Antibody Capture Enzyme-linked Immunosorbent Assay Research Articles

A Serological Assay for the Detection of Antibodies Generated Against California Serogroup Virus Infection.

The California serogroup (CSG) viruses are orthobunyaviruses endemic in North America and responsible for the second most common cause of mosquito-borne viral encephalitis in the United States. As the CSG viruses have been neglected and are poorly studied, there are no commercial diagnostic serological assays or reagents available for detection. Therefore, diagnostic laboratories have had to rely on the development of their own in-house serological assays. To develop serological assays, antigenic materials such as recombinant protein, virus-like particles (VLP), or inactivated virus can be used in the IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) to detect CSG virus-specific IgM antibodies. All positive MAC-ELISA results should be confirmed by a well-defined gold standard test method such as the plaque-reduction neutralization test (PRNT).

Evaluation of the correlation of serological and intradermal allergen testing with clinical history in 29 dogs with atopic dermatitis.

Limited information exists about the correlation between clinical history and positive serum (SAT) and intradermal allergen test (IDAT) results in atopic dogs. To evaluate the correlation between clinical history and SAT/IDAT results in atopic dogs. Twenty-nine client-owned dogs with nonseasonal atopic dermatitis with or without seasonal exacerbation were enrolled. IDAT, SAT (immunoglobulin (Ig)M antibody capture enzyme-linked immunosorbent assay [MacELISA] with bromelain CCD inhibitor) and clinical information collected in a questionnaire regarding seasonal variations in pruritus affecting the dogs were performed on the same day. Two independent investigators (Inv A and Inv B) recorded IDAT results. The kappa coefficients agreement for positive IDAT scores between Inv A and B was substantial. The agreement between IDAT and SAT results at different ELISA absorbance units (EAU) cut-offs (>79 and ≥300) was slight and fair for both investigators, respectively. A higher agreement was observed between IDAT and SAT (≥300 EAU) than between IDAT and SAT (>79 EAU) with the exception of mite and flea allergens. There was a statistically significant association between clinical history and positive IDAT results for seasonal allergens (Inv A and Inv B, p = 0.016). There was no significance between positive SAT results and clinical history. Five (IDAT) and 12 of 13 (SAT) atopic dogs without clinical seasonal exacerbation showed positive results for seasonal allergens. The agreement between IDAT and SAT ≥300 EAU results was fair and the agreement between IDAT and SAT >79 EAU results was slight for all allergens. Only positive IDAT results significantly correlated with clinical history.

A comparative study of NS1 and IgM using enzyme-linked immunosorbent assay and immunochromatography test for detection of dengue.

Dengue is the most common arboviral infection that spreads by Aedes aegypti and Aedes albopictus mosquitoes, and is quickly gaining prominence as a major mosquito-borne viral disease. One of the major public health issues is dengue fever (DF), which can also cause dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS). Therefore, this study focused on comparison of dengue antigen non-structural protein (NS1) and immunoglobulin M (IgM) using enzyme-linked immunosorbent assay (ELISA) and immunochromatography test (ICT) for detection of dengue. In a Tertiary Care Hospital (TCH), sociodemographic status of probable dengue cases from February 2021 to February 2022 was studied. The results of the Dengue Antigen NS1 and IgM ICT, Dengue NS1 Microlisa, and Dengue IgM Microlisa were compared in order to determine the effective one at managing patients and preventing complications like DHF and DSS. In distribution of 100 ICT reactive samples, 50% were NS1 reactive and 50% were IgM reactive. One hundred ICT reactive samples were further processed for IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) for both NS1 and IgM. Sensitivity and specificity of NS1 ICT were 89.3% and 71.4% and that of IgM ICT was 88% and 64.5%. As a result of antigenic cross-reactivity, false positive cases were reported. Platelet count of the patients was correlated with an optical density (OD) value of ELISA for both NS1 and IgM. In the present study, patients having low platelet count showed high OD value. In cases of severe thrombocytopenia (platelet count <50000), early diagnosis by screening ICT and confirmation by ELISA (NS1 and IgM) would reduce the complications like DHF and DSS.

Characterization of a monoclonal antibody specific to California serogroup orthobunyaviruses and development as a chimeric immunoglobulin M-positive control in human diagnostics.

