Field Evaluation of Alternative Testing Strategies for the Detection of HIV Infection in Beijing

Objective To identify a cost-efficient alternative antibody testing strategy for screening and confirmation of HIV infection by rapid simple tests(RSTs)and enzyme-linked immunosorbent assays(ELISAs).Methods Four RSTs(RST1,RST2,RST3,and RST4)and five ELISAs(ELISA1,ELISA2,ELISA3,ELISA4,and ELISA5)were evaluated in two phases by using banked and serum specimens prospectively collected at regional hospitals and voluntary counseling and testing(VCT)centers in Beijing.A total of 200 banked serum specimens were included in the first phase,including 62 HIV-positive,127 HIV-negative and 11 indeterminate specimens.All specimens were tested by four RSTs and five ELISAs respectively.The second phase involved prospective testing of 389 routine specimens,including 92 HIV-positive,287 HIV-negative,and 10 indeterminate specimens.All the specimens were tested by two RSTs(RST2 and RST4)and three ELISAs(ELISA1,ELISA3,and ELISA4),which were selected for their respective excellent sensitivity and/or specificity.Western blot(WB)was used as a gold standard for confirming the reactivity of all the specimens.Results Sensitivity,specificity,and efficacy were calculated for each assay in two phases.In the first phase,four assays(ELISA4,RST2,RST3,and RST4)had a specificity of 100%.For the determination of efficacy,ELISA4,RST2,and RST4 were selected in the second phase.ELISA1 and ELISA3 which have a sensitivity of 95.9% and 93.2% respectively also entered this phase.In the second phase,all the five assays(ELISA1,ELISA3,ELISA4,RST2,and RST4)had a sensitivity and specifity of over 90%.ELISA1 had a sensitivity of 99% and ELISA4 a specificity of 99%.Conclusion The sensitivity ELISA1 and the specificit of ELISA4 are comparable to ELISA/WB standard strategy.Application of this alternative testing strategy provides a cost-effective method for determining HIV prevalence in Beijing.     

ELISA、MEIA和WB检测TORCH—IgM和IgG抗体的效果

目的探讨三种方法对TORCH—IgM、IgG抗体检测结果的相关性,评价免疫印迹法在临床上检测TORCH—IgM、IgG抗体的应用价值。方法应用酶联免疫法（ELISA）、微粒子酶免疫法（MEIA）和免疫印迹法（WB）对196份临床孕妇筛查样本进行TORCH—IgM、IgG抗体检测,分析各种方法的抗体检出率和总符合率。结果ELISA、MEIA和wB检测TORCH—IgG抗体符合率分别为抗HSVl／2IgG为90％,抗CMVIgG为91％,抗RvIgG为84％,抗ToxIgG为98％。检测TORCH—IgM抗体符合率分别为抗HSV1／2IgM为87％,抗CMVIgM为89％,抗RvIgM为85％,抗ToxIgM为94％。结论WB检测临床标本TORCH—IgM、IgG抗体结果与ELISA、MEIA法所获得的结果具有较高的符合率,其灵敏度高、特异强为临床检测TORCH—IgM、IgG抗体提供了新的检测手段。     

广州市荔湾区HIV抗体筛查阳性与免疫印迹试验结果比较

目的通过对HIV抗体试验初筛(ELISA)阳性与免疫印迹试验(WB)结果进行对比分析,探求HIV抗体筛查阳性与确证实验结果的关系。方法对98份ELISA方法检测为阳性的样本与其WB法确证结果进行比较,分析ELI-SA检测S/CO值变化与WB结果的关系。结果 HIV抗体筛查阳性标本经免疫印迹确证试验,阳性的有91例,均为HIV-1抗体阳性,阴性3例,结果不确定的4例。ELISA与WB的阳性符合率为92.86%。确认为阳性标本的S/CO平均值为14.01;不确定标本S/CO值的平均为6.65;阴性标本S/CO值的平均为5.17。在阳性标本中,gp160、gp120出现率最高为100%,p24为98.90%,而p55,p17出现率较低,分别为58.24%及69.23%,其余条带出现率均达到90%以上;不确定标本中,gp160、gp120、p24条带出现的几率最高,均为100%,p17出现率为25%。结论 HIV初筛试验存在假阳性结果,HIV抗体结果的报告必须以确认结果为准。高S/CO值预示HIV抗体阳性的可能性较大。WB确认方法检测不确定标本有一定的缺陷。     

