探讨酶联免疫吸附试验检测乙肝核心抗体假阴性的问题

目的:了解用酶联免疫吸附试验(ELISA)检测乙肝二对半核心抗体(抗-HBc)的假阴性。方法:留取用ELISA检测HBsAg阳性、HBeAg阳性、抗-HBc阴性血清标本201份,分别用美国雅培AXSYM免疫发光仪微粒子酶免疫技术(MEIA)定量检测抗HBc、ELISA进行原倍和生理盐水15倍稀释测定。结果:MEIA法定量检测抗-HBc阳性166份,阳性检出率为82. 6%;阴性(S/Co>1 0)35份,与ELISA一步法相比阴性符合率为19 .9%,生理盐水15倍稀释阳性33份,阳性检出率为19 4%,原倍血清100% 阳性。结论:MEIA法定量检测的阳性率远远高于ELISA法检测, 15倍稀释测定结果阳性率比30倍稀释有所提高,原倍血清仅作为流行病学调查结果。     

酶联免疫吸附法和微粒子酶免疫分析法检测HBsAb的比较

目的:用酶联免疫吸附法(ELISA)和微粒子酶免疫分析法(MEIA)检测接种乙肝疫苗后儿童的HBsAb,并对结果进行比较。方法:用美国雅培AXSYM免疫发光仪(MEIA法)定量测定HBsAb,ELISA法定性测定HBsAb。结果:在232份标本中,MEIA法检出HBsAb阳性185份,阳性率79.74%;ELISA法检出阳性165份,阳性率71.12%。MEIA法与ELISA法相比阳性符合率为91.38%。两种方法阳性率经χ2检验,存在显著性差异(χ2=18.5,P<0.01),且MEIA法测定HBsAb浓度13.9 IU/L时,ELISA法为阴性。结论:MEIA法定量检测HBsAb的阳性率高于ELISA法,且MEIA法具有灵敏度高、特异性强、重复性好等优点,可作为乙肝疫苗接种后判断免疫效果的良好方法,还可根据HBsAb浓度的变化确定需要再次免疫的时间。     

定量与半定量酶联免疫吸附试验在麻疹IgG抗体检测中的比较

[目的]通过对麻疹病毒IgG抗体定量酶联免疫吸附试验(ELISA)与传统半定量酶联免疫吸附试验(ELISA)进行比较,评价传统半定量ELISA法的实用价值.[方法]随机抽取2008年的180份云南省保山市两所边远小学小学生血清,用德国维润公司定量ELISA试剂盒测定麻疹IgG抗体.这180血清已经用半定量方法将抗体滴度测出,之后将两种方法测定的结果进行比较.[结果]定性结果分析发现,180份血清标本中,8份阴性,3份可疑,162份阳性,与传统半定量ELISA方法的一致率为96.05%,统计分析两实验结果差异无统计学意义(P>0.05),Kappa检验得两法存在高度一致性(Kappa值=0.677,P<0.001).同时得出传统半定量法的灵敏度为95.86%,特异度为100%,阴性似然比为0.04,正确指数为95.86%,阳性预测值为98.18%,阴性预测值为53.33%.定量测定方面,随着抗体滴度的增高,该组血清抗体国际单位(IU)也随之上升,抗体滴度分组与抗体IU明显的正相关,相关系数(rs)为0.41,P<0.001.[结论]通过本次定量与半定量EHSA法在麻疹IgG抗体检测中的比较发现,半定量法的定性、定量结果一定程度上已经能够较好反映人群麻疹抗体水平,对麻疹的监测仍具有重要的实用意义.     

