ELISA法检测梅毒螺旋体抗体的评价

目前在国内医院、血站的实验室中梅毒血清学诊断主要应用非特异性试验 ,如快速血浆反应素环状卡片试验 (RPR)或甲苯胺红不加热血清试验(TRUST) ,特异性试验主要应用 TPPA或 TPHA。我们用国产 ELISA试剂 (双抗原夹心法 ) ,对梅毒患者与非梅毒患者的血清进行检测 ,并同时作TRUST与 TPPA检测 ,现将结果报告如下。1　材料与方法1 .1　对象　患者组 ,两院皮肤性病科确诊梅毒患者84例 ;非患者组 ,两院门诊、住院及健康查体者各随机抽取 1 5 0例 ,并排除梅毒螺旋体感染。1 .2　试剂　 ELISA试剂由广东中山生物工程有限公司提供 ;TP…     

早期先天梅毒几种实验室诊断方法的评价

目的评价梅毒螺旋体蛋白印迹试验(TPPA-IgM-WB)和梅毒螺旋体19(s)-IgM酶联免疫吸附法[TP-19(s)-IgM-ELISA]在先天梅毒早期诊断中的作用。方法对45例梅毒孕妇所产46例(1例双胞胎)新生儿运用血清IgM-WB试验、梅毒螺旋体19(s)-IgM酶联免疫吸附法[TP-19(s)-IgM-ELISA]和常规血清学方法(TPPA、RPR、FTA-ABS-IgM)检测,评价上述试验诊断方法在先天梅毒早期诊断中的作用。结果45例梅毒孕妇所生的新生儿中,按常规综合诊断方法21例确诊为先天梅毒,新生儿血清IgM蛋白印迹试验23例阳性,梅毒螺旋体19(s)-IgM酶联免疫吸附法24例阳性(21例常规方法诊断为先天梅毒)。30例作为对照的非梅毒孕妇及新生儿各项检查均为阴性。结论血清IgM蛋白印迹试验和梅毒螺旋体19(s)-IgM酶联免疫吸附法[TP-19(s)-IgM-ELISA]诊断先天梅毒具有较高的特异性和敏感性,结果显示可能高于现行的常规综合诊断方法的诊断价值。     

梅毒血清抗体检测与临床的关系分析

目的探讨梅毒血清抗体检测与临床的相关性。方法对我院10710例进行梅毒血清抗体检测者,根据性别、年龄的不同比较它们之间的关系,并进行分析结果判断与临床的相关性。结果不同性别患者梅毒血清抗体检测无显著性差异（P〉0.05）,而不同年龄患者梅毒血清抗体检测有显著性差异（P〈0.01）。结论由于患者自身原因、试剂原因及HIV感染等因素,造成梅毒血清抗体试验有一定的假阳性和假阴性,因此对梅毒血清抗体试验结果应结合病史及临床情况进行综合分析判断。     

脑脊液TP-ELISA、TRUST和VDRL检测对神经梅毒的诊断价值探讨

摘要：目的 探讨脑脊液梅毒螺旋体抗体酶联免疫法（TP-ELISA）、梅毒甲苯胺红不加热血清试验（TRUST）和性病研究实验室试验（venereal disease research laboratory,VDRL）对于神经梅毒的诊断价值。方法 对我院2011年7月至2014年7月三年内123例疑似神经梅毒患者的临床资料及脑脊液等进行综合分析并对三种方法检测神经梅毒的敏感性与特异性进行比较。结果 共诊断25例神经梅毒患者,其中1例抗-HIV阳性,24例抗-HIV阴性;有症状神经梅毒患者8例,无症状神经梅毒患者17例;有症状神经梅毒患者平均白细胞计数>5×106/L,异常率为62.50%;无症状神经梅毒患者平均白细胞计数<5×106/L,异常率为58.82%。有症状神经梅毒患者平均脑脊液蛋白>0.5 g/L,异常率为75.00%;无症状神经梅毒患者平均脑脊液蛋白<0.5 g/L,异常率为64.71%。TP-ELISA检测神经梅毒的敏感性与特异性分别为100% 和43.88%,TRUST检测神经梅毒的敏感性与特异性分别为96.94%和100%,VDRL检测神经梅毒的敏感性与特异性分别为100%和100%。结论 脑脊液TP-ELISA不可作为神经梅毒的确诊病例标准,脑脊液TRUST可以代替 VDRL用于神经梅毒的诊断,亦可作为其疗效的参考指标。     

