IgM Kits Research Articles

Comparison of three commercial IgG and IgM ELISA kits for the detection of tick-borne encephalitis virus antibodies

Tick-borne encephalitis (TBE) is endemic in many parts of Europe and Asia. The diagnosis of this disease is essentially based on the demonstration of specific antibodies. For reasons of simplicity, automatization and quick availability of test results, enzyme-linked immunosorbent assays (ELISAs) are the method of choice for serological diagnosis of TBE. Here, we evaluated three commercially available anti-TBEV IgG and IgM ELISAs using 251 serum samples: the SERION ELISA classic FSME Virus/TBE Virus IgG and IgM kit (Virion\\Serion), the RIDASCREEN® FSME/TBE IgG and IgM kit (R-Biopharm), and the anti-FSME/TBE virus ELISA “Vienna” IgG/anti-FSME/TBE virus ELISA IgM kit (Euroimmun). In total, discrepant test results for IgG and/or IgM were observed for 37/251 (14.7 %) of tested samples; differences were statistically significant. Reference values defined by serum neutralization test (SNT, n = 25) or results provided by EQA organizers (n = 2) were established for a subset of samples. In relation to these values, false-positive results were observed mainly for Euroimmun Vienna IgG and RIDASCREEN IgG, whereas false-negative results were primarily observed for Virion\\Serion IgG and RIDASCREEN IgM kits. In routine diagnostics, specificity problems are of major relevance and may be addressed by analyzing the respective samples using SNT.

Comparison of six commercial tick-borne encephalitis IgM and IgG ELISA kits and the molecular characterization of their antigenic design

Tick-borne encephalitis virus (TBEV) diagnosis is mainly based on the detection of viral-specific antibodies in serum. Several commercial assays are available, but published data on their performance remain unclear. We assessed six IgM and six IgG commercial enzyme-linked immunosorbent assay (ELISA) kits (ELISA-1 through ELISA-6) using 94 samples, including precharacterized TBEV-positive samples (n=50) and -negative samples (n=44). The six manufacturers showed satisfactory sensitivity and specificity and high overall agreement for both IgM and IgG. Three manufacturers showed better reproducibility and were the most sensitive (100%) and specific (95.5–98.1%) for both IgM and IgG. Two of them were also in agreement with the clinical interpretation in more than 90% of the cases. All the assays use inactivated virus as antigen, with strains showing approximately 94% homology at the amino acid level. The antigenic format of the assays was discussed to further improve this TBEV diagnostic tool.

P004 Retrospective analysis of deceased donor samples for ZIKA virus infection in high-risk population, a three-year study

Aim The recent epidemic of Zika Virus in the United States has necessitated screening for the presence of this agent in high-risk transplant solid organ donors to avoid the transmission to potential recipients. In this study, we performed a retrospective analysis of Cadaver Donors from Auxilio Mutuo Hospital (HAM) in Puerto Rico. Methods One hundred fifty-six (156) serum samples from Deceased Donors were obtained from Puerto Rico. Aliquots of serum, were maintained at −20 °C since collection. There were 38 samples from 2014, 62 from 2015, and 56 from 2016. These samples were tested with the RealStar® Zika Virus RT-PCR Kit U.S.® kit (Altona Diagnostics), and Anti-Zika Virus ELISA IgG and IgM kits (EUROIMMUN). These assays were validated with a separate group of freshly obtained Zika-positive samples from an ambulatory clinic at HAM. Results Of the 156 total deceased donor specimens retrospectively tested, none were positive for PCR, 2 were positive for IgM, and 22 were positive or borderline for IgG. The breakdown over the 3-year period indicated an increase in long-term exposure, as indicated by the increase in IgG positive samples. In 2014, only 5.2% were positive. However, by 2015 19.4% of the samples were positive. This indicates that almost 20% of the Deceased Donors tested had some contact with the Zika Virus (or a related Flavivirus , such as Dengue or West Nile). Of the positive IgG samples, only 2 were positive for IgM, indicating the exposure was likely more than 3 months prior. The results of the PCR study were not surprising, as we have seen in our laboratory, the long-term storage of serum for later RNA-based PCR testing has been unsuccessful. Conclusions Zika testing utilizing PCR-based assays in conjunction with serological assays in areas of known infection is essential, especially when servicing solid organ transplant programs. The use of donors potentially infected with Zika virus could have a significant impact in transplant success as there are some indications that immunocompromised individuals may develop more severe symptoms or illnesses. The correct storage of serum samples is crucial to obtain reliable results of this test.

