丙型肝炎病毒抗体筛查阳性结果确证方案的探讨

目的明确抗-HCV酶免检测结果与确证阳性结果之间的相互关系,以期建立简便、经济的血液筛查实验室抗-HCV确证试验方案。方法使用重组免疫印迹试验结合核酸检测方法对134份酶免抗-HCV阳性样本确证,初步探讨2或3种抗-HCV酶免试剂(Ortho、Murex和科华联合复检的S/Co值与阳性预期值的关系及不同试剂组合检测的阳性预期值。结果134份样本中,92份真阳性,5份可疑,其余均为阴性。Ortho和Murex试剂的S/Co与阳性预期值呈正相关,当S/Co≥3.8时,阳性预期值分别可达98.33%和97.78%。Murex联合科华、Ortho联合科华以及3种试剂同时检测为阳性时的阳性预期值为100%;Ortho联合Murex的阳性预期值为98.48%,与上述其它2或3种试剂组合比较,差异无统计学意义(P>0.05)。结论2种或3种酶免试剂联合复检的确证方案优于美国CDC推荐的S/Co≥3.8方案。在常规血液筛查实验室,可以选择3种抗-HCV试剂中的任2种同时复检,先行对抗-HCV阳性标本确证,对无法确证的样本再作重组免疫印迹试验分析。     

献血者HBsAg、抗-HCV、抗-HIV、抗-TPELISA检测阳性与确证试验的对比研究

目的评价ELISA两步法用于献血者血液HBsAg、抗-HCV、抗-HIV、抗-TP筛检阳性标本与确证试验结果的符合性,探讨确证试验结果用于献血者管理、酶免试剂选择和ELISA灰区范围设置的理论依据。方法 HB-sAg采用电化学发光(ECLIA)中和试验、抗-HCV采用重组免疫印迹试验(RIBA)、抗-HIV采用蛋白质印迹(WB)法、抗-TP采用凝集法(TPPA)确证试验对ELISA两步法检测阳性及灰区标本456份进行检测,将2者结果对比分析。结果 HBsAg、抗-HCV、抗-HIV和抗-TP确认阳性率分别为41.18%、38.00%、18.52%和48.82%;抗-HIV、抗-TP灰区(S/CO值0.5～1.0)标本确证试验无阳性,HBsAg灰区(S/CO值0.8～1.0)、抗-HCV灰区(S/CO值0.7～1.0)均有阳性和不确定标本检出。结论为ELISA两步法应用于献血者酶免4项检验效果进行了科学评价,为假阳性献血者检验结果的告知及ELISA灰区设立原则提供了实验依据。     

梅毒抗体酶联免疫吸附试验S/CO比值与TPPA结果的相关性研究

目的探讨梅毒抗体ELISA试验的"灰区"设定值和确证试验阳性预测阈值的制定策略,建立输血系统梅毒筛检和确证程序。方法采用2种国产梅毒抗体ELISA试剂对本中心无偿献血者标本进行初复检测,收集抗梅毒抗体ELISA测定为阳性反应的献血者血清标本进行梅毒螺旋体明胶颗粒凝集试验(TPPA)确认试验,并进行统计学分析。结果无偿献血者中梅毒抗体ELISA试验可疑阳性反应率为2.26‰(116/51 207),确证试验阳性率为1.23‰(63/51 207),确证试验阳性有1份标本的S/CO值在"灰区"范围内。万泰试剂可预测确证试验阳性的S/CO阈值是1.61,预测率为98.3%,丽珠试剂可预测确证试验阳性的S/CO阈值是1.85,预测率为96.5%。结论 "灰区"的设定可有效降低输血传播梅毒的风险。梅毒抗体酶联免疫吸附试验S/CO值的高低和确证试验分级结果存在正相关性。     