神经梅毒的诊断与治疗（附23例分析）

观察神经梅毒的临床特点,以提高对神经梅毒的诊断与治疗水平。回顾性分析哈尔滨医科大学附属第一医院2005年1月至2010年12月收治的23例神经梅毒患者的临床资料。神经梅毒患者男17例（73.9%）,女6例（26.1%）,男女比约为2.8∶1;年龄27~71岁,平均年龄43.1岁。本组首发症状：麻痹性痴呆（7例）、精神异常（3例）、急性脑梗死（3例）、癫痫（2例）、脊髓病变（2例）、颅高压（2例）、周围神经损害（2例）、脑神经损害（1例）、无症状性神经梅毒（1例）。23例患者血清及脑脊液快速血浆反应素实验及梅毒螺旋体血凝试验均呈阳性反应。颅脑电子计算机断层扫描（CT）和/或磁共振成像（MRI）检查多表现为额叶、顶叶、颞叶、基底节等多发病变。本组患者经大剂量青霉素治疗后病情有显著改善20例,死亡1例,自动出院2例。神经梅毒的临床表现复杂多样,神经系统各部位均可受累,诊断依靠病史及临床表现、实验室血清及脑脊液梅毒抗体检测,误诊率高,应早期诊断,诊断后应进行规范治疗,早期治疗效果较好。     

西门子ADVIA Centaur XP化学发光免疫分析仪检测梅毒螺旋体特异性抗体的测量阈值建立及结果比较

本研究旨在探讨西门子ADVIA Centaur XP梅毒血清学试验化学发光免疫分析法 (CLIA) 检测梅毒螺旋体特异性抗体的测量阈值,并与化学发光微粒子免疫分析法 (CMIA)、梅毒螺旋体免疫印迹法 (TP-WB) 及梅毒螺旋体抗体颗粒凝集试验 (TPPA) 法检测结果进行比较,为CLIA方法的规范应用提供参考。收集河北燕达医院2018年7月至2019年7月雅培ARCHITECT i2000 CMIA法检测梅毒螺旋体特异性抗体筛查样本30 887例,选取CMIA法筛查梅毒特异性抗体中样品吸光度与临界值的比值 (S/CO) 为1–9的153例患者为研究对象,采用梅毒血清学检测逆序流程,并分别以TP-WB及TPPA法为确认方法,运用MedCalc对结果进行受试者工作特征曲线 (ROC曲线) 分析,获得截断值,采用卡方检验进行计数资料的差异显著性检验。采用不同方法对同一批血清样本梅毒螺旋体特异性抗体的检测结果存在差异,CLIA法与TPPA法差异不显著,与TP-WB法及CMIA法差异显著;分别以TPPA检测结果和TP-WB检测结果为金标准,ROC曲线分析发现,CLIA法的最佳诊断截断值分别为4.01和16.06,曲线下面积分别为0.961和0.838。采用不同梅毒血清学试验方法作为金标准时,CLIA法建议截断值差异较大,因此,CLIA测定梅毒抗体S/CO为1.00–16.06时,实验室血清学检测应推荐首选TP-WB方法学进行复核确证,避免临床误诊发生。     

基因重组抗原检测梅毒螺旋体抗体研究

梅毒是一种传染性很强的性传播疾病,早期诊断是防止其传播及治疗的关键。采用基因重组的梅毒螺旋体P47和P15抗原对289份临床标本进行梅毒螺旋体抗体的检测,并与常规方法进行了比较,结果表明：重组抗原ELISA法具有较高的敏感性和特异性,并能对梅毒进行早期诊断,可以代替常规方法检测梅毒螺旋体抗体。186份现患和已治愈梅毒患者标本,重组抗原ELISA法、TPHA法和RPR法均为阳性;60份健康献血员标本,重组抗原ELISA法和TPHA法、RPR法均为阴性;17份与梅毒患者有性接触者的标本,重组抗原ELISA法有2份阳性,而TPHA法、RPR法均为阴性,1个月后复查这2份血清TPHA和RPR均为阳性;6份RPR和类风湿因子均为阳性的血清,重组抗原ELISA法和TPHA法均为阴性,;20份肝硬化患者血清,3种方法检测均为阴性。     

