EB病毒衣壳抗原IgM抗体检测试剂参考品的建立

目的 建立EB病毒衣壳抗原IgM抗体检测试剂国家参考品并制定质量标准。方法 收集并筛选EB病毒衣壳抗原IgM抗体阳性和阴性血浆样本,建立EB病毒衣壳抗原IgM抗体检测试剂国家参考品并进行均匀性和稳定性研究,经10个实验室的协助标定,确定参考品的质量标准。结果 建立的EB病毒衣壳抗原IgM抗体检测试剂国家参考品包括阳性参考品6份、阴性参考品10份、重复性参考品1份和检测限参考品3份。参考品均匀性变异系数(coefficient of variation,CV)为3.1%,满足行业标准CV≤15.0%的要求;2～8℃放置7 d、室温放置3 d和反复冻融3次对参考品均无影响。质量标准为：阳性符合率应≥4/6,阴性符合率应为10/10,重复性(2个浓度水平)的检测结果应均为阳性且CV均≤15.0%,检测限参考品L1应为阳性,L2～L3不作要求。结论 建立的EB病毒衣壳抗原IgM抗体检测试剂国家参考品可用于相关试剂研发的质量控制及评价。     

丙型肝炎病毒诊断参考品的研究进展

体外诊断试剂的参考品是由逐一反复论证的一套样品所组成,用于全面控制试剂质量,它对于试剂应达到的各种指标提出了全面要求。目前国际上常用的丙型肝炎诊断试剂参考品为抗HCV抗体血清参考品和核酸检测参考品,我们简要综述了丙型肝炎病毒诊断试剂参考品的研制及发展。     

HIV-1 P24抗原国家参考品的研制

收集正常人、HIV感染者和疑似感染者血浆以及HIV-1病毒培养裂解液,对其进行HIV抗体、HIVP24抗原、HCV抗体和HBsAg检测,对HIVP24抗原阳性者进行HIVRNA检测,并对部分样品进行基因分型。以NIBSCP24抗原标准品的系列稀释样品作为线性灵敏度参考品。经过实验筛选出20份阴性参考品,10份阳性参考品,10份线性灵敏度参考品,2份精密性参考品,共同组成HIV-1P24抗原国家参考品,经多家不同的试剂进行标定,制定了相应的标准。稳定性研究结果表明,反复冻融三次对该参考品的稳定性没有影响。由此,初步建立了HIV-1P24抗原国家参考品,该参考品将对HIV-1P24抗原、HIV抗体/P24抗原联合检测试剂的质量控制提供重要依据。     

HIV-1 P24抗原国家参考品的研制

收集正常人、HIV感染者和疑似感染者血浆以及HIV-1病毒培养裂解液,对其进行HIV抗体、HIV P24抗原、HCV抗体和HBsAg检测,对HIV P 24抗原阳性者进行HIVRNA检测,并对部分样品进行基因分型.以NIBSCP 24抗原标准品的系列稀释样品作为线性灵敏度参考品.经过实验筛选出20份阴性参考品,10份阳性参考品,10份线性灵敏度参考品,2份精密性参考品,共同组成HIV-1 P24抗原国家参考品,经多家不同的试剂进行标定,制定了相应的标准.稳定性研究结果表明,反复冻融三次对该参考品的稳定性没有影响.由此,初步建立了HIV-1 P24抗原国家参考品,该参考品将对HIV-1 P24抗原、HIV抗体/P 24抗原联合检测试剂的质量控制提供重要依据.     

Dot-ELISA法检测血液及唾液HIV抗体的应用评价

评价人类免疫缺陷病毒1+2型抗体检测试剂盒(Dot-ELISA法)检测血清和唾液样本的临床性能。采用对照试验研究,选取背景清晰的研究对象200例,采集同一研究对象的血清和唾液样本,应用万泰生物药业公司生产的人类免疫缺陷病毒1+2型抗体检测试剂盒作为考核试剂,法国生物梅里埃公司生产的人类免疫缺陷病毒抗体诊断试剂盒(ELISA法)作为参考试剂,考核试剂检测结果与参考试剂及研究对象背景进行比较分析。考核试剂检测血清HIV抗体与参考试剂相比较,阳性符合率100%,阴性符合率100%,总符合率100%,Kappa值1.00,一致性为最强;考核试剂检测唾液HIV抗体与参考试剂检测结果相比较,阳性符合率98.78%,阴性符合率100%,总符合率99.50%,Kappa值0.99,一致性为最强。Dot-ELISA法人类免疫缺陷病毒1+2型抗体检测试剂盒对血清及唾液样本检测性能优越,适合HIV抗体快速筛查。     

