溶组织内阿米巴病的免疫学诊断

溶组织内阿米巴病是一种世界性分布的疾病,全世界约有10%的人口感染本病。某些热带国家感染人数可超过40%。肠阿米巴病的诊断,目前仍以粪便中找到阿米巴原虫为最可靠的依据,但可因实验人员的技术水平或因标本质量等因素而导致漏检,此外对某些可疑的肠阿米巴病病人,因服了影响粪检结果的药物而无法粪检,以及某些超越乙状结肠镜所及范围的局部肠阿米巴病等,往往均需求助于免疫学方法。至于肠外阿米巴病的诊断,则免疫学方法更有突出的地位。无菌培养法的建立和改进为免疫学试验提供了良好的抗原,从而促进了免疫学诊断的发展。现将目前国外最常用的诊断阿米巴病的免疫学方法简述如下:     

英格兰和威尔斯的阿米巴病

作者报告英格兰和威尔斯每年约有200例新发的阿米巴病患者及3例死于阿米巴病。死亡是由于诊断的延误和治疗的错误而造成。特别是溃疡性结肠炎与阿米巴病的鉴别极为重要,因为两病的症状很相近似,如果采取治疗溃疡件结肠炎的方法用类固醇类药物和结肠切除术治疗阿米巴病,可造成病人     

间接荧光抗体试验和酶联免疫吸附试验在孟加拉国诊断肝阿米巴病的评价

由溶组织内阿米巴引起的阿米巴病每年引起11万人死亡,其中肝阿米巴病(HA)是侵袭性阿米巴病中引起死亡最常见的原因。孟加拉国是肠阿米巴病的流行国家,但没有关于肠外阿米巴病的详细资料。至今,HA的诊断仍然靠病史、临床发现以及肝脓肿的物理特征;偶尔也检查粪便和脓液里的溶组织内阿米巴,两者都不是太敏感的方法。血     

酶联免疫吸附试验对儿童阿米巴病的血清学诊断

酶联免疫吸附试验(ELISA)已被应用于多种寄生虫感染的血清学诊断。新近已有使用本法诊断成人阿米巴病的报告。但对儿童阿米巴病却很少使用。作者用无菌的溶组织内阿米巴抗原做ELISA对儿童阿米巴病进行了血清学诊断。从甘地医院和联合医院的儿科病房及门诊选择儿童,分为对照组40例(连续3天粪检没有寄生虫感染);有胃肠紊乱组,此组又分为(1)肠阿米巴病儿童42例;     

北尼日利亚采用凝胶扩散试验诊断阿米巴病的评价

用于证实阿米巴抗体存在的方法有补体结合、凝胶扩散、间接血凝、乳胶凝集、免疫荧光素、对流免疫电泳和 ELISA 试验。间接血凝较为敏感,但特异性低于凝胶扩散;补体结合试验相对地不敏感。1976年 Stamm 等报道在经济条件差的地区,免疫荧光素和凝胶扩散试验对诊断活动性阿米巴病最有用处。作者在1972年1月起就用凝胶扩散试验诊断尼日利亚北部的阿米巴病,本文报道该试验对这一地区阿米巴病的诊断价值。     

阿米巴抗原对阿米巴肝脓肿的免疫诊断和预后的意义

虽然大多数肠道阿米巴病能找到病原体作为诊断依据,但肠外阿米巴病则往往很难检出病原体,故曾采用过很多免疫诊断法,但它们的敏感性、特异性和可重复性很不一致,作者着重介绍测定阿米巴抗原诊断阿米巴肝脓肿的方法和意义,并研讨抗原与疾病预后的关系。     

对流免疫电泳诊断阿米巴病

为了探讨对流免疫电泳对阿米巴病的诊断价值,共检测了13例阿米巴病患者的血清。其中有10例为肠阿米巴病,系经查见滋养体所证实,3例为肠外阿米巴病,是根据临床检查所确诊。对照组为14例非阿米巴性的肝或肠道病病人,包括肝硬化10例,慢性结肠炎2例,细菌性痢疾2例的血清及     