Role of Cytomegalovirus and Toxoplasma Gondii in Women Abortion and Congenital Anomalies in Kirkuk City Using ELISA

Background: Bad obstetric history (BOH) due to Cytomegalovirus (CMV) and Toxoplasma gondii among women with abortion and previous congenital anomalies were watched in Kirkuk city-Iraq. Objective: To achieve this aim a total of 770 serum samples were collected from women attending Ibn-Nafies medical private lab, who complaining from single or more of abortions. Sera were collected, separated and examined by using ELISA machine and using both IgM and IgG kits for both infectious agents. The second aim was to study the impact of 200 mg twice daily and 3million unit twice daily were administrated by some positive women against Cytomegalovirus and Toxoplasma gondii respectively .Positive cases were watched for rising titer . Methodology: 7 positive women for Cytomegalovirus and 11 women positive for toxoplasmosis were agreed to continue these trials which extends for 3 months involve 3 trials of retesting both infectious agents by ELISA. Results: The overall positive rate for toxoplasmosis and Cytomegalovirus antibodies was 71.94% in 554 sera. This rate was divided into 49.87 % for Cytomegalovirus antibodies and 22.07 % for toxoplasmosis, P<0.05. Primary infection rates contributed 7.79 % and 6.10 % from the overall rate; whereas IgG antibodies positive 36.23 % and 13.89 % were found for Cytomegalovirus and toxoplasmosis respectively, p< 0.05. Moreover 47 (6. 10%) of the tested sera exert both IgM and IgG antibodies with high frequency 45(5.84 %) for CMV compare to 2(0.25%) for Toxoplasma gondii ; p<0.05 . Equivocal antibody levels (from 0.9 to 0.99 IU/ml) were recorded in 61 sera 7.92 %. Therelationship between both infectious agents' distributions with seasons was not significant. The impacts of acyclovir and spiramycin administrations exert the following results, for CMV-IgMmean antibody (1.18, 0.88 and 0.64 IU/ml) was obtained for first, second and third month respectively. While the same patients' sera reveal increasing CMV-IgG antibody titers from 1.37 in the first month to 3.20 IU/ml in the third month. Only sera belongs to patient number 7 remains 0.9 IU/ml equivocal. A Cure rate for CMV-IgM was 85.71 %. While all sera show increasing of CMV-IgG Abs titers (100 %) of cures. Spiramycin influences on toxoplasmosis showmean IgM antibodies rates: 1.28, 0.99 and 0.47 IU/ml for first, second and third months respectively p<0.05. Watching rising titer also determined as of IgM antibodies; only 7 sera reveal rising titer of one fold increase while the rest 4 sera no reveal any increase in spite of their IgM antibodies were declining below than 1.0 IU/ml (negative). The following total means of IgG antibodies 1.03, 1.23 and 1.90 IU/ml were recorded for first, second and third months respectively. Conclusions: CMV and toxoplasmosis rates among women with BOH were high. For getting a sure about the real role of spiramycin and acyclovir employee against Toxoplasma gondii and CMV respectively; further studies using a large number of patients and other drug doses are demanded, because the obtained results in the current study was primary.

Serological Diagnosis of Acute Scrub Typhus in Southern India: Evaluation of InBios Scrub Typhus Detect IgM Rapid Test and Comparison with other Serological Tests

Scrub Typhus (ST) is being reported from different parts of India in the recent past. However, the diagnosis and confirmation of ST cases require specific serological and molecular diagnostic tests. Both rapid and conventional ELISA tests need to be properly evaluated. Evaluation of a new ST IgM Immunochromatography (ICT) test kit (InBios Scrub Typhus Detect IgM Rapid Test) and compare it with another rapid kit, conventional ELISA kit and Weil-Felix (WF) test. This prospective study was carried out in Mahatma Gandhi Medical College and Research Institute, Puducherry, during November 2015 to June 2016. Clinically suspected 220 ST patients were examined by a new kit, InBios Scrub Typhus Detect IgM Rapid Test, taking the conventional InBios Scrub Typhus Detect IgM ELISA as reference. Additional comparison was made with ImmuneMed Scrub Typhus Rapid, and WF test (single OXK titers ≥1:320). Statistical analysis was performed (Chi-square, Spearman's correlation and Kappa) using IBM SPSS Statistics 17 for Windows (SPSS Inc; Chicago, USA). Percentage Sensitivity, Specificity, Positive Predictive and Negative Predictive Values for InBios, ImmuneMed and WF were 99.25, 93.02, 95.68, 98.77; 94.87, 94.19, 96.21, 92.05 and 50.38, 95.51, 94.29, 56.67 respectively. A total of 134 patients were positive in reference standard InBios IgM ELISA. This new rapid ST IgM kit validated for the first time in India, showed good sensitivity and specificity. As a Point-of-Care (PoC) test, the kit would be helpful in both urban and remote rural parts of India.

