Evaluation of the Architect Epstein-Barr Virus (EBV) Viral Capsid Antigen (VCA) IgG,VCA IgM,and EBV Nuclear Antigen 1 IgG Chemiluminescent Immunoassays for Detection of EBV Antibodies and Categorization of EBV Infection Status Using Immunofluorescence Assays as the Reference Method

Commercial immunoassays for detecting IgG and IgM antibodies against Epstein-Barr virus (EBV), viral capsid antigens (VCA), and IgGs toward EBV nuclear antigen-1 (EBNA-1) are routinely used in combination to categorize EBV infection status. In this study, we evaluated the performances of the Architect EBV VCA IgG, VCA IgM, and EBNA-1 IgG chemiluminescent microparticle assays (CMIAs) in EBV serological analyses using indirect immunofluorescence assays and anticomplement immunofluorescence assays as the reference methods for VCA IgG, VCA IgM, and EBNA-1 IgG antibody detection, respectively. A total of 365 serum samples representing different EBV serological profiles were included in this study. The κ values (concordances between the results) obtained in the Architect CMIA and those in the reference assays were 0.905 (P < 0.0001) for VCA IgM, 0.889 (P < 0.0001) for VCA IgG, and 0.961 (P < 0.0001) for EBNA-1 IgG. The sensitivities and specificities were, respectively, 91.08% and 99.48% for VCA IgM, 99.23% and 86.27% for VCA IgG, and 96.77% and 99.16% for EBNA-1 IgG. The sensitivities and specificities of the Architect CMIA panel were, respectively, 99.15% and 98.6% for diagnosing a primary infection, 97.62% and 93.39% for diagnosing a past EBV infection, and 92.42% and 97.82% for diagnosing the absence of an EBV infection. In summary, we demonstrated that the Architect EBV antibody panel performs very well for EBV antibody detection and correctly categorizes clinically relevant EBV infection states.     

Evaluation of 12 commercial tests for detection of Epstein-Barr virus-specific and heterophile antibodies

Ten microbiological departments in Norway have participated in a multicenter evaluation of the following commercial tests for detection of Epstein-Barr virus (EBV)-specific and heterophile antibodies: CAPTIA Select viral capsid antigen (VCA)-M/G/EBNA (Centocor Inc.), Enzygnost anti-EBV/immunoglobulin M (IgM) and IgG (Dade Behring), Vironostika EBV VCA IgM/IgG/EBNA enzyme-linked immunosorbent assay (ELISA) (Organon Teknika), SEROFLUOR immunofluorescence assay and EBV Combi-Test (Institute Virion Ltd.), anti-EBV recombinant IgM- and IgG-early antigen/EBNA IgG ELISA (Biotest Diagnostics), EBV IgM/IgG/EBNA ELISA (Gull Laboratories), Paul-Bunnell-Davidsohn test (Sanofi Diagnostics Pasteur), Monosticon Dri-Dot (Organon Teknika), Avitex-IM (Omega Diagnostics Ltd.), Alexon Serascan infectious mononucleosis test (Alexon Biomedical Inc. ), Clearview IM (Unipath Ltd.), and Cards+/-OS Mono (Pacific Biotech, Inc.). The test panel included sera from patients with primary EBV infection, immunocompromised patients with recent cytomegalovirus infection, healthy persons (blood donors), and EBV-seronegative persons. Among the tests for EBV-specific antibodies the sensitivity was good, with only small differences between the different assays. However, there was a greater variation in specificity, which varied between 100% (Enzygnost) and 86% (Biotest). Tests for detection of heterophile antibodies based on purified or selected antigen (Avitex, Alexon, Clearview IM, and Cards+/-OS Mono) were more sensitive than the Paul-Bunnell-Davidsohn and Monosticon tests.     