阿米巴病的酶联免疫吸附试验

间接荧光抗体试验(IFT)是诊断阿米巴病最特异和最敏感的方法之一。酶联免疫吸附试验(ELISA)是近来介绍的一种既经济又方便的诊断方法。本文研究了用该法诊断阿米巴病的效果并与IFT试验作了比较。选择临床诊断并经病原检查肯定为阿米巴病的病人血清作IFT试验。将IFT滴度大于1:80的107例血清作ELISA试验。并以粪便检查溶组织阿米巴阴性的66名正常人的血清作对照。IFT试验,取多凹井载玻片,每井注满含有活的阿米巴滋养体(经Diamonds’TPS-1培养基培养后洗涤过的NIH:200株阿米巴)生理盐水悬液,空气干     

阿米巴病人的皮内试验和红细胞凝集抗体滴度

阿米巴病皮内试验主要用作流行区内流行病学调查的过筛试验。对个体阿米巴病的血清诊断,以间接红细胞凝集或其他体外试验比皮内试验为优。作者对皮内注射溶组织素(即溶组织内阿米巴抗原—histolyticin)是否会影响抗体滴度进行了试验。在加拿大的一个阿米巴病流行区内,从早先曾患过阿米巴病并已治疗过的9例采集血清样本,随后     

阿米巴病的血清学诊断

作者用培养的溶组织内阿米巴制成的每毫升含有一千万个阿米巴,含氮量为1.86毫克的抗原,对间接血球凝集、补体结合及琼脂凝胶扩散3种血清试验诊断阿米巴病的价值进行了比较。在345例有阿米巴病临床表现的患者中,107例作了间接血球凝集试验,阳性率为85%。16例肠道外阿米巴病患者3种试验的阳性率均为88%。另外127例肠道阿米巴病患者3种试验的结果表明,间接血     

Use of ELISA to measure antinuclear antibodies in children with juvenile rheumatoid arthritis.

OBJECTIVE: To compare a series of commercial ELISA tests with an indirect immunofluorescent antibody (IFA) test for the detection of antinuclear antibodies (ANA) in children with juvenile rheumatoid arthritis (JRA). METHODS: Sera from 178 patients with JRA (88 pauciarticular, 68 polyarticular, 22 systemic) were compared with 26 healthy pediatric subjects. Twenty-one samples from patients with systemic lupus erythematosus (SLE) were also tested. All samples were analyzed by IFA and by 3 commercial ELISA methods. Concordance of ELISA results with IFA results (selected standard) were used as a measure of performance. Sensitivity and specificity were calculated for each test and likelihood ratios (LR) were established for IFA and ELISA in pauciarticular and polyarticular JRA sera. The increment in pretest probability was then obtained for each test as an additional measure of test performance. RESULTS: IFA rendered positive results on 18-77% of the JRA sera depending upon the subset, 100% of SLE sera, and 15% of normal patient sera. Using IFA as the standard, correspondence with positive results among patients with JRA ranged from 0 to 74% for the 3 ELISA tests, while it ranged from 5 to 73% in IFA negative sera. IFA tests showed intermediate range likelihood ratios (0.3, 0.5, 3.5, and 5) and increments in pretest probability ranging from 25 to 45%. While one of the ELISA tests attained 50% of increment in pretest probability for the positive test, it showed 0% increment as a negative test. The other 2 ELISA tests incremented the pretest probability from 0 to 25%. CONCLUSION: Our findings indicate that in JRA, the lack of correspondence with the historic standard IFA precludes the use of ELISA tests for detection of ANA. In addition, IFA out-performs ELISA by a substantial degree when "clinical utility" analysis of test performance is utilized. Detection of ANA in children with JRA should either continue to rely on IFA or be based on a different set of antigens if an ELISA format is chosen.     

Serodiagnosis of Rocky Mountain spotted fever: comparison of IgM and IgG enzyme-linked immunosorbent assays and indirect fluorescent antibody test

To characterize IgM and IgG antibody responses in Rocky Mountain spotted fever (RMSF), a microtiter enzyme-linked immunosorbent assay (ELISA) using density gradient-purified Rickettsia rickettsii as antigen was developed. Sera of vaccinated individuals and patients with RMSF were tested by ELISA and by indirect fluorescent antibody (IFA) tests. Diagnostic agreement between ELISA and the IFA test was 76% and 52% for IgG and IgM antibody, respectively. Diagnostic agreement between the ELISA for IgG antibody and the IFA test for total immunoglobulins was 84%. The ELISAs for IgM and IgG antibody were as specific (100%) and as sensitive (100%) as the IFA test (83%-100%) in detecting antibody increases in paired sera from persons with RMSF and were superior to the IFA test in detecting seroconversions in vaccinees. The ELISA also detected antibodies in a single convalescent-phase serum with sensitivity and reliability. The ELISA for IgG antibody is appropriate for seroepidemiology and serodiagnosis since it permits measurement of antibody at a single dilution of serum up to a year after illness.     