Orthobunyaviruses in the California serogroup cause severe neurological disease in children and adults. While these viruses are known to circulate widely in North America, their occurrence is rare. Serological testing for CSGVs is hindered by the limited availability and volumes of human-positive specimens needed as controls in serologic assays. Here, we described the development of a murine monoclonal antibody cross-reactive to CSGVs engineered to contain the variable regions of the murine antibody on the backbone of human IgM. The chimeric IgM produced from the stably expressing HEK293 cell line was evaluated for use as a surrogate human-positive control in a serologic diagnostic test.

Seropositivity of dengue cases at a tertiary care centre in Chhindwara, Madhya Pradesh: A three year trend

BackgroundDuring the recent decades, dengue virus infection has been emerged as a major public health problem. Dengue is one of the important mosquito borne infections causing high mortality and morbidity of humans. Methods: This study was carried out from October 2018 to December 2020. A total of 354 serum samples of clinically suspected dengue patients were tested for immunoglobulin M (IgM) anti-dengue antibodies by dengue monoclonal antibody capture enzyme-linked immunosorbent assay (NIV DEN IgM Capture MAC ELISA). Seasonal variations, age and sex wise incidences were also determined. ResultsTotal of 354 serum samples were processed from October 2018 to December 2020. Each year males were mostly infected with Dengue 08, 10, and 03 in 2018, 2019, and 2020, respectively. Age group 11–20 was found to be mostly infected by Dengue in case of both male and female. The prevalence of Dengue in each year was from July to November might be due to the rainy season. Clinical characteristics of patients such as fever, headache, abdominal pain and nausea/vomiting, retro-orbital pain, epistaxis, petechiae, altered sensorium, positive tourniquet test were reported. ConclusionsContinuous dengue virus surveillance is required for monitoring of dengue virus so that early detection can be carried out. Effective vector control measures should be implemented for early detection of impending outbreak and to initiate timely control measures.

Ebola Virus Disease (Evd): Nigeria Perspective

The deadly but uncommon Ebola virus disease affects both humans and primates (EVD). The Ebola virus causes a severe form of hemorrhagic fever in which the victim’s blood clots abnormally, leading to internal bleeding. After initial contact with the virus, "dry" symptoms such as fever, aches and pains, and exhaustion typically appear, followed by "wet" symptoms such as diarrhoea and vomiting anywhere from two to twenty-one days (on average, eight to ten) later Virologists believe Laupland and Valiquette are hosting the virus. It is believed that the onlyway for the Ebola virus to spread is through direct contact between people and blood or other body fluids from a person showing symptoms of the disease. Saliva, mucus, vomit, faeces, tears, perspiration, breast milk, urine, and sperm all contain the Ebola virus. The term "spillover" is used to describe the zoonotic spread of the Ebola virus from infected hosts like the fruit bat or nonhuman primates to other animals. The Ebola virus is amember of the viral family known as Filoviridae in the order of Mononegavirales the Marburg virus is also. Ebola virus infection can be diagnosed through a variety of techniques, including electron microscopy, antigen capture detection tests, serum neutralisation tests, reverse transcriptase polymerase chain reaction (RT PCR) assays, antibody-capture enzyme-linked immunosorbent assays (ELISAs), and virus isolation through cell culture. The term "Ebola vaccine" refers to both already available and planned vaccines against the virus. Only Zaire ebolavirus and rVSV-ZEBOV vaccines are effective against this disease. Treatment that is purely supportive, such as relieving patients of their symptoms and giving them water orally or intravenously, does not improve prognosis. This research intends to give Nigerians an up-to-date picture of the spread of EVD in the country in the wake of the recent pandemic in neighboring Uganda.

Evaluation of Two Serological Assays for Diagnosing Zika Virus Infection.