Evaluation of 12 Commercial Tests for Detection of Epstein-Barr Virus-Specific and Heterophile Antibodies

Ten microbiological departments in Norway have participated in a multicenter evaluation of the following commercial tests for detection of Epstein-Barr virus (EBV)-specific and heterophile antibodies: CAPTIA Select viral capsid antigen (VCA)-M/G/EBNA (Centocor Inc.), Enzygnost anti-EBV/immunoglobulin M (IgM) and IgG (Dade Behring), Vironostika EBV VCA IgM/IgG/EBNA enzyme-linked immunosorbent assay (ELISA) (Organon Teknika), SEROFLUOR immunofluorescence assay and EBV Combi-Test (Institute Virion Ltd.), anti-EBV recombinant IgM- and IgG-early antigen/EBNA IgG ELISA (Biotest Diagnostics), EBV IgM/IgG/EBNA ELISA (Gull Laboratories), Paul-Bunnell-Davidsohn test (Sanofi Diagnostics Pasteur), Monosticon Dri-Dot (Organon Teknika), Avitex-IM (Omega Diagnostics Ltd.), Alexon Serascan infectious mononucleosis test (Alexon Biomedical Inc.), Clearview IM (Unipath Ltd.), and Cards±OS Mono (Pacific Biotech, Inc.). The test panel included sera from patients with primary EBV infection, immunocompromised patients with recent cytomegalovirus infection, healthy persons (blood donors), and EBV-seronegative persons. Among the tests for EBV-specific antibodies the sensitivity was good, with only small differences between the different assays. However, there was a greater variation in specificity, which varied between 100% (Enzygnost) and 86% (Biotest). Tests for detection of heterophile antibodies based on purified or selected antigen (Avitex, Alexon, Clearview IM, and Cards±OS Mono) were more sensitive than the Paul-Bunnell-Davidsohn and Monosticon tests.     

Seroepidemiology of EBV and interpretation of the “isolated VCA IgG” pattern

The presence of VCA IgG in the absence of VCA IgM and EBNA‐1 IgG antibodies makes classifying EBV infection more difficult as this serological picture can be seen in the case of past infection with EBNA‐1 IgG loss or non‐appearance, or acute infections with the early disappearance or delayed onset of VCA IgM. The aim of this study was to assess the prevalence of this pattern in 2,422 outpatients with suspected EBV infection examined in 2005–2006, and to interpret its significance by means of immunoblotting. One hundred and seventy‐seven (7.3%) of the patients were VCA IgG‐positive, VCA IgM‐negative and EBNA‐1 IgG‐negative, 15 of whom (8.5%) presented with heterophile antibodies. Analysis by age class showed that the prevalence of isolated VCA IgG ranged from 4.5% in the subjects aged 1–10 years to 9% in those aged >60 years. Immunoblotting allowed 18.9% of the cases to be classified as acute and 81.1% as past infections, the latter being observed in about 37% of the patients aged less than 10 years and in 100% of those aged >30 years. Therefore, in our case series, the presence of isolated VCA IgG was associated usually with past infection, particularly among adults. In children aged less than 10 years, it was associated mainly with acute infection but as past infection may be present in about one‐third of such children, this possibility should not be overlooked. J. Med. Virol. 81:325–331, 2009. © 2008 Wiley‐Liss, Inc.     

Serological diagnosis of Epstein-Barr virus infection: Problems and solutions

Serological tests for antibodies specific for Epstein-Barr virus (EBV) antigens are frequently used to define infection status and for the differential diagnosis of other pathogens responsible for mononucleosis syndrome. Using only three parameters [viral capsid antigen (VCA) IgG, VCA IgM and EBV nuclear antigen (EBNA)-1 IgG],it is normally possible to distinguish acute from past infection: the presence of VCA IgM and VCA IgG without EBNA-1 IgG indicates acute infection, whereas the presence of VCA IgG and EBNA-1 IgG without VCA IgM is typical of past infection. However, serological findings may sometimes be difficult to interpret as VCA IgG can be present without VCA IgM or EBNA-1 IgG in cases of acute or past infection, or all the three parameters may be detected simultaneously in the case of recent infection or during the course of reactivation. A profile of isolated EBNA-1 IgG may also create some doubts. In order to interpret these patterns correctly, it is necessary to determine IgG avidity, identify anti-EBV IgG and IgM antibodies by immunoblotting, and look for heterophile antibodies, anti-EA (D) antibodies or viral genome using molecular biology methods. These tests make it possible to define the status of the infection and solve any problems that may arise in routine laboratory practice.     

