scholarly journals Development of a Sensitive and Specific Serological Assay Based on Luminex Technology for Detection of Antibodies to Zaire Ebola Virus

2016 ◽  
Vol 55 (1) ◽  
pp. 165-176 ◽  
Author(s):  
Ahidjo Ayouba ◽  
Abdoulaye Touré ◽  
Christelle Butel ◽  
Alpha Kabinet Keita ◽  
Florian Binetruy ◽  
...  
Keyword(s):  
Test Performance ◽  
Ebola Virus ◽  
High Specificity ◽  
Antibody Detection ◽  
Lower Sensitivity ◽  
Serological Assay ◽  
Epidemiological Surveys ◽  
Luminex Technology ◽  
Ebov Infection ◽  
Almost All

ABSTRACT The recent Zaire Ebola virus (EBOV) outbreak in West Africa illustrates clearly the need for additional studies with humans and animals to elucidate the ecology of Ebola viruses (EBVs). In this study, we developed a serological assay based on the Luminex technology. Nine recombinant proteins representing different viral regions (nucleoprotein [NP], 40-kDa viral protein [VP40], and glycoprotein [GP]) from four of the five EBV lineages were used. Samples from 94 survivors of the EBOV outbreak in Guinea and negative samples from 108 patients in France were used to calculate test performance for EBOV detection and cross-reaction with other Ebola virus lineages. For EBOV antibody detection, sensitivities of 95.7%, 96.8%, and 92.5% and specificities of 94.4%, 95.4%, and 96.3% for NP, GP, and VP40, respectively, were observed. All EBOV-negative samples that presented a reaction, except for one, interacted with a single antigen, whereas almost all samples from EBOV survivors were simultaneously reactive with NP and GP (90/94) or with NP, GP, and VP40 (87/94). Considering as positive for past EBOV infection only samples that reacted with EBOV NP and GP, sensitivity was 95.7% and specificity increased to 99.1%. Comparing results with commercial EBOV NP and GP enzyme-linked immunosorbent assays (ELISAs; Alpha Diagnostic, San Antonio, TX), lower sensitivity (92.5%) and high specificity (100%) were observed with the same positivity criteria. Samples from EBOV survivors cross-reacted with GP from Sudan Ebola virus (GP-SUDV) (81.9%), GP from Bundibugyo Ebola virus (GP-BDBV) (51.1%), GP from Reston Ebola virus (GP-RESTV) (9.6%), VP40-SUDV (76.6%), and VP40-BDBV (38.3%). Overall, we developed a sensitive and specific high-throughput serological assay, and defined an algorithm, for epidemiological surveys with humans.

Validation of Claims Algorithms to Identify Alzheimer’s Disease and Related Dementias

2021 ◽  
Author(s):  
Ellen P McCarthy ◽  
Chiang-Hua Chang ◽  
Nicholas Tilton ◽  
Mohammed U Kabeto ◽  
Kenneth M Langa ◽  
...  
Keyword(s):  
Test Performance ◽  
Healthcare Delivery ◽  
High Specificity ◽  
Cognitive Status ◽  
Lower Sensitivity ◽  
Billing Data ◽  
Trade Offs ◽  
Low Sensitivity ◽  
Study Participants ◽  
Retirement Study

Abstract BACKGROUND Using billing data generated through healthcare delivery to identify individuals with dementia has become important in research. To inform tradeoffs between approaches, we tested the validity of different Medicare claims-based algorithms. METHODS We included 5,784 Medicare-enrolled, Health and Retirement Study participants aged >65 years in 2012 clinically assessed for cognitive status over multiple waves and determined performance characteristics of different claims-based algorithms. RESULTS Positive predictive value (PPV) of claims ranged from 53.8-70.3% and was highest using a revised algorithm and 1-year of observation. The trade-off of greater PPV was lower sensitivity; sensitivity could be maximized using 3-years of observation. All algorithms had low sensitivity (31.3-56.8%) and high specificity (92.3-98.0%). Algorithm test performance varied by participant characteristics, including age and race. CONCLUSIONS Revised algorithms for dementia diagnosis using Medicare administrative data have reasonable accuracy for research purposes, but investigators should be cognizant of the trade-offs in accuracy among the approaches they consider.