ORTHO抗-HCV酶联免疫试剂2种孵育试验程序在血液筛查中的比较研究

目的确定1种3代抗-HCV酶免试剂(ORTHO HCV 3.0 ELISA试剂)2种孵育试验过程在血液筛查中是否存在差异。方法随机留取常规献血者血液筛查中检出的抗-HCV反应性的血液标本180(人)份作HCVRNA检测,并用RIBA和不同于血站常规抗-HCV筛查的酶免试剂作抗-HCV复测;依据ORTHO HCV 3.0 ELISA检测试剂说明书中的长、短2种孵育检测程序,同时作对比检测。结果 180份初筛抗-HCV阳性标本中,有16份ORTHO HCV 3.0 ELISA 2种检测程序的检测结果不一致,其中5份为短孵育试验反应性、11份为长孵育试验反应性,短孵育试验漏检2份被确证抗-HCV阳性标本。ORTHO HCV 3.0 ELISA试剂的长孵育检测程序灵敏度高于短孵育试验程序,2种试验程序的S/CO值分布没有差别,但RIBA不确定标本其S/CO值分布在一定的灰区范围内。结论在献血人群血液筛查中,采用具有更高灵敏度的长孵育酶免程序和设定合理的结果判定灰区,有助于预防输血传播HCV,提高血液的安全。     

梅毒螺旋体筛查反应性献血者S/CO值与真阳性的相关性研究

目的探讨献血者梅毒抗体(抗-TP)初筛反应性结果的S/CO值与真阳性的相关性,为制定合理的初筛梅毒反应性献血者归队策略提供数据支撑。方法采用2种抗-TP酶联免疫吸附试验(ELISA)国产试剂进行献血者血清标本初筛试验,反应性献血者(包括单试剂反应性、双试剂反应性和灰区反应性)血清标本进行梅毒螺旋体明胶颗粒凝集试验(TPPA)确证评价。采用SPSS 20.0软件绘制抗-TP S/CO值ROC(receiver operating characteristic)曲线,分析各S/CO值区间的阳性预测值,灵敏度和特异性最佳的S/CO值临界点。结果 1)抗-TP初筛反应性献血者血清样本110例,TPPA阳性61例,阴性43例,6例不确定。2) 2种ELISA试剂与TPPA真阳性符合率分别为66.30%、77.22%,真阴性符合率为100%、96.77%。3) ROC分析:A试剂抗-TP初筛试验阳性预测值≥95%的S/CO值为8.99,敏感度为1,特异性为0.959;B试剂抗-TP初筛试验阳性预测值≥95%的S/CO值为4.99,敏感度为1,特异性为0.939。结论根据本研究结果,当两种试剂筛查的S/CO值分别≥9或者≥5时,可以直接判为阳性,无需追踪;当初筛S/CO值分别9和5时,进一步做确证试验,判断是否为真阳性。本研究中,61例TPPA为阳性的献血者直接屏蔽,43例阴性和6例不确定献血者可继续追踪确定是感染状态。     

11家血站实验室抗-TP酶联免疫吸附试验临界值的评价

目的评价11家血站实验室采用酶联免疫吸附试验(ELISA)检测无偿献血者梅毒螺旋体抗体(抗-TP)过程中,血站实验室采用的工作临界值(CO)的适宜性及合理性。方法 11家血站实验室采用8种ELISA试剂中的1/2种均对1 372例标本进行抗-TP检测。对结果有差异的标本进行梅毒螺旋体颗粒凝集试验(TPPA)确证试验,利用确证试验结果明确标本真实血清学状态。对数据进行如下分析:1)分析11家血站实验室采用8种ELISA试剂中的1/2种试剂真阳性检出率、灰区标本确证阳性率;2)分析11家血站实验室抗-TP试验"灰区"设置的合理性,通过绘制ROC曲线确定11家血站实验室采用8种ELISA试剂中的1/2种试剂最佳CO值,比较不同CO值下(最佳CO值、厂商推荐CO值、血站实验室因采用灰区而设置的工作CO值)灵敏度与特异性的变化。结果 1)11家血站实验室采用8种ELISA试剂中的1/2种试剂对1 372例标本进行检测,真阳性检出率均为100%(489/489)、真阳性标本无1例漏检;9家设有灰区的血站实验室共检出136例灰区标本,经确证均为阴性,即灰区标本确证阳性率均为0。2)11家血站实验室采用8种ELISA试剂中的1/2种试剂ROC曲线确定的最佳CO值均大于厂商推荐CO值,设置灰区的9家血站实验室采用工作CO值灵敏度提高有限、特异性有所下降。结论 11家血站实验室使用厂商推荐CO值就可获得较高灵敏度、满足血液筛查的要求,实验结果支持血站实验室取消灰区设置。     