Evaluation of a multiplex fluorescent microsphere immunoassay for the determination of epstein-barr virus serologic status

Epstein-Barr virus (EBV), a human herpesvirus, affects up to 95% of adults. Diagnosis of acute EBV infection can be challenging and often relies on the serologic antibody pattern to 3 distinct antigens, most often determined by indirect fluorescent antibody (IFA), enzyme-linked immunosorbent assays (ELISAs), and, more recently, multiplex assays. We compared a multiplex assay for the simultaneous detection of antibodies to viral capsid (VCA), nuclear (EBNA), and early (EA) EBV antigens with ELISAs using IFA for discrepancy resolution. Concordance of the multiplex assay was good for all 4 antigens: VCA IgM, 86.6% vs ELISA and 92.9% vs IFA; VCA IgG, 92.8% vs ELISA and 98.0% vs IFA; EBNA IgG, 90.3% vs ELISA and 98.1% vs IFA; and EA IgG, 83.8% vs ELISA and 92.8% vs IFA. After IFA resolution, correlation between the multiplex assay and ELISA for serologic disease stage, based on the antibody profile of all 4 analytes, was 90%. The multiplex assay showed good correlation with an established ELISA and even better correlation with the "gold standard" IFA. Advantages of the multiplex assay over traditional methods include multiple results per assay, inclusion of internal controls for each assay, and well-to-well monitoring of assay drift.     

五厂家EB病毒抗体检测试剂盒血清学诊断鼻咽癌的比较

目的 通过比较EB病毒抗体检测试剂盒血清学诊断鼻咽癌的准确性和检测结果的一致性,为试剂盒在临床上的使用选择和性能改进提供依据.方法 使用五厂家的EB病毒衣壳抗原IgA和IgG抗体检测试剂盒（VCA IgA和VCA IgG试剂盒）、核抗原I IgA和IgG抗体检测试剂盒（EBNA1 IgA和EBNA1IgG试剂盒）、早期抗原IgA和IgG抗体检测试剂盒（EA IgA和EA IgG试剂盒）以及Zta IgA抗体检测试剂盒,分别检测33例鼻咽癌患者（NPC）、30例健康体检者（HD）和41例非鼻咽癌的其他肿瘤患者（NNPC）血清或血浆样本.结果 A厂家的VCA IgA试剂盒灵敏度高于其他厂家同品种试剂盒,但对于NNPC特异度最低（36.6％）;而D厂家VCA IgA试剂盒的特异度最高（97.6％）,且对HD的特异度均大于90％.B和D厂家的EBNA1 IgA试剂盒间阳性、阴性符合率分别为92.1％和100.0％.A和E厂家的EA IgA试剂盒的灵敏度均较低而特异度高,试剂盒间阳性符合率低（39.4％）,阴性符合率高（98.6％）;而VCA IgG试剂盒的灵敏度高但特异度低.A和C厂家的EBNA1IgG试剂盒的灵敏度高（100.0％,97.0％）但特异度低（3.3％,13.3％）.C厂家EA IgG试剂盒检测所有样本结果均为阴性.结论 五个不同厂家VCA LgA、EA IgA试剂盒诊断鼻咽癌的准确性和检测结果的一致性存在差异,特别是A厂家和其他国内厂家同品种试剂间差异明显,需根据临床目的进行选择.三家国产VCA IgA试剂盒的灵敏度需进一步提高.相反,EBNA IgA试剂盒诊断鼻咽癌的准确性和结果一致性较好.单独使用VCA IgG和EBNA1 IgG试剂盒血清学诊断鼻咽癌的特异度差,其判读界值可能需根据检测且的进行调整.     