鼠疫耶尔森菌抗原检测试剂用国家参考品的研制

目的研制鼠疫耶尔森菌(Yersinia pestis)抗原检测试剂用国家参考品。方法通过对5株鼠疫耶尔森菌和10株非鼠疫耶尔森菌的菌种检定、培养及灭活、抗原检测,组建鼠疫耶尔森菌抗原检测试剂用国家参考品。对参考品进行样品均匀性以及稳定性评估,组织5家实验室协作标定。结果参考品由5份阳性、10份阴性、1份最低检出量以及1份重复性样品组成,均匀性和稳定性良好。协作标定结果显示:①5份阳性参考品阳性率100%;②10份阴性参考品阴性率100%;③最低检出量参考品的检出量不高于1.0×10~6个菌/mL;④重复性参考品检测反应结果应一致(酶联免疫法、上转发光免疫层析法等CV<5%)。结论建立的鼠疫耶尔森菌抗原检测试剂用国家参考品填补了相关领域的空白,可用于相关试剂的质量控制。     

免疫渗滤法检测血液及尿液HIV抗体的应用评价

评价免疫渗滤法人类免疫缺陷病毒1+2型抗体诊断试剂盒检测人血浆和尿液样本的临床性能。采用对照试验研究,选取背景清晰的研究对象200例,采集同一研究对象的血浆和尿液样本,应用万泰生物药业公司生产的人类免疫缺陷病毒1+2型抗体诊断试剂盒作为考核试剂,法国生物梅里埃公司生产的人类免疫缺陷病毒抗体诊断试剂盒(ELISA法)作为参考试剂进行检测,考核试剂检测结果与参考试剂及研究对象背景进行比较分析。考核试剂检测血浆HIV抗体与参考试剂相比较,阳性符合率100.00%,阴性符合率100.00%,总符合率100.00%,Kappa值1.00,一致性强度为最强;考核试剂检测尿液HIV抗体与参考试剂检测结果相比较,阳性符合率68.29%,阴性符合率100.00%,总符合率87.00%,Kappa值0.72,一致性强度为高度。免疫渗滤法人类免疫缺陷病毒1+2型抗体诊断试剂盒对血浆、尿液样本检测性能优越,适合临床快速诊断。     

肠道病毒EV71 IgM抗体参考品的建立

目的建立肠道病毒EV71 IgM抗体检测用参考血清盘。方法通过收集手足口病感染早期患者的咽拭子和血清,对咽拭子病毒进行分离、鉴定、基因分型,通过血清中和试验及酶联免疫吸附试验(捕获法)的验证,确定EV71 IgM抗体阳性样品,组建EV71 IgM抗体参考血清盘,并经3家实验室对该参考血清盘进行协同标定和确认。结果 12名患儿的咽拭子中均分离到EV71病毒,在RD细胞上引起细胞病变。通过套式PCR扩增、序列测定后进化树分析确认均为流行的C4基因亚型。每名患儿的双份血清均可中和EV71病毒,抗体效价为1∶512~1∶2048。通过捕获法进行EV71 IgM抗体检测结果均为阳性。以此12份样品为原料制备EV71 IgM抗体阳性参考品,同时以12份EV71 IgM抗体阴性血清制备阴性参考品,建立了由12份阳性参考品、12份阴性参考品、1份最低检出限参考品和1份精密性参考品组成的肠道病毒EV71 IgM抗体参考血清盘。通过3家实验室协同标定,各实验室间差异均无统计学意义。结论建立了EV71 IgM抗体检测参考血清盘,为相关检测试剂的质量控制和评价提供了参考标准。     