AIDS serology testing in low- and high-risk groups

The performance characteristics of the acquired immunodeficiency syndrome (AIDS)-retrovirus serological tests including enzyme-linked immunosorbent assay (ELISA), Western blot, and immunofluorescence assay were defined in a clinical laboratory setting by testing 1,257 serum specimens from low- and high-risk groups for AIDS. The three prototype AIDS retroviruses (lymphadenopathy-associated virus, human T-lymphotropic virus III, and AIDS-associated retrovirus) were equally suitable as target antigen for these assays. Sera from six of 74 laboratory and health care personnel and 91 of 1,014 unselected blood donors were falsely positive by ELISA (positive to negative ratio [P/N], greater than or equal to 2) based on the lack of Western blot confirmation. Only two true-positives (two [0.2%] of 1,014 blood donors) were detected in these low-risk groups. In contrast, 106 of 108 specimens with ELISA P/N ratios of 2 or greater from the high-risk groups including asymptomatic homosexual men, hemophiliacs, AIDS-related complex patients, and AIDS patients were positive by Western blot and immunofluorescence assay. Four false-negative ELISA results based on positive immunofluorescence assay and Western blot were found in the AIDS patient group. Ten of 69 AIDS patients were negative by all three serological tests. The consequence of maintaining high sensitivity for the ELISA (P/N ratio, greater than or equal to 2) as a screening test was a loss of specificity. The number of false-positive results necessitated the use of a confirmation test with greater specificity.     

3TP法与ELISA法检测梅毒螺旋体抗体的价值对比研究

目的:比较乳胶凝集免疫比浊法( 3TP )与酶联免疫吸附法( ELISA)检测诊断梅毒的临床应用价值. 方法:对80份确诊为梅毒的患者血清与60份确诊梅毒特异性抗体检测阴性体检者血清标本分别采用3TP 法与ELISA法检测,比较两种检测方法检测结果. 结果:ELISA法检测出现3例假阴性、4例假阳性,检测梅毒的敏感性及特异性、阳性预测值分别为95.00%(57/60)、93.33%(56/60)、93.44%(57/61),3TP 法检测出现3例假阳性,未出现假阴性,检测梅毒的敏感性及特异性、阳性预测值分别为100.00%(60/60)、95.00%(57/60)、95.24%(60/63),两组检测方法诊断梅毒的敏感性、特异性及阳性预测值比较差异无统计学意义( P>0.05);梅毒血清标本全部稀释至3TP 法能检出最低的稀释浓度,此浓度下用ELISA法检测有47份标本S/CO在阳性范围内. 结论:3TP 法与ELISA法两种检测方法诊断梅毒的敏感性、特异性均较高,均能用于诊断梅毒血清学筛查,但是3TP 法相对在梅毒螺旋体低浓度时诊断敏感性更高一些,并且具有检测方法方便的优势.     

基因重组抗原ELISA法在梅毒螺旋体抗体检测中的评价

目的 评价基因重组抗原ELISA法在梅毒螺旋体抗体检测中的意义。方法 用甲苯胺红不加热血清试验(TRUST)、梅毒螺旋体重组抗原酶联免疫吸附试验(ELISA)和梅毒螺旋体明胶凝集试验(TPPA)对335份梅毒患者和非梅毒者的临床血清标本进行检测。结果 以TPPA阳性者为标准，TRUST有6份为假阴性，4份为假阳性；ELISA假阳性1份，无假阴性。TRUST和ELISA的敏感性、特异性分别为94．8％、98．2％和100%、99．5％。TRUST与TPPA的符合率为97．0%，ELISA与TPPA的符合率为99．7％。ELISA的敏感性、特异性都优于TRUST，与TPPA符合率高。结论 重组抗原ELISA法检测梅毒螺旋体特异性抗体具有敏感性高、特异性好、结果客观、自动化程度高等优点，适用于梅毒初筛和确诊。     