The seroepidemiology of infection due to Epstein-Barr virus in southern India

We investigated the seroepidemiology of infection due to Epstein-Barr virus (EBV) in 181 south Indian subjects aged 0-25 years using the indirect immunofluorescence method to titrate antibodies to viral capsid antigen (VCA), nuclear antigen (EBNA), and early antigen (EA). The age-specific prevalence of IgG antibodies to VCA rose rapidly to 90% by the age of 5 years. The prevalence of VCA-specific IgM and the geometric mean titre of VCA-specific IgG antibodies were highest between the ages of 6 months and 2 years, the median age of primary infection being 1.4 years. Thus primary EBV infection occurs early in life. EA antibody prevalence was highest (55%) in the third year of life and remained between 30% and 40% thereafter. This pattern of EA antibody prevalence suggests that the latent EBV infection that persists lifelong after primary infection may be reactivated in many individuals. EBNA antibody prevalence was low until the age of 2 years but rose to 80% in the fourth year. Geometric mean titres of antibodies to EA and EBNA were low and stable at all ages. These results are similar to data from areas where EBV-associated Burkitt's lymphoma is endemic and indicate a high EBV infection load early in life.     

Evaluation of four commercially available Epstein-Barr virus enzyme immunoassays with an immunofluorescence assay as the reference method

Four commercially available enzyme immunoassays (EIAs) (Novitec, Biotest, Virotech, and DiaSorin) were evaluated, with an indirect immunofluorescence assay as the reference method, for Epstein-Barr virus (EBV) VCA (viral capsid antigen) immunoglobulin G (IgG), VCA IgM, or EBNA (EBV nuclear antigen) IgG at three different locations (Homburg, Stuttgart, and Dresden). Serum samples from 66 immunocompetent patients with infectious mononucleosis, 73 patients without prior EBV infection, and 96 patients with past EBV infections and 29 serum samples with possible cross-reactions to other herpesviruses were included. In addition, 25 samples from an extensively pretested panel that is commercially available (Boston Biomedica) were tested. Each sample was tested at only one location. The four EIAs varied considerably in performance. When analyzing for EBV diagnosis, the Novitec assay performed the best, with 4.9% discrepant diagnoses, followed by the Biotest, Virotech, and DiaSorin assays, with 6.8, 11.7, and 14.0% discrepant diagnoses, respectively. On the basis of single-parameter analysis, the Novitec assay also showed the lowest number of discrepant results, with 3.5%, compared with the Virotech, Biotest, and DiaSorin assays, which produced 5.4, 6.4, and 8.6% discrepant results, respectively. VCA assays using affinity-purified native antigens performed better than assays with recombinant or synthetic antigens. The synthetic EBNA-1s showed the lowest concordance with the reference compared to recombinant p72. Commercially available EBV EIAs differed considerably in performance; however, some proved to be reliable and convenient alternatives to the indirect immunofluorescence assay for routine diagnostics. Native antigens, rather than synthetic peptides, are favored for EBV serology testing.     

Evaluation of Four Commercially Available Epstein-Barr Virus Enzyme Immunoassays with an Immunofluorescence Assay as the Reference Method

Four commercially available enzyme immunoassays (EIAs) (Novitec, Biotest, Virotech, and DiaSorin) were evaluated, with an indirect immunofluorescence assay as the reference method, for Epstein-Barr virus (EBV) VCA (viral capsid antigen) immunoglobulin G (IgG), VCA IgM, or EBNA (EBV nuclear antigen) IgG at three different locations (Homburg, Stuttgart, and Dresden). Serum samples from 66 immunocompetent patients with infectious mononucleosis, 73 patients without prior EBV infection, and 96 patients with past EBV infections and 29 serum samples with possible cross-reactions to other herpesviruses were included. In addition, 25 samples from an extensively pretested panel that is commercially available (Boston Biomedica) were tested. Each sample was tested at only one location. The four EIAs varied considerably in performance. When analyzing for EBV diagnosis, the Novitec assay performed the best, with 4.9% discrepant diagnoses, followed by the Biotest, Virotech, and DiaSorin assays, with 6.8, 11.7, and 14.0% discrepant diagnoses, respectively. On the basis of single-parameter analysis, the Novitec assay also showed the lowest number of discrepant results, with 3.5%, compared with the Virotech, Biotest, and DiaSorin assays, which produced 5.4, 6.4, and 8.6% discrepant results, respectively. VCA assays using affinity-purified native antigens performed better than assays with recombinant or synthetic antigens. The synthetic EBNA-1s showed the lowest concordance with the reference compared to recombinant p72. Commercially available EBV EIAs differed considerably in performance; however, some proved to be reliable and convenient alternatives to the indirect immunofluorescence assay for routine diagnostics. Native antigens, rather than synthetic peptides, are favored for EBV serology testing.     