间接免疫荧光法和酶联免疫吸附法检测抗双链DNA抗体的比较

目的比较间接荧光法（IIF）和酶联免疫吸附法（ELISA）两种方法学在检测抗双链DNA（ds-DNA）抗体的异同。方法分别采用IIF和ELISA对系统性红斑狼疮（SLE）患者89例、非SLE自身免疫患者66例及30例健康体检者的血清抗ds-DNA抗体进行检测,并以临床诊断为金标准评价两种方法学的性能。同时采用IIFA法和ELISA法检测SLE患者的抗核抗体（ANA）。结果 89例SLE患者抗ds-DNA抗体的阳性率IIF和ELISA分别为60.7%和75%,在SLE稳定期较活动期差异尤为显著,存在多例IIF检测抗ds-DNA抗体阴性而ELISA结果阳性的样本（9/41）;在系统性红斑狼疮SLE活动期定量检测抗ds-DNA抗体的浓度范围主要集中于〉380 IU/ml,而SLE稳定期的浓度为121~225 IU/ml之间;非SLE疾病组的抗ds-DNA抗体浓度为104~241 IU/ml。结论两种方法检测抗ds-DNA抗体定性结果差异有统计学意义,溯源定量检测抗ds-DNA可辅助监测SLE患者抗体水平,掌握病情变化。     

国产HAVAB-E在甲肝疫苗抗体检测中的应用效果

目的评估国产HAVAB-E诊断试剂盒在甲肝减毒活疫苗抗体检测中的应用效果.方法用Abbott实验室的HAVAB-IMx以及中国医学科学院医学生物学研究所(昆明)和浙江省医学科学院普康生物技术公司生产的HAVAB-E 3种试剂对184份疫苗接种者的12周血进行检测对比试验.IMx试剂经用WHO甲肝免疫球蛋白标准品标化后定量检测标本的mIU/ml.结果总体GMT为27.2mIU/ml,其中167份(90.8%)抗体水平＞10mIU/ml.此结果较接近疫苗的保护效果.国产试剂的阳性率分别为95.1%(175/184,昆明-E)和90.2%(166/184,浙江-E),两试剂结果一致率为92.9%.国产试剂阳性率随抗体水平升高呈增加趋势,当滴度＞20mIU/ml时,与IMx的符合率分别为98.1%(105/107,昆明-E)和94.4%(101/107,浙江-E).结论两种国产酶免诊断试剂的定性检测结果真实可靠,在甲肝减毒活疫苗抗体检测中能客观反映疫苗的免疫原性和保护效果,是值得推广使用的诊断试剂.     

酶联免疫吸附试验与中和抗体试验检测麻疹抗体比较研究

目的探讨酶联免疫吸附试验(ELISA)和中和抗体试验(NT)在麻疹抗体检测中的应用价值。方法以NT为"金标准",同时用德国Virion/Serion的定量ELISA试剂盒检测364份麻疹抗体滴度,将两种方法测定的结果进行比较。结果 NT的阳性率为57.69%,几何平均滴度(GMT)为1∶5.48,ELISA的阳性率为42.86%,平均抗体活性值为48.57IU/L。定性结果发现,ELISA特异度为99.35%,其敏感度即阳性符合率为73.81%,且阳性符合率随着滴度增加呈现增高的趋势(z=-5.99,P<0.001)。Fisher精确概率法发现,滴度1∶2组、滴度1∶4组与其他各组阳性符合率差异均有统计学意义(P<0.05),滴度1∶8组与滴度≥1∶64组阳性符合率差异有统计学意义(P<0.05),其余各组间阳性符合率差异均无统计学意义(P>0.05)。定量结果发现,ELISA抗体活性值与NT滴度呈明显正相关,相关系数r=0.884,P<0.001。结论德国Virion/Serion的定量ELISA试剂盒在检测低滴度麻疹抗体时易出现假阴性,检测高滴度麻疹抗体时,两种方法敏感性接近;滴度临界值为1∶8～1∶16。该试剂可推荐用于健康人群麻疹抗体水平监测。     

