Parameters,followed by protein level,protein is the most sensitive indicator,and ADA is the most specific indicator.With effective anti-tuberculosis treatment,the ADA level in CSF of TBM patients shows a downward trend,but the time window for diagnosis with VM is longer(about 3 weeks).