神经梅毒54例临床及实验室特点分析

目的了解神经梅毒的临床及实验室特点。方法回顾性分析2015-2019年本院120例梅毒住院患者,使用SPSS软件进行统计分析。结果 66例非神经梅毒和54例神经梅毒患者,性别、年龄差异均有统计学意义(P<0.001)。29例有症状神经梅毒者,从出现神经精神系统症状到诊断神经梅毒的时间为(11.53±17.00)个月。神经梅毒患者血清TRUST滴度高于非神经梅毒患者,有症状神经梅毒患者脑脊液TRUST滴度高于无症状神经梅毒患者,其中18例神经梅毒患者治疗前后比较,治疗后血清TRUST滴度、脑脊液TRUST滴度均低于治疗前,差异均有统计学意义(P<0.001)。有症状神经梅毒比无症状神经梅毒患者脑脊液有核细胞数高,但是差异无统计学意义(P=0.227)。有症状神经梅毒比无症状神经梅毒患者脑脊液蛋白、IgG、IgA、IgM高,差异均有统计学意义(P<0.001)。神经梅毒治疗后脑脊液有核细胞数、蛋白、IgG、IgA、IgM均下降,差异有统计学意义(P<0.001)。ROC曲线显示,脑脊液免疫球蛋白曲线下面积大于脑脊液细胞数和蛋白。结论神经梅毒的诊断常延迟。男性患者、出现精神症状,同时伴有神经系统症状者,需要积极行腰穿脑脊液检查以早日发现神经梅毒。除了脑脊液TRUST、TPPA、有核细胞数、蛋白等检测外,脑脊液免疫球蛋白检测有助于神经梅毒的诊断。     

36例神经梅毒临床资料分析

对我院2010-2019年收治的36例HIV阴性的神经梅毒患者资料进行回顾性分析。36例患者中男29例,女7例;平均年龄49岁;无症状神经梅毒9例,平均年龄(36.07±8.05)岁,症状性神经梅毒27例,平均年龄(58.12±13.33)岁,差异具有统计学意义(P<0.001);脑脊液检查示:TPPA阳性36例,RPR阳性21例;白细胞升高13例;蛋白阳性24例。症状性神经梅毒组脑脊液白细胞计数、蛋白质阳性率、RPR阳性率和蛋白质定量水平高于无症状神经梅毒组,差异均有统计学意义(P=0.005;P=0.036;P=0.019;P=0.002)。     

129例未经治疗的早期梅毒患者脑脊液检测结果的分析

目的:探讨未经治疗的早期梅毒脑脊液各项检测的意义及其对神经梅毒的诊断价值。方法:对129例未经治疗的早期梅毒患者脑脊液进行细胞计数和蛋白定量、VDRL、FTA-ABS、RPR、TPPA检测以及RT-PCR检测TP,并分析不同RPR滴度组及不同RT-PCR结果组脑脊液异常率的差异。结果:脑脊液细胞或蛋白异常者30例(23.26%),VDRL阳性2例(1.55%),FTA-ABS阳性3例(2.33%),RPR阳性5例(3.88%),TPPA阳性10例(7.75%),RT-PCR阳性32例(24.81%)。2例(1.55%)确诊为神经梅毒。血清RPR滴度≤1∶16组与≥1∶32组患者CSF异常率差异有统计学意义(2=8.37,P=0.004)。脑脊液RT-PCR检测阳性与阴性组脑脊液异常率差异有统计学意义(2=4.49,P=0.034)。结论:血清RPR滴度≥1∶32者脑脊液异常率较高,临床中应引起重视。单纯对于未经治疗的早期梅毒而言,用PCR检测脑脊液中TP含量的方法对神经梅毒的诊断不具有明显价值。     