血液筛查中丙型肝炎病毒检测方法的应用评价

目的比较血液筛查中丙型肝炎病毒的检测方法,并探讨其应用价值。方法收集2011年8～12月血液筛查中酶联免疫吸附试验(ELISA)、丙型肝炎病毒抗体(抗-HCV)阳性标本共41例,使用重组免疫印迹试验进行确证;同时用新创、Ortho两种抗-HCV ELISA试剂以及Architect Anti-HCV Reagent化学发光试剂进行检测,比较三者结果的差异。结果统计学分析显示,3种检测方法的检测结果差异有统计学意义。重组免疫印迹试验检测HCV阳性35例,阴性6例,与Architect化学发光法结果相符,新创ELISA法检测41例全为阳性,Ortho ELISA法检测阳性33例,阴性8例。结论 Ortho试剂对HCV检测的特异性高于新创试剂,化学发光法对HCV检测的特异性高于ELISA法,化学发光法与ELISA法联合检测能提高血液筛查中HCV的阳性检出率,对可疑标本再做重组免疫印迹试验分析。     

无偿献血者乙肝表面抗原ELISA试剂筛查S/CO值与HBsAg阳性的相关性研究

目的了解献血者乙肝病毒表面抗原(HBsAg)初筛(试剂)反应性结果S/CO值与真阳性的相关性,为制定合理的HBsAg初筛反应性献血者归队策略提供依据。方法采用3种HBsAg酶联免疫吸附试验(ELISA)试剂(以国产试剂1、国产试剂2、进口试剂代称)和1种国产核酸检测(NAT)试剂对2017年7月-2017年9月在长春市献血的9 951(人)份献血者血标本做初筛试验,凡是反应性[包括所有试剂(试验)反应性、单试剂反应性和灰区反应性(0.8≤S/CO﹤1.0)]血清标本再以中和试验(ELISA法)确证。使用SPSS 16.0统计学软件绘制HBsAg S/CO值与确证结果的接受者操作特性曲线(ROC),分析各S/CO值区间的阳性预测值,寻找灵敏度和特异性相适的S/CO值临界点。结果 1)献血者HBsAg初筛反应性率0.58%(58/9951),中和试验确证HBsAg阳性者比例20.69%(12/58)、阴性者比例79.31%(46/58)例;ELISA国产试剂1、2及进口试剂初筛与中和试验的阴性符合率均为100%,阳性符合率分别为57.14%(12/21)、66.67%(12/18)及27.27%(12/44)。2)ROC分析:国产试剂1、2及进口试剂HBsAg初筛试验相适的S/CO值临界点分别为1.635、3.605及3.245,敏感度为1、0.917及1,特异性为0.957、0.978及0.761。3)中和试验确证:12例HBV为阳性的献血者直接屏蔽(其中10例为NAT阳性),46例阴性献血者可继续追踪确定是否为感染状态(46例均NAT阴性)。结论每种ELISA试剂都有1个适宜的S/CO值,检测结果大于等于这个S/CO值时,其HBsAg真阳性率较高,可直接判为阳性,无需追踪确证。     

抗-HIV检测结果分析及灰区设置探讨

目的探讨ELISA检测的灰区设置以及如何利用检测值/临界值(S/CO比值)对献血者管理提供指导。方法对48 466份无偿献血者标本检测结果中双试剂检测有反应性的241份送疾病预防控制中心(CDC)HIV确证实验室进行确证试验的反馈结果进行回顾性分析。结果灰区调整前后,抗-HIV的检测不合格率差异有统计学意义。抗-HIV检测双试剂有反应性的46份标本中,确证阳性39份,确证阴性5份,不确定2份。195份单试剂检测呈反应性的标本中,确证阴性192份,不确定3份。确证阳性标本的S/CO值明显高于不确定和阴性标本的S/CO值。结论根据ELISA筛查反应性不同强度(S/CO比值高低)的确证结果合理设置灰区范围,有助于献血者管理。     