Evaluation of enzyme linked immunosorbent assay in the immunodiagnosis of schistosomiasis.

Eighty-six bilharzial patients divided into 5 clinical groups were studied. Enzyme linked immunosorbent assay (ELISA), indirect fluorescent antibody (IFA) and indirect haemagglutination (IHA) test were performed for all the patients. ELISA gave the most sensitive results (82.6% and 80.2% positivity rate in Egypt and Lille respectively), followed by IFA (79.1% positivity rate) and IHA (77.9% and 75.6% positivity rate in Egypt and Lille respectively). The humoral antibodies detected by all methods (ELISA, IFA and IHA) showed increasing values with the progress of the disease which is parallel to the antigenicity of the disease. Both the positivity rate and the mean value of antibody titres recorded by the 3 diagnostic techniques (ELISA, IFA and IHA) were significantly higher in mansoni than haematobium infection. This may be explained by species specificity of antibody response. The superiority of ELISA over IFA and IHA techniques was discussed.     

Use of an enzyme-linked immunosorbent assay to detect anti-adherence protein antibodies in sera of patients with invasive amebiasis in Cairo, Egypt.

We used enzyme-linked immunosorbent assay (ELISA) to detect IgG antibodies to the Entamoeba histolytica galactose-inhibitable adherence protein in the sera of 50 uninfected controls, 50 cases with asymptomatic cyst passage, 100 patients with amebic colitis, and six patients with amebic liver abscess from Cairo, Egypt, and in 50 healthy controls from the United States. When the mean + 3 SD value above that of the controls from the United States was used as a criterion for a positive ELISA result, 100% of those with invasive amebiasis, 80% of those with asymptomatic infection, and 64% of the Egyptian controls had anti-adherence protein antibodies. However, when the mean + 2 SD value of Egyptian control sera (optical density = 0.094) was used as the criterion for positivity, 33 (89%) of 37 sera from individuals with invasive amebiasis having symptoms for at least one week were antibody positive, in contrast to only 12% of asymptomatic cyst passers (P < 0.01). In a highly endemic area such as Cairo, Egypt, detection of serum anti-adherence protein antibodies by ELISA may have greatest diagnostic use in patients with symptomatic invasive amebiasis of greater than one week duration.     

Comparison of enzyme-linked immunosorbent assay and indirect immunofluorescence assay in the diagnosis of human strongyloidiasis.

BACKGROUND: An enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence assay (IFA) were evaluated for serological diagnosis of human strongyloidiasis. METHODS: Serum specimens obtained from 46 individuals infected with Strongyloides stercoralis, 37 healthy persons and 381 persons with other parasitic infections were tested using an IgG-ELISA that used crude antigen of S. stercoralis filariform larvae and an IFA. Test sera were pre-incubated with antigens from Ascaris, Toxocara and hydatid protoscolices to remove non-specific antibodies. RESULTS: The sensitivity, specificity, positive predictive value and negative predictive value for ELISA were 93.5%, 96.1%, 72.9% and 99.2%, respectively, and those for IFA were 87%, 90.1%, 49.4% and 98.4%, respectively. Both assays showed false positivity in hydatidosis, ascariasis and toxocariasis; however, this was less common with ELISA. CONCLUSION: ELISA method using filariform larval antigen may be a sensitive and specific test for human strongyloidiasis, and may be preferable to IFA.     

Evaluation of the micro enzyme-linked immunosorbent assay for antibodies to Trypanosoma cruzi

A micro enzyme-linked immunosorbent assay (ELISA) for antibodies to Trypanosoma cruzi was evaluated and the results obtained by ELISA were compared with those obtained by the complement fixation test (CF) and indirect fluorescent antibody test (IFA). Fifty sera collected from residents of the southeastern United States all had reciprocal ELISA titers less than or equal to 320. Similarly, serum samples from 17 patients with T. cruzi infection proven by xenodiagnosis had reciprocal ELISA titers of greater than or equal to 1,280. Specimens from 302 El Salvador Army recruits were tested by ELISA, IFA, and CF. Excellent correlation was observed between results obtained by the three serologic tests; 62.9% of the samples were negative by each of the three tests and 24.5% were positive by all. Overall, 29.5% of the sera were positive for antibodies to T. cruzi by ELISA, 29.5% by IFA, and 31.5% by CF. The data suggest that the micro ELISA is a promising serologic test for measuring antibodies to T. cruzi in individuals and in populations.     