酶联免疫吸附试验、梅毒螺旋体颗粒凝集试验及甲苯胺红不加热血清试验在梅毒检测中的检验效能评价

目的:研究三种常用的不同血清学诊断方法对梅毒螺旋抗体的检测效果,从而为提高梅毒螺旋抗体的检出率提供较好的诊断方法。方法:选取2013年1月至2014年7月于我科门诊就诊的274例患者为观察对象,根据有无感染梅毒将其分为两组,其中177例感染梅毒患者为观察组,97例非梅毒患者为对照组,分别应用酶联免疫吸附试验(ELISA)、梅毒螺旋体明胶颗粒凝集试验(TPPA)、甲苯胺红不加热血清试验(TRUST)三种常用的不同血清学诊断方法对两组患者进行梅毒螺旋抗体的检测,分别比较三种检测方法检测的梅毒螺旋抗体的阳性例数、敏感性和特异性,并进行分析。结果:在检测梅毒患者血清标本的阳性率方面,ELISA法最高,为98.87%,TRUST法最低,为88.70%,ELISA法与TPPA法比较,差异无统计学意义(P0.05),TRUST法分别与ELISA法、TPPA法比较,差异均具有统计学意义(P0.05);ELISA法、TRUST法、TPPA法检测梅毒患者血清的敏感性分别为98.87%、88.70%、97.18%,特异性分别为98.97%、95.88%、100.00%,阴性预测值分别为97.96%、82.30%、95.10%,阳性预测值分别为99.43%、97.52%、100.00%;ELISA法敏感性和阴性预测值最高,与TRUST法比较,差异有统计学意义(P0.05);TPPA法特异性和阳性预测值最高,与TRUST法比较,差异有统计学意义(P0.05);三种血清学检测方法同时显示梅毒患者血清阳性者有155例,同时显示阴性者有1例,TRUST法显示阴性而TPPA法和ELISA法显示阳性者17例。结论:三种血清学检测方法的侧重点各不相同,ELISA法适用于大批量样本筛查、TPPA法适用于进行梅毒确诊、TRUST法应用于对梅毒患者治疗疗效及预后的判断,在临床中应结合实际情况进行选择。     

实验室检查对神经梅毒诊断的重要性

近年来由于典型的神经梅毒已不多见,很多患者临床表现不典型.因此,神经梅毒要根据病史、临床表现、梅毒血清学检查、脑脊液(CSF)检查及脑部影像学检查的综合结果作出诊断.其中CSF中梅毒血清学检查的阳性结果,说明中枢神经系统(CNS)存在活动性的梅毒感染.如果结果为阴性,但临床又怀疑为神经梅毒,可选择用IgG指数、IgM指数、梅毒螺旋体血凝试验TPHA指数及荧光螺旋体抗体吸收(CSF-IgM-FTA-ABS)试验和CSF固相血吸附(SPHA)试验来确诊.     

神经梅毒合并HIV阳性患者的脑脊液及血液指标分析

目的：探讨脑脊液实验室检测在神经梅毒合并HIV阳性患者中的诊断价值及血清快速血浆反应素试验（rapid plasma reagent test, RPR）滴度、CD4+T细胞计数在神经梅毒腰穿指征中的应用。方法：收集2015年1月至2019年12月就诊于北京佑安医院的梅毒合并HIV阳性患者106例，采集脑脊液(cerebrospinal fluid, CSF)进行脑脊液白细胞（CSF-WBC）、脑脊液蛋白（CSF-protein）及脑脊液梅毒螺旋体颗粒凝集试验(treponema pallidum particle assay, TPPA)、RPR滴度检测，采集血液进行RPR滴度、CD4+T细胞计数检测，根据神经梅毒的诊断分神经梅毒组和非神经梅毒组，对两组的脑脊液检测结果、血清RPR滴度及CD4+T细胞计数检测结果进行分析。结果：106例梅毒合并HIV阳性患者中神经梅毒发病率为33.02%，CSF-RPR及CSF-TPPA对HIV阳性梅毒患者发生神经梅毒的诊断敏感性为68.57％和97.14％，特异性为92.96％和49.29％；CSF-WBC和CSF-protein的ROC（受试者工作特征曲线）分析曲线下面积（area under curve, AUC）分别为0.911和0.913，CSF-WBC为10.5/μL、CSF-protein为272.15 mg/L时，约登指数最大；血清RPR≥1∶16患者发生神经梅毒的几率是血清RPR<1∶16患者的1.52倍（OR 1.52，CI 1.14～2.04，P<0.05），CD4+T细胞≤350个/μL发生神经梅毒的几率为CD4+ T细胞>350个/μL患者的2.37倍（OR 2.37, 95％ CI 1.64～3.41,P<0.05）。结论：HIV阳性患者神经梅毒的发病率较高，CSF-RPR对HIV阳性患者发生神经梅毒具有较高的诊断价值，血清RPR滴度≥1∶16和CD4+T≤350个/μL，是HIV阳性患者神经梅毒的危险因素。     