The aetiology of community associated pneumonia in children in Nanjing, China and aetiological patterns associated with age and season.

BackgroundViral and atypical bacterial pathogens play an important role in respiratory tract infection. Using the Pneumoslide IgM test, the presented study explored the aetiology of community-acquired pneumonia and investigated further whether there was an association between age or season and aetiological organisms.MethodsSerum samples, taken between August 2011 and August 2013, from patients with CAP were tested with the Pneumoslide IgM kit. The Pneumoslide IgM technology can simultaneously diagnose 9 viral and atypical bacterial pathogens: Legionella pneumophila serogroup 1 (LP1), Mycoplasma pneumoniae (MP), Coxiella burnetii (COX), Chlamydophila pneumonia (CP), Adenovirus (ADV), Respiratory syncytial virus (RSV), Influenza A (INFA), Influenza B (INFB), Parainfluenza 1, 2 and 3 (PIVs). The data was analyzed by using Statistical Package for the Social Sciences for Windows (SPSS, version 11.0).ResultsOf a total of 1204 serum samples tested, 624 samples were positive. M. pneumoniae was the dominant pathogen, with INFB, PIVs, and RSV ranking second to fourth, respectively. The positive percentages of MP, INFB, PIVs and RSV were found to be associated with age, especially MP, INFB and PIVs. The positive percentages of MP, PIVs and RSV were also found to be associated with season. The positive percentage of MP in autumn was the highest. The positive percentages of LP1 in August and September, ADV in June and INFB in March were relatively higher than that in other months.ConclusionsThe results show there were 4 main viral and atypical bacterial pathogens causing CAP in our study. Some pathogens were found to be associated with age and season. M. pneumoniae was the most predominant pathogen among these 9 pathogens. It is necessary to take preventative measures in order to prevent the spread of these pathogens in susceptible age groups during peak season.

Is there a relationship between Parkinson's disease and Chlamydia pneumoniae?

The aim was to investigate a possible relationship between Chlamydia pneumoniae and Parkinson's disease (PD). Serum samples obtained from a cohort of 51 patients with PD and from 37 age- and sex-matched controls were assessed for the presence of antibodies. The control group was selected from healthy people. In both groups, 5 mL of blood was taken and after centrifugation frozen at -80°C. Presence and concentration for C. pneumoniae IgM and IgG were determined by the enzyme linked immunosorbent assay (ELISA) and immunofluorescence (IFA), using C. pneumoniae IgG and IgM kit (Euroimmun, Germany). Chlamydia pneumoniae IgG was positive in 50 (98%) patients in ELISA study. C. pneumoniae IgG was positive in 34 (92%) control subjects in ELISA study. C. pneumoniae IgG positivity in patients was slightly higher, but the difference did not reach statistical significance (P = 0.17). No statistically significant difference was found between the patient and the control groups in IFA study (P ≥ 0.5). C. pneumoniae IgM results (both ELISA and IFA study) was negative in the both PD group and control group.

A new ELISA method for serological diagnosis of Legionella pneumophila: use of five purified proteins, FLA, MOMP, MIP, IP, and PILE, as diagnostic antigen.