丙型肝炎病毒分片段抗体检测蛋白质芯片质控参比品的建立及质量验证

建立能同时检测丙型肝炎病毒(HCV)嵌合抗体、核心抗体和NS3、NS4、NS5抗体的蛋白质芯片质控参比品,对质控合格的芯片进行质量验证。用3种HCV EIA试剂分别检测从3家医院收集的丙型肝炎病毒感染患血清及其他非HCV感染患血清,从3种EIA试剂同时阴性或阳性的血样中挑取阳性和阴性血清,然后用RNA hyb PCR试剂进行检测,从中再选取部分样本用RIBA3．0进行检测,确定HCV分片段抗体检测蛋白质芯片质控参比品。经质检合格的芯片用中国药品生物制品检定所的HCV参比品进行检定。通过490例临床标本的检测对芯片的质量进行进一步的验证。从收集的240份丙型肝炎病毒感染患血清及其他非HCV感染患血清筛选出30份血样(15份阳性,15份阴性)作为HCV分片段抗体检测蛋白芯片质控参比品。中国药品生物制品检定所的80份HCV参比品检定结果表明,混合抗体阳性检出率为39／40,阴性符合率为40／40,总符合率为98．7％;核心抗体阳性检出率为27／40,阴性符合率为40／40;NS3抗体阳性检出率为26／40,阴性符合率为39／40;NS4抗体阳性检出率为19／40,阴性符合率为40／40;NS5抗体阳性检出率2／40,阴性符合率为40／40。490例临床标本的检测结果表明,对于194例HCV阳性标本,蛋白质芯片混合抗体与ELISA的符合率达99．5％,分片段抗体符合率达97．4％,两种方法检测结果不符的标本经RIBA试剂确认,蛋白质芯片与RIBA试剂的符合率高度一致。对于296例各种HCV抗体阴性标本,蛋白质芯片检测结果全部为阴性。以上结果表明,制备的丙型肝炎病毒分片段抗体检测蛋白质芯片质控参比品可用于芯片生产的质量控制,经质控合格的芯片符合国家标准的要求,可用于临床检测。     

A族链球菌核酸检测试剂国家参考品的研制

目的研制A族链球菌核酸检测试剂国家参考品。方法将10株A族链球菌株和10株非A族链球菌参考菌株分别在各自适宜的培养基和温度下培养,收获新鲜培养物进行计数、灭活、稀释和分装,并对参考品进行均匀性和稳定性评估。采用A族链球菌核酸检测试剂对阳性参考品符合率、阴性参考品符合率、重复性和最低检出限进行了适用性验证,并组织4家实验室开展了协作标定。结果建立了由10个阳性参考品、10个阴性参考品、最低检出限参考品和重复性参考品组成的A族链球菌核酸检测试剂评价用国家参考品。经评估该参考品具有良好的均匀性及稳定性,协作标定结果显示阳性参考品符合率、阴性参考品符合率、重复性参考品均符合要求,最低检出限参考品菌液浓度两家实验室标定为1×10~4个/mL,两家实验室标定为1×10~3个/mL。结论研制的参考品可以用于A族链球菌核酸检测试剂的质量评价。     

Comparison of Real-time PCR to ELISA for the detection of human cytomegalovirus infection in renal transplant patients in the Sudan

Background

This study was carried out to detect human cytomegalovirus (HCMV) IgG and IgM antibodies using an Enzyme-linked immunosorbent assay (ELISA) in renal transplant patients in Khartoum state, Sudan and to improve the diagnosis of HCMV through the introduction of Real-time Polymerase Chain Reaction (PCR) testing. A total of 98 plasma samples were collected randomly from renal transplant patients at Ibin Sina Hospital and Salma Centre for Transplantation and Haemodialysis during the period from August to September 2006.

Results

Among the 98 renal transplant patients, 65 were males and 33 females. The results revealed that HCMV IgG was present in all patients' plasma 98/98 (100%), while only 6/98 (6.1%) had IgM antibodies in their plasma. HCMV DNA viral loads were detected in 32 patients 32/98 (32.7%) using Real-time PCR.

Conclusions

The HCMV IgG results indicate a high prevalence of past HCMV infection in all tested groups, while the finding of IgM may reflect a recent infection or reactivation. HCMV detection by real-time PCR in the present study indicated a high prevalence among renal transplant patients in Khartoum. In conclusion, the prevalence of HCMV in Khartoum State was documented through detection of HCMV-specific antibodies. Further study using various diagnostic methods should be considered to determine the prevalence of HCMV disease at the national level.

     

Novel evolved immunoglobulin (Ig)-binding molecules enhance the detection of IgM against hepatitis C virus

Detection of specific antibodies against hepatitis C virus (HCV) is the most widely available test for viral diagnosis and monitoring of HCV infections. However, narrowing the serologic window of anti-HCV detection by enhancing anti-HCV IgM detection has remained to be a problem. Herein, we used LD5, a novel evolved immunoglobulin-binding molecule (NEIBM) with a high affinity for IgM, to develop a new anti-HCV enzyme-linked immunosorbent assay (ELISA) using horseradish peroxidase-labeled LD5 (HRP-LD5) as the conjugated enzyme complex. The HRP-LD5 assay showed detection efficacy that is comparable with two kinds of domestic diagnostic kits and the Abbott 3.0 kit when tested against the national reference panel. Moreover, the HRP-LD5 assay showed a higher detection rate (55.9%, 95% confidence intervals (95% CI) 0.489, 0.629) than that of a domestic diagnostic ELISA kit (Chang Zheng) (53.3%, 95% CI 0.463, 0.603) in 195 hemodialysis patient serum samples. Five serum samples that were positive using the HRP-LD5 assay and negative with the conventional anti-HCV diagnostic ELISA kits were all positive for HCV RNA, and 4 of them had detectable antibodies when tested with the established anti-HCV IgM assay. An IgM confirmation study revealed the IgM reaction nature of these five serum samples. These results demonstrate that HRP-LD5 improved anti-HCV detection by enhancing the detection of anti-HCV IgM, which may have potential value for the early diagnosis and screening of hepatitis C and other infectious diseases.     