脑脊液VDRL、TRUST、IgM抗体检测对神经梅毒的诊断价值

目的:通过对梅毒患者脑脊液进行非梅毒螺旋体抗体和梅毒螺旋体抗体检测结果的综合分析,探讨神经梅毒诊断的最佳检测方法,提高神经梅毒检出率。方法:采用性病研究实验室试验(VDRL)检测非梅毒螺旋体抗体,免疫印迹法(WB)检测梅毒螺旋体IgM抗体,用上述两种方法同时对280例梅毒患者脑脊液(CSF)标本进行检测。VDRL阳性者同时做甲苯胺红不加热血清试验(TRUST)。结果:280例怀疑神经梅毒患者脑脊液标本,VDRL和IgM均阳性50例;VDRL阳性IgM阴性10例;VDRL阴性IgM阳性8例。VDRL与IgM试验阳性率比较,差异无统计学意义(x~2=0.26,P0.05);60例VDRL阳性脑脊液中TRUST试验阳性51例,两者试验阳性率结果比较,差异有统计学意义(x~2=76.1,P0.01)。结论:对神经梅毒患者脑脊液检测,VDRL试验敏感性高于TRUST试验;对怀疑神经梅毒患者脑脊液进行VDRL和IgM联合检测,可提高神经梅毒的检出率。     

免疫层析技术和化学发光法免疫分析法在梅毒检测中的效果比较

目的:考察全自动微粒子化学发光免疫实验(CMIA)与免疫层析技术(GICA)在梅毒检测中的应用效果差异。方法:采用TPPA法作为金标准检测1500例住院患者血清标准,评价CMIA与GICA在梅毒检测中敏感性和特异性。结果:金标准中1500例血清标本梅毒检出率为12.1%,CMIA阳性检出率为12.5%,GICA为12.7%。CMIA法灵敏度为92.86%,特异性为98.,6%,阳性预测值为89.89%,阴性预测值为99.01%。GICA法灵敏度为98.35%,特异性为99.77%,阳性预测值为98.35%,阴性预测值为99.77%。两组间灵敏度和阴性预测值存在显著差异(P0.05)。结论:GICA的灵敏性和阴性预测值优于GICA法,可以提到TPPA成为梅毒检测的血清学检测首选方法。     

HIV阴性神经梅毒患者血清和脑脊液实验室检查回顾性分析

目的分析神经梅毒患者血清和脑脊液实验室检查结果在不同病程分组之间是否具有差异性。方法以30名正常人为阴性对照,对28名HIV阴性神经梅毒患者的住院病案进行回顾性分析,用SPSS13.0软件包进行统计学分析。结果早期神经梅毒患者16例(57.1%),晚期神经梅毒患者12例(42.9%),没有无症状神经梅毒患者入院接受治疗。神经梅毒患者脑脊液白细胞计数、葡萄糖含量以及蛋白含量比对照组明显升高,早期与晚期患者之间血清和脑脊液RPR滴度、TPAb检测、白细胞计数、葡萄糖含量及蛋白含量实验室检查结果差异无统计学意义。结论早期神经梅毒在入院病人中所占比重较大;神经梅毒患者血清和脑脊液RPR滴度与TPAb检测敏感性高,脑脊液细胞计数和生化检查结果可以为诊断提供参考;不能将神经梅毒患者血清和脑脊液实验室检查结果作为判定神经梅毒病程进展情况及分期的依据。     

19S-IgM-TPPA试验诊断先天梅毒评价

目的:评价血清19S-IgM-梅毒螺旋体明胶颗粒凝集试验(19S-IgM-TPPA)诊断早期先天梅毒的应用价值,以指导临床实践。方法:以2003年3月-2006年2月期间符合纳入标准的156例婴儿为研究对象,对他们进行血清19S-IgM-TPPA试验,并随访至明确诊断。以回顾诊断为标准。结果:156例婴儿中,141例婴儿完成随访,其中123例排除先天梅毒,18例婴儿被确诊为早期先天梅毒(有症状14例,无症状4例)。19S-IgM-TPPA试验阳性结果16例,假阳性2例,假阴性4例,敏感性77.78%(有症状78.57%,无症状75%),特异性98.37%,诊断指数176.15%;阳性预测值87.5%,阴性预测值96.8%,调整预测值无改变;阳性似然比47.83,阴性似然比0.226。结论:19S-IgM-TP-PA诊断先天梅毒敏感性较好,特异性很高,对有症状早期先天梅毒,在常规标准血清试验确定前即可证实感染的存在,用于先天梅毒的诊断是良好的预测工具,在已经有TPPA的实验室中,19S-IgM-TP-PA不失为一种诊断先天梅毒的可供选择的方法。     