艾滋病病毒感染对酶联免疫吸附试验试剂检测静脉吸毒人员丙型肝炎病毒抗体反应强度影响的探讨

目的探讨艾滋病病毒(HIV)感染对ELISA试剂检测静脉吸毒人员丙型肝炎病毒(HCV)抗体的影响,为HIV、HCV混合感染检测策略的提出和修改提供理论依据。方法按是否感染HIV分组对两种抗-HCVELISA试剂检测反应强度(S/CO)≥1的分布进行对比,采用SPSS 15.0软件分析。结果两组样本经两种试剂检测反应强度(S/CO)的构成差异有统计学意义(P0.05),HIV阳性组HCV抗体检测低反应强度的构成高于HIV阴性组(P0.05)。对科华试剂检测为低反应强度的标本,与用Ortho试剂检测结果的一致性在两组间差异有统计学意义(P0.05)。结论是否感染HIV对科华HCV抗体ELISA试剂及Ortho HCV 3.0 ELISA试剂反应强度均有影响。HIV感染者可能出现HCV抗体ELISA检测不确定或假阴性反应,弱阳性反应标本可增加假阳性可能。     

Significance of the signal-to-cutoff ratios of anti-hepatitis C virus enzyme immunoassays in screening of Chinese blood donors

BACKGROUND: The correlation between signal-to-cutoff (S/CO) ratios of a second-generation hepatitis C virus (HCV) enzyme immunoassay (EIA; Abbott) and a third-generation HCV enzyme-linked immunosorbent assay (ELISA; Ortho) and confirmed HCV infection has been reported. The utility of the values for the Chinese anti-HCV EIA kits, however, has not been studied in evaluating test results in Chinese blood donors. STUDY DESIGN AND METHODS: A total of 156 donor samples repeat reactive for anti-HCV at routine screening from five representative regions of China were retested for anti-HCV by the Ortho third-generation HCV ELISA and six Chinese EIA kits and for HCV RNA by a human immunodeficiency virus-1 and HCV assay (Procleix, Chiron Corp.). The HCV RNA-nonreactive samples were further tested for anti-HCV by a third-generation recombinant immunoblot assay RIBA (Chiron Corp.). The positive result by either nucleic acid amplification test or RIBA was interpreted as confirmed HCV infection. RESULTS: The confirmed HCV prevalence rate in donors in five representative regions obtained in this study was 0.20 percent (77/37,900) in 2004. All seven anti-HCV EIA kits had a significant correlation between S/CO ratios and confirmed HCV infection. The threshold S/CO ratios, which predicted more than 95 percent of confirmed HCV infections for the Ortho, SABC, BGI-GBI, InTec, GWK, KHB, and WANTAI kits, were 3.8, 6.0, 7.0, 8.6, 10.0, 10.0, and 14.0, respectively. CONCLUSIONS: Anti-HCV EIA kits commonly used in Chinese donors screening demonstrate good correlation between S/CO ratios and the confirmed infection. For the Ortho third-generation HCV ELISA, the S/CO ratio of 3.8 determined by the US Centers for Disease Control and Prevention is applicable to Chinese blood donors. The Chinese domestic EIA kits evaluated show a diverse range of threshold S/CO ratios.     

上海地区抗-HCV反应性献血者随访研究

目的对抗-HCV反应性献血者进行随访以分析反应性献血者的归队途径。方法随机对上海地区52名抗-HCV单试剂反应性献血者献血间隔6个月后随访,使用4种采供血机构常用的抗-HCV ELISA试剂检测,对于抗-HCV反应性标本使用重组免疫印迹试验确证,同时使用罗氏cobas Taqscreen MPX核酸检测试剂(NAT)单人份检测;3～6个月后进行第2次随访,开展相同实验。结果 2次随访研究发现,52名献血者中,39名(75%)献血者4种抗-HCV试剂检测结果均为阴性,13名(25%)献血者4种抗-HCV试剂至少有1种试剂检测结果为反应性,与原抗-HCV试剂检测结果相同,且S/CO数值保持基本一致,13名抗-HCV反应性献血者中有1名免疫印迹检测结果为阳性;52名献血者NAT结果均为阴性。结论献血者抗-HCV单试剂反应性,经过至少6个月间隔,使用包含原抗-HCV在内的2种试剂检测结果阴性,同时NAT检测阴性者可恢复献血权利。     