Comparative evaluation of three recombinant antigen-based enzyme immunoassays for detection of IgM and IgG antibodies to human parvovirus B19

Background: Diagnosis of acute and past infection with parvovirus B19 is based on detection of IgM and IgG antibodies.Objectives: To evaluate two commercial recombinant antigen-based enzyme immunoassay (EIA) test kits for detection of IgM and IgG antibodies to parvovirus B19 and to compare the commercial EIAs to in-house EIA test procedures.Study design: A panel of 121 sera was used to compare the three IgM EIAs. The panel included 84 sera submitted for parvovirus B19 testing and 37 sera that were IgM positive for other viral pathogens. The same serum panel plus an additional 14 sera submitted for B19 testing was used to compare the three IgG EIAs. The commercial EIAs were performed according to manufacturers' instructions. Using the in-house EIA test procedures as the reference, sensitivity and specificity for each of the commercial EIAs was determined.Results: The commercial B19 IgM EIAs showed agreements of 95.0 and 93.4% to the in-house IgM EIA. Compared to the in-house B19 IgM EIA, the commercial B19 IgM EIAs, were 97.4 and 97.5% sensitive, respectively. Specificities were 93.5 and 91.4%, respectively. Sensitivities for the commercial IgG EIAs, compared to in-house IgG EIA, were 88.0 and 85.2%, respectively, and specificities were 94.1 and 98.0%.Conclusion: We found that the commercial parvovirus B19 IgM and IgG EIAs are comparable to standard in-house EIAs and are suitable for testing for B19 antibodies in human sera.     

Comparison of diagnostic performances of ten different immunoassays detecting anti-CCHFV IgM and IgG antibodies from acute to subsided phases of Crimean-Congo hemorrhagic fever

Crimean-Congo Hemorrhagic Fever Virus (CCHFV) is a geographically widespread tick-borne arbovirus that has been recognized by the WHO as an emerging pathogen needing urgent attention to ensure preparedness for potential outbreaks. Therefore, availability of accurate diagnostic tools for identification of acute cases is necessary.A panel comprising 121 sequential serum samples collected during acute, convalescent and subsided phase of PCR-proven CCHFV infection from 16 Kosovar patients was used to assess sensitivity. Serum samples from 60 healthy Kosovar blood donors were used to assess specificity. All samples were tested with two IgM/IgG immunofluorescence assays (IFA) from BNITM, the CCHFV Mosaic 2 IgG and IgM indirect immunofluorescence tests (IIFT) from EUROIMMUN, two BlackBox ELISAs for the detection of CCHFV-specific IgM and IgG antibodies (BNITM), two Anti-CCHFV ELISAs IgM and IgG from EUROIMMUN using recombinant structural proteins of CCHFV antigens, and two ELISAs from Vector-Best (IgM: μ-capture ELISA, IgG: indirect ELISA using immobilized CCHFV antigen). Diagnostic performances were compared between methods using sensitivity, specificity, concordance and degree of agreement with particular focus on the phase of the infection.In early and convalescent phases of infection, the sensitivities for detecting specific IgG antibodies differed for the ELISA test. The BlackBox IgG ELISA yielded the highest, followed by the EUROIMMUN IgG ELISA and finally the VectorBest IgG ELISA with the lowest sensitivities. In the subsided phase, the VectorBest IgM ELISA detected a high rate of samples that were positive for anti-CCHFV IgM antibodies. Both test systems based on immunofluorescence showed an identical sensitivity for detection of anti-CCHFV IgM antibodies in acute and convalescent phases of infection.Available serological test systems detect anti-CCHFV IgM and IgG antibodies accurately, but their diagnostic performances vary with respect to the phase of the infection.     

Establishment of a reference panel for the detection of anti-SARS-CoV antibodies.