Legionella pneumophila plays an important role in human infection. Commercial ELISA kits commonly used, which take Legionella pneumophila whole-cell protein as the coating antigen, often have cross-reactivity among serogroups or species. In this study, five Legionella pneumophila proteins FLA, MOMP, MIP, IP, and PILE were purified and further applied in serological diagnosis of Legionella pneumophila infections compared with R & D Legionella ELISA kits. The five recombinant plasmids pET-fla, pET-momp, pET-mip, pET-ip, and pET-pile were transformed into E. coli BL21 and then induced them with IPTG. The expression products were analyzed by SDS-PAGE and purified by affinity chromatography. Indirect enzyme-linked immunosorbent assays (ELISAs) were established with the five purified proteins FLA, MOMP, MIP, IP, and PILE altogether as the coating antigen and tested for the presence of IgG, IgM, and IgA antibody independently from 50 positive sera and 40 negative sera, compared with R & D IgG, IgM, and IgA Legionella ELISA kits. The FLA protein about 42 kDa in size, the MOMP protein about 45 kDa, the MIP protein about 40 kDa, the IP protein about 46 kDa, and the PILE protein about 35.7 kDa were separately expressed and purified. Compared with R & D IgG, IgM, and IgA Legionella ELISA kit, the outcome of indirect ELISAs set up with the five purified proteins showed that for IgG the sensitivity was 90.4%, the specificity was 97.4%, the area under ROC curve was 0.939, the kappa value was 0.865, the 95% confidence interval was 0.883 - 0.995. For IgM the sensitivity was 91.8%, the specificity was 95.1%, the area under ROC curve was 0.935, the kappa value was 0.866, the 95% confidence interval was 0.876 - 0.994. For IgA the sensitivity was 93.6%, the specificity was 95.3%, the area under ROC curve was 0.945, the kappa value was 0.889, the 95% confidence interval was 0.890 - 0.999. The proteins FLA, MOMP, MIP, IP, and PILE were successfully expressed and purified, and they seemed to be suitable coating antigens for the serological diagnosis of Legionella pneumophila.

High seroprevalence of echinococossis, schistosomiasis and toxoplasmosis among the populations in Babati and Monduli districts, Tanzania.

BackgroundThe neglected tropical diseases, echinococcosis, schistosomiasis and toxoplasmosis are all globally widespread zoonotic diseases with potentially harmful consequences. There is very limited data available on the prevalence of these infections, except for schistosmiasis, in underdeveloped countries. This study aimed to determine the seroprevalence of Echinococcus multilocularis, Schistosoma mansoni, and Toxoplasma gondii antibodies in populations from the Monduli and Babati districts in Tanzania.MethodsA total of 345 blood samples were collected from 160 and 185 randomly selected households from Babati and Monduli districts, Tanzania between February and May of 2012 and analyzed them using the enzyme linked immunosorbent assay. The antibodies were determined using the NovaLisa® Toxoplasma gondii IgG, NovaLisa® Schistosoma Mansoni IgG, NovaLisa® Echinococcus IgG and NovaLisa® Toxoplasma gondii IgM kits (Novatec, Germany).ResultsThe seropositivity estimated for E. multilocularis, S. mansoni, and T. gondii IgG was 11.3% (95% confidence interval (CI): 7.96 - 14.6), 51.3% (95% CI: 46.0 - 56.5), and 57.68% (95% CI: 52.5 - 62.9), respectively. The seropositivity for T. gondii IgM was 11.3% (95% CI: 7.96 - 14.6). Living in the Monduli district was found to be the main risk factor for IgG seropositivity for both schistosomiasis (OR =1.94; 95% CI: 1.23 - 3.08; p =0.005) and toxoplasmosis (OR =2.09; 95% CI: 1.31-3.33; p =0.002).ConclusionsThese results suggest that restricting disease transmission, implementing control measures, and introducing training projects to increase public awareness are imperative, particularly for the Monduli district.

Investigation Correlates of Chlamydia Anti-Body Testing and Hysterosalpingography among Women with Tubal Infertility

Background: Chlamydia trachomatis infection is an important preventable cause of infertility. In women, up to 70% of genital infection with Chlamydia trachomatis are asymptomatic. In the management of infertility patients, a lot of clinicians or centres do not routinely screen for Chlamydia trachomatis infection. Hence all patients being investigated for infertility may potentially be at risk of tubal blockage in addition to non-tubal factor aetiology. Those with primary tubal blockage also are at risk of worsening of the blockage. Objective: To determine if there is a relationship between IgG and IgM Chlamydia antibody testing (CAT) and tubal factor infertility. Design: It was a cross sectional descriptive study. Method: The sera of 400 consecutive consenting infertile patients presenting to the gynaecological clinic of the Ahmadu Bello University Teaching Hospital, Zaria, Northern Nigeria were tested for Chlamydia antibodies using ELISA IgG and IgM kits produced by Diagnostic Automation, Inc., 23961 Craftsman Road, Suite D/E/F, Calabasas, CA 91302, USA. Results: Up to 264 (66%) of the patients had tubal factor, 64 (16%) had uterine, 56 (14%) had ovarian, 50 (12.5%) had male while 40 (10%) had others. The causative factors were not mutually exclusive. The sero-prevalence of IgG and IgMChlamydia trachomatis amongst patients with tubal infertility were 35.6% and 35.6% respectively. There was a stronger significant relation (P = 0.008) between IgM sero-positivity which suggests recent infection and tubal infertility. The relation between IgG sero-positivity which suggest chronic infection and tubal infertility was also significant (P = 0.036) but relatively lower. Conclusion: The sero-prevalence of Chlamydia trachomatis infection, IgG and IgM was significantly higher among the sub-population with tubal infertility. Chlamydia antibody testing (CAT) has predictive value for tubal infertility.

