人类免疫缺陷病毒感染抗体检测窗口期血清的检出

目的　搜索高危人群中HIV抗体“窗口期”样品。方法　使用HIV抗体检测、HIV 1 p2 4抗原检测和病毒载量检测等多种方法对 1 580份高危人群血清和血浆进行筛查。结果　发现 1份样品抗体检测为阴性 ,p2 4抗原检测为阳性 ,病毒载量HIV 1RNA含量极高 ,拷贝数为每毫升 41万 (RT PCR法 )和 76万 (NASB法 )。结论　该份样品HIV抗体水平极低 ,用国内目前使用的进口和国产HIV抗体检测试剂均不能检出 ,确定其为 1份处于HIV感染抗体窗口期的样品     

第4代HIV抗原抗体联合检测试剂的评价

目的评价HIV(1+2)抗原抗体联合检测试剂,了解其是否适合于血液筛查。方法用HIV抗原抗体联合检测试剂和第3代HIV抗体检测试剂平行检测HIV感染或疑似感染样本205份、吸毒人群样本1486份、有既往献血史人群样本427份、献血和献浆人群样本7237份和丙型肝炎患者样本176份,对两种试剂检测结果不一致样本进行HIV p24抗原或RNA的检测,并分析其特异性和灵敏度。结果联合检测试剂检测HIV p24抗原的分析灵敏度为(2.5~5.0)U/ml,检测HIV抗体的分析灵敏度与第3代HIV抗体检测试剂相当。共检测出8996份HIV抗体阴性样本和503份HIV抗体阳性样本,与第3代试剂相比其特异为99.67%,灵敏度为100%,而且2份HIV感染“窗口期”样本也能检出。结论该试剂在增加HIV p24抗原检测的情况下,对HIV抗体检测的特异性和敏感性没有降低,可用于血液筛查以减少“窗口期”样本传播HIV的风险。     

评估第4代HIV酶联免疫法诊断试剂对静脉吸毒者感染窗口期的检测能力

目的应用BBI公司血清抗体阳转盘评价第4代人类免疫缺陷病毒（HIV）酶联免疫法诊断试剂（以下简称第4代试剂）对窗口期感染的检测能力,并应用其从静脉吸毒人群样本中筛查窗口期感染者,从而分析第四代试剂检测临床样本的特异性和敏感性。方法首先应用第3代HIV酶联免疫法诊断试剂筛查BBI血清阳转盘和收集的吸毒人群样本,阳性样本进一步用免疫印迹法确认。再用第4代试剂分别检测阴性和阳性样本,阴性样本中出现阳性反应者,进行p24抗原和HIV RNA病毒载量检测,证实是否为窗口期样本。对证实为窗口期的感染者随访至抗体阳转。结果用第3代试剂检测BBI阳转血清盘,未发现阳性样本;检测静脉吸毒人群样本2629份,发现HIV抗体阳性样本77份,经免疫印迹法（WB）确认均为阳性,阴性样本2552份。第4代试剂可检出BBI阳转血清盘第14天的窗口期样本;在2552份静脉吸毒人群抗体阴性样本中检出2份窗口期样本,一例随访至血清阳转,一例失访。临床检测特异性为99.2％,假阳性率0.8％（95％可信区间0．4％～1．1％）。结论第4代试剂比第3代试剂能够更早地发现HIV感染者,降低窗口期漏检,减少HIV传播。     

核酸检测技术(NAT)在献血者人类免疫缺陷病毒筛查中的应用

目的应用核酸扩增检测(Nucleic Acid Amplification Testing,NAT)技术对人类免疫缺陷病毒(human im-munodeficiency virus,HIV)酶联免疫吸附测定(Enzyme-Linked Immuno Sorbent Assay,ELISA)合格的献血者血液标本进行核酸检测,探讨NAT技术对缩短ELISA检测HIV感染"窗口期"的作用。方法对献血者血液标本进行HIV抗原抗体、乙型肝炎病毒表面抗原、丙型肝炎病毒抗体、梅毒螺旋体抗体2遍ELISA检测,将检测结果合格的血液标本进行核酸检测。结果在177229例ELISA检测合格的献血者标本中发现HBV DNA阳性献血者24例,HIV-1RNA阳性献血者1例,未发现HCV RNA阳性献血者。对HIV-1RNA阳性献血者追踪调查并在献血后的d4、d11、d16、d37采样检测,d4病毒载量由献血时的4.61×102copy/ml上升至5.10×104copy/ml,P24抗原和抗体仍为阴性;d11P24抗原检测阳性,HIV抗体检测仍为阴性。d16HIV抗体检测结果阳性,免疫印迹法(Western blot,WB)确证试验结果为HIV抗体不确定;d37WB确证试验结果为HIV-1抗体阳性。结论 HIV-1RNA阳性献血者,经追踪调查及对不同时间采集的标本采用各种方法学检测,证实该献血者为HIV感染早期ELISA法漏检的"窗口期"献血者。因此,NAT检测技术比ELISA检测能更进一步地缩短HIV检测的"窗口期"。     