Zika virus (ZIKV) emerged and spread rapidly in South American countries during 2015. Efforts to diagnose ZIKV infection using serological tools were challenging in dengue-endemic areas because of antigenic similarities between both viruses. Here, we assessed the performance of an in-house developed IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) and the plaque reduction neutralization test (PRNT) to diagnose ZIKV infection. Acute and convalescent paired serum samples from 51 patients who presented with clinical symptoms suggestive of an arbovirus illness in dengue-endemic areas of Honduras, Venezuela, Colombia and Peru were used in the assessment. Samples were tested for ZIKV, dengue and chikungunya virus using a variety of laboratory techniques. The results for the ZIKV-RNA screening and seroconversion detected by the microneutralization test were used to construct a composite reference standard. The overall sensitivity and specificity for the MAC-ELISA were 93.5% and 100.0%, respectively. Contrastingly, the overall sensitivity and specificity for the PRNT were 96.8% and 95.0%, respectively. Restricting the analysis according to IgM or neutralizing antibodies against dengue, the performances of both serological assays were adequate. The findings of this study reveal that the MAC-ELISA and PRNT would provide initial reliable laboratory diagnostic assays for ZIKV infection in dengue-endemic areas.

Frequency of Zika Virus Immunoglobulin M Antibody in Persons with West Nile Virus Infection.

West Nile virus (WNV) and Zika virus (ZIKV) are mosquito-borne viruses in the family Flaviviridae. Residents in, and travelers to, areas where the viruses are circulating are at risk for infection, and both viruses can cause an acute febrile illness. Given known cross-reactivity in flavivirus serologic assays, it is possible a patient with acute WNV infection could be misdiagnosed as having ZIKV infection if appropriate testing is not conducted. To understand how frequently persons with WNV infection have detectable cross-reactive ZIKV immunoglobulin M (IgM) antibody, we used archived serum samples from patients in the United States with recent WNV infection confirmed by a microsphere-based immunoassay test for IgM antibody and neutralizing antibody testing. Samples were tested for ZIKV IgM antibody with the Centers for Disease Control and Prevention (CDC) ZIKV IgM antibody capture enzyme-linked immunosorbent assay. Among 153 sera from patients with acute WNV infection, the ZIKV IgM antibody result was positive in 56 (37%; 95% confidence interval [CI] 29-44%) and equivocal in 28 (18%; 95% CI 13-25%). With 55% of samples having cross-reactive antibodies, it is important for health care providers to request appropriate testing based on the most likely cause of a patient's possible arboviral infection considering their clinical symptoms and signs, travel history, and place of residence. For cases where the epidemiology does not support the preliminary IgM findings, confirmatory neutralizing antibody testing should be performed. These measures will avoid an incorrect diagnosis of ZIKV infection, based on cross-reactive antibodies, in a person truly infected with WNV.

Technical viability of the YF MAC-HD ELISA kit for use in yellow fever-endemic regions.

Yellow fever (YF), an arboviral disease, affects an estimated 200,000 people and causes 30,000 deaths per year and recently has caused major epidemics in Africa and South America. Timely and accurate diagnosis of YF is critical for managing outbreaks and implementing vaccination campaigns. A YF immunoglobulin M (IgM) antibody-capture (MAC) enzyme-linked immunosorbent assay (ELISA) kit, the YF MAC-HD, was successfully introduced starting in 2018 to laboratories in Africa and South America. The YF MAC-HD kit can be performed in 3.5 hours, test up to 24 samples, and includes all reagents necessary to perform the test, except for water used to dilute wash buffer. In 2018 and 2019, a total of 56 laboratory personnel from 39 countries in Africa and South America were trained to use the kit during workshops, followed by take-home YF IgM proficiency testing (PT) exercises. Participants received either a 10- or 20-sample YF PT panel and performed testing using the YF MAC-HD kit. All countries obtained 90% or higher correct results. These results verified the technical viability and transferability of YF MAC-HD kit use for laboratories in YF-endemic countries.