The immunological assays for detection of antibodies against SARS-CoV were developed in-house and some of them are available commercially. However, the antigens used in these assays differed. In order to validate the reliability of these assays, the standard panel should be established. In this study, we have expressed and purified severe acute respiratory syndrome (SARS) structural proteins and their fragments and developed indirect enzyme-linked immunosorbent assays (ELISAs) that detect antibodies against the SARS N, N(1), N(2), S(1), S(C), S(2), and M proteins as well as the human coronavirus OC43 and 229E N proteins. These assays were used to screen 58 samples from SARS convalescent patients, 40 serial serum specimens from patients at different phases of SARS infection, and 88 plasma specimens from normal blood donors. The samples from normal blood donors were also tested for antibodies against other respiratory virus. The representative samples were chosen to comprise a reference panel of SARS antibodies that may be used for the detection of SARS. The panel is composed of 25 positive samples, 25 negative samples, 7 diluted samples for anti-N antibody, 6 diluted samples for anti-S antibody, and one sample for validating precision. Comparison of detection results with different SARS antibody assays indicated that our panel should differentiate the specificity and sensitivity of different assays.     

Immunodiagnosis of Dengue Virus Infection Using Saliva

Keeping in view the complications and the case fatality associated with dengue virus, several serologic tests have been developed. However, the major drawback of these serologic tests is the need for a venous blood sample obtained by invasive venipuncture. As a noninvasive alternative, saliva provides a body fluid that contains antibodies of diagnostic importance. Hence, the detection of DEN-specific IgM and IgG antibodies in serum and saliva from 80 patients was compared. Salivary IgM antibodies were detected in 100% of the serum IgM-positive samples and in 30% of the serum samples that were negative for IgM antibodies. Salivary IgG antibodies were detected in 93.3% of the serum samples that were positive for anti-dengue IgG antibodies and in none of the serum IgG-negative cases. None of the specimens from the healthy controls showed the presence of IgM or IgG antibodies. The detection of both IgG and IgM antibodies in saliva correlated well with the serum IgG and IgM detection by the ELISA test (r = 0.6322 and r = 0.4227). Detection of salivary IgM antibodies by ELISA showed 100% sensitivity, 70% specificity, 90.9% positive predictive value, and 100% negative predictive value. The detection of IgG in saliva proved to be a promising tool as the sensitivity, specificity, positive predictive value, and negative predictive value were found out to be 93.3%, 100%, 100%, and 83.3%, respectively. Thus, from this study we conclude that the detection of DEN-specific salivary IgG and IgM antibodies are useful markers for dengue infection.     

献血员巨细胞病毒感染的研究

用ＰＣＲ法和ＤＮＡ杂交法检测同一献血员的白细胞及血清中的ＨＣＭＶ－ＤＮＡ,并用ＥＬＩＳＡ法检测血清中的ＨＣＭＶ－ＩｇＭ、ＩｇＧ（测四个不度）,连续两年共检测白细胞和血清样本各２００人份。ＰＣＲ法检测白细胞中的ＨＣＭＶ－ＤＮＡ阳性率分别为６３％和７０％,ＤＮＡ杂交法检测的阳性率为４２％和５０％。ＰＣＲ法检测血清中的ＨＣＭＶ－ＤＮＡ的阳性率为４９％和５３％,ＤＮＡ杂交法检测的阳性率为３３％和３９％。Ｈ     

Epitope analysis of antibodies in Japanese to human cytomegalovirus phosphoprotein 150 with synthetic peptides

Serological detection of antibodies specific to human cytomegalovirus (HCMV) is not reliable because the assay uses the whole HCMV protein fraction. Antigenic materials composed of well-characterized viral proteins are being tried for serodiagnosis in Europe. Epitopes of antibodies to HCMV phosphoprotein 150 (pp150) encoded by UL32 in Japanese individuals were investigated for comparison with the results in Europe. The major epitopes on amino acid residues 496 to 652 of HCMV pp150 were identified and the detection of antibodies with an enzyme-linked immunosorbent assay (ELISA) of synthetic peptides against the main epitopes was established. Fifteen seropositive and five seronegative serum samples for the epitope mapping and 131 seropositive and 50 seronegative samples for ELISA were investigated. Overlapping 15-mer peptides moving by two amino acids through V496-H652 were synthesized. The main epitope regions were V508-D530, L526-Q544, S536-D554, T616-G634, S624-P642, and L632-H652. When each peptide was conjugated with bovine serum albumin for ELISA, 80.9% of the seropositive samples were judged to be positive. The results of this study are the same as those for European sera, so the antigenic materials developed in Europe might be used to replace the whole HCMV protein fraction in Japanese.     

重组人巨细胞病毒(HCMV)优势表位嵌合抗原的构建表达以及捕获法检测IgM抗体

勘误：重组人巨细胞病毒(HCMV)优势表位嵌合抗原的构建表达以及捕获法检测 IgM 抗体