Porcine reproductive and respiratory syndrome virus (PRRSV) surveillance using pre-weaning oral fluid samples detects circulation of wild-type PRRSV

Oral fluid samples collected from litters of piglets (n=600) one day prior to weaning were evaluated as a method to surveil for porcine reproductive and respiratory syndrome virus (PRRSV) infections in four sow herds of approximately 12,500 sow each. Serum samples from the litters’ dam (n=600) were included for comparison. All four herds were endemically infected with PRRSV and all sows had been vaccinated ≥2 times with PRRSV modified-live virus vaccines. After all specimens had been collected, samples were randomized and assayed by PRRSV real-time reverse transcription polymerase chain reaction (RT-qPCR) and four PRRSV antibody ELISA assays (IgM, IgA, IgG, and Commercial Kit). All sow serum samples were negative by PRRSV RT-qPCR, but 9 of 600 oral fluid samples tested positive at two laboratories. Open reading frame 5 (ORF5) sequencing of 2 of the 9 positive oral fluid samples identified wild-type viruses as the source of the infection. A comparison of antibody responses in RT-qPCR positive vs. negative oral fluid samples showed significantly higher IgG S/P ratios in RT-qPCR-positive oral fluid samples (mean S/P 3.46 vs. 2.36; p=0.02). Likewise, sow serum samples from RT-qPCR-positive litter oral fluid samples showed significantly higher serum IgG (mean S/P 1.73 vs. 0.98; p<0.001) and Commercial Kit (mean S/P 1.97 vs. 0.98; p<0.001) S/P ratios. Overall, the study showed that pre-weaning litter oral fluid samples could provide an efficient and sensitive approach to surveil for PRRSV in infected, vaccinated, or presumed-negative pig breeding herds.

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Bartonella henselae, the etiologic agent of cat-scratch disease, causes a self-limited syndrome of fever and regional lymphadenopathy in immunocompetent hosts. In immunocompromised hosts, however, B. henselae can cause severe disseminated disease and pathologic vasoproliferation known as bacillary angiomatosis or bacillary peliosis. The spectrum of disease, diagnosis and management of B. henselae infection in solid organ transplant recipients has not been well characterized. The purpose of this study has been to determine the seroprevalence of B. henselae in patients awaiting heart transplantation, in our Regional Reference Transplantation Centre. The diagnosis of B. henselae is usually based on serological methods (IgM, IgG). Immunofluorescent assays (IFA) are used for the detection of IgG or IgM antibodies against specific antigens. Bartonella IgM and IgG test kits are designed to detect the antigen-antibody complexes when diluted sera are presented with Bartonella antigens on commercially produced slides. A fluorescein-labeled anti-IgG or IgM conjugate is responsible for visualization of reactions. Serum samples from 21 (16M, 5F) patients awaiting heart transplantation, with a median age of 53 ± 15SD (range 8-68 years) and 20 healthy donors (10M and 10F), with a median age of 37 ± 5.9SD (range 28-49 years) were examined by indirect immunofluorescence assay. In our study we have found, in patients awaiting heart transplantation, a B. henselae antibody positivity rate of 19.04% (4/21) and in particular, 1/21 (4.76%) patients presented IgM while 3/21 (14.28%) presented IgG. All healthy donors were found negative. Our preliminary serological data seems to indicate that B. henselae is present in our area and more interestingly it can be also present in patients awaiting heart transplantation. Thus, on the basis of our data, we would recommend the importance of including B. henselae diagnosis also in pre-transplant patients.