Routine HCV PCR screening of blood donations to identify early HCV infection in blood donors lacking antibodies to HCV

BACKGROUND: Detection of early hepatitis C infection of blood donors is still a major problem for blood transfusion. Common anti-HCV screening assays show differences in sensitivity and specificity. The often mild symptoms of acute hepatitis C also cause difficulties in the identification of early HCV infection. The feasibility and efficacy of routine screening of blood donations for HCV RNA were investigated. STUDY DESIGN AND METHODS: Blood donations (n = 251,737) were screened for HCV RNA over 4 years. RNA extraction, amplification, and detection were done by two commercial HCV PCR kits (HCV Cobas Amplicor and HCV Cobas Amplicor 2.0, Roche Diagnostics). Screening was done by pool testing with a maximum pool size of 40 serum samples. RESULTS: Three donations out of 251,737 were HCV RNA positive and anti-HCV negative. ALT levels of these donations were 271, 32, and 10 U per L. The HCV infection of a fourth HCV RNA-positive donor could not be identified by routine, second-generation HCV EIA (Abbott Diagnostika). In this case, two previous donations were also HCV RNA positive, and three second-generation test systems (Abbott) could not detect anti-HCV, whereas third-generation anti-HCV screening assays detected antibody with different sensitivity. The first HCV RNA-positive donation was identified only by the HCV ELISA 3.0 (Ortho Diagnostic Systems). The results of confirmatory assays like RIBA HCV 3.0 (Ortho) and Matrix (Abbott) indicate a restricted immune response to NS3 only. CONCLUSION: HCV RNA detection by PCR can be carried out routinely in blood donor screening without significant delay of release of the components. The residual risk of transmission can be reduced by identification of early infection, which can lead to an improved safety of blood components. RNA screening can also be advantageous in cases of incomplete or lack of antibody response to HCV.     

The significance of repeat testing in Turkish blood donors screened with HBV,HCV and HIV immunoassays and the importance of S/CO ratios in the interpretation of HCV/HIV screening test results and as a determinant for further confirmatory testing

The purpose of this study was to investigate the intra‐assay correlations amongst initial reactive and repeat screening results used in enzyme immunoassays (EIAs) for hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV in blood donors. This study evaluated the value of using the power of the signal to cut‐off (S/CO) ratio index for confirming anti‐HCV/HIV reactive screening results, thereby touching upon the utility of S/CO indices in determining whether further confirmatory testing was necessary. Screening test results of the 72 695 blood donors were evaluated over a 1‐year period. Correlation analysis among each initial test and retests was done by Pearson r test. Appropriate S/CO values to determine the need of the confirmation testing was investigated by ROC analyses. EIA intra‐assay correlations were of statistical significance and were determined as follows: 0·948 for anti‐HCV, 0·827 for anti‐HIV and 0·948 for HBsAg. The threshold S/CO ratio values which predicted more than 95% of the confirmation test result were 3·8 for HCV and 5·6 for HIV. We were able to demonstrate a strong level of intra‐assay correlation amongst EIAs, thereby eliminating the need for repetition of the screening test. Hence, we suggest that repeat screening should only be limited to HBV and HIV tests with low EIA S/CO ratios. Thus, using the power of the S/CO ratio in determining the need for HCV confirmation testing can be a cost‐effective measure, especially if the S/CO value is ≥3·8.     