Reiter株研究现状

<正>在研究梅毒血清学密螺旋体试验时,如荧光抗体吸收试验(Fluoresoent Treponermal Antibody Absorption Test,简称FTA——ABS)、梅毒螺旋体血凝试验(Treponema pallidum Hemagglutination Assay简称TPHA)等,人们经常要使用两株重要的菌株即Nichols株和Reter株,前者为梅毒螺旋体毒株,在上述试验中做为抗原用以检测特异性梅毒抗体;后者则是非致病性螺旋体,为上述试验中吸收剂主要成分,以吸收除去被检血清中的非特异性抗体。     

15881例患者梅毒血清学诊断的方法学比较

目的了解本区域特殊群体梅毒检测的方法学意义。方法对2010—2013年在大连市皮肤病医院进行梅毒血清学检测的15881例患者和其中确证梅毒患者6488例资料进行回顾性分析,同时评价TRUST、TP—ELISA、TPPA和乳胶层析法检测特殊群体患者血清的意义。结果2010—2013年梅毒血清学阳性患者分别为1347例、1679例、1787例、1675例,共6488例,占大连市沙河口区梅毒确诊患者的82．13％、82．02％、75．18％、71．67％。TRUST、TP-ELISA、TPPA和乳胶层析法敏感性分别为74．48％、99．75％、99．46％、86．24％,特异性分别为99．65％、99．98％、99．95％、99．92％。结论梅毒患者和全国一样,有死灰复燃的趋势,且有从高危人群向普通人群蔓延的趋势;在大样本梅毒血清学试验中,TRUST和TP—ELISA结合法具有高度敏感性和特异性,可作为高危人群体检的方法首选。     

同时检测血清中多种抗体的蛋白质微阵列研究

建立一种用蛋白质微阵列法可同时检测血清中艾滋病毒（HIV）, 丙型肝炎病毒（HCV）和梅毒螺旋体（TP）抗体的方法.将基因工程HIV、HCV和TP 3种融合抗原共价结合于固相载体玻片上,制成蛋白质微阵列,血清样本经稀释、加样、孵育、洗涤后,加上Cy3荧光标记二抗,洗涤,激光共聚扫描,将获得的图片用Bio-discover公司的Imagene专用分析软件进行分析,所获数据在经过自行编写的软件,根据Cutoff值自动生成判断结果.用此蛋白质微阵列系统检测了400例阴性血清,确定了Cutoff值,检测中国药品生物制品检定研究所的HIV, HCV和TP 3种参比品,并与3种ELISA试剂盒的结果进行了比较.蛋白质微阵列的艾滋病毒阳性和阴性符合率均为100%(20/20); 丙型肝炎病毒阳性和阴性符合率均为95%(38/40).梅毒螺旋体参比品阳性符合率为100%(10/10),阴性符合率为100%(20/20),蛋白质微阵列与三种ELISA试剂检测国家HIV、TP、HCV参比品（共150份血清样本）,结果具有高度的符合率.     

化学发光法在梅毒实验诊断中的应用价值

目的:探讨化学发光法在梅毒实验诊断中的应用价值。方法:采用化学发光法、RPR法、TPPA法分别检测150例梅毒患者及125例非梅毒患者血清。结果:化学发光法、RPR法、TPPA法对150例梅毒血清标本和125例非梅毒血清标本对照组的敏感性分别为98.0%、75.3%和97.3%,特异性分别为98.3%、81.6%和97.5%。化学发光法、TPPA法敏感性和特异性明显高于RPR法,差异有统计学意义(P<0.05);化学发光法和TPPA法相比,敏感性和特异性差别不大,差异没有统计学意义(P>0.05);联合3种方法检测,梅毒诊断阳性率可提高到100%。结论:梅毒的化学发光检测法具有极高的敏感性和特异性,是一种自动化、定量检测方法,能够用于梅毒的准确诊断和疗效观察,与传统方法联检可防止误诊、漏诊,具有较大的临床应用价值。     

Sensitivity and Specificity of Point-of-Care Rapid Combination Syphilis-HIV-HCV Tests

Background

New rapid point-of-care (POC) tests are being developed that would offer the opportunity to increase screening and treatment of several infections, including syphilis. This study evaluated three of these new rapid POC tests at a site in Southern California.

Methods

Participants were recruited from a testing center in Long Beach, California. A whole blood specimen was used to evaluate the performance of the Dual Path Platform (DPP) Syphilis Screen & Confirm, DPP HIV-Syphilis, and DPP HIV-HCV-Syphilis rapid tests. The gold-standard comparisons were Treponema pallidum passive particle agglutination (TPPA), rapid plasma reagin (RPR), HCV enzyme immunoassay (EIA), and HIV-1/2 EIA.