Burden of Dengue and Chikungunya – A Retrospective Study

Arboviral infections like dengue fever and chikungunya are the most common infections that share the same Aedes mosquito vectors. Clinical presentations of these two infections are also similar, especially in initial stages. Non-structural antigen (NS1 Ag)detection for dengue and detection of IgM antibodies by capture ELISA for chikungunya and dengue infection may help in the early diagnosis. Early diagnosis is essential for the treatment and control measures. The present study was conducted to know the burden of dengue and chikungunya. A retrospective study was conducted for a period of 1 year from Dec 2017 to Nov 2018 to know the burden of dengue and chikungunya in Chamarajanagar. Dengue (&gt; 5 days fever) and chikungunya testing was done by IgM antibody capture ELISA kits produced by NIV. Dengue samples (&lt; 5 days fever) were subjected to NS1 antigen detection by microwell enzyme-linked immunosorbent assay (ELISA) from Qualpro diagnostics. The tests were carried out following manufacturer’s instruction. Samples received for dengue NS1 Ag testing was 446, of which, 49(11.0%) were positive and of 730 samples received for IgM antibody, 53 (7.3%) were positive. Age group commonly affected was 0-20 years 44(43.1%). Of 668 samples received for chikungunya test, 86 (12.9%) were positive. Maximum number of cases was seen in age group of 21-40 years 45(52.3%). Males 56(54.9%) were affected higher than female 46(45.1%) in dengue infection while in chikungunya, females 45(52.3%) were more affected than males 41(47.7%). Both infections are high in the month of June and July. Early detection of dengue by NS1 antigen and detection of Ig M antibodies by capture ELISA chikungunya and dengue infection helps in appropriate treatment and initiation of prevention and control measures by community awareness and vector control.

Comparable Accuracies of Nonstructural Protein 1- and Envelope Protein-Based Enzyme-Linked Immunosorbent Assays in Detecting Anti-Dengue Immunoglobulin G Antibodies.

Background: Dengue virus (DENV) infection remains a global public health concern. Enzyme-linked immunosorbent assays (ELISAs), which detect antibodies targeting the envelope (E) protein of DENV, serve as the front-line serological test for presumptive dengue diagnosis. Very few studies have determined the serostatus by detecting antibodies targeting the nonstructural protein 1 (NS1), which can function as diagnostic biomarkers to distinguish natural immunity from vaccine-induced immunity. Methods: We used community-acquired human serum specimens, with the serostatus confirmed by focus reduction microneutralization test (FRμNT), to evaluate the diagnostic performances of two NS1-based ELISA methods, namely, immunoglobulin G antibody-capture ELISA (NS1 GAC–ELISA) and indirect NS1 IgG ELISA, and compared the results with an E-based virus-like particle (VLP) GAC–ELISA. Results: NS1-based methods had comparable accuracies as VLP GAC–ELISA. Although the sensitivity in detecting anti-NS1 IgM was poor, indirect NS1 IgG ELISA showed similar limits of detection (~1–2 ng/mL) as NS1 GAC–ELISA in detecting anti-NS1 IgG. Combining the results from two or more tests as a composite reference standard can determine the DENV serostatus with a specificity reaching 100%. Conclusion: NS1-based ELISAs have comparable accuracies as VLP GAC–ELISA in determining dengue serostatus, which could effectively assist clinicians during assessments of vaccine eligibility.

Accuracy of the Zika IgM Antibody Capture Enzyme-Linked Immunosorbent Assay from the Centers for Disease Control and Prevention (CDC Zika MAC-ELISA) for Diagnosis of Zika Virus Infection.

Serological diagnosis of Zika virus (ZIKV) infection is challenging because of antigenic cross-reactivity with dengue virus (DENV). This study evaluated the accuracy of the Zika IgM antibody capture enzyme-linked immunosorbent assay (CDC Zika IgM MAC-ELISA) in differentiating between ZIKV and DENV infections. To determine sensitivity, we used acute- and convalescent-phase sera from 21 patients with RT-PCR-confirmed ZIKV infection. To determine specificity, we used acute- and convalescent-phase sera from 60 RT-PCR-confirmed dengue cases and sera from 23 blood donors. During the acute-phase of the illness, the assay presented a sensitivity of 12.5% (2/16) for samples collected 0–4 days post symptoms onset (DPSO), and of 75.0% (3/4) for samples collected 5–9 DPSO. During the convalescent-phase of the illness, the test sensitivity was 90.9% (10/11), 100% (2/2), and 0% (0/2) for samples obtained 12–102, 258–260, and 722–727 DPSO, respectively. Specificity for acute- and convalescent-phase samples from RT-PCR-confirmed dengue cases was 100% and 93.2%, respectively. Specificity for blood donor samples was 100%. The assay is an accurate method for Zika serological diagnosis and proved to be reliable for use during surveillance and outbreak investigations in settings where ZIKV and DENV cocirculate.