scholarly journals In vivo single-cell profiling of lncRNAs during Ebola virus infection

2022 ◽  
Author(s):  
Luisa Santus ◽  
Raquel García-Pérez ◽  
Maria Sopena-Rios ◽  
Aaron E Lin ◽  
Gordon C Adams ◽  
...  
Keyword(s):  
Viral Infection ◽  
Single Cell ◽  
Ebola Virus ◽  
Cell Type ◽  
Protein Coding ◽  
Expression Variation ◽  
Lncrna Expression ◽  
Ebov Infection ◽  
Cell Type Specific

Long non-coding RNAs (lncRNAs) are pivotal mediators of systemic immune response to viral infection, yet most studies concerning their expression and functions upon immune stimulation are limited to in vitro bulk cell populations. This strongly constrains our understanding of how lncRNA expression varies at single-cell resolution, and how their cell-type specific immune regulatory roles may differ compared to protein-coding genes. Here, we perform the first in-depth characterization of lncRNA expression variation at single-cell resolution during Ebola virus (EBOV) infection in vivo. Using bulk RNA-sequencing from 119 samples and 12 tissue types, we significantly expand the current macaque lncRNA annotation. We then profile lncRNA expression variation in immune circulating single-cells during EBOV infection and find that lncRNAs' expression in fewer cells is a major differentiating factor from their protein-coding gene counterparts. Upon EBOV infection, lncRNAs present dynamic and mostly cell-type specific changes in their expression profiles especially in monocytes, the main cell type targeted by EBOV. Such changes are associated with gene regulatory modules related to important innate immune responses such as interferon response and purine metabolism. Within infected cells, several lncRNAs have positively and negatively correlated expression with viral load, suggesting that expression of some of these lncRNAs might be directly hijacked by EBOV to attack host cells. This study provides novel insights into the roles that lncRNAs play in the host response to acute viral infection and paves the way for future lncRNA studies at single-cell resolution.

scholarly journals Human Immunodeficiency Virus Antibody Testing by Enzyme-Linked Fluorescent and Western Blot Assays Using Serum, Gingival-Crevicular Transudate, and Urine Samples

1999 ◽  
Vol 37 (4) ◽  
pp. 1100-1106 ◽  
Author(s):  
Prudencio Martínez Martínez ◽  
Antonio Rodríguez Torres ◽  
Raul Ortiz de Lejarazu ◽  
Ana Montoya ◽  
José Francisco Martín ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Hiv Infection ◽  
Western Blot ◽  
Stage Iv ◽  
Urine Samples ◽  
World Health ◽  
Antibody Detection ◽  
Lower Sensitivity ◽  
Antibody Testing ◽  
Immunodeficiency Virus

The aim of the present study was to evaluate the possible utilization of saliva and urine as alternative samples to serum for the diagnosis of human immunodeficiency virus (HIV) infection. A total of 302 individuals participated in the study: 187 HIV-infected individuals (106 had Centers for Disease Control and Prevention [CDC] stage II infection, 19 had CDC stage III infection, and 62 had CDC stage IV infection) and 115 noninfected persons (46 of the noninfected persons were blood donors and 69 belonged to a group at high risk of HIV infection). Paired saliva and urine samples were taken from each of the participants in the study. The presence of HIV-specific antibodies was detected by an enzyme-linked fluorescent assay (ELFA), and the result was confirmed by Western blot analysis (WB). The ELFA with saliva gave maximum sensitivity and specificity values, while ELFA had lower sensitivity (95.2%) and specificity (97.4%) values for detection of HIV antibody in urine samples. WB with all saliva samples fulfilled the World Health Organization criterion for positivity, while only 96.8% of the urine samples were confirmed to be positive by WB. Among the four reactivity patterns found by WB of these alternative samples, the most frequent included bands against three groups of HIV structural proteins (was ENV, POL, and GAG). The reactivity bands most frequently observed were those for the proteins gp160 and gp120. The least common reactivity band was the band for protein p17. The detection of HIV antibodies in saliva samples by means of ELFA with the possibility of later confirmation by WB makes saliva an alternative to serum for possible use in the diagnosis of infection. In contrast, HIV antibody detection in urine samples by the same methodology (ELFA) could be taken into consideration for use in epidemiological studies.