隐血与蛋白对尿HIV-1抗体检测影响的研究与分析

[ 摘要 ] 目的 评价一种尿液HIV-1抗体检测试剂的特异性,研究尿液中蛋白含量和隐血程度对尿液中HIV-1抗体检测结果的影响。方法 平行采集受检者的血液与尿液标本,分别用血液和尿液酶联免疫吸附法检测HIV-1抗体,检测尿液HIV-1抗体结果为假阳性与真阴性的尿标本中免疫球蛋白、转铁蛋白、尿微量清蛋白与尿α1微球蛋白的含量,且检测其隐血情况。 结果 真阴性组与假阳性组尿液中各种相应的蛋白含量差异具有显著性(P<0.001),假阳性组尿液中所含的蛋白均高于真阴性组相应的蛋白含量(P<0.001)。结论 当尿液中蛋白含量高或存在隐血阳性时,用HIV-1型尿液抗体诊断试剂盒检测尿液HIV-1抗体易出现假阳性。     

Leptospirosis in Kuala Lumpur and the comparative evaluation of two rapid commercial diagnostic kits against the MAT test for the detection of antibodies to leptospira interrogans

The aim of the study was to look into the epidemiology of serodiagnosed cases of leptospirosis at the University Hospital and compare two commercial ELISA Assays to the Microscopic Agglutination Test (MAT). Demographic data for all serodiagnosed cases for the years 1991-1997 were collected. From this data, 104 sera (n = 104) were selected as samples for comparative evaluation of the commercial ELISAs (INDX Dip-S-Ticks and PanBio ELISA) to the MAT test. Thirty two (n = 32) negative control sera were selected from serodiagnosed cases of other differential diagnosis of leptospira infection. The MAT test is a standard test that detects agglutination antibodies to leptospira biflexa, while the INDX Dip-S-Ticks is an ELISA dot test assaying for total anti-leptospira antibodies. The PanBio ELISA is a colorometric assay in test well strips to detect anti-leptospira IgM. The sensitivity, specificity, and efficiency of tests were calculated at a MAT cut-off value of 1:320. Demographic data showed that leptospirosis peaks during March-May and Aug-Nov coinciding with the inter-monsoon period with more men being infected than women and more adults than children. The sensitivity, specificity, and efficiency of test for the INDX Dip-S-Ticks were 83.3%, 93.8% and 87.5% while the values for the PanBio ELISA were 54.2%, 96.9% and 71.3%. The suboptimal PanBio result could be related to the blocking effect of high IgG titres or could be related to the diagnostic MAT cut-off values used in this study. The data hence reflects a pattern of transmission that is related to "wet" occupational risk factors. The commercial assays evaluated, are easier to perform but interpretation of results should be based on level of endemicity. The INDX Dip-S-Ticks allows this flexibility and is a practical alternative to the MAT test.     

尿透明质酸-透明质酸酶1联合检测对膀胱癌诊断和治疗的意义

目的:探讨尿透明质酸(HA)和透明质酸酶1(HYAL1)联合检验对膀胱癌诊断和治疗的意义。方法:取自40位膀胱肿瘤患者术前(40份)及术后(40份)尿液标本80份,另20份尿液取自对照组(包括正常人、泌尿生殖系其他疾病患者)。采用放射免疫标记技术和ELISA技术检测尿液HA和HYAL1水平,并对其结果进行讨论分析。结果:患者术前组中HYAL1水平是术后组的1.5倍(P<0.05),是对照组的2～4倍(P<0.05);而术前组中HA水平在G2/G3移行细胞癌患者中显著升高,是术后组的1.5倍(P<0.05),是对照组的1.5～3倍(P<0.05),但在G1级患者尿中无显著升高(P>0.05)。而HA HYAL1联检在膀胱癌诊断中具有较高的灵敏度(95%)、特异度(75%)和精确度(88.33%)。结论:HA HYAL1联检是诊断膀胱癌和手术评估的一种非侵入性、高灵敏度、高特异度的检测方法。     