Assessment of Immunoglobulin M Enzyme-Linked Immunosorbent Assay Ratios to Identify West Nile Virus and St. Louis Encephalitis Virus Infections During Concurrent Outbreaks of West Nile Virus and St. Louis Encephalitis Virus Diseases, Arizona 2015.

West Nile virus (WNV) and St. Louis encephalitis virus (SLEV) are closely related mosquito-borne flaviviruses that cause clinical disease ranging from febrile illness to encephalitis. The standard for serological diagnosis is immunoglobulin M (IgM) testing followed by confirmatory plaque reduction neutralization test (PRNT) to differentiate the infecting virus. However, the PRNT is time-consuming and requires manipulation of live virus. During concurrent WNV and SLEV outbreaks in Arizona in 2015, we assessed use of a diagnostic algorithm to simplify testing. It incorporated WNV and SLEV ratios based on positive-to-negative (P/N) values derived from the IgM antibody-capture enzyme-linked immunosorbent assay. We compared each sample's ratio-based result with the confirmed WNV or SLEV sample result indicated by PRNT or PCR testing. We analyzed data from 70 patients with 77 serum and cerebrospinal fluid samples, including 53 patients with confirmed WNV infection and 17 patients with confirmed SLEV infection. Both WNV and SLEV ratios had specificity ≥95%, indicating a high likelihood that each ratio was correctly identifying the infecting virus. The SLEV ratio sensitivity of 30% was much lower than the WNV ratio sensitivity of 91%, likely because of higher cross-reactivity of SLEV antibodies and generation of lower P/N values. The standard for serological diagnosis of WNV and SLEV infections remains IgM testing followed by PRNT. However, these results suggest the ratios could potentially be used as part of a diagnostic algorithm in outbreaks to substantially reduce the need for PRNTs.

Mosquito Cell-Derived Japanese Encephalitis Virus-Like Particles Induce Specific Humoral and Cellular Immune Responses in Mice.

The Japanese encephalitis virus (JEV) is the major cause of an acute encephalitis syndrome in many Asian countries, despite the fact that an effective vaccine has been developed. Virus-like particles (VLPs) are self-assembled multi-subunit protein structures which possess specific epitope antigenicities related to corresponding native viruses. These properties mean that VLPs are considered safe antigens that can be used in clinical applications. In this study, we developed a novel baculovirus/mosquito (BacMos) expression system which potentially enables the scalable production of JEV genotype III (GIII) VLPs (which are secreted from mosquito cells). The mosquito-cell-derived JEV VLPs comprised 30-nm spherical particles as well as precursor membrane protein (prM) and envelope (E) proteins with densities that ranged from 30% to 55% across a sucrose gradient. We used IgM antibody-capture enzyme-linked immunosorbent assays to assess the resemblance between VLPs and authentic virions and thereby characterized the epitope specific antigenicity of VLPs. VLP immunization was found to elicit a specific immune response toward a balanced IgG2a/IgG1 ratio. This response effectively neutralized both JEV GI and GIII and elicited a mixed Th1/Th2 response in mice. This study supports the development of mosquito cell-derived JEV VLPs to serve as candidate vaccines against JEV.

Fluorescein Angiography Findings in Children With Congenital Zika Syndrome.

To evaluate the retinal and vasculature changes in infants with congenital Zika syndrome (CZS) using fluorescein angiography (FA). This consecutive case series included six infants with CZS. FA and color fundus imaging were performed under general anesthesia in both eyes of all infants using a contact widefield digital imaging system. All color fundus images were obtained using a 130° field of view lens, and the FA images were captured using either a 130° or 80° field of view lens. The immunoglobulin M antibody capture enzyme-linked immunosorbent assay was positive for Zika virus in the cerebrospinal fluid samples of all infants. Other congenital infections were ruled out. The mean ± standard deviation age of the infants at the time of examination was 1.4 years ± 0.1 years (range: 1.3 years to 1.5 years). Contact fundus photographs showed macular abnormalities in seven eyes (58%) and retinal vasculature changes in two eyes (17%). FA detected macular abnormalities in all 12 eyes (100%) and retinal vasculature changes in five eyes (42%). The main retinal vasculature changes were peripheral avascularity in five eyes (42%) and microvasculature abnormalities in three eyes (25%). FA may be an important tool for detecting subtle macular and retinal vasculature changes in CZS. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:702-708.].