scholarly journals A rapid and affordable point of care test for antibodies against SARS-CoV-2 based on hemagglutination and artificial intelligence interpretation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vanessa Redecke ◽  
Kazuki Tawaratsumida ◽  
Erin T. Larragoite ◽  
Elizabeth S. C. P. Williams ◽  
Vicente Planelles ◽  
...  
Keyword(s):  
Test Performance ◽  
Learning Algorithm ◽  
Point Of Care ◽  
Method Comparison ◽  
High Specificity ◽  
Turnaround Time ◽  
Analysis Tool ◽  
Point Of Care Test ◽  
Specificity And Sensitivity ◽  
A Cell

AbstractDiagnostic tests that detect antibodies (AB) against SARS-CoV-2 for evaluation of seroprevalence and guidance of health care measures are important tools for managing the COVID-19 pandemic. Current tests have certain limitations with regard to turnaround time, costs and availability, particularly in point-of-care (POC) settings. We established a hemagglutination-based AB test that is based on bi-specific proteins which contain a dromedary-derived antibody (nanobody) binding red blood cells (RBD) and a SARS-CoV-2-derived antigen, such as the receptor-binding domain of the Spike protein (Spike-RBD). While the nanobody mediates swift binding to RBC, the antigen moiety directs instantaneous, visually apparent hemagglutination in the presence of SARS-CoV-2-specific AB generated in COVID-19 patients or vaccinated individuals. Method comparison studies with assays cleared by emergency use authorization demonstrate high specificity and sensitivity. To further increase objectivity of test interpretation, we developed an image analysis tool based on digital image acquisition (via a cell phone) and a machine learning algorithm based on defined sample-training and -validation datasets. Preliminary data, including a small clinical study, provides proof of principle for test performance in a POC setting. Together, the data support the interpretation that this AB test format, which we refer to as ‘NanoSpot.ai’, is suitable for POC testing, can be manufactured at very low costs and, based on its generic mode of action, can likely be adapted to a variety of other pathogens.

scholarly journals The Rule of Histology in the Diagnosis of Periprosthetic Infection: Specific Granulocyte Counting Methods and New Immunohistologic Staining Techniques may Increase the Diagnostic Value

2016 ◽  
Vol 10 (1) ◽  
pp. 457-465 ◽  
Author(s):  
Friedrich Boettner ◽  
Gabriele Koehler ◽  
Alexander Wegner ◽  
Tom Schmidt-Braekling ◽  
Georg Gosheger ◽  
...  
Keyword(s):  
Periprosthetic Infection ◽  
High Specificity ◽  
Diagnostic Value ◽  
Lower Sensitivity ◽  
Specific Staining ◽  
Tissue Samples ◽  
Hip And Knee Arthroplasty ◽  
Staining Techniques ◽  
Low Sensitivity ◽  
Intraoperative Test

Objective: The current study investigates the diagnostic accuracy of the criteria described for frozen sections and whether modern leukocyte specific staining techniques including leukocyte peroxidase and Naphtol-AS-D-chloroacetate-esterase will improve the accuracy of the intra-operative histology. Method: 77 patients undergoing revision total hip and knee arthroplasty were included in this retrospective study. Patients were grouped into septic and aseptic based on intraoperative cultures. Tissue samples were analyzed utilizing the Mirra, Feldman, Lonner, Banit and Athanasou criteria. Results: An experienced pathologist had a high specificity (96%), but rather low sensitivity (57%) diagnosing infection. By using the Banit-, Mirra-, or Athanasou-criteria the sensitivity is increased to 0.90. The Feldman- and Lonner-criteria have a lower sensitivity (0.48 and 0.38), however, an increased specificity of 0.96 and 0.98, respectively. The Banit cut off has the highest accuracy (86%). MPOX and NACE staining increased the sensitivity and accuracy up to 100% and 92% respectively. Conclusion: Banit’s cut off is the most accurate histologic criteria to diagnose infection. Modern leukocyte specific staining techniques slightly improve the accuracy. The synovial fluid white blood cell count appears to be the most accurate intraoperative test.

scholarly journals Enhancement of Ebola virus infection by seminal amyloid fibrils