A comparison of the ELISA with other serological tests in the serodiagnosis of amoebiasis

The sera of 78 patients with invasive amoebiasis were tested for antiamoebic antibodies by the techniques of enzyme-linked immunosorbent assay (ELISA), indirect haemagglutination (IHA), indirect fluorescent antibody (IFA) and counterimmunoelectrophoresis (CIEP). Results showed that the ELISA compared favourably with IHA and IFA tests in terms of sensitivity and specificity. ELISA, IHA and IFA detected 97.4%, 96.2% and 98.7% of the patients respectively. CIEP was the least sensitive of the 4 serological methods with a sensitivity of 88.5%. The advantages and disadvantages of the 4 serodiagnostic procedures are discussed.     

Comparison of haemagglutination test, enzyme-linked immunosorbent assay and indirect immunofluorescence antibody test for determination of rubella immune status

Comparative evaluations of immune status for rubella are described for the enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence (IFA) and two standard haemagglutination inhibition tests (HAI kaolin; HAI heparin-MnCl2). In general, a reasonably good correlation was obtained between the level of rubella antibodies measured by the HAI (kaolin) test and by ELISA, but an appreciable proportion (15%) of ELISA positive specimens were encountered among HAI (kaolin) negative sera. All of these HAI negative, ELISA positive sera, except one were found to be positive for rubella antibodies by IFA. Neutralization test performed on this serum positive by ELISA only, confirmed the presence of protective rubella antibodies. Of all the tests evaluated ELISA appeared unequivocally to be the most sensitive test followed closely by IFA. The standard HAI (heparin-MnCl2) was more suitable than the HAI (kaolin), for the determination of immune status. Further, no linear relationship between single rubella virus HAI and ELISA values was observed.     

Serodiagnosis of canine visceral leishmaniasis in Portugal: comparison of three methods.

Sera collected in Portugal from 43 dogs were screened for specific antibodies to Leishmania donovani antigens. Three different techniques were compared: an indirect immunofluorescence assay (IFA), a direct enzyme-linked immunosorbent assay (ELISA) and a competitive-ELISA (C-ELISA) using two species-specific monoclonal antibodies, D2 and D13. By IFA, 22 of the sera examined showed positive reactions, compared with 26 by ELISA or 27 by C-ELISA. There was no direct correlation observed between the serum titre by IFA and the strength of the reaction in ELISA or inhibition in C-ELISA. However, a good correlation was observed between sera identified as positive (95.5%) by all three techniques. Western blotting on leishmanial membranes showed that common antigens with Mr of 26,000 and 70-84,000 were recognized by all infected dog sera, regardless of the serum titre. In large scale studies, ELISAs are preferred to IFA for the rapid diagnosis of canine visceral leishmaniasis because of their greater simplicity.     

传染性非典型肺炎的血清学诊断研究

目的 评估传染性非典型肺炎(世界卫生组织又称严重急性呼吸综合征，SARS)血清病毒特异性抗体检测在SARS诊断中的实用价值，了解免疫荧光抗体法(IFA)和酶联免疫吸附法(ELISA)对SARS病毒特异性抗体检测结果的一致性程度。方法 用IFA和ELISA检测267例不同病程SARS患和132例对照组血清SARS病毒特异性抗体，以敏感度、特异度、阳性预测值(17PV)、阴性预测值(NPV)和准确度评价其诊断价值，并以Kappa值评价两种检测方法结果的一致性。结果 以IFA检测的血清特异性IgM类和IgG类抗体阳性率在病程第11天明显增高，病程≥11天，IgM类抗体诊断SARS的敏感度为65．6％，特异度100．0％，PPV 100．0％，NPV 71．0％，准确度81．3％；IgG类抗体则分别为敏感度91．1％，特异度97．0％，PPV 97．3％，NPV 90．1％，准确度93．8％。以ELISA方法所测结果与IFA结果相仿。对IFA和ELISA法检测的一致性检验示Kappa值分别为0．640和0．779。结论 血清病毒特异性抗体在SARS发病10天以上阳性率高，抗体检测有助于确立发病10天以上SARS的血清学诊断。IFA和ELISA检测SARS病毒抗体的一致性较好。