Results

A total of 948 whole blood specimens were analyzed in this study. The sensitivity of the HIV tests ranged from 95.7–100% and the specificity was 99.7–100%. The sensitivity and specificity of the HCV test were 91.8% and 99.3%, respectively. The treponemal-test sensitivity when compared to TPPA ranged from 44.0–52.7% and specificity was 98.7–99.6%. The non-treponemal test sensitivity and specificity when compared to RPR was 47.8% and 98.9%, respectively. The sensitivity of the Screen & Confirm test improved to 90.0% when cases who were both treponemal and nontreponemal positive were compared to TPPA+/RPR ≥1∶8.

Conclusions

The HIV and HCV on the multi-infection tests showed good performance, but the treponemal and nontreponemal tests had low sensitivity. These results could be due to a low prevalence of active syphilis in the sample population because the sensitivity improved when the gold standard was limited to those more likely to be active cases. Further evaluation of the new syphilis POC tests is required before implementation into testing programs.     

一期梅毒实验室诊断差异性研究

目的通过梅毒螺旋体初筛试验、确认试验和鉴别诊断试验,探讨一期梅毒实验室诊断差异性,最大限度减少漏诊与误诊,为深入研发新型早期梅毒诊断试剂奠定基础。方法依据2000年中国卫生部防疫司颁布的性病诊断标准,临床筛选一期梅毒患者86例（研究组）和非梅毒患者100例（对照组）,对患者血清进行甲苯胺红不加热血清试验（TRUST）初筛和梅毒螺旋体明胶颗粒凝集试验（TPPA）确认。筛选临床体征、TRUST法和TPPA法三者结果有差异的患者进一步鉴别诊断,鉴别诊断主要应用荧光定量PCR（FQ-PCR）法、免疫PCR法与自身抗体检测等试验。结果初筛TRUST法灵敏度和特异性分别为62．8％、93．0％;确认TPPA法灵敏度与特异性分别为66．3％、100％。TRUST法和TPPA法两者结果差异占12．8％;临床体征诊断、TRUST法和TPPA法三者结果差异占41．9％。TPPA法与TRUST法两者均阴性的一期梅毒患者中,FQ-PCR阳性率达88．0％,免疫PCR阳性率占40．0％。TPPA法阳性、TRUST法阴性的一期梅毒患者免疫PCR法与TPPA法结果一致;TPPA法阴性、TRUST法阳性11例患者中结核抗体阳性2例,类风湿因子阳性3例与抗Sm抗体结果阳性6例。结论一期梅毒患者实验室诊断结果差异性较大,漏诊与误诊的比例较高,有待研发新型的诊断试剂和提高诊断水平。     

Evaluation of a Rapid Diagnostic Test for Yaws Infection in a Community Surveillance Setting

Yaws is a non-venereal treponemal infection caused by Treponema pallidum ssp. pertenue. The WHO has launched a worldwide control programme, which aims to eradicate yaws by 2020. The development of a rapid diagnostic test (RDT) for serological diagnosis in the isolated communities affected by yaws is a key requirement for the successful implementation of the WHO strategy. We conducted a study to evaluate the utility of the DPP test in screening for yaws, utilizing samples collected as part of a community prevalence survey conducted in the Solomon Islands. 415 serum samples were tested using both traditional syphilis serology (TPPA and quantitative RPR) and the Chembio DPP Syphilis Screen and Confirm RDT. We calculated the sensitivity and specificity of the RDT as compared to gold standard serology. The sensitivity of the RDT against TPPA was 58.5% and the specificity was 97.6%. The sensitivity of the RDT against RPR was 41.7% and the specificity was 95.2%. The sensitivity of the DPP was strongly related to the RPR titre with a sensitivity of 92.0% for an RPR titre of >1/16. Wider access to DPP testing would improve our understanding of worldwide yaws case reporting and the test may play a key role in assessing patients presenting with yaws like lesions in a post-mass drug administration (MDA) setting.     