2018 ◽  
Vol 115 (28) ◽  
pp. 7410-7415 ◽  
Author(s):  
Stephen M. Bart ◽  
Courtney Cohen ◽  
John M. Dye ◽  
James Shorter ◽  
Paul Bates
Keyword(s):  
Cell Lines ◽  
Ebola Virus ◽  
Amyloid Fibrils ◽  
Sexual Transmission ◽  
Fluid Phase ◽  
Infectious Individual ◽  
Transmission Potential ◽  
Western Africa ◽  
Ebov Infection

The 2014 western Africa Ebola virus (EBOV) epidemic was unprecedented in magnitude, infecting over 28,000 and causing over 11,000 deaths. During this outbreak, multiple instances of EBOV sexual transmission were reported, including cases where the infectious individual had recovered from EBOV disease months before transmission. Potential human host factors in EBOV sexual transmission remain unstudied. Several basic seminal amyloids, most notably semen-derived enhancer of viral infection (SEVI), enhance in vitro infection by HIV and several other viruses. To test the ability of these peptides to enhance EBOV infection, viruses bearing the EBOV glycoprotein (EboGP) were preincubated with physiological concentrations of SEVI before infection of physiologically relevant cell lines and primary cells. Preincubation with SEVI significantly increased EboGP-mediated infectivity and replication in epithelium- and monocyte-derived cell lines. This enhancement was dependent upon amyloidogenesis and positive charge, and infection results were observed with both viruses carrying EboGP and authentic EBOV as well as with semen. SEVI enhanced binding of virus to cells and markedly increased its subsequent internalization. SEVI also stimulated uptake of a fluid phase marker by macropinocytosis, a critical mechanism by which cells internalize EBOV. We report a previously unrecognized ability of SEVI and semen to significantly alter viral physical properties critical for transmissibility by increasing the stability of EboGP-bearing recombinant viruses during incubation at elevated temperature and providing resistance to desiccation. Given the potential for EBOV sexual transmission to spark new transmission chains, these findings represent an important interrogation of factors potentially important for this EBOV transmission route.

scholarly journals Statins Suppress Ebola Virus Infectivity by Interfering with Glycoprotein Processing

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Punya Shrivastava-Ranjan ◽  
Mike Flint ◽  
Éric Bergeron ◽  
Anita K. McElroy ◽  
Payel Chatterjee ◽  
...  
Keyword(s):  
Ebola Virus ◽  
Virus Disease ◽  
Statin Treatment ◽  
Ebola Virus Disease ◽  
Health Concern ◽  
Virus Infectivity ◽  
Viral Glycoprotein ◽  
Antiviral Effects ◽  
Ebov Infection ◽  
Glycoprotein Processing

ABSTRACTEbola virus (EBOV) infection is a major public health concern due to high fatality rates and limited effective treatments. Statins, widely used cholesterol-lowering drugs, have pleiotropic mechanisms of action and were suggested as potential adjunct therapy for Ebola virus disease (EVD) during the 2013–2016 outbreak in West Africa. Here, we evaluated the antiviral effects of statin (lovastatin) on EBOV infectionin vitro. Statin treatment decreased infectious EBOV production in primary human monocyte-derived macrophages and in the hepatic cell line Huh7. Statin treatment did not interfere with viral entry, but the viral particles released from treated cells showed reduced infectivity due to inhibition of viral glycoprotein processing, as evidenced by decreased ratios of the mature glycoprotein form to precursor form. Statin-induced inhibition of infectious virus production and glycoprotein processing was reversed by exogenous mevalonate, the rate-limiting product of the cholesterol biosynthesis pathway, but not by low-density lipoprotein. Finally, statin-treated cells produced EBOV particles devoid of the surface glycoproteins required for virus infectivity. Our findings demonstrate that statin treatment inhibits EBOV infection and suggest that the efficacy of statin treatment should be evaluated in appropriate animal models of EVD.IMPORTANCETreatments targeting Ebola virus disease (EVD) are experimental, expensive, and scarce. Statins are inexpensive generic drugs that have been used for many years for the treatment of hypercholesterolemia and have a favorable safety profile. Here, we show the antiviral effects of statins on infectious Ebola virus (EBOV) production. Our study reveals a novel molecular mechanism in which statin regulates EBOV particle infectivity by preventing glycoprotein processing and incorporation into virus particles. Additionally, statins have anti-inflammatory and immunomodulatory effects. Since inflammation and dysregulation of the immune system are characteristic features of EVD, statins could be explored as part of EVD therapeutics.