天津市高危人群艾滋病早期感染检测策略研究

目的 本研究利用天津市现有的高危人群HIV-1抗体筛查检测体系, 比较核酸检测、P31条带分析法与捕获酶联免疫(BED)检测组合方法, 探讨天津市适合的艾滋病急性期感染检测策略。方法 2013年天津市市区自愿咨询检测门诊的男男性行为人群三代HIV筛查试剂筛查阴性的样本, 采用四代HIV抗体筛查试剂进一步筛查, 发现阳性后做确证实验, 确证阴性及不确定者进行核酸检测;以及经第四代试剂筛查阴性的样本, 采用集合核酸方法进一步检测。天津市2012-2013年部分经免疫印迹实验(WB)检测新确认的HIV抗体阳性并且CD4计数200的感染者, BED检测判为新近和既往感染者, 并进行P31条带分析。结果 2320例MSM样本三代试剂筛查并确证阳性样本140例; 2180例筛查阴性的样本, 应用四代试剂检测, 进一步筛出19例阳性样本, 进行WB检测确认6例阳性, 11例阴性, 2例不确定;对13例阴性及不确定样本进行核酸验证, 发现4例阳性; 2161例四代试剂筛查阴性样本, 经集合核酸进一步检测、拆分发现阳性样本1 例, 总计检核酸测出5例阳性。294份WB阳性样本进行BED检测, 117份判定为新近感染, 177份为既往感染, 从WB结果中p31条带情况分析, 新近感染者中p31阴性者占23.9%(28/117), 长期感染者0例(0/177), AIDS患者1例, 占1.1%(1/95), 结果差异有统计学意义。结论 针对高危人群应分人群进行不同检测策略的组合, 并应重点针对天津市MSM HIV阳性群体进行更加精确的新发感染时间段构成情况连续监测。     

抗-HIV ELISA检测窗口期献血者的1例追踪随访分析

获得性免疫缺陷综合征是由人类免疫缺陷病毒(HIV)感染所导致的以免疫系统功能缺陷为特征的致命性疾病.输血是 HIV 传播的重要途径之一,采供血机构开展 HIV 抗原抗体等检测后,输血安全性有了较大的提高,但由于酶联免疫吸附试验(ELISA)检测窗口期漏检、病毒变异、试剂的灵敏度低、免疫静默感染和人工失误等原因[1],仍然存在输血传播 HIV的残余风险.本血站在进行常规血液筛查时发现,某献血者的ELISA检测各项指标均为阴性,6 人份混样核酸检测(NAT)结果为 HIV-RNA反应性,在征得献血者的知情同意后,先后进行了 4 次追踪检测,免疫印迹法由早期的阴性、不确定到后期确认为 HIV-1 抗体阳性,最终确证该献血者为 1 例低浓度 HIV 窗口期献血者,现将该献血者的追踪检测情况报道如下.     

人类免疫缺陷病毒抗体酶联免疫诊断试剂的质量评价

目的 评价市场流通中HIV抗体酶联免疫诊断试剂的质量。方法 从使用单位抽取20家试剂，用国家参考品、确证为阳性的样品和阴性样品对其进行检测和分析。结果 20家试剂均符合200107批国家参考品的质量要求，对76份确证为阳性样品的检出率为100．0％，16家试剂对88份阴性样品的检出率为100．0％，3家试剂为98．9％，1家试剂为97．7％。结论 我国HIV抗体诊断试剂的灵敏度较高，但某些试剂的特异性仍需提高。     

核酸检测对HIV筛查的影响

目的 分析开展核酸检测后青岛地区献血者HIV检测情况,探讨减少一遍ELISA检测及实施献血者归队的可行性.方法 对2012年9月13日～2013年6月1日期间的献血者标本,应用两种ELISA试剂检测HIV抗原/抗体,并用Roche Cobas S201血液筛查系统进行核酸检测,将HIV抗原/抗体反应性标本送至市疾控中心HIV确认实验室进行HIV确认.结果 ELISA方法共检出HIV抗原/抗体反应性标本90例,确认试验阳性13例,确认试验阴性77例,假阳性率85.56％(77/90),确认阳性者全部为ELISA双试剂反应性标本.HIV抗原/抗体非反应性标本经NAT检测无一例HIV RNA反应性;HIV抗原/抗体反应性标本90例,经NAT检测HIV RNA反应性标本13例,全部为ELISA双试剂反应性标本.结论 NAT与HIV确认试验有很好的符合性,开展NAT检测可以减少1遍HIV ELISA检测.     

