IFA、ELISA及RPHI三种方法检测流行性出血热抗体的结果分析

本文用免疫荧光测定(IFA)、酶联免疫吸附测定(ELISA)及反向血凝抑制试验(RPHI)三种方法对89份流行性出血热(EHF)患者恢复期血清进行抗体检测,发现 IFA 和 ELISA 两法阳性检出率较高,两法测定结果无显著性差异,由于 ELISA 方法简单,操作方便,基层卫生防     

酶标葡萄球菌A蛋白组化法用于肾综合征出血热诊断的研究

本文报告应用HRP-SPA组化法检测用4株不同来源的HFRS病毒抗原免疫的家兔血清和10例HFRS病人双份血清的抗体滴度，结果与IFA法基本一致，证明了HRP-SPA组化法的特异性。用HRP-SPA组化法和IFA法检测了不同疫区30例病人的恢复期血清，来源于黑线姬鼠和褐家鼠的Vero-E6细胞HFRS病毒抗原和7只HFRS抗原阳性黑线姬鼠肺洗液中的抗体，两法结果相同，证明了HRP-SPA组化法与IFA法一样，具有较高的灵敏性。此外，HRP-抗人IgG组化法用于HFRS的诊断也是可行的。     

应用Guthrie卡改良IFA检测弓形虫抗体IgG

目的 为获取诊断先天性弓形虫病有效，廉价的实验方法，我们应用Guthrie卡改良了常规IFA法检测弓形虫抗体IgG。方法 分别观察了干血滴与新鲜血滴，干血滴与新鲜血清的检测效果。结果 各组之间无显著性差异。结论 提示改良IFA的敏感性与常规IFA无并差别。     

IFA法和ELISA法对感染后血清汉坦病毒血清型的研究

本文用IFA法、间接ELISA法和复合捕捉阻断ELISA法(CTB ELISA)对11 例接触实验鼠后感染汉坦病毒者和16例接触野生啮齿类动物感染者进行了血清分型,并对这3种方法进行了比较。参考血清有鼠特异性Ⅰ、Ⅱ型血清和兔特异性Ⅲ、Ⅳ型血清。 IFA法检测表明,11例接触实验鼠后感染的病人血清与汉坦病毒Ⅰ型、Ⅱ型均呈高度反应性,Ⅰ、Ⅱ型抗体滴度相同,而16例接触啮齿类动物感染者的血清,则与Hallnas(Ⅲ型)病毒呈高度反应性,Ⅲ型抗体普遍高于其它型抗体。但在间接ELISA法中,其中2份血清与Ⅰ、Ⅱ型病毒的反应性高于Ⅲ型。为了进一步证实人抗血清与不同     

Q热立克次体微量凝集试验

本文应用Q热立克次体微量凝集试验检查新疆地区216份热性病人、有肝炎症状和体征患者,以及其它疾患病人的血清标本其阳性率为9.7%,并对其中35份临床诊断为肺炎、伤寒、发热待诊及肝炎患者血清标本用MA、CF及IFA平行检查,结果表明MA抗体滴度与CF、IFA抗体滴度之间有非常显著的相关。对9份Q热病人血清标本以2ME处理后,用MA试验检测IgM凝集素,其中至少有6份滴度下降4倍以上,最显著者≥32倍,与间接免疫荧光试验检测其抗体的结果相一致。     

在抗-HAV IgM酶联免疫试验中代用抗-HAV阴性的恒河猴血清的研究

国内外一些学者报告,在应用酶联免疫试验(EIA)检测抗-HAV Ig M时,为了减少非特异性反应,在抗-HAV Ig G酶结合物的稀释液中,加入1～10%抗-HAV阴性的正常人血清。我国甲肝呈地方性流行,抗-HAV阴性的正常人血清不易获得。为此,我们用抗-HAV阴性的恒河猴血清代替,并与常规法比较,共检测100份急性甲肝患者血清,100份正常人血清以及84份各型急性肝炎血清,两法结果完全一致。与美国Abbott HAV AB-M EIA药盒比较,共检测149份各类肝炎病人和健康献血员血清抗-HAV Ig M,     

金标免疫层析法检测恙虫病抗体的效果测评

目的对新开发的恙虫病金标试剂做特异性和敏感性的效果测评。方法采用微量间接免疫荧光试验（IFA）检测发热患者血清的恙虫病IgG抗体,然后选取阴性及强阳性血清共242份,用3种金标免疫层析试剂条检测恙虫病东方体IgM、IgG和总抗体。在对照成立的情况下,观察检测线的反应情况,以出现红色条带判为阳性,再用统计学方法进行分析。结果金标免疫层析法检测恙虫病IgM、IgG和总抗体的敏感性分别为62.25%、30.12%和93.98%,特异性分别为98.11%、98.74%和96.23%,与IFA比较的统计学结果分别为P〈0.05、P〈0.05和P〉0.05。结论 IgG和IgM抗体试剂条的检测结果与IFA检测结果差异有统计学意义;总抗体试剂条的检测结果与IFA检测结果差异无统计学意义,可替代IFA检测恙虫病抗体。     