BACTERIAL PROFILE, ANTIBIOTIC SENSITIVITY AND RESISTANCE OF LOWER RESPIRATORY TRACT INFECTIONS IN UPPER EGYPT

BackgroundLower respiratory tract infections (LRTI) account for a considerable proportion of morbidity and antibiotic use. We aimed to identify the causative bacteria, antibiotic sensitivity and resistance of hospitalized adult patients due to LRTI in Upper Egypt.MethodsA multicentre prospective study was performed at 3 University Hospitals for 3 years. Samples included sputum or bronchoalveolar lavage (BAL) for staining and culture, and serum for serology. Samples were cultured on 3 bacteriological media (Nutrient, Chocolate, MacConkey's agars). Colonies were identified via MicroScan WalkAway-96. Pneumoslide IgM kit was used for detection of atypical pathogens via indirect immunofluorescent assay.ResultsThe predominant isolates in 360 patients with CAP were S. pneumoniae (36%), C. pneumoniae (18%), and M. pneumoniae (12%). A higher sensitivity was recorded for moxifloxacin, levofloxacin, macrolides, and cefepime. A higher of resistance was recorded for doxycycline, cephalosporins, and β-lactam-β-lactamase inhibitors. The predominant isolates in 318 patients with HAP were, methicillin-resistant Staphylococcus aureus; MRSA (23%), K. pneumoniae (14%), and polymicrobial in 12%. A higher sensitivity was recorded for vancomycin, ciprofloxacin, and moxifloxacin. Very high resistance was recorded for β-lactam-β-lactamase inhibitors and cephalosporins. The predominant organisms in 376 patients with acute exacerbation of chronic obstructive pulmonary diseases (AECOPD) were H. influnzae (30%), S. pneumoniae (25%), and M. catarrhalis (18%). A higher sensitivity was recorded for moxifloxacin, macrolides and cefepime. A higher rate of resistance was recorded for aminoglycosides and cephalosporins.ConclusionsThe most predominant bacteria for CAP in Upper Egypt are S. pneumoniae and atypical organisms, while that for HAP are MRSA and Gram negative bacteria. For acute exacerbation of COPD, H. influnzae was the commonest organism. Respiratory quinolones, macrolides, and cefepime are the most efficient antibiotics in treatment of LRTI in our locality.

Diagnostic Performance of Commercially Available Enzyme-Linked Immunosorbent Assay Kit in the Diagnosis of Extrapulmonary Tuberculosis

Objectives:Antibody based serodiagnosis tests for tuberculosis (TB) was used widely in developed and developing countries. Pathozyme Myco® immunoglobulin (Ig) M, IgA, and IgG were evaluated in pulmonary TB in many studies.Materials and Methods:In this study we assessed this commercially available kit in detecting extrapulmonary TB (EPTB).Results:A total of 354 subjects were recruited for the study, of which 217 (61.2%) were EPTB patients and 137 (38.7%) were subjects with no suggestive TB. The mean age was 29.7 ± 13.7 and 31.2 ± 15.2 years, respectively for two groups. Serum samples were tested for IgM, IgA, and IgG using Pathozyme Myco® IgM, IgA, and IgG kit. The individual specificity rates of IgM, IgA, and IgG were 70.8% (95% confidence interval (CI): 62.7-77.7), 77.3% (95% CI: 68.6-83.5), and 68.6%. (95% CI: 60.4-75.7); while their sensitivity was 29% (95% CI: 23.4-35.4), 24.4% (95% CI: 19.1-30.5), and 34.5% (95% CI: 28.5-41.1); respectively.Conclusion:The serological tests either singly or in combination failed or performed poorly to diagnose EPTB.

Antigenic determinants of hepatitis E virus and vaccine-induced immunogenicity and efficacy

There is emerging evidence for an under-recognized hepatitis E virus (HEV) as a human pathogen. Among different reasons for this neglect are the unsatisfactory performance and under-utilization of commercial HEV diagnostic kits; for instance, the number of anti-HEV IgM kits marketed in China is about one-fifth of that of hepatitis A kits. Over the last two decades, substantial progress has been achieved in furthering our knowledge on the HEV-specific immune responses, antigenic features of HEV virions, and development of serological assays and more recently prophylactic vaccines. This review will focus on presenting the evidence of the importance of HEV infection for certain cohorts such as pregnant women, the key antigenic determinants of the virus, and immunogenicity and clinical efficacy conferred by a newly developed prophylactic vaccine. Robust immunogenicity, greater than 195-fold and approximately 50-fold increase of anti-HEV IgG level in seronegative and seropositive vaccinees, respectively, as well as impressive clinical efficacy of this vaccine was demonstrated. The protection rate against the hepatitis E disease and the virus infection was shown to be 100 % (95 % CI 75–100) and 78 % (95 % CI 66–86), respectively.