酶联免疫法与时间分辨荧光免疫法检测HBsAg

目的比较两种方法4种试剂对乙型肝炎病毒(HBV)表面抗原(HBsAg)的检测性能,并探讨HBsAg阳性模式组间及其与HBsAg阴性模式组间的HBsAg浓度差异。方法酶联免疫法(ELISA)定性检测1205例标本。其中153例标本再用3个厂家的时间分辨荧光免疫法(TrFIA)定量测试试剂进行HBsAg比对检测,其余的1052例标本均再用TrFIA法进行HBsAg定量检测,再对1205例标本HBsAg定量结果按抗原抗体模式分组统计分析。结果两种方法4种试剂间HBsAg阳性检出率均无统计学差异(p>0.05),3个厂家的TrFIA法试剂HBsAg定量检测结果相关性良好,r>0.95。TrFIA法能对0.2～1.0ng/ml的低浓度HB-sAg标本进行有效检测。研究发现TrFIA法定量检测未经稀释的HBV感染者血标本HBsAg浓度在0.2～650.0ng/ml间。研究中HBsAg阳性模式中除"HBsAg、抗-HBc"阳性模式组与"HBsAg、e抗体(抗-HBe)、抗-HBc"阳性模式的HBsAg浓度差异无统计学意义(p>0.05)外,其它HBsAg阳性模式间HBsAg浓度差异均有统计学意义(p<0.05),HBsAg阳性模式与HBsAg阴性模式间HBsAg浓度差异均有统计学意义(p<0.05)。结论HBeAg或抗-HBe的出现与HBsAg的浓度呈一定的关系,HBsAg浓度与病毒的复制存在一定的关系。ELISA法HBVM定性检测结合TrFIA法HBsAg定量检测对HBV感染诊断和防治具有重要意义。     

孩尔来福甲型肝炎灭活疫苗免疫儿童后近期抗体动态观察

为观察孩尔来福 (Healive)甲型肝炎 (甲肝 )灭活疫苗免疫儿童后的抗体水平及下降规律 ,探讨甲肝灭活疫苗诱导的抗体所提供的持续保护时间 ,对曾接种 5 0 0U/剂 (0、3个月和 0、6个月免疫程序 )Healive甲肝灭活疫苗的113名儿童 ,用酶联免疫吸附试验 (ELISA)分别检测免疫后 12、2 4、36个月的血清抗甲肝病毒抗体。结果显示 :至第 36个月检测时 ,10 0 %的儿童甲肝抗体保持阳性 ;0、3个月程序组 74 1% ,0、6个月程序组 85 4 %的儿童甲肝抗体滴度≥ 2 0 0mIU/ml。     

MEIA法测定HBV血清标志物的临床应用意义

目的通过与酶联免疫吸附试验(ELISA)的比较,了解微粒子酶免疫分析法(MEIA)对乙型肝炎病毒(HBV)血清标志物的检测性能。方法分别用MEIA法和ELISA法对HBV感染者的血清标志物(HBsAg、HBeAg、抗HBc和抗HBe)进行检测。结果1140例患者血清HBV标志物检测,MEIA法阳性率为:HBsAg94.00%,HBeAg46.75%,抗HBc97.96%,抗HBe61.41%;ELISA法阳性率为:HBsAg91.89%,HBeAg36.14%,抗HBc93.26%,抗HBe18.11%;MEIA法阳性率高于ELISA法,其中对HBeAg和抗HBe的检测,两种方法差异有高度显著性(P<0.01)。与MEIA法比较,ELISA法检测HBsAg的相对灵敏度达97.46%,抗HBc为94.93%,HBeAg为73.41%,抗HBe最低,为41.73%。对一些低滴度的HBeAg/抗HBe的HBV感染者,ELISA法检测可出现假阴性。结论对于血清HBV标志物的检测,MEIA法和ELISA法均有较高的特异性,但MEIA法敏感性优于ELISA法。     