梅毒患者外周血淋巴细胞亚群测定的意义

目的检测HIV阴性隐性梅毒患者外周血T淋巴细胞亚群及NK淋巴细胞的比例,并探讨其临床意义.方法应用流式细胞仪检测43例未经治疗的隐性梅毒患者和46例已经数疗程驱梅治疗但RPR持续阳性2年以上的隐性梅毒患者外周血T淋巴细胞亚群及NK淋巴细胞的比例,并与30例健康人群的检测结果相对照.结果1.未经治疗的隐性梅毒患者和已经治疗但RPR持续阳性2年以上的隐性梅毒CD3、CD4及NK淋巴细胞的比例分别与健康人群的检测结果相比,差异均无显著性(P＞0.05);未经治疗的隐性梅毒患者CD8淋巴细胞的比例明显高于对照组(P＜0.001);已经治疗但RPR持续阳性2年以上的隐性梅毒患者CD8淋巴细胞的比例高于对照组(P＜0.05);未经治疗的隐性梅毒患者CD4/CD8的比率明显低于对照组(P＜0.001),而已经治疗但RPR持续阳性2年以上的隐性梅毒患者CD4/CD8的比率与对照组相比差异无显著性(P＞0.05);2.未经治疗的隐性梅毒患者和已经治疗但RPR持续阳性2年以上的隐性梅毒患者的检测结果相比,CD3、CD4及NK淋巴细胞的比例及CD4/CD8的比率差异无显著性(P＞0.05);未经治疗梅毒患者CD8淋巴细胞比例高于已经治疗但RPR持续阳性2年以上的隐性梅毒患者(P＜0.05).结论未经治疗的隐性梅毒患者和已经治疗但RPR持续阳性2年以上的隐性梅毒患者均存在细胞免疫不平衡和免疫抑制,这种异常可降低机体抵抗和消除梅毒螺旋体感染的能力,并且可能是梅毒患者难于治愈,RPR持续阳性的主要原因.     

Evaluation of two human plasma pools as candidate international standard preparations for syphilitic antibodies

A collaborative study was designed to asses two freeze-dried human plasma preparations containing anti-Treponema pallidum antibodies, 05/132 and 05/122, for their suitability as international reference reagents for syphilis serology. Both preparations are intended as replacements of the first international standard (IS) for syphilitic serum antibodies (HS). Samples were tested by eight laboratories using the T. pallidum passive particle agglutination assay (TPPA), the venereal disease research laboratory test (VDRL) and the rapid plasma reagin test (RPR). In addition a range of immunoassays was also used. The outcome of the collaborative study revealed that candidate standard 05/132 contains T. pallidum-specific IgG and IgM and is reactive in VDRL or RPR, and that 05/122 contains T. pallidum-specific IgG but is not reactive in either the VDRL or RPR test. Both 05/132 and 05/122 are reactive in the TPPA. On the basis of these results the Expert Committee on Biological Standardization of the World Health Organization designated 05/132 as the 1st IS for human syphilitic plasma IgG and IgM with a unitage of 3 IU per ampoule relative to HS and 05/122 as the 1st IS for human syphilitic plasma IgG with a unitage of 300 mIU per ampoule relative to 05/132.     

3670 例早期妊娠妇女梅毒血清学检查及处理

目的:了解早期妊娠妇女梅毒感染情况,采取防治措施,减少先天梅毒的发生。方法:采用梅毒明胶颗粒试验(TPPA)和梅毒甲苯胺红试验(TRUST)对早期妊娠妇女进行梅毒血清学检查,两项结果均阳性者诊为妊娠期梅毒,可采取驱梅治疗或终止妊娠。结果:3670例早期妊娠妇女中,确诊为妊娠期梅毒的29例,其中TRUST滴度大于1:8的有8例,小于1:8的有21例;有12人接受驱梅治疗,有17人选择终止妊娠。结论:在早期妊娠妇女中进行梅毒血清学检查,可及早采取措施,减少先天梅毒的发生。     

Factors Associated with Serological Cure and the Serofast State of HIV-Negative Patients with Primary,Secondary, Latent,and Tertiary Syphilis

Background

Some syphilis patients remain in a serologically active state after the recommended therapy. We currently know too little about the characteristics of this serological response.

Methods

We conducted a cohort study using the clinical database from Zhongshan Hospital, Medical College of Xiamen. In total, 1,327 HIV-negative patients with primary, secondary, latent, and tertiary syphilis were enrolled. Bivariate and multivariate analyses were utilised to identify factors associated with a serological cure and serofast state in syphilis patients one year after therapy. Chi-square tests were used to determine the differences in the serological cure rate across different therapy time points.

Results

One year after the recommended therapy, 870 patients achieved a serological cure, and 457 patients (34.4%) remained in the serofast state. The serological cure rate increased only within the first 6 months. The bivariate analysis indicated that male or younger patients had a higher likelihood of a serological cure than female or older patients. Having a baseline titre ≤1∶2 or ≥1∶64 was associated with an increased likelihood of a serological cure. The serological cure rate decreased for the different disease stages in the order of primary, secondary, latent, and tertiary syphilis. A distinction should be drawn between early and late syphilis. The multivariate analysis indicated that a serological cure was significantly associated with the disease phase, gender, age, and baseline rapid plasma reagin (RPR) titre.