Single-assay combination of Epstein-Barr Virus (EBV) EBNA1- and viral capsid antigen-p18-derived synthetic peptides for measuring anti-EBV immunoglobulin G (IgG) and IgA antibody levels in sera from nasopharyngeal carcinoma patients: options for field screening

Assessment of immunoglobulin A (IgA) antibody responses to various Epstein-Barr virus (EBV) antigen complexes, usually involving multiple serological assays, is important for the early diagnosis of nasopharyngeal carcinoma (NPC). Through combination of two synthetic peptides representing immunodominant epitopes of EBNA1 and viral capsid antigen (VCA)-p18 we developed a one-step sandwich enzyme-linked immunosorbent assay (ELISA) for the specific detection of EBV reactive IgG and IgA antibodies in NPC patients (EBV IgG/IgA ELISA). Sera were obtained from healthy donors (n = 367), non-NPC head and neck cancer patients (n = 43), and biopsy-proven NPC patients (n = 296) of Indonesian and Chinese origin. Higher values of optical density at 450 nm for EBV IgG were observed in NPC patients compared to the healthy EBV carriers, but the large overlap limits its use for NPC diagnosis. Using either EBNA1 or VCA-p18 peptides alone IgA ELISA correctly identified 88.5% and 79.8% of Indonesian NPC patients, with specificities of 80.1% and 70.9%, whereas combined single-well coating with both peptides yielded sensitivity and specificity values of 90.1 and 85.4%, respectively. The positive and negative predictive values (PPV and NPV, respectively) for the combined EBNA1 plus VCA EBV IgA ELISA were 78.7% and 93.9%, respectively. In the Indonesia panel, the level of EBV IgA reactivity was not associated with NPC tumor size, lymph node involvement, and metastasis stage, sex, and age group. In the China panel the sensitivity/specificity values were 86.2/92.0% (EBNA1 IgA) and 84.1/90.3% (VCA-p18 IgA) for single-peptide assays and 95.1/90.6% for the combined VCA plus EBNA1 IgA ELISA, with a PPV and an NPV for the combined EBV IgA ELISA of 95.6 and 89.3%, respectively. Virtually all NPC patients had abnormal anti-EBV IgG diversity patterns as determined by immunoblot analysis. On the other hand, healthy EBV carriers with positive EBV IgA ELISA result showed normal IgG diversity patterns. By using EBV IgG immunoblot diversity as confirmation assay for EBV IgA ELISA-positive samples, the sensitivity and specificity for NPC diagnosis increased to 98% and 99.2%, respectively, in the Indonesian NPC samples. The use of these combined methods for seroepidemiological screening studies is proposed.     

Performance of Two Commercially Available Automated Immunoassays for the Determination of Epstein-Barr Virus Serological Status

This study evaluated the performance of two automated Vidas (V) and Liaison (L) immunoassays for Epstein-Barr virus (EBV) serology. The detection of the viral capsid antigen (VCA) IgM, the VCA/early antigen (VCA/EA) IgG, and the Epstein-Barr nuclear antigen (EBNA) IgG was assessed on 526 sera collected for routine EBV testing in immunocompetent subjects. The determination of expected EBV status (186 EBV primary infections, 183 past EBV infections, and 157 EBV-seronegative individuals) was based on results of routine laboratory enzyme immunoassays (EIAs) together with clinical data. The sensitivity and specificity of each individual marker were determined in comparison to the expected EBV status. The agreement between the V and L profiles and the expected EBV status was established through the interpretation of combinations of the different EBV markers. Statistically significant differences between the two tests were found for the specificity of the VCA IgM marker (96.2% for V versus 93.2% for L), the sensitivity of the VCA/EA IgG marker (89% for V versus 94% for L), and the specificity of the EBNA IgG marker (96.5% for V versus 74.2% for L). The results determined for the two assays with respect to overall agreement with the established expected EBV status were not significantly different (89.7% for V versus 88.2% for L), with discrepancies mainly observed in sera referenced as primary infections. These findings demonstrated the similar performances of the Vidas and the Liaison assays for the establishment of an EBV serological status using the VCA, EA, and EBNA markers.     