An evaluation of oligoclonal banding and CSF IgG index in the diagnosis of neurosyphilis

It can be difficult to determine which patients would benefit from therapy to control central nervous system infection with Treponema pallidum. The authors have followed patients prospectively to evaluate two new diagnostic tests available. They performed lumbar punctures on 107 consecutive patients with syphilis of unknown duration, untreated (n = 19) or with serology that did not decrease sufficiently during follow-up (n = 88). The mean age was 47 years, with 91 males and 16 females. Twelve had neurologic symptoms. In order to establish a gold standard, the authors required the cerebrospinal fluid Venereal Disease Research Laboratory (CSF VDRL) test to be reactive (n = 25). They then examined oligoclonal banding and CSF IgG index as diagnostic tests by comparing them to the gold standard. Oligoclonal banding, abnormal in 20, had a sensitivity of 52% and a specificity of 91%. The CSF IgG index, abnormal in 56, had a sensitivity of 92% and a specificity of 60%. The posttest likelihoods of a positive test result were low, and hence neither test ruled in the diagnosis. With a post-test likelihood (PTL) negative of 4%, a negative CSF IgG index assisted in ruling out the diagnosis. Oligoclonal banding was not a satisfactory test for neurosyphilis. The CSF IgG index appears to help only in ruling out infection. Further effort is needed in developing diagnostic tests to assist the clinician in the diagnosis of neurosyphilis.     

几种实验室检测方法在神经梅毒诊断中的比较

目的 探讨性病研究实验室试验(VDRL)与几种检测方法在神经梅毒诊断中的敏感性和特异性差异.方法 取未经治疗或经治疗梅毒血清固定的隐性梅毒患者脑脊液(CSF),进行VDRL、RPR、TPPA、荧光梅毒螺旋体抗体吸收试验(FTA-ABS)、CSF常规和生化等检查.比较VDRL与这几种试验的敏感性、特异性、阳性预测值、阴性预测值的差异.结果 在总共61例符合隐性梅毒诊断的病例中,CSFRPR的敏感性、特异性、阳性预测值(PPV)、阴性预测值(NPV)分别为93.44%(57/61)、99.32%(293/295)、96.61%(57/59)、98.65%(293/297),CSF-TPPA分别为91.80%(56/61)、82.71%(244/295)、52.34%(56/107)、97.99(244/249),CSF-FTA-ABS分别为93.44%(57/61)、82.71%(244/295)、52.78%(57/108)、98.39%(244/248),蛋白定量分别为49.18%(30/61)、97.29%(287/295)、78.95%(30/38)、90.25%(287/318).结论 目前CSF-RPR、CSF-TPPA、CSF-FTA-ABS、蛋白定量等均不能替代CSF-VDRL作为NS诊断试验.CSF-RPR有较高的敏感性和特异性,其诊断效用指标ROC(receiver operating characteristic)曲线下面积(area under curve,AUC)与CSF-TPPA、CSF-FTA-ABS以及蛋白定量有统计学差异.

Abstract：

Objective To compare the sensitivity and specificity of venereal disease research laboratory (VDRL) test versus several other laboratory tests in the diagnosis of neurosyphilis. Methods Lumber puncture was conducted to obtain cerebrospinal fluid (CSF) from untreated outpatients with latent syphilis (LS) or serofast outpatients with LS. Then, VDRL test, rapid plasma regain (RPR) test, Treponema pallidum particle agglutination (TPPA) assay, fluorescent treponemal antibody-absorption (FTA-ABS) test and protein quantification were performed on these CSF samples. The sensitivity, specificity, positive predictive value and negative predictive value were compared between VDRL test and four other laboratory tests in the diagnosis of neurosyphilis. Results Totally, 61 cases of latent syphilis were included in this study. The sensitivity, specificity,positive predictive value and negative predictive value were 93.44% (57/61), 99.32%(293/295), 96.61%(57/59), 98.65% (293/297)for CSF-RPR, respectively, 91.80% (56/61), 82.71% (244/295), 52.34% (56/107),97.99 (244/249) for CSF-TPPA, respectively, 93.44% (57/61), 82.71% (244/295), 52.78%(57/108), 98.39%(244/248) for CSF-FTA-ABS, respectively, and 49.18%(30/61), 97.29% (287/295), 78.95% (30/38),90.25% (287/318) for CSF protein quantification, respectively. Conclusions CSF-VDRL cannot be replaced by CSF-RPR, -TPPA, -FTA-ABS, or CSF protein quantification in the diagnosis of neurosyphilis. CSF-RPR shows a high sensitivity and specificity in the diagnosis of neurosyphilis, with an increased diagnostic capability (area under the receiver operating characteristic curve) compared with CSF-TPPA, CSF-FTA-ABS or CSF protein quantification.     