Conclusions

The serofast state is common in clinical work. After one year of the recommended therapy, quite a few syphilis patients remained RPR positive. The primary endpoint of the study indicated that disease phase, gender, age and baseline RPR titre were crucial factors associated with a serological cure.     

Prevalence of Active and Latent Yaws in the Solomon Islands 18 Months after Azithromycin Mass Drug Administration for Trachoma

IntroductionBoth yaws and trachoma are endemic in the Pacific. Mass treatment with azithromycin is the mainstay of the WHO strategy for both the eradication of yaws and the elimination of trachoma as a public health problem, but the dose recommended for trachoma is lower than that for yaws. In countries where both diseases are endemic, there is a potential for synergy between yaws and trachoma control programs if mass treatment with the lower dose of azithromycin was shown to be effective for the treatment of yaws. In an earlier study, we demonstrated a profound reduction in the clinical and serological prevalence of yaws following a single round of mass treatment with azithromycin 20 mg/kg undertaken for the purposes of trachoma elimination.MethodsThis survey was conducted 18 months following a single round of azithromycin mass treatment in the same communities in which we had conducted our previous six-month follow-up survey. We examined children aged 1–14 years and took blood and lesion samples for yaws diagnosis using the Treponema pallidum particle agglutination assay (TPPA) and the non-treponemal Rapid Plasma Reagin (RPR) test.ResultsA total of 1,284 children were enrolled in the study. Amongst children aged 5–14 years, 223 had a positive TPPA (27.5%, 95% CI 13.6–47.7%). The TPPA seroprevalence amongst this age group did not differ significantly from either our pre-mass treatment survey or our initial follow-up survey. Thirty-five children had positive TPPA and positive RPR (4.3%, 95% CI 2.1–8.7%), and this did not differ significantly from our initial post-mass drug administration (MDA) follow-up survey (4.3% versus 3.5%, p = 0.43) but remained significantly lower than our initial pre-MDA survey (4.3% vs 21.7%, p <0.0001). Village-level MDA coverage was strongly associated with dual-seropositivity (p = 0.005). Amongst children aged 1–4 years, 16 had a positive TPPA (3.5%, 95% CI 1.6–7.1%). This did not differ significantly from the seroprevalence in this age group that had been predicted based on our previous surveys (3.5% vs 5%, p = 0.11). Fourteen children (1.1%) were considered to have a skin lesion clinically consistent with yaws, but none of these individuals was seropositive for yaws. Of nine cases where a swab could be collected for PCR, all were negative for Treponema pallidum subsp. pertenue DNA.DiscussionIn this study we have shown that the benefit of a single round of mass treatment with azithromycin 20mg/kg appears to extend to 18 months without any further intervention. The lack of a significant change in seroprevalence from 6 to 18 months after mass treatment might suggest that interventions could be spaced at yearly intervals without a significant loss of impact, and that this might facilitate integration of yaws eradication with other neglected tropical disease (NTD) control programmes. MDA coverage above 90% was associated with significantly better outcomes than coverages lower than this threshold, and strategies to improve coverage at all stages of yaws eradication efforts should be investigated.     

Depressed CD4/CD8 ratio in TPHA-negative patients with syphilis.

The Treponema pallidum hemagglutination assay (TPHA) is a widely used method for screening syphilis. We report our experience with six elderly (age 72.4 +/- 8.3 years) patients with syphilis, whose TPHA was negative. Their cardiolipin (RPR) and absorbed fluorescence treponemal tests (FTA-ABS) were positive. TPHA-negative patients with syphilis were compared with TPHA-positive syphilitics by immunological analysis. We found that both the numbers and the percentage of CD4 cells in TPHA-negative syphilitics were significantly lower than those in TPHA-positive syphilitics (722 +/- 142 vs. 1,064 +/- 141/mm3, P less than 0.01: 35.1 +/- 6.9 vs. 48.4 +/- 6.4%, P less than 0.01) and that the ratio of CD4 to CD8 was also lower in TPHA-negative syphilitics compared with TPHA-positive syphilitics (1.08 +/- 0.46 vs. 2.24 +/- 1.07, P less than 0.05). These data suggest that the TPHA is insufficient for excluding elderly syphilitics because of immunological impairment seen in aged patients.