免疫印迹和酶联免疫吸附法检测糖尿病自身抗体的结果比较

目的:探讨免疫印迹(IB)和酶联免疫吸附法(ELISA)在糖尿病自身抗体检测中的差异。方法:用IB和ELISA分别测定43例Ⅰ型糖尿病(T_1DM)和50例正常人血清中胰岛细胞抗体(IcA)、谷氨酸脱羧酶抗体(GADA)和胰岛素抗体(IAA),评价其敏感性和特异性。结果:IB法检测T_1DM患者血清中IcA、GADA和IAA的阳性率分别为69. 7%、67.4%和23.3%。3种抗体联合检测的敏感性和特异性分别是93.0%和98.0%;ELISA检测IcA、GADA和IAA的阳性率分剐为72.1%、81.4%和41.9%,3种抗体联合检测的敏感性和特异性分别是97.7%和88%。结论:IB法检测糖尿病自身抗体的敏感性低于ELIsA(P<0.05);而IB法的特异性明显高于ELISA(P<0.05)。     

双抗体间接夹心ELISA法检测血清MUC1蛋白方法的建立及其在肺癌诊断中的应用

目的:建立双抗体间接夹心酶联免疫吸附法（ELISA）试剂盒,检测血清黏蛋
白1（MUC1）水平,探讨其在肺癌诊断中的应用,阐明血清MUC1蛋白检测的临床应用
价值。方法:在前期制备的MUC1蛋白和兔抗人MUC1多克隆抗体的基础上,建立以鼠抗人MUC1
单克隆抗体为包被抗体,兔抗人MUC1多克隆抗体为检测抗体的双抗体间接夹心ELISA方法,
并通过对MUC1蛋白标准品的检测,绘制出标准曲线。临床上收集48例肺癌患者、7例肺良性
疾病患者和20例健康人的血清,应用本研究建立的ELISA方法检测各组标本血清MUC1蛋白表
达水平,绘制ROC曲线,确定最佳cut-off值,得出双抗体间接夹心ELISA方法检测肺癌的敏
感度、特异度及约登指数。同时与临床应用的CA15-3试剂盒检测结果进行比较。结果:应用双抗体间接夹心ELISA法确定血清MUC1的临界值为1.98 μg?L-1,检测
肺癌的敏感度为62.5%,特异度为100%,约登指数为0.625　0。CA15-3试剂盒检测肺癌的敏感度
为18.75%,特异度为100%,约登指数为0.187 5。结论:建立的双抗体间接夹心ELISA
试剂盒检测肺癌有更高的敏感度和特异度,优于临床常用的CA15-3试剂盒。     

Elementary school students' performance with two ELISA test systems.

OBJECTIVE--To examine analytic performance by previously untrained and inexperienced subjects using enzyme-linked immunosorbent assay (ELISA) tests developed for decentralized laboratories. Performance variability between tests assigned to the "simple" and "moderately complex" Health Care Financing Administration laboratory levels was evaluated. DESIGN--A nonrandomized trial of the Surecell Strep-A chorionic gonadotropin ELISA tests. Each subject processed nine unknown specimens (three negative, three weakly positive, and three strongly positive) for each ELISA test. Subjects were blinded to expected test results. SETTING--An elementary school. SUBJECTS--A convenience sample of 52 students enrolled in the sixth and seventh grades. This age group was chosen because of their ability to generally comprehend instructions and remain attentive to the testing task. INTERVENTIONS--Subjects were either self-trained by reading package insert directions or trained by a manufacturer's sales representative. MAIN OUTCOME MEASURES--Performance was measured as the percentage of correct test results for the unknown specimens. The sensitivity and specificity for each test by operator group were calculated. RESULTS--Subjects demonstrated an overall sensitivity of 97.1% and specificity of 94.7% for human chorionic gonadotropin unknown specimens and a 95.9% sensitivity and 96.8% specificity for group A streptococcus unknown specimens. No significant differences between the self-trained group and the representative-trained group were observed for either group A streptococcus or human chorionic gonadotropin tests. Performance was so high with the first specimen that improvement over time (ie, a "learning curve") could not be demonstrated. CONCLUSION--These ELISA test systems are able to achieve high levels of performance by subjects with no formal laboratory background, no previous method specific experience, and limited self-training.     