间接免疫荧光试验在HIV抗体检测中的应用

目的：评价间接免疫荧光试验（IFA）作为一种确认实验在HIV抗体检测中的应用。方法：用T嗜性的HIV毒株感染MT4细胞制备抗原片,并与不同稀释度的免疫血清相结合,再滴加荧光素标记的羊抗人IgG,在荧光显微镜下检测特异性免疫荧光,结果：用IFA检测43分血清样本（其中包括17份WB阳性血清,14份阴性血清和12份ELISA阳性或WB出现可疑条带但按标准不能判为阳性的可疑血清）,除HIV－2血清呈阴性反应外,其余检测结果与WB相符,IFA对HIV－1抗体检测的敏感性和特异性均达到100％,HIV－1阳性血清抗体最高滴度达到1：10240。结论：IFA可用于HIV－1抗体检测的确认,它可作为Western Blot的一种补充或替代实验。     

应用抗白蛋白单价免疫血清作对流免疫电泳鉴定蚊胃血血源

以抗白蛋白单价免疫血清作对流免疫电泳试用于蚊胃血血源的鉴定,以抗全血清免疫血清作对照。抗原为1:500~1:4000,检出全数抗原标本所需最低抗血清的浓度前者为1:64,后者为l:2~1:4。抗血清为≤ 1:4,检出最低的抗原浓度前者为1:8000,后者为1:1000~1:4000。以1:16和1:32稀释度抗白蛋白血清作对流免疫电泳,鉴定276份离体吸羊血及1,145和1,329份现场采集的中华按蚊胃血标本,以1:16抗全血清免疫血清作环状沉淀试验同时对比。结果两种方法的阳性检出率离体吸羊血标本均为100%,现场标本分别为46%及91%。两法检测的结果相一致。证明以抗白蛋白单价免疫血清作对流免疫电泳是鉴定蚊胃血血源的又一有效方法。     

血清处理方法与保存条件对凝集素抗体效价的影响

血清学试验是血清流行病学调查的重要手段。血清标本的运送与保存,直接影响试验结果的可靠性。为探讨在基层收集大批血清标本时的运送保存条件,我们于1983年5～11月对抗血清标本的处理方法与保存条件进行了实验观察,现将结果报告如下。材料和方法一、血清标本的来源及处理方法用肠道革兰氏阴性杆菌,免疫家兔制备抗血清,用正常兔血清稀释成不同效价血清标     

应用VIDAS免疫分析系统检测血清抗伯氏包柔螺旋体抗体

莱姆病（Ｌｙｍｅｄｉｓｅａｓｅ）是最近十年来才被认识的一种蜱媒传染流行病，Ｌｙｍｅ病的血清学诊断方法有间接荧光免疫法（ＩＦＡ），酶免疫试验（）ＥＩＡ），免疫印迹法（ＷＢ），梅里埃生物公司（Ｂｉｏｍｅｒｉｅｕｘ）推出ＶＩＤＡＳ免疫诊断系统能够自动定性和半定量地检查Ｌｙｍｅ病的抗伯氏包柔螺旋体抗（抗ＢＢ抗体）。本方法结合了酶和荧光免疫两种方法。硷性磷酸酶标记二抗的底物是４ｍｅｔｈｙｌｕｍｂｅｌｌｉｆｅ     

以异种抗原间接荧光抗体试验检测间日疟原虫抗体的评价

使用Pc及Pf抗原对单纯间日疟流行区的疟疾病人血清进行IFA试验,以评价其替代PV抗原检测间日疟原虫抗体的效应程度。用Pc,Pc及Pf抗原分别检测155例确诊的间日疟病人血清,其GMRT依次为175.8,37.4及12.7,两两相比均有非常显著差异;其阳性符合率依次为97.4％,81.9％及63.9％,差异亦非常显著。3种抗原测得的抗体滴度进行直线回归分析,获得表示Pv和Pc抗原检测间日疟原虫抗体时抗体滴度关系的回归方程Y=1.22+0.65X。假此方程,通过Pc抗原检测时的抗体滴度,可能推算用Pv抗原检测时的抗体滴度。     