HIV初筛实验不同策略的选择及其在临床应用中的评价

目的：回顾分析南京医科大学第一附属医院近5年332例初筛阳性标本使用的多种血清学方法的检测结果,为临床实验室推荐人类免疫缺陷病毒（H IV ）初筛实验的优选方案。方法对2010年1月至2014年4月在南京医科大学第一附属医院就诊者的331968份样本进行 H IV抗体初筛,332例初筛阳性样本用第四代酶联免疫吸附试验（ELISA）试剂复检,以蛋白印迹试验（WB）结果为金标准,比较分析第三代 ELISA试剂、第四代ELISA试剂以及分别与胶体金组合检测的结果。结果332例H IV抗体筛查阳性样本,经WB试验确证阳性189例。第三代ELISA试剂检测确证阳性符合率为57．27％,第四代ELISA试剂检测确证阳性符合率为89．15％,两者比较,差异有统计学意义（P＝0．00）。第三代ELISA试剂检测漏检1例确证阳性标本和1例确证不确定标本;第四代ELISA试剂检测未发现漏检阳性标本,并检出1例窗口期标本。第四代ELISA与胶体金组合后,确证阳性符合率较第三代ELISA与胶体金组合提高了3．91％。结论第四代ELISA试剂用于 HIV抗体筛查优于第三代 ELISA试剂,尤其是与胶体金的组合,明显提高了H IV检测的确证阳性符合率,并有利于H IV感染窗口期的检测,推荐作为临床实验室 H IV优选筛查方案。     

化学发光技术在CITIC血液筛查室间质评中的应用情况分析

目的分析化学发光技术(ChLIA)在血液筛查中的应用情况。方法对2017年6月—2018年4月一共3次室间质评的结果报告数据进行分析,统计ChLIA与酶联免疫法(ELISA)检测的不正常结果,以及既往室间质评中抗-HCV弱阳性样品和HIV p24抗原定量和HIV窗口期样品的检出情况。结果全球共有140余家实验室参加了室间质评活动,其中国内参评实验室50余家。全部参评实验室3次室间质评共使用检测试剂1 567个,ChLIA试剂占34%。ChLIA检测的假阴性和假反应性发生率分别为0.08%(8/10 569)和0.35%(37/10 569),ELISA分别为0.04%(7/18 145)和0.50%(91/18 145)。ChLIA与ELISA试剂检测HIV的假反应性发生率分别为0.31%(9/2 896)和0.68%(34/5 010)(P0.05)。大部分ChLIA试剂(3/4种)能检出抗-HCV弱阳性样品,全部ChLIA试剂(4种)对HIV p24抗原定量为1.5 IU/mL的样品和窗口期样品均无检出结果。结论化学发光技术已经用于国外血液筛查,其假反应性发生率低于ELISA,但其对HIV p24抗原检测的应用效果值得进一步探讨。     

57例抗HIV初筛阳性确认实验带型分析

目的 调查HIV感染初筛实验的准确率及确认抗HIV初筛试验阳性血清的感染和感染型别。方法 调查我国艾滋病高发农村，对部分初筛阳性和可疑的血清进行确认实验。结果 57例初筛为抗HIV阳性和可疑血清进行确认实验，56份为HIV—l阳性，其中1份样本出现HIV—2型反应条带；1份阴性。确认阳性标本的反应条带中，抗外膜蛋白(env)抗体阳性率最高，gpl60为100％，gpl20为94．6％，gp41为91．1％；多聚酶抗原(pol)p66为82．1％；核心抗原(gag)P24为53．6％。提示无症状携带组确认反应条带的pol和gag的阳性率显著高于艾滋病组(P＜0．01)。儿童组gag阳性率显著低于成人组(P＜0．05)。结论 HIV感染初筛实验的准确率较高，但确定感染需靠确认实验。外膜蛋白、p66和p24抗原是HIV感染的重要抗原，对确认HIV的感染具有指导意义。     