献血员血清和血液制品的HIV抗体检测及试验方法的优选

输血是HIV传播的重要途径。本文报道对四川省十市县10422名献血员的11251份血清标本和各种血液制品150批进行了HIV抗体检测,结果均为阴性。对各种血液制品进行了4种HIV抗体试验方法的优选,表明检测丙种球蛋白用ELISA法和免疫荧光法易出现假阳性,建议对丙种球蛋白选用明胶颗粒凝集等法作初筛。蛋白印迹法是公认检测HIV抗体的最灵敏与最特异的方法,但操作费时及试剂昂贵,宜选作确证试验。     

抗双链DNA抗体检测策略研究

目的 研究临床检测抗双链DNA抗体（anti-dsDNA）的最佳检测方案.方法 将60例系统性红斑狼疮（SLE）血清,30例其他疾病对照组（ODC）血清和30例正常对照组（NC）血清样本同时进行线性免疫印迹法（LIA）,绿蝇短膜虫间接免疫荧光实验（CLIFT）,鲑鱼精子纯化抗原酶联免疫吸附实验（ELISA-Ⅰ）和胎牛胸腺纯化抗原酶联免疫吸附实验（ELISA-Ⅱ）,检测血清标本中的anti-dsDNA.结果 LIA检测anti-dsDNA灵敏度为58.33％,CLIFT为56.67％,ELISA-Ⅰ 51.67％,ELISA-Ⅱ73.33％;特异性分别为：LIA 71.67％,CLIFT100.00％,ELISA-Ⅰ 93.33％,ELISA-Ⅱ86.67％.ELISA-Ⅰ与LIA、CLIFT比较,检测结果差异无统计学意义（P＞0.05）;ELISAⅡ与LIA、CLIFT、ELISA-Ⅰ比较,检测结果差异具有统计学意义（P＜0.01）.ROC分析显示ELISA-Ⅰ、ELISA-Ⅱ曲线下面积（AUC）分别为0.764和0.882（P＜0.01）;如采用ROC曲线的截断点（cut-off point）,ELISA-Ⅰ的灵敏度和特异性为55.00％和91.67％,ELISA-Ⅱ为81.67％和83.33％;根据ROC曲线将特异性设置为95.00％时,ELISA-Ⅰ和ELISA-Ⅱ的灵敏度分别降低到48.33％和50.00％.结论 4种不同的anti-dsDNA检测试剂盒显示出不同的检测性能.CLIFT和ELISA均可用于anti-dsDNA的常规检测,由于ELISA具有良好的灵敏度,因此可作为anti-dsDNA的筛查实验;而CLIFT特异性最佳,可作为确证实验.无论临床实验室采取何种检测方法,针对anti-dsDNA的阳性检测结果,实验室工作人员应与临床医生始终保持足够的联系和沟通,并意识到临床实验室选择不同anti-dsDNA检测方法的灵敏度和特异性差异问题.     

Multiple false-positive serologic tests for HIV, HTLV-1, and hepatitis C following influenza vaccination, 1991.