HIV and syphilis: when to perform a lumbar puncture

OBJECTIVES: The objectives of this study were to determine predictive factors for neurosyphilis in HIV-infected patients with syphilis and optimize the use of lumbar puncture. STUDY DESIGN: The authors reviewed 112 cases of HIV-infected patients with syphilis who underwent a lumbar puncture. Diagnosis of neurosyphilis was based on a cerebrospinal fluid white blood cells count > or =20/microL, and/or a reactive cerebrospinal fluid-Venereal Disease Research Laboratory, and/or a positive intrathecal T. pallidum antibody (ITPA) index. RESULTS: Twenty-six of 112 had neurosyphilis. Neurologic manifestations and serum rapid plasma reagin (RPR) were associated with neurosyphilis (P = 0.036, P = 0.018, respectively). In multivariate analysis, log(2)RPR was still associated with neurosyphilis (P = 0.005). In patients without neurologic manifestations, the risk of neurosyphilis increases gradually with log(2)RPR. A serum RPR of 1/32 seems to be the best cutoff point to decide the performance or not of a lumbar puncture (sensitivity 100%, specificity 40%). CONCLUSION: In HIV-infected patients with syphilis, lumbar puncture could be restricted to those with neurologic manifestations or a serum RPR > or =1/32.     

梅毒血清固定患者神经梅毒发生情况及相关因素分析

目的:了解规范治疗后梅毒血清固定患者中神经梅毒发生情况,并探讨其相关影响因素。方法:收集2013年1月至2021年6月在我院行腰穿术的梅毒血清固定患者临床资料进行回顾性分析,采用多因素logistic回归模型分析神经梅毒发生的相关因素,运用ROC曲线评价血清初始TRUST滴度对神经梅毒的诊断价值。结果:共分析101例患者,其中神经梅毒组30例(男26例,女4例),非神经梅毒组71例(男25例,女46例)。男性(OR=9.210,95%CI 2.450~34.620,P=0.001)、血清初始TRUST滴度≥1∶16(OR=1.808,95%CI 1.143~2.858,P=0.011)与神经梅毒的发病有关。血清TRUST初始滴度预测神经梅毒ROC曲线下面积为0.708(P=0.001),约登指数最大值0.407。结论:男性、血清初始TRUST滴度≥1∶16是神经梅毒发生的危险因素,但根据ROC曲线下面积,血清初始TRUST滴度对神经梅毒的诊断价值较低。     

Study of FTA-CFS test using monospecific anti-immunoglobulin conjugates IgG, IgM, and IgA

The fluorescent treponemal antibody test for cerebrospinal fluid (FTA-CSF) using monospecific conjugates anti-IgG, IgM, and IgA was used to determine the presence of anti-treponemal antibodies in the spinal fluid of 335 patients with primary, secondary, and latent syphilis and symptomatic and asymptomatic neurosyphilis and of patients with certain neurological disorders. Of these, 230 (68·65%) patients had non-reactive results to this test. Of the remaining 105 patients, 78, 63, and 10 had reactive results with anti-IgG, IgM, and IgA conjugates respectively. Of the 129 cases of known syphilis, 11 were diagnosed as primary, 32 as secondary, and 50 as latent, and 36 patients had neurosyphilis. None of the specimens from the patients with primary syphilis gave reactive results to the test. Specimens from 21 (65·62%) of the 32 patients with secondary syphilis, 30 (60%) of the 50 patients with latent syphilis, and all (97·22%), except one, of the 36 patients with neurosyphilis gave reactive results to one at least of the IgG, IgM, or IgA FTA-CSF tests. Among the specimens from patients with secondary syphilis twice as many gave reactive results with anti-IgG conjugate than with anti-IgM conjugate. However, with specimens from patients with latent syphilis and neurosyphilis this ratio was diminished to 1·5:1. The Kolmer complement-fixation test, although superior in sensitivity and specificity to the Venereal Disease Research Laboratory (VDRL) test, in patients with secondary and latent syphilis and neurosyphilis, was greatly inferior to the FTA-CSF test. Data indicate that anti-treponemal antibodies can be detected in the spinal fluid even in patients with no neurological symptoms in cases of secondary syphilis and that the FTA-CSF test can be a valuable tool in the early detection of an immunological response to treponemal infection in the spinal fluid.     