Glaucoma Workup in Congenital Zika Syndrome.

The main aim of this study was to perform a glaucoma workup in infants with congenital Zika syndrome (CZS). This cross-sectional study included 188 eyes of 107 children (1.1±0.3 y; range, 0.3 to 1.8 y) with CZS. The confirmation of the syndrome was possible in 77 of 107 (72.0%) of the enrolled infants based on positive immunoglobulin M antibody capture enzyme-linked immunosorbent assay for Zika virus in the cerebrospinal fluid. All infants underwent a complete ophthalmic examination and bilateral fundus imaging was captured using a wide-angle digital fundus camera (RetCam). Five eyes (2.6%) presented 2 criteria for glaucoma diagnosis: 1 eye (0.5%) presented increased intraocular pressure and increased vertical cup-to-disc ratio (CDR); 3 eyes (1.6%) presented increased horizontal corneal diameter and increased vertical, and 1 eye (0.5%) presented myopia related to increased axial length and increased vertical CDR. When excluding the CDR criterion, there was no case of glaucoma in this sample. A significant correlation was observed between high vertical CDR and small cephalic perimeter at birth (P=0.002) and the presence of clinical macular lesions (P=0.031). Although childhood glaucoma was not detected in this sample, increased vertical CDR is present in children with CZS, associated with microcephaly and clinical macular lesions at birth. This finding may lead to a misdiagnosis of glaucoma.

A Descriptive Study on Prevalence Pattern of Japanese Encephalitis in State of Manipur

AbstractBackground and Objective: Japanese encephalitis (JE) surveillance is not well established in many countries, and laboratory confirmation is challenging, the true extent and prevalence of the virus and burden of disease are not well understood. It is estimated that 67,900 clinical cases of JE occur annually despite the widespread availability of vaccine, with approximately 13,600–20,400 deaths and an overall incidence rate of 1.8/100,000 in the 24 countries with JE risk. The present study aimed at determining the prevalence rate (PR) and distribution (time, place and person) of JE cases in Manipur. This descriptive study was conducted over 24-month period (2016–2017). Materials and Methods: A total of 1770 cases of acute encephalitis syndrome tested for JE including 251 confirmed JE were diagnosed by IgM antibody-capture enzyme-linked immunosorbent assay. Results: The JE cases were most commonly reported in the age group of >15 years. Most of JE prevalence was seen in rural distribution in our study. There is a strong seasonal pattern of JE occurrence in Manipur which peaked in July–August and declined by October each year, which corresponds to the monsoon season. The JE cases were reported in all the districts of the state expanding in the plains and hill regions. Conclusions: The changing pattern of JE cases among different age groups was also observed in our study. The present study reveals the changing pattern of the prevalence of JE in the State of Manipur and initiated a systematic approach of JE surveillance also highlights the need for further expanding of surveillance across the state.

Advances in Diagnostic Methods for Zika Virus Infection.

The Zika virus (ZIKV) is one of the most infamous mosquito-borne flavivirus on recent memory due to its potential association with high mortality rates in fetuses, microcephaly and neurological impairments in neonates, and autoimmune disorders. The severity of the disease, as well as its fast spread over several continents, has urged the World Health Organization (WHO) to declare ZIKV a global health concern. In consequence, over the past couple of years, there has been a significant effort for the development of ZIKV diagnostic methods, vaccine development, and prevention strategies. This review focuses on the most recent aspects of ZIKV research which includes the outbreaks, genome structure, multiplication and propagation of the virus, and more importantly, the development of serological and molecular detection tools such as Zika IgM antibody capture enzyme-linked immunosorbent assay (Zika MAC-ELISA), plaque reduction neutralization test (PRNT), reverse transcription quantitative real-time polymerase chain reaction (qRT-PCR), reverse transcription-loop mediated isothermal amplification (RT-LAMP), localized surface plasmon resonance (LSPR) biosensors, nucleic acid sequence-based amplification (NASBA), and recombinase polymerase amplification (RPA). Additionally, we discuss the limitations of currently available diagnostic methods, the potential of newly developed sensing technologies, and also provide insight into future areas of research.