两种方法检测慢性乙型肝炎患者E抗原/E抗体双阳性的情况分析

目的 分析化学发光微粒子免疫分析（CMIA）法与酶联免疫吸附试验（ELISA）法检测慢性乙型肝炎（CHB）患者E抗原（HBeAg）/E抗体（Anti-HBe）双阳性情况。方法 回顾性分析2017年7月至2021年6月诊断为CHB患者的资料，经CMIA、ELISA法检测为HBeAg/Anti-HBe双阳性分别为350、84例。比较CMIA法检测的350例样本中Anti-HBs在10～100 mIU/ml水平下的HBeAg、Anti-HBe水平，H B V-D N A在2～8水平下的HBeAg、Anti-HBe水平差异，并分析两种方法检测HBV-M双阳性的情况。结果 不同Anti-HBs水平下的HBe Ag、Anti-HBe水平比较，差异有统计学意义（P<0.05）;Anti-HBs>100 mIU/ml的HBe Ag、Anti-HBe高于Anti-HBs 10～100 mIU/ml和Anti-HBs <10 mIU/ml，差异有统计学意义（P<0.05）;Anti-HBs<10 mIU/ml与Anti-HBs 10～100 mIU/ml水平下的HBe Ag、...     

甲型肝炎病毒TZ84株单克隆抗体在甲型肝炎抗体检测中的应用

将不同位点的甲型肝炎 (甲肝 )病毒 (HAV)TZ84单克隆抗体 (单抗 )或酶标单抗进行混合做包被和酶 ,代替现有试剂中的多克隆抗体 (多抗 ) ,采用竞争抑制法对试剂的灵敏度和可靠性进行测定 ,并通过 2 2 9份甲肝灭活疫苗临床观察血清甲肝病毒抗体的检测 ,对单抗试剂的应用进行研究 ,并对该单抗试剂进行评价。结果表明 :该单抗试剂的灵敏度为 94 % ,特异度均为 98% ,最低检出浓度的变异系数为 9 3% ;单抗试剂、多抗试剂和雅培试剂的最低检出浓度分别为 5 5、98、31mIU/ml。单抗试剂的灵敏度高于多抗试剂 ,特异度低于多抗试剂。     

Comparison of long-term (10 years) immunogenicity of two- and three-dose regimens of a combined hepatitis A and B vaccine in adolescents

300 adolescents aged 12–15 years were randomised (1:1) into two groups to compare the long-term (10 years) immunogenicity profile of two doses of an Adult formulation [Group HAB_2D: 150; 0–6 months] vs. three doses of a Paediatric formulation [Group HAB_3D: 150; 0–1–6 months] of a combined hepatitis A and B (HAB) vaccine. At Year 10, anti-HAV seropositivity rate was 100% in both groups, while 85.9% and 85.1% subjects in the HAB_2D and HAB_3D groups, respectively, had anti-HBs antibody concentrations ≥10 mIU/mL. The anti-HAV antibody GMCs (HAB_2D: 429.3 mIU/mL; HAB_3D: 335.5 mIU/mL) and anti-HBs antibody GMCs (HAB_2D: 50.6 mIU/mL; HAB_3D: 60.1 mIU/mL) were similar in both groups. No vaccine-related serious adverse events were reported. Hence, with respect to long-term antibody persistence, the two-dose schedule of the combined HAB vaccine Adult formulation is an effective alternative to the conventional three-dose schedule of the Paediatric formulation in adolescents.     

Detection of antibodies against hepatitis A in blood spots dried on filter paper. Is this a reliable method for epidemiological studies?

Diluted dried blood drops on filter paper were compared with serum samples as a specimen source for qualitative anti-HAV antibody determination by ELISA. A total of 298 serum samples and dried blood drops were collected from a population of healthy adolescents (15.3 +/- 1.2 years old). The prevalence of anti-HAV antibody obtained by testing serum samples was 7.7% (95% CI:4.8 10.1). Compared with serum sampling the sensitivity and specificity of diluted dried blood drops were 91.3 and 99.3%. The positive and negative predictive values were 91.3 and 99.3%, respectively, and the likelihood ratios of positive and negative results were 91 and 0.09. It is proposed that this test represents a reliable procedure for anti-HAV antibody testing.     