OBJECTIVE--(1) To assess factors associated with the occurrence of multiple false-positive viral enzyme-linked immunosorbent assays (ELISAs) for human immunodeficiency virus (HIV), human T-cell lymphotrophic virus type 1 (HTLV-1), and hepatitis C virus (HCV) among individual blood donors and (2) to determine the frequency and time course of this phenomenon. DESIGN--Case-control study. SETTING--A regional blood center. PARTICIPANTS--Blood donors found to have multiple false-positive viral ELISAs (case donors) and randomly selected seronegative controls (control donors) who donated between October 31, 1991, and December 15, 1991. An additional random sample of 262 donation records was reviewed to calculate the proportion of donors who received influenza vaccine. MAIN OUTCOME MEASURES--Multiple false-positive viral ELISAs, receipt of influenza vaccination formulated for the 1991-1992 influenza season, and follow-up ELISA results on serum samples obtained from case donors. RESULTS--Among 17,941 donors, 10 case donors were identified. Nine of the 10 case donors received influenza vaccine, compared with three of 30 control donors (odds ratio [OR] = 81; 95% confidence interval [CI], 6 to 3670; P less than .001). Among nine case donors, the mean time between vaccination and blood donation was 26 days (range, 9 to 68 days). Follow-up ELISAs of serum samples from seven case donors obtained 52 to 130 days (mean, 75 days) after vaccination demonstrated reversion to HIV and HTLV-1 seronegativity in all but one specimen, with persistence of positive HCV ELISAs in four specimens. We estimate between 0.6% and 1.7% of blood donors who received influenza vaccine this season had multiple false-positive viral ELISAs. CONCLUSIONS--The occurrence of multiple false-positive viral ELISAs among blood donors was associated with influenza vaccination, but was infrequent among vaccinees. This phenomenon is of short duration for HIV and HTLV-1, but may persist longer for HCV. We recommend influenza vaccinees not be deferred from blood donation. Blood donors with multiple false-positive viral ELISAs should be considered for future reentry as blood donors.     

3种方法检测胰岛素自身抗体的结果比较

目的比较酶联免疫（ELISA）、放射免疫（RIA）和免疫印迹（IB）法检测胰岛素自身抗体（IAA）敏感性和特异性的差别。方法用ELISA、RIA和IB法分别检测45例1型糖尿病和50例健康对照者血清中IAA，计算敏感性和特异性，用统计学方法分析3种方法的差异。结果ELISA、RIA和IB法检测T1DM患者血清中IAA的阳性率分别为35．56％、37．78％和24．44％，检测50例对照组的特异性分别为90．00％、92．00％和100％，三者的敏感性依次为RIA〉ELISA〉IB，特异性依次为IB〉RIA〉ELISA，经统计学分析ELISA和RIA的特异性和敏感性差异均无统计学意义（P〉0．05），两者的敏感性均高于IB法（P〈0．05），而两者的特异性明显低于IB法（P〈0．05）。结论IB法检测IAA的敏感性低于ELISA和RIA法，而其特异性可达100％，明显高于ELISA和RIA，可以作为IAA的确认试验。     

ESM-1和CEA联合检测在鉴别良恶性胸腔积液中的价值

目的：探讨胸腔积液中细胞内皮特异因子-1（malignant pleural effusion, ESM-1）、癌胚抗原（carcino embryonie antigen, CEA）联合检测对肺癌所致恶性胸腔积液（malignant pleural effusion, MPE）和结核性胸腔积液（tuberculous pleural effusion, TPE）的鉴别诊断价值。方法：收集110例胸腔积液患者,其中肺癌伴MPE 65例,TPE 45例,分别采用ELISA法和化学发光法对两组患者胸腔积液组的ESM-1和CEA水平进行测定,根据受试者工作曲线（ROC）计算临床诊断界值,并对结果进行统计分析。结果：MPE中ESM-1和CEA的水平明显高于TPE组,差异有统计学意义（P均<0.001）。ESM-1取19.58 ng/mL时,诊断MPE的敏感度、特异度和准确性分别为81.50%、84.60%、82.73%;CEA取8.52 ng/mL时,诊断MPE的敏感度、特异度和准确性分别为73.80%、95.60%和82.73%。二者联合检测的敏感度、特异度和准确性为83.1%、93.3%和82.73%。结论：MPE患者胸腔积液中ESM-1显著增高,ESM-1对MPE有一定的诊断价值,联合检测ESM-1和CEA可进一步提高MPE诊断敏感度。     

Usefulness of enzyme immunoassay (EIA) for screening of anti HIV antibodies in urinary specimens: A comparative analysis

Background

Standard HIV testing is done using serum or plasma. FDA approved ELISA to screen urine for IgG antibodies to HIV-1 in 1996. It is a simple, noninvasive test and is appropriate for developing countries where health care personnel may not be professionally trained or where clean needles for drawing blood may not always be available.