我国5城市合格献血者血液HIV及HCV残余风险研究

目的研究我国献血者血液HIV及HCV残余风险;评估我国开展血液核酸检测(NAT)的可行性和必要性。方法采集乌鲁木齐、昆明、北京、广州、杭州5城市献血者血样,用Chiron Procleix HIV-1/HCV Assay血液核酸检测体系,对各项血清学筛查均合格的89 467份血液作16人份混合血样NAT检测,凡筛查不合格血样再作单人份检测;对于抗-HCV阴性而HCV RNA NAT阳性者,用备用管作抗-HCV、ALT、及HCV RNA NAT复检。结果共检出HCV RNA NAT阳性但抗-HCV EIA阴性标本3例,未检出HIV RNA NAT阳性但抗-HIV EIA阴性标本;在87 034份血清学筛查合格献血者中,检出HCV NAT阳性2例,其中1例复检ALT为254U/L,未检出HIVNAT阳性;在2 613份血清学筛查不合格者中,检出1例HCV NAT阳性但抗-HCV EIA阴性标本,该献血者抗-HIV阳性、ALT 372U/L;未检出HIV NAT阳性但抗-HIV EIA阴性的标本。结论血清学筛查使我国的血液安全性已有相当高的保障;而NAT技术可进一步提高血液的安全性,但在我国是否可应用于常规血液筛查,需考虑成本与效益比。此外,ALT筛查对排除抗-HCV漏检血液仍有一定的作用。     

Hepatitis C antibody intraassay correlation: is retest in duplicate necessary?

BACKGROUND: The hepatitis C virus antibody (anti-HCV) can be identified with third-generation immunoassays. The purpose of this study was to define the correlation or agreement between first and second reactive results of anti-HCV microparticle-based enzyme immunoassay (MEIA) and of chemiluminescence assays (ChLIAs) in blood donors, to determine whether repeat testing is necessary. STUDY DESIGN AND METHODS: Commercially available assays, third-generation HCV MEIA (Abbott), third-generation HCV ChLIA (Ortho), and third-generation HCV ChLIA (Abbott), were used to evaluate anti-HCV repeatedly reactive blood obtained from donations made at 23 Mexican blood centers over a period of 1 year. The intraassay correlation between first and second reactive anti-HCV tests with the Pearson r test and the coefficient of variation (CV) were determined. RESULTS: The intraassay correlation of 565 anti-HCV repeatedly reactive samples was 0.996 for the Abbott third-generation HCV MEIA, 0.995 for the Ortho third-generation HCV ChLIA, and 0.993 for the Abbott third-generation HCV ChLIA. The CVs of these assay systems were 2.82, 5.33, and 5.69 percent, respectively. CONCLUSION: A highly significant intraassay correlation between anti-HCV duplicates was found. Specimens with a single reactive anti-HCV result with the Abbott third-generation HCV MEIA, Ortho third-generation HCV ChLIA, and Abbott third-generation HCV ChLIA assays should be considered as positive and need not be retested. Such a change in the algorithm for blood donor screening is feasible because of the availability of highly automated platforms.     

Safety and efficacy of hepatitis C virus antibody screening of blood donors with two sequential screening assays

BACKGROUND: Reactive samples in hepatitis C virus (HCV) antibody screening of blood donors are currently referred for a confirmatory assay. This scheme is not optimally efficient and is expensive because of the lack of specificity and cost of confirmatory tests, as well as the need to discard false-positive donations. As in some human immunodeficiency virus antibody-confirmatory schemes, the safety and efficacy of confirming anti-HCV with two sequential screening assays were evaluated. STUDY DESIGN AND METHODS: Three combinations of two anti-HCV screening assays were used to test 75,874 blood donors. Results were compared with the routine testing scheme and HCV RNA detection in any enzyme immunoassay-repeatably reactive samples. RESULTS: The use of an alternative screening assay for repeat testing decreased the proportion of enzyme immunoassay-positive donors from 0.28 to 0.05 percent. All samples that were "confirmed" as positive by the standard combination of immunoassays and all HCV RNA-positive samples were detected by the sequential screening assays. No samples that had discordant results on primary and secondary screening assays were confirmed by recombinant immunoblot assay or were found to contain detectable HCV RNA. CONCLUSION: The combination of screening assays for anti-HCV confirmation was as safe as, cheaper than, and nearly as efficient as the standard testing scheme.