Long-term clinical observation of the immunogenicity of inactivated hepatitis A vaccine in children

110 children who were given the complete course of the inactivated hepatitis A vaccine (Havrix™) were followed up 10 years later. Age-matched healthy children who were not inoculated served as controls. One month after two primary injections, all children were positive for serum antibody. After 10 years, 99.09% of inoculated children remained positive for serum anti-HAV antibody, with a geometric mean concentration (GMC) of 61.59 mIU/mL. GMC values following a secondary immunization in children with antibody levels <20 mIU/mL were significantly elevated (567.9 mIU/mL), compared with the primary injection alone. Havrix™ appears to induce persistent immunity and potent immune memory.     

Long-term (5-year) antibody persistence following two- and three-dose regimens of a combined hepatitis A and B vaccine in children aged 1–11 years

This study compared the long-term persistence of anti-hepatitis A (anti-HAV) and B (anti-HBs) antibodies, 5 years after vaccination of subjects aged 1–11 years with a combined hepatitis A and B vaccine either in a two-dose (0, 6 months, Adult formulation) or a three-dose (0, 1, 6 months, Paediatric formulation) schedule. At the end of the 5 years, all subjects (100%) in both groups continued to have anti-HAV antibodies ≥15 mIU/mL, while 94–97% of subjects in both groups had anti-HBs antibody concentrations ≥10 mIU/mL. Subjects with anti-HBs antibody concentration ≤10 mIU/mL were administered a challenge dose of hepatitis B vaccine. All subjects mounted a vigorous immune response to the challenge indicating the presence of immunological memory to HBV.     

Immunogenicity of an inactivated hepatitis A pediatric vaccine: three-year post-booster follow-up

The persistence of anti-hepatitis A virus antibody concentrations was followed over 3 years in 177 healthy children following primary and booster vaccination with an inactivated hepatitis A vaccine, Avaxim 80 pediatric. Seroconversion rates (post-immunization anti-HAV antibody concentration >or=20 mIU/mL) and geometric mean concentrations (GMC) were estimated for each of three age groups: 18 month--3 years, 4--8 years, and 9--15 years. Only subjects who were initially HAV-seronegative at inclusion (<20 mIU/mL) were analyzed. Follow-up visits at years 1, 2, and 3 involved 177, 149, and 135 children, respectively. A decline in GMCs of about 74% occurred during the first year, from 3,060 to 814 mIU/mL overall, but did not continue during years 2 and 3. All subjects remained seropositive (antibody concentration >or=20 mIU/mL), with overall GMCs of 814, 891, and 924 mIU/mL in years 1--3, respectively. The inactivated hepatitis A study-vaccine resulted in sustained seroprotective antibody concentrations in 100% of these children, without a significant decline in antibiotic concentrations over the 3 years following booster injection, thus demonstrating the long-term protection expected with this vaccine.     

Immunogenicity of the hepatitis A vaccine 20 years after infant immunization

To determine the duration of immunity provided by the Hepatitis A vaccination (HepA), we evaluated a cohort of participants in Alaska 20 years after being immunized as infants. At recruitment, participants received two doses of inactivated HepA vaccine on one of three schedules. We conducted hepatitis A antibody (anti-HAV) testing for participants at the 20-year time-point. Seventy-five of the original 183 participants (41%) were available for follow-up. The overall anti-HAV geometric mean concentration was 29.9 mIU/mL (95% CI 22.4 mIU/mL, 39.7 mIU/mL) and 50 participants (68%) remained seropositive (titer ≥ 20 mIU/mL). Using a fractional polynomial model, the predicted percent seropositive at 25 years was 55.3%, 49.8% at 30 years and 45.7% at 35 years, suggesting that the percent sero-positive could drop below 50% earlier than previously expected. Further research is necessary to understand if protection continues after seropositivity diminishes or if a HepA booster dose may become necessary.