间接免疫荧光试验在检测风疹病毒感染中的应用

目的建立检测风疹病毒(RV)抗原E1、E2、C的间接免疫荧光试验(IFA),为快速、敏感地检测临床标本中的RV提供一种重要的检测手段。方法采用荧光素标记的羊抗鼠IgG抗体,检测病毒抗原与抗风疹病毒衣壳蛋白E1、E2、C蛋白的单克隆抗体的结合物。用该系统测定中国麻疹实验室网络送检的咽拭子标本,并与病毒分离结果和临床诊断进行比较。结果IFA方法可以快速、敏感地检测临床标本中的RV。经检测咽拭子标本38份,其中28份采集于临床诊断风疹病例;6例采集于出疹患者,但诊断不明;4份采集于风疹病例的接触者。检测结果有22份风疹阳性标本。IFA的结果与病毒分离结果完全一致,但与临床诊断不一致,IFA结果的阳性数低于临床诊断风疹病例数。结论IFA方法简单可行、敏感特异,结果易于判断,是中国麻疹实验室网络中进行RV检测的重要方法之一。同时IFA方法也可以作为临床快速诊断RV感染的备选方法之一。     

False positive results of HIV virus tests in patients undergoing chronic hemodialysis

The sera of 173 haemodialysis patients treated in two dialysis centers in Hungary were tested for the presence of HIV (HTLV III/LAV) antibodies. Four different commercial enzyme immunoassay (EIA) kits and two types (CEM/LAV, and H9/HTLV III) of indirect immunofluorescence assay (IFA) were used. The Western blot technique was applied as confirmatory test in the study. No confirmed positive results were found in any of the cases. However, in 15 patients (8.7%) false positive (not confirmable by the Western blot assay) results were obtained in at least one but mostly in all of the three type 1 EIA kits (ORGANON, ELECTRONUCLEONICS, SORIN) applied. In 4 patients, the IFA assay also gave false positive results which could be repeated in sequential samples taken from the same patients. Increased reactivity in the control plate (coated with a concentrate of cellular material shed by uninfected H9 cell line) of the SORIN kit was found only in a few false positive samples and no fluorescence with the uninfected H9 or CEM cells was observed in any of the sera showing a false positive IFA. These results indicate that the false positive anti-HIV results frequently observable in haemodialysis patients are not simply the consequence of the presence of antibodies reacting with the uninfected H9 and/or CEM cells but they are most probably due to antibodies against antigens expressed on these cells only after infection with the human immunodeficiency virus.     

PCR和免疫荧光法诊断急性肺炎衣原体感染的研究

[目的 ]探讨聚合酶链式反应 (PCR)和免疫荧光法 (IF)联合应用诊断急性肺炎衣原体感染 ,寻找早期诊断的有效方法。[方法 ]采集咽拭子标本 ,用PCR法检测肺炎衣原体DNA ,采静脉血用IF法检测IgG和IgM抗体。[结果 ]在所有 76个病例中 ,PCR检测和血清抗体同为阳性 6例 ,只有PCR阳性的病例 3例 ,只有血清抗体为阳性的 1例。联合使用 2种方法 ,检出结果的阳性率比单独任何 1种方法高 (P <0 0 1)。[结论 ]联合应用PCR和免疫荧光法在诊断急性肺炎衣原体感染中较单独使用任何 1种检测方法具有快速、全面、敏感和特异的优点。     

双抗原夹心法ELISA在肾综合征出血热诊断中的应用

目的建立一种敏感、特异的检测肾综合征出血热(HFRS)血清总抗体的双抗原夹心法ELISA。方法应用重组汉坦病毒(HV)NP抗原e1.3S作为包被抗原和e6-119-HRP作为酶标抗原建立双抗原夹心法ELISA,检测血清总抗体,并与间接免疫荧光法(IFA)相比较。结果共检测188份人血清和378份鼠血清标本,2种方法的总符合率为97.70%。以IFA为参照标准,双抗原夹心法ELISA的敏感性为97.54%,特异性为97.87%。结论双抗原夹心法ELISA检测HFRS血清总抗体具有很高的敏感性和特异性,适用于大规模的流行病学调查。     

Iron-Folic Acid Supplementation During Pregnancy Reduces the Risk of Stunting in Children Less Than 2 Years of Age: A Retrospective Cohort Study from Nepal