Diagnostic evaluation of a new combined HIV p24 antigen and anti-HIV1/2/O screening assay

To evaluate a new fourth generation assay for simultaneous detection of antibodies to the human immunodeficiency virus (HIV) 1 and 2 and HIV p24 antigen in daily routine we tested 675 sera obtained from 673 patients and compared the results to conventional antibody tests. In 546 uninfected patients the rate of unspecific reactivities was slightly higher in the new screening assay as compared to conventional antibody assays (1.1% vs. 0.4%). All 121 sera derived from patients with known HIV infection were detected correctly. In six patients from whom sera were obtained during early seroconversion the fourth generation ELISA was positive in three cases, while conventional third generation tests still were negative. In patients negative for HIV antibodies and low amounts of p24 antigen less than 100 pg/ml also the fourth generation ELISA remained negative. Thus, this new assay permits earlier detection of HIV infection and reduces the diagnostic window. It is a reliable tool for routine diagnosis of HIV, especially in blood donors and patients with high risk behavior.     

Performance evaluation of the new fully automated human immunodeficiency virus antigen-antibody combination assay designed for blood screening

BACKGROUND: Before the introduction of human immunodeficiency virus (HIV) combination assays, serologic diagnosis of HIV infection was performed with assays that detected either antibodies or p24 antigen. Owing to the capability to detect the early appearance of p24 antigen, combination assays that are designed for simultaneous detection of antibodies and antigen can significantly reduce the diagnostic window. STUDY DESIGN AND METHODS: Specificity and sensitivity of a commercially available HIV antigen‐antibody combination assay (Abbott PRISM; assay is not licensed by the FDA for use in the United States) were evaluated in a multicenter study by testing volunteer blood donors, hospitalized patients, seroconversion panels, and p24 antigen and HIV antibody subtype panels. Performance data were compared to a commercially available HIV combination assay and the PRISM HIV O Plus assay. RESULTS: Apparent specificity of 99.95 percent was observed in the donor population for the PRISM HIV antigen‐antibody combination assay, and better seroconversion sensitivity was demonstrated compared with another combination assay and the PRISM HIV O Plus assay. Analytical HIV antigen detection sensitivity averaged 33 pg per mL on the Agence Française de Sécurité Sanitaire des Produits de Santé (AFSSAPS) panel. Furthermore, comparable antigen sensitivity was demonstrated for 32 HIV‐1 group M subtype and group O panels. The PRISM HIV combination assay detected all HIV‐1 group M and O and HIV‐2 antibody–positive specimens evaluated. CONCLUSIONS: The PRISM HIV antigen‐antibody combination assay demonstrated a significant reduction of the window period for diagnosis of HIV infection. The assay demonstrated enhanced specificity and sensitivity along with broad subtype detection. The assay performance represents the “state‐of‐the art” technology for serologic blood screening of HIV infection.     

Time course of detection of viral and serologic markers preceding human immunodeficiency virus type 1 seroconversion: implications for screening of blood and tissue donors

BACKGROUND: Almost all human immunodeficiency virus (HIV) transmission via blood or tissues that has occurred since anti-HIV screening was implemented in 1985 is traceable to blood given after infection but before antibody seroconversion, a time that is referred to as the window period. In this study, the performance of newer assays designed to detect viral and serologic markers soon after infection is assessed, and the reduction in the window period achieved by these assays is estimated. STUDY DESIGN AND METHODS: Three cohort studies of persons at high risk for acquiring HIV infection were identified. These studies included well-controlled HIV type 1 (HIV-1) polymerase chain reaction (PCR) analyses of serial preseroconversion specimens from HIV-1- seroconverting homosexual men or intravenous drug users. Of 81 enrollees with anti-HIV-1 seroconversion documented by a viral lysate anti-HIV-1 enzyme immunosorbent assay (EIA) available in 1989, 13 (16%) had PCR-positive preseroconversion specimens. In the present study, sera from these 13 PCR-positive samples were further tested for anti- HIV by 10 contemporary EIAs and 6 supplemental assays, as well as being tested for plasma p24 antigen and HIV-1 RNA. Preseroconversion sera from 38 HIV-1 DNA PCR-negative cohort participants were also tested by selected anti-HIV EIAs and tested for p24 antigen and HIV-1 RNA. On the basis of these laboratory data and the intervals between blood drawing in all 81 men, the reduction in the preseroconversion window period achieved by these new assays was estimated with a mathematical model developed to analyze seroconversion data. RESULTS: Nine (69%) of the 13 preseroconversion PCR-positive samples had anti-HIV that was detectable by one or more contemporary anti-HIV-1 or anti-HIV type 2 EIA. Supplemental antibody assays were negative on all four EIA-nonreactive preseroconversion samples and negative or indeterminate on a high proportion of the nine EIA-reactive PCR-positive samples. Eight (61%) of the 13 samples were p24 antigen-positive, and 11 (85%) were HIV-1 RNA-positive. The estimated reductions in the window period (relative to the index viral lysate-based anti-HIV EIA) were as follows: contemporary anti-HIV-1/2 EIAs, 20.3 days (95% Cl, 8.0–32.5); p24 antigen and DNA PCR, 26.4 days (95% Cl, 12.6–38.7); and RNA PCR, 31.0 days (95% Cl, 16.7–45.3). CONCLUSION: Recent improvement in the sensitivity of anti-HIV assays has resulted in significant shortening of the preseroconversion window period. Consequently, the incremental reduction in the window period that could be achieved by implementing direct virus-detection assays has diminished significantly.     