Mycoplasma pneumoniae: IgG and IgM antibody response in presence of different antigens. Evaluation of commercial tests

Background. P1 adhesin protein (170-kDa) is responsible for the interaction between M. pneumoniae and the host. Such protein is the target of specific antibodies produced by the host in response to M. pneumoniae infection. Objectives. The aim of this study was to evaluate the performance of serological tests for Mycoplasma pneumoniae IgG and IgM on chemiluminescence analyzer LIAISON® and to demonstrate how the determination of specific antibodies is the main tool for accurate diagnosis of Mycoplasma infection. Study Design. Eighty-one unselected samples were assayed by ELISA kits Vircell IgG and IgM (bacterial lysate) and LIAISON® Mycoplasma IgG and IgM (recombinant protein P1). The discordant samples were tested with ELISA Savyon Serorecombinant IgG and IgM (recombinant protein P1) and reclassified according to the consensus rule. Results. Fifty-one samples were concordant between ELISA Vircell IgG and LIAISON® Mycoplasma IgG. After resolution of the 30 discordant: twenty-eight samples were classified concordant negative and one positive. Seventy-seven samples were concordant between ELISA Vircell IgM and LIAISON® Mycoplasma IgM. After resolution of 4 discordant samples: three samples were classified as negative. Conclusions. The higher correlation between LIAISON® and Savyon Serorecombinant is determined by the use of recombinant protein P1 in the solid phase and the type of cut-off calculation allows high specificity and sensitivity. The Mycoplasma pneumoniae IgG and IgM kits, performed in full automation on LIAISON® analyzer, show characteristics comparable to other kits and an easy handling of the sample.

Anti-Babesia microti antibodies in foresters highly exposed to tick bites in Poland

Human babesiosis caused by Babesia microti and Babesia divergens parasites is an emerging tick-borne disease worldwide. The prevalence of infection and frequency of the disease caused by B. microti in Europe is not well known. The aim of our study was to evaluate the frequency of anti-B. microti antibodies in the serum of forest employees (a population highly exposed to tick bites) from 2 different regions of Poland. We studied 114 foresters from 2 separate forest inspectorates in north-eastern and central Poland. Direct immunofluorescence assays (Babesia microti IgM and IgG IFA kits) were used to detect serum IgM and IgG anti-B. microti antibodies. Simultaneously, anti-B. burgdorferi antibodies were detected using an enzyme-linked immunosorbent assay kit, and positive cases were confirmed with immunoblot. Anti-B. microti IgG antibodies were detected in 5 foresters (4.4%), all from the forest inspectorate in Białowieża in the northeast of the country. All persons with anti-B. microti antibodies were also IgG-seropositive for B. burgdorferi. Our results suggest that unrecognized infections with B. microti occur in the Polish population and should be considered in the differential diagnosis of a febrile illness occurring after exposure to ticks, particularly in patients from endemic regions.

874 Serological Diagnosis of Lyme Neuroborreliosis in Children with Various Neurological Disorders - Comparison of Two Elisa Tests

Aim: We wanted to compare two ELISA kits for detection of IgG and IgM antibodies against Borrelia in samples taken from children with suspected neuroborreliosis. Methods: Between 01.04.2009 and 31.03.2010 serum and cerebrospinal fluid from children with various neurological symptoms were analyzed using Biomedica kits. Positive samples were confirmed with MIKROGEN Diagnostik Immunoblot assay and tested with DRG Diagnostics kits. The Biomedica IgG kit contains recombinant antigens: OspC, p18, p100 and VIsE ; the IgM Biomedica kit contains recombinant antigens: OspC (B.afzelii, B.garinii), p41/I, VIsE. The DRG IgG kit contains recombinant VIsE antigen and lysate antigens from B.burgdorferi s.s., B.afzelii and B.garinii; the DRG IgM kit contains recombinant 14 kD protein and native OspC. Interpretation of the ELISA and Immunoblot was done according to the manufacturer's instructions. Results: A total of 379 samples (353 sera and 26 CSF) were analyzed for Borrelia antibodies. Antibodies against B.burgdorferi were detected by Biomedica kit in 55 samples from which 29 (52%) were confirmed with Immunoblot. Based on the Immunoblot analysis 29 / 379 (7,3 %) samples were considered as “true positive”. Among two ELISA tests, 26 sera were false-positive with the Biomedica test and 13 sera were false-positive with the DRG Diagnostics test. However, DRG Diagnostics test failed to detect two sera that were positive with the Biomedica test and Immunoblot. Conclusions: We observed significant differences between the two ELISA tests. Biomedica test showed higher sensitivity but it produced more false-positive results. DRG Diagnostics test was more specific, but less sensitive.