Seroepidemiological study of Epstein-Barr virus infection in Bangladesh

A seroepidemiological study was carried out on 502 sera to determine the prevalence of EBV infection in a group of Bangladeshi people (age range: 15 days–90 years). All sera were tested for IgG antibody to the EBV viral capsid antigen (VCA) by a commercially available enzyme linked immunosorbent assay (ELISA) and the negative sera were checked subsequently by indirect immunofluorescence (IF) methods. The prevalence of EBV infection in the study group was 81.27%. 42.37% of infants had antibodies to EBV by the age of 1 year. A significant rise in the percentage of seropositives between 0–1- and 1–2-year-old children was demonstrated, indicating a high rate of primary infection at these ages. The prevalence of IgG antibody to VCA was 87.93% in the 2–10 years age group and was sustained at over 85% thereafter. Higher ELISA values were more common both in the 0–2- and >25-year age groups, the latter being statistically significant (P < 0.025). Similar higher values were also observed in females as compared to males (P = 0.05). Eighteen out of 109 negative sera and two equivocal sera by ELISA were found to be positive by indirect IF, indicating a negative predictive value of 82% for ELISA. The concordance between the two methods was 97% with ELISA proving to be less sensitive than indirect IF. It is concluded that the prevalence of EBV infection in Bangladeshi population is similar to that observed in other developing countries and that ELISA can be used for seroepidemiological surveys; however, the sera negative by ELISA should be checked routinely by indirect IF. © 1996 Wiley-Liss, Inc.     

Antibodies to Epstein-Barr virus in nasopharyngeal carcinoma, tonsillar carcinoma and control groups

In the sera of 17 patients with nasopharyngeal carcinoma (NPC) and of 19 patients with tonsillar carcinoma (TC) the titres of IgA, IgG and IgM antibodies to EBV VCA (viral capsid antigen) and of IgG antibodies to EBV EA (early antigen) were determined by the indirect immunofluorescence (IF) method. Significant difference was observed in the frequency of IgA antibodies to EBV VCA and IgG antibodies to EBV EA between NPC patients and controls. There was also a significant difference between the frequency of IgM antibody to EBV VCA and EBV EA antibody titres in TC patients and controls. The geometric mean titre (GMT) of IgG antibodies to EBV VCA was significantly higher in the NPC and TC patients as compared to controls.     

Synthetic peptides deduced from the amino acid sequence of Epstein-Barr virus nuclear antigen 6 (EBNA 6): Antigenic properties,production of monoreactive reagents,and analysis of antibody responses in man

Studies on the antibody responses to various Epstein-Barr virus (EBV) antigens have been instrumental in the understanding of the seroepidemiology and diagnosis of this viral infection and the subsequent carrier state. While antibodies to the viral capsid antigen (VCA), early antigen (EA), and nuclear antigens 1 and 2 (EBNA 1 and 2) have been well characterized, the antibody response to the other nuclear antigens is not well understood. EBNA 6 is expressed by lymphoblasts during acute EBV infection and may be an important antigen for diagnosis and evaluation of the immune response. In order to analyze the antibody response to EBNA 6, ten peptides (20–21 amino acids), deduced from the EBNA 6 coding region, were synthesized and evaluated for antigenicity by ELISA. One peptide (p-63; PA-PQAPYQGYQEPPAPQAPY) derived from the amino acid repeats showed the highest specific reactivity with human sera. This peptide was evaluated further for detection of human EBNA 6-reactive antibodies. Forty-two of forty-nine (86%) EBV-seropositive healthy donors had p-63- specific IgG reactivity, while none of 50 EBV seronegative patients reacted with the p-63 peptide. Twenty-two of fifty-one (43%) patients with ongoing primary EBV infection had detectable p-63-specific IgG. Serum samples drawn sequentially from patients during and after primary EBV infection revealed an increase in p-63-reactive IgG over time. A similar pattern was found for reactivity with an EBNA I-specific peptide (p-107), in contrast to the EBNA 2 (polyproline) response, which decreased over time. Some EBV seropositive individuals who had no detectable IgG against peptide p-63 did have antibodies against the native EBNA 6 by anticomplement immunofluorescence to EBNA 6 transfected cells. Rabbit antiserum raised against p-63 reacted specifically with native EBNA 6 by an immunofluorescence assay and by immunoblotting, indicating the EBNA 6-specific antigenicity of the peptide. Thus, the peptide p-63 derived from the amino acid repeats of the EBNA 6 coding region constitutes a predominant, although not exclusive, epitope in the EBNA 6 antibody response. © 1995 Wiley-Liss, Inc.     