Effect of early and late syphilis on central nervous system: cerebrospinal fluid changes and neurological deficit.

Neurological examination and investigation of the cerebrospinal fluid (CSF) was performed on 24 patients with early and 180 patients with late syphilis. In 21 (12%) patients with late syphilis positive CSF treponemal test results and neurological deficits suggestive of symptomatic neurosyphilis were found. Concomitantly all but three patients with neurosyphilis showed one or more of the following abnormal CSF variables: CSF concentration of albumin X 10(3)/serum concentration (albumin ratio) greater than or equal to 7.9; mononuclear cells greater than 5 microliters: ratio of CSF to serum IgG concentrations/ratio of CSF to serum albumin concentrations (IgG index) greater than or equal to 0.7 or of IgM/albumin (IgM index) greater than or equal to 0.1; or oligoclonal CSF immunoglobulins. In 20 (95%) patients with neurosyphilis evidence of the production of treponemal antibodies within the central nervous system (CNS) was shown. Ten (48%) patients with neurosyphilis had been treated previously for late syphilis. These observations emphasise the need to screen for neurosyphilis in patients with late syphilis. Intrathecal production of treponemal antibodies was detected in six (25%) patients with early and 44 (28%) with late syphilis who did not show any neurological deficit. Intrathecal production of treponemal antibodies indicating that the CNS was affected led us to suspect asymptomatic neurosyphilis in these patients. Seventeen (11%) patients with late syphilis but no neurosyphilis and only one (4%) with early syphilis showed additional abnormal CSF variables. Surprisingly, six out of 22 patients with treated early and 20 out of 68 patients with treated late syphilis showed evidence of treponema antibody production within the CNS. We do not know whether these findings indicate that the CNS was affected because of inadequate treatment or merely reflect persistent synthesis of treponemal antibodies associated with cured infection. In one (4%) patient with early and in 21 (13%) with late syphilis but no neurosyphilis abnormal CSF variables in the absence of positive CSF treponemal test results were observed, which excluded syphilitic inflammation of the CNS.     

Serologic diagnosis of syphilis: comparison of different diagnostic methods

Diagnostic and therapeutic approaches in syphilis show wide variation. The use of only one type of serologic test is insufficient for diagnosis. However, current international recommendations cannot be applied due to various reasons (cost, availability, etc.). The aim of the study was to review serologic data of syphilis patients to determine diagnostic performance of three different methods. In 117 patients suspected of having syphilis, syphilis was diagnosed serologically and clinically. Three different methods were used for detection of antibodies: Rapid Plasma Reagin (RPR), Treponemal Chemiluminescence Microparticle Enzyme Immunoassay (CMIA) and Treponema pallidum hemagglutination (TPHA). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated for the former two methods against TPHA. The sensitivity of RPR and CMIA against TPHA was 58% and 98%, respectively. The specificity of RPR and CMIA against TPHA was 0% and 100%, respectively. Automated enzyme immunoassay systems could contribute to reducing errors that depend on the person, especially while monitoring titration changes.     

Cerebrospinal fluid tau protein is increased in neurosyphilis: a discrimination from syphilis without nervous system involvement?

OBJECTIVE: The objective of this study was to investigate the levels of tau protein in neurosyphilis. STUDY DESIGN: Total tau protein in the cerebrospinal fluid of 12 patients with neurosyphilis, 17 with syphilis without nervous system involvement, 14 controls, and 14 patients with Alzheimer disease of comparable age were analyzed. Double-sandwich enzyme-linked immunosorbent assay was used for measurements. RESULTS: Increased levels of cerebrospinal fluid total tau were observed in neurosyphilis (median [25th-75th percentile]: 349 pg/mL [312-429]) and in Alzheimer disease (543 [441-1017]) as compared with the controls (189 [106-220]) and syphilis without nervous system involvement (190 [160-223]). Using a cutoff level of 300 pg/mL, increased tau discriminated cases of neurosyphilis from syphilis without nervous system involvement with a sensitivity and specificity of 83% and 94%, respectively. CONCLUSIONS: These results indicate that increased total tau may be useful in the discrimination of neurosyphilis from syphilis without nervous system involvement.