Methods

436 individuals with high-risk behavior and strong clinical suspicion of HIV infection were screened for IgG antibodies to HIV-1 in urine by ELISA. Urine HIV testing was performed by enzyme immunoassay, at the ongoing Voluntary Confidential Counseling and Testing Center (VCCTC) at a large tertiary care microbiology lab. The individuals enrolled for the study had high-risk exposure to the virus and majorities were from a state with a high incidence of HIV infection. In all individuals, both serum and urine were tested for IgG antibodies to HIV-1.

Results

Overall, 135 individuals (30.96%) were HIV-positive, of whom 96 (71%) had never previously tested positive; 87% of those who tested positive received their results, and most were referred for medical care. Sensitivity, specificity and predictive values of HIV-1 urine ELISA test kit were determined. Sensitivity was found to be 89.6%; 95% CI [82.9–94.0], specificity 97.3%; 95% CI [94.6–98.8], positive predictive value 93.8%; 95% CI [87.8–97.1] and negative predictive value 95.4%; 95% CI [92.3–97.4].

Conclusion

Efficiency, sensitivity, and specificity of the urine-based screening for HIV-1 test kits were excellent as compared to the reference test.     

Usefulness of enzyme immunoassay (EIA) for screening of anti HIV antibodies in urinary specimens: A comparative analysis

Background

Standard HIV testing is done using serum or plasma. FDA approved ELISA to screen urine for IgG antibodies to HIV-1 in 1996. It is a simple, noninvasive test and is appropriate for developing countries where health care personnel may not be professionally trained or where clean needles for drawing blood may not always be available.

Methods

436 individuals with high-risk behavior and strong clinical suspicion of HIV infection were screened for IgG antibodies to HIV-1 in urine by ELISA. Urine HIV testing was performed by enzyme immunoassay, at the ongoing Voluntary Confidential Counseling and Testing Center (VCCTC) at a large tertiary care microbiology lab. The individuals enrolled for the study had high-risk exposure to the virus and majorities were from a state with a high incidence of HIV infection. In all individuals, both serum and urine were tested for IgG antibodies to HIV-1.

Results

Overall, 135 individuals (30.96%) were HIV-positive, of whom 96 (71%) had never previously tested positive; 87% of those who tested positive received their results, and most were referred for medical care. Sensitivity, specificity and predictive values of HIV-1 urine ELISA test kit were determined. Sensitivity was found to be 89.6%; 95% CI [82.9–94.0], specificity 97.3%; 95% CI [94.6–98.8], positive predictive value 93.8%; 95% CI [87.8–97.1] and negative predictive value 95.4%; 95% CI [92.3–97.4].

Conclusion

Efficiency, sensitivity, and specificity of the urine-based screening for HIV-1 test kits were excellent as compared to the reference test.     

二种方法检测糖尿病自身抗体的结果比较

目的探讨免疫印迹（IB）和酶联免疫吸附法（ELISA）在糖尿病自身抗体检测中的差异。方法用IB和ELISA分别测定43例Ⅰ型糖尿病（T1DM）和50例正常人血清中胰岛细胞抗体（ICA）、谷氨酸脱羧酶抗体（GADA）和胰岛素抗体（IAA）评价其敏感性和特异性。结果IB法检测T1DM患者血清中ICA、GADA和IAA的阳性率分别为69．7％、67．4％和23-3％。3种抗体联合检测的敏感性和特异性分别是93．0％和98．O％;ELISA检测ICA、GADA和IAA的阳性率分别为72．1％、81．4％和41．9％,3种抗体联合检测的敏感性和特异性分别是97．7％和88％。结论IB法检测糖尿病自身抗体的敏感性低于ELISA（P〈0．05）;而IB法的特异性明显高于ELISA（P〈0．05）。