Coupled particle light scattering: a new technique for serodiagnosis of Epstein-Barr virus infection

The Coupled Particle Light Scattering technique was evaluated for serological diagnosis of Epstein-Barr Virus (EBV) infection. Two hundred ninety-six patient sera selected from several clinical categories (acute infection, non-primary infection, interfering non-EBV infection, non-infected) were tested for IgM and IgG antibodies (anti-VCA, anti-EBNA and anti-EA). Determination of EBV IgG with Copalis multiplex was accurate when compared with Enzygnost Anti-EBV/IgG ELISA. Although the sensitivity of Copalis IgM for acute infections was 100% a positive IgM result did not always indicate an acute infection. Strong reactivity to IgG EA (ratio 3, 1) and IgG VCA (ratio 13, 3) correlated with persistent infection or reactivation. The CopalisI has many advantages over the existing methods, such as the possibility to measure three semi-quantitative IgG responses to three different EBV antigens simultaneously.     

The risk of systemic lupus erythematosus associated with Epstein–Barr virus infection: a systematic review and meta-analysis

Previous systematic reviews have found a higher sero-prevalence of EBV antibodies in SLE patients compared with controls. Because many studies have been published, there is a need to apply more precise systematic review methods. We examined the association between EBV and SLE patients by conducting a systematic review and meta-analysis of case–control studies that examined the prevalence of EBV antibodies and the DNA-positive rate. We searched the MEDLINE and EMBASE databases from 1966 to 2018 with no language restrictions. The Mantel–Haenszel odds ratios (OR) for EBV antibody sero-positivity were calculated, and meta-analyses were conducted. Quality assessment was performed using a modified version of the Newcastle–Ottawa scale, and 33 studies were included. Most studies found a higher sero-prevalence of VCA IgG and EA IgG in SLE patients compared with controls. Meta-analysis demonstrated a significantly higher OR for sero-positivity to VCA IgG and EA IgG for SLE cases (2.06 [95% confidence interval (CI) 1.30–3.26, p = 0.002] and 7.70, [95% CI 4.64–12.76, p < 0.001], respectively). The overall OR for the DNA-positive rate for SLE patients compared with controls was 3.86 (95% CI 1.52–9.83, p = 0.005). Other antibodies, i.e., VCA IgA/IgM, EBNA IgA, and EA IgA/IgM, also demonstrated a significant difference between SLE patients and controls. These findings support previous systematic reviews; however, publication bias cannot be excluded. The methodological conduct of studies could be improved, particularly when selecting controls and analyses of laboratory conduct.

     

Evaluation of chlamydial tests in early trachoma

An enzyme linked immunosorbent assay (ELISA) and an immunofluorescence (IF) test were compared with culture for their value in the diagnosis of chlamydial infection in early trachoma. Conjunctival swabs and scrapings from 81 school children with active trachoma from Khartoum, Sudan, were tested. Fourteen (17.3%) of the children with signs of active trachoma were positive by isolation. The sensitivities of the ELISA and IF tests, compared to cultures, were 85.0% and 68.2%, while the specificities for the ELISA and IF tests were 99.2% and 99.3%, respectively. Chlamydial IgM and IgG antibodies reactive with serotypes A-C and D-K of Chlamydia trachomatis were detected in sera of 28 (71.2%) of the 39 children from whom serum was obtained. Only eight of the 14 isolation-positive children were tested for chlamydial antibodies, and all of them had IgM and IgG antibodies at a titer of greater than or equal to 1:16. An IgG antibody titer of 1:16 or greater was detected in 20 (65.0%) of the 31 isolation-negative patients tested for chlamydial antibodies. The geometric mean titers of IgG antibodies to the antigen pools A-C and D-K were 132 and 42, respectively. Our study suggests that trachoma is prevalent in the child population studied. Clinical signs of active trachoma were found in 47.0% of the altogether 172 children investigated. ELISA can be recommended as a diagnostic tool in trachoma field surveys.     

