结核性脑膜炎实验诊断及病情评价方法的研究

A STUDY ON THE METHODS OF LABORATORY DIAGNOSIS AND EVALUATION OF TUBERCULOUS MENINGITIS

目的:通过评价脑脊液抗酸杆菌(AFB)、结核杆菌DNA(TB—DNA)、抗阿拉伯糖甘露糖脂IgG抗体(LAM-IgG)、腺苷脱氨酶(ADA)等指标诊断结核性脑膜炎(结脑)及评价病情的价值,选择更实用的结脑实验诊断及评价病情的方法。方法:对脑脊液标本(结脑组121例、对照组49例)进行改良罗氏法培养结核杆菌、PCR法检测TB-DNA、离心甩片一步法和经典法检查AFB、斑点免疫金渗滤试验法检测LAM—IgG、酶促反应终点法检测ADA,比较各种方法的特异性和敏感性。结果:结脑组的阳性率,培养结核杆菌6．7％、TB- DNA81．7％、经典法AFB16．7％、离心甩片一步法AFB64．3％、LAM—IgG50．4％、ADA59．1％。对照组有16例ADA阳性结果,余均无阳性发现。TB-DNA、离心甩片一步法检查AFB和LAM-IgG的特异性与常用方法一致(100％),敏感性显著性高于常用方法(P<0．01);ADA的敏感性也显著性高于常用方法(P<0．01),但特异性显著性低于常用方法(P<0．01)。结论:在实验诊断结脑方面,PCR法检测TB-DNA和离心甩片一步法检测AFB既具有较高的特异性和敏感性,应用价值高于其他方法;TB-DNA+LAM-IgG或AFB+ LAM-IgG联合试验诊断效率最佳。在评价病情方面,ADA具有良好的价值。

Objective： The aim was to find more practical laboratory methods ways to diagnose and evaluate tuberculous meningitis through appreciating the value specificity and sensitivity of AFB、DNA（TB- DNA）、 LAM-IgG and ADA in cerebrospinal fluid.Methods： To detect tubercle bacillus with the ameliorating Lowenstein＇ s culture method, TB-DNA with PCR, AFB with the centrifugal smear one stage process and the routine method, LAM-IgG with dot immunogold filtration assay and ADA with the continuous monitoring assay in cerebrospinal fluid （121tuberculous and 49 non-tuberculous）.The differences of specificity and sensitivity of each method were paralleled by Chi-square test.Results： In tuberculous meningitis group, the positive rate of the culture of tubercle bacillus was 6.7%, the detection of TB-DNA was 81.7%,the detection of AFB with the routine method was 16.7%, the detection of AFB with the centrifugal smear one stage process was 64.3%,the detection of LAM-IgG was 50.4% and the detection of ADA was 59.1%. In the control group, 16 cases had positive results of ADA but others were all negative.The specificity of TB-DNA, AFB with the centrifugal smear one stage process and LAM-IgG was same as common methods （100%） and the sensitivity was significantly higher than the latter （P〈0.01）.The sensitivity of ADA was higher than routine method （P〈0.01） but the specificity was lower than the latter significantly （P〈0.01）.Conclusions： For diagnosing tuberculous meningitis, the detection of TB-DNA with PCR and AFB with the centrifugal smear one stage process had high specificity and sensitivity. It was more valuable than others methods. TB-DNA ＋ LAM-IgG or AFB ＋ LAM-IgG were the most effective ways for the laboratory diagnosis. ADA possessed high value for appraising the disease： ADA upturned when tuberculous meningitis developed while it was downwards when the disease recovered.