Hepatitis E virus in HIV-infected patients

Many cases of acute autochthonous hepatitic E virus (HEV) hepatitis have been reported in France, mainly from the south. Chronic HEV infection has recently been described in immunosuppressed patients. Although a potential risk of chronicity exists in HIV-infected patients, no survey has been conducted in this population. The aim of this study was to assess the sero-virological prevalence of HEV in French HIV-infected patients. Two hundred and forty-five HIV-infected patients followed at two Infectious Diseases Departments (one in the south, one in the north) were included from January to March 2009. Sera were collected from all patients and tested using anti-HEV IgG and IgM kits. HEV RNA was systematically amplified in the ORF2 region with an in-house method. The IgG avidity index of all IgG-positive samples was determined. Three of the 133 southern patients showed both anti-HEV IgG and IgM positivities, along with cytolysis and biological cholestasis; HEV RNA was amplified in two of these cases, whereas a low IgG avidity index was observed in all three samples. Twelve of the 130 remaining southern patients (9%) showed anti-HEV IgG positivity. The serological prevalence in the 112 northern patients was 3%, which was significantly lower than in the southern patients (P=0.04). No case of acute hepatitis was reported in the north, whereas the prevalence of patients with biochemical liver abnormalities was similar in both areas (P=0.22). In France, HIV-infected patients are at risk of HEV infection with a serological north-to-south gradient. No case of chronic HEV infection was detected in this study.

Evaluation of the diagnostic kits for hepatitis E and establishment of a quantification method for de-tecting anti-HEY IgG

Objective To evaluate anti-HEV IgG and IgM diagnostic kits with sera from convalescent hepatitis E patients and to establish the quantification method of detecting anti-HEV lgG.Methods Detect 42 convalescent serum samples of over 6 months after onset of hepatitis E patients from Jiangsu province with anti-HEV IgM and IgG diagnostic kits. Select and mix the anti-HEV IgG positive sera which were confirmed by Western blot with ORF2 and ORF3 antigen. The mixed serum was calibrated with a WHO anti-HEV Ig standard. A series quantitative linear standard was made for quantitative detection of anti-HEV IgG in hepatitis E vaccine clinical trials phase Ⅲ. Results The positive rates of the anti-HEV IgG di-agnose kits of G, K, MP, Wantai were 71.4%, 78.6%, 92.9% and 100% respectively. The positive rates of G was lower than that of MP (X2 = 5.19, P<0.05) and obviously lower than Wantai (X2 = 11.76,P<0.01). The positive rates of K was also obviously lower than that of Wantai (X2 =7.96, P <0.01).The positive rates of the anti-HEV lgM diagnose kits of MP, G, X, Wantai, K were 21.4%, 7.1%,21.4%, 64.3%, 78.6% respectively. The positive rate of both K and Wantai were obviously higher than that of MP(X2 = 15.75 ,P<0.01 ; X2 = 27.43 ,P< 0.01). With the Western blot confirmation test, 30 and 18 sera were reactive to ORF2 and ORF3 antigen separately. The anti-HEV IgG concentration of HEV-D01 mixed by 13 samples was 57.94 U/ml by the calibration. Prepare seven 1.5-fold dilution series of quantita-tive linear standard for HEV vaccine clinical trials phase Ⅲ, concentration range from 0.077 to 0.877 U/ml. The quantitive values of high, medium and low concentrations quality control samples lay in the range of average ± 2s, and the CV of quantitative values were 16%, 16%, 12% respectively. Conclusion The quality of different anti-HEY IgM and IgG diagnose kits were different. This study had set up a set of anti-HEV IgG linear quantitative standard, which fit for detecting anti-HEV IgG antibodies quantitatively in HEVvaccine clinical trial phase Ⅲ. Key words: Hepatitis E virus; IgG antibody; IgM antibody; Quantitation