应用基于Logistic回归的ROC曲线评价鼻咽癌EB病毒抗体联合检测

目的 以基于Logistic回归的受试者工作特征(ROC)曲线分析方法,评价VCA/IgA、EA/IgA、Rta/IgG和EBNA1/IgA等EB病毒抗体不同组合在鼻咽癌诊断中的价值.方法 收集211例初治鼻咽癌和203例相似症状的非鼻咽癌病例的血清,采用免疫酶法检测VCA/IgA及EA/IgA,酶联免疫吸附法检测Rta/lgG和EBNA1/IgA.对各种的抗体组合建立Logistic回归模型,以预测概率为分析指标,应用ROC曲线分析,评价不同组合对鼻咽癌的诊断价值.结果 单一指标评价,VCA/IgA敏感度最高(98.1%),EA/IgA特异度最高(98.5%).以基于Logistic同归的ROC曲线分析各项组合,敏感度和特异度均有所提高.双指标组合中,VCA/IgA+Rta/lgG组合的ROC曲线下面积(AUC)为0.991,诊断效能最高,敏感度、特异度及约登指数分别为94.8%、98.0%及0.928.VCA/IgA+Rta/IgG+EBNA1/IgA组合和4项指标组合的敏感度、特异度及约登指数分别为94.8%、98.5%、0.933和96.7%、97.0%、0.937;这两种多指标组合的AUC与VCA/IgA+Rta/IgG组合比较差异均无统计学意义(P＞0.05).结论 基于Logistic回归的ROC曲线分析方法可以为多指标联合诊断试验提供更客观的综合分析,VCA/IgA和Rta/IgG联合检测具有互补作用,是鼻咽癌血清学诊断的合适组合.     

Epstein–Barr virus can infect rabbits by the intranasal or peroral route: An animal model for natural primary EBV infection in humans

Epstein–Barr virus (EBV) is spread universally in humans, and it causes infectious mononucleosis and sometimes induces serious EBV‐associated disease. The detailed mechanism of primary infection in humans has remained unclear, because it is difficult to examine the dynamics of EBV in vivo. In this study, a natural EBV‐infection rabbit model by intranasal or peroral inoculation is described. Ten male rabbits were examined for EBV‐DNA or mRNA expression and anti‐EBV antibodies in blood. Four of 10 rabbits showed the evidence of EBV infection; detection of EBV‐DNA or EBV‐related genes mRNA in peripheral blood mononuclear cells, increased EBV antibodies in the plasma, and the presence of lymphocytes expressing EBER1 and EBV‐related gene proteins in the lymphoid tissues of a rabbit. Three of four infected rabbits were detected transiently EBV‐DNA and/or mRNA of EBV‐related genes such as EBNA1, EBNA2, BZLF1, and EA in blood, while in one of four, EBV‐DNA and/or mRNA were detected for more than 200 days after viral inoculation. The level of EA‐IgG increased and its level was maintained in all infected rabbits, whereas those of VCA‐IgM and VCA‐IgG increased transiently, and EBNA‐IgG was not elevated. Pathological examination of a rabbit infected transiently revealed some scattered lymphocytes expressing EBER1, LMP1, and EBNA2 in the spleen and lymph nodes. EA expression was also observed in the spleen. These findings suggest that EBV can infect the rabbit by the intranasal or peroral route, and that this rabbit model is useful for examining the pathophysiology of natural primary EBV infection in humans. J. Med. Virol. 82:977–986, 2010. © 2010 Wiley‐Liss, Inc.