Clinical significance of plasma anti-TOPO48 autoantibody and blood survivin-expressing circulating cancer cells in patients with early stage endometrial carcinoma.

To examine the clinical significance of an autoantibody (AAb) against a novel tumor-associated antigen (TAA) derived from human DNA-topoisomerase I, termed as TOPO48 AAb, and peripheral blood survivin-expressing circulating cells (CCC) in patients with early stage endometrial cancer (EC). Blood samples were collected from 80 patients with early stage EC and 80 age-matched healthy subjects. Plasma levels of the TOPO48 AAb were measured with a specific antibody capture enzyme-linked immunosorbent assay (ELISA) and blood survivin-expressing CCC assessed with a reverse transcription-polymerase chain reaction products based on a hybridization-enzyme-linked immunosorbent assay (RT-PCR-ELISA). Sixty patients were followed up for 36months after the initial assay test. There were 75% and 60% samples with positive levels of the TOPO48 AAb and survivin-expressing CCC in the cancer patients, respectively. However, the cumulative positive rate of combination of the two markers was increased to 93.3% with 0.927 (95% CI 0.871-0.984) of area under the curve (AUC) in receiver operating characteristic (ROC) curve analysis. During the follow-up period, patients with positive TOPO48 AAb but negative surviving-expressing CCC had a higher survival rate and a longer survival time than those with negative AAb but positive CCC (P = 0.01). The combination of TOPO48 AAb and survivin-expressing CCC may be used as a novel recipe to improve the efficiency of early diagnosis and provide more accurate prognostic prediction in patients with early stage EC.

A Novel Approach for Differential Serodiagnosis between Zika and Dengue Viral Infection with Comprehensive Evaluation

Background: Diagnostic testing for Zika virus (ZIKV) or dengue virus (DENV) infection can be accomplished by a nucleic acid detection method; however, a negative result does not exclude infection due to the low virus titer during infection depending on the timing of sample collection. Therefore, a ZIKV- or DENV-specific serological assay is essential for the accurate diagnosis of patients and to prevent potential severe health outcomes. Methods: A retrospective study design with dual approaches of collecting human serum samples for testing was developed. All serum samples were extensively evaluated by using both non-infectious virus-like particles (VLPs) and soluble non-structural protein 1 (NS1) in the standard immunoglobulin M (IgM) antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA). Findings: Both VLP- and NS1-MAC-ELISAs were found to have similar sensitivity for detecting anti-premembrane/envelope and NS1 antibodies from ZIKV-infected patient sera. Group cross reactive (GR)-antibody-ablated homologous fusion peptide-mutated (FP)-VLPs consistently showed higher P/N values than homologous wild-type VLPs. Therefore, FP-VLPs were used to develop the algorithm for differentiating ZIKV from DENV infection. Overall, the sensitivity and specificity of the FP-VLP-MAC-ELISA and the NS1-MAC-ELISA were each higher than 80% with no statistical significance. Interpretation: A novel approach to differentiate ZIKV from DENV infection serologically has been developed. The accuracy can reach up to 95% when combining both VLP and NS1 assays. In comparison to current guidelines using neutralization tests to measure ZIKV antibody, this approach can facilitate laboratory screening for ZIKV infection, especially in regions where DENV infection is endemic and capacity for neutralization testing does not exist. Funding Statement: Portions of this publication was made possible through support provided by the CDC intramural research fund and the Office of Infectious Disease, Bureau for Global Health, U.S. Agency for International Development, under the terms of an Interagency Agreement with CDC. The opinions expressed herein are those of the author(s) and do not necessarily reflect the views of the CDC and U.S. Agency for International Development. Declaration of Interests: We declare no competing interests. Ethics Approval Statement: This study was conducted and reported in accordance with the Standards for Reporting Diagnostic Accuracy Studies (STARD) guidelines. Informed consent documents for all eligible participants were waived based on the protocol number 6874. An institutional review board (IRB) waiver to use this serum panel for research purposes was approved by the CDC-human studies review board.