Multicenter evaluation of a new 4th generation HIV screening assay Elecsys HIV combi

Fourth-generation screening assays which permit a simultaneous detection of human immunodeficiency virus (HIV) antigen and antibody reduce the diagnostic window on average by four days in comparison to third-generation antibody assays. Recently, the new automated Elecsys HIV combi was compared in a multicenter study to alternative fourth- and third-generation assays, p24 antigen test and HIV-1 RNA RT-PCR. A total of 104 serocon-version panels, samples of the acute phase of infection after seroconversion (n = 33), anti-HIV-1 positive specimens (n = 572) from patients in different stages of the disease, 535 subtyped samples from different geographical locations, including group M (subtypes A-J) and group O, anti-HIV-2 positive sera (n = 364), dilutions of cell culture supernatants (n = 60) infected with different HIV-1 subtypes, selected performance panels, 8406 unselected samples from blood donors originating from different blood transfusion centers, 3810 unselected sera from daily routine and from hospitalized patients, 9927 unselected samples from South Africa and 1943 potentially interfering samples were tested with the Elecsys HIV combi. Elecsys HIV combi showed a comparable sensitivity to HIV-1 Ag stand-alone assays for early detection of HIV infection in seroconversion panels. The mean time delay of Elecsys HIV combi (last negative sample + 1 day) in comparison to HIV-1 RT-PCR for 92 panels tested with both methods was 3.23 days. The diagnostic window was reduced with Elecsys HIV combi between 1.56 and 5.32 days in comparison to third-generation assays. The specificity of Elecsys HIV combi in blood donors was 99.80% after repeated testing. Our results show that a fourth-generation assay with improved specificity and sensitivity like the Elecsys HIV combi is suitable for blood donor screening due to its low number of false positives and since it detects HIV p24 antigen with a comparable sensitivity to single antigen assays.     

艾滋病病毒抗原检测试剂盒研制及应用

目的建立双单抗夹心酶联免疫法检测人类免疫缺陷病毒核心抗原（ＨＩＶ－１ｐ２４）的试剂盒。方法用识别ＨＩＶ－１ｐ２４抗原不同位点的单克隆抗体，构建双单抗夹心酶联免疫法，检测ＨＩＶ－１ｐ２４抗原，测定试剂盒的临界值及灵敏度；对４５２份抗ＨＩＶ阳性样品及１５２５份高危人群抗ＨＩＶ阴性样品进行测定，用抗体阻断抑制法确证，并与聚合酶链反应病毒核酸测定结果进行比较。结果获得６株单抗，免疫印迹法测定结果显示均为ｐ２４特异性。交叉组合试验确定单抗ｐ２４－１和１０用于固相，ｐ２４－６用于标记辣根过氧化物酶。试剂盒临界值为０．１５＋阴性对照值；检测灵敏度为２ｎｇ／ｍｌ。４５２份抗体阳性样品，抗原检测阳性４９份（１０．８％），１５２５份抗体阴性样品，经阻断试验确证，抗原阳性１７份。４９份抗体阳性样品中，ＨＩＶ－ＲＮＡ阳性３６份，符合率达７３％；１７份高危人群抗原阳性样品，１０份为病毒核酸阳性。结论双单抗夹心酶联免疫检测ＨＩＶ－１ｐ２４抗原方法敏感、操作简便，可用于临床ＨＩＶ感染的辅助检测手段。