The aim of the study was to investigate the effect of antenatal iron-folic acid (IFA) supplementation on child stunting in Nepalese children age <2 years. A retrospective cohort study design was used, in which a pooled cohort of 5235 most recent live births 2 years prior to interview from three Nepal Demographic and Health Surveys (2001, 2006 and 2011) was analysed. The primary outcome was stunting in children age <2 years. The main exposure variable was antenatal IFA supplementation. Multivariate Poisson regression analysis was performed. In our sample, 31% and 10% of Nepalese children age <2 years were stunted and severely stunted, respectively. The adjusted relative risk of being stunted was 14% lower in children whose mothers used IFA supplements compared to those whose mothers did not use (aRR = 0.86, 95% CI = 0.77–0.97). Additionally, the adjusted relative risk of being stunted was significantly reduced by 23% when antenatal IFA supplementation was started ≤6 months with ≥90 IFA supplements used during pregnancy (aRR = 0.77, 95% CI = 0.64–0.92). Antenatal IFA supplementation significantly reduced the risk of stunting in Nepalese children age <2 years. The greatest impact on the risk reduction of child stunting was when IFA supplements were started ≤6 months with ≥90 supplements were used.     

Evaluation of Confounders in Toxoplasmosis Indirect Fluorescent Antibody Assay

Background

The IFA test is one of the most usual methods for detecting anti-Toxoplasma antibodies, although it has not any unique standardization. It seems that the microscopic judgment of results is an important confounder in IFA test. Therefore, we conducted the present study to clarify the role of microscopic observer, and other confounders on the test.

Methods

Eighty sera were collected from patients suspicious to toxoplasmosis for detection IgG anti-T. gondii by this test. Samples were examined against different series of antigens, IgG anti-human conjugates, and observers.

Results

There were no significant differences between the two series of antigens and conjugates. For the observers groups the kappa coefficient of the test results in the experts group (0.97, 0.94–1.00) were significantly higher than the less experienced observers (0.77, 0.68–0.87).

Conclusion

We recommend the IFA test to be performed only in reference laboratories and by laboratory technicians that have enough experience for this test. Otherwise, we suggest the substitution of this test with other tests like ELISA for the diagnosis and epidemiological studies.     

Comparative analysis of ELISAs employing repetitive peptides to detect antibodies to Plasmodium falciparum sporozoites

In the last few years, a number of different recombinant and synthetic peptides consisting of the repetitive sequence of the Plasmodium falciparum circumsporozoite protein (NANP)n have been produced and used to develop immunoassays for the detection of antibodies against P. falciparum sporozoites in human sera. A comparative study of three enzyme-linked immunosorbent assays (ELISAs) that employed different (NANP)n peptides (the synthetic peptides (NANP)3 and (NANP)40 as well as the recombinant peptides R32tet32 and R32LR) was carried out using serum samples from individuals who were living in different malaria-endemic areas. The results obtained for these peptide-based ELISAs were compared with those obtained for an immunofluorescence assay (IFA) that used glutaraldehyde-fixed sporozoites. All the methods tested exhibited 100% specificity on sera from persons not exposed to malaria, good reproducibility (coefficients of variation ranged from 3% to 15% for peptide-based ELISAs), and good sensitivity. Reproducibility and sensitivity were lower for the IFA than for the peptide-based ELISAs, perhaps because of the subjective element in the interpretation of the results which is inherent in the IFA method. ELISAs based on peptides that contain a higher number of (NANP) repeats, i.e., (NANP)40 and R32tet32 or R32LR, gave results which correlated better with each other than with those obtained with the ELISA that employed a shorter (NANP)3 peptide. (NANP)n-based ELISAs are relatively simple and inexpensive methods for the detection of anti-P. falciparum sporozoite antibodies and can readily be used in epidemiological research in the field. These assays could contribute to a better understanding of the natural history of the host-parasite relationship in malaria research.     

A micro-capture ELISA for detecting Mycoplasma pneumoniae IgM: comparison with indirect immunofluorescence and indirect ELISA.

A mu-capture ELISA was developed for detecting Mycoplasma pneumoniae-specific IgM, and compared with an indirect immunofluorescent antibody (IFA) technique and an indirect ELISA. mu-capture ELISA and IFA compared well and were found to be the most sensitive assays. The IFA test can be completed in 2 h whilst the results of the mu-capture ELISA can be available in 24 h. Both tests are amenable to routine diagnostic use and have similar sensitivity. Indirect ELISA was found to be less sensitive and less specific, giving high assay values with several sera having undetectable M. pneumoniae CF antibody or CF antibody in low titre. Serum samples obtained from 11 patients at various times after M. pneumoniae infection showed maximum antibody levels within the first month by all assays, with a gradual fall in amount of IgM with time when assayed by mu-capture ELISA, a more gradual decline by IFA and hardly any decline with indirect ELISA. It was concluded that the indirect ELISA is unsuitable for the investigation of possible M. pneumoniae infection because the sustained high assay values with serum samples taken many months after infection, make interpretation of the test results very difficult.