Characterization of an Anti-Ebola virus Hyperimmune Globulin Derived from Convalescent Plasma

2021 ◽  
Author(s):  
Jonathan M Ciencewicki ◽  
Andrew S Herbert ◽  
Nadia Storm ◽  
Nicole M Josleyn ◽  
Kathleen Huie ◽  
...  
Keyword(s):  
Ebola Virus ◽  
Virus Disease ◽  
Fold Increase ◽  
Surface Glycoprotein ◽  
Post Exposure Prophylaxis ◽  
Emerging Viruses ◽  
Live Virus ◽  
Glycoprotein Antigen ◽  
Ebov Infection ◽  
Exposure Prophylaxis

Abstract Backrgound Convalescent plasma has been used to treat many viral diseases including Ebola. The manufacture of a purified anti-Ebola virus (EBOV) intravenous immunoglobulin (IVIG) from pooled convalescent plasma is described in this paper. Methods An ELISA targeting an EBOV surface glycoprotein antigen was used to determine the immunoglobulin titer of pooled plasma and purified anti-EBOV IVIG. Anti-EBOV IVIG was also tested in neutralization assays using a vesicular stomatitis virus pseudovirion expressing EBOV glycoprotein on its surface and with live EBOV. Finally, the efficacy of the anti-EBOV IVIG was assessed in a mouse model of EBOV infection. Results In the ELISA, the anti-EBOV IVIG was shown to have a seven-fold increase in IgG titer over pooled convalescent plasma. In both the pseudovirion and live virus assays, the anti-EBOV IVIG showed approximately five- to six-fold increased potency over pooled plasma. Anti-EBOV IVIG also significantly improved survivability in mice infected with the virus when administered concurrently or two days after infection. Conclusions These data support this purified anti-EBOV IVIG merits additional investigation and clinical trials for treatment and post-exposure prophylaxis of Ebola virus disease. The experience gained can be applied to manufacture hyperimmune globulins against other emerging viruses.

Development of Dual Fluorescent Microsphere Immunological Assay for Detection of Pseudorabies Virus gE and gB IgG Antibodies

2020 ◽  
Author(s):  
chihai ji ◽  
Jingyu Wang ◽  
Yuchen Zeng ◽  
Haoming Pan ◽  
Yingfang Wei ◽  
...  
Keyword(s):  
Pseudorabies Virus ◽  
High Specificity ◽  
Antibody Detection ◽  
Economic Losses ◽  
Igg Antibodies ◽  
Wild Type ◽  
Swine Industry ◽  
Igg Antibody ◽  
Fluorescent Microsphere ◽  
Specificity And Sensitivity

Abstract Background Pseudorabies, also known as Aujezsky’s disease, is an acute viral infection caused by pseudorabies virus (PRV). Swine are one of the natural hosts of pseudorabies, therefore, the disease brings huge economic losses to the swine industry. Establishment of a differential diagnosis technique that can distinguish between wild-type infected and vaccinated pigs, and monitor vaccine-induced IgG is crucial for eventual eradication of pseudorabies.Results The aim of this study was to develop a rapid dual detection method for PRV gE and gB protein IgG antibodies with high specificity and sensitivity. PRV gE codons at amino acid residues (aa) 52–238 and gB codons at aa 539–741 were expressed to obtain recombinant PRV gE and gB proteins by pMAL-c5x vector. After purification with Qiagen Ni–NTA agarose affinity, the two proteins were analyzed by SDS-PAGE and immunoblotting assay. Two single fluorescent-microsphere immunoassays (FMIA) were established by coupling two recombinant proteins (gE and gB) with two magnetic microbeads and an effective dual FMIA was developed by integrating the two single assays. Optimal serum dilution for each assay, correlation with other common swine virus-positive sera and comparison with ELISA for two PRV antigens were tested for validation. Compared with ELISA, the specificity and sensitivity were 99.26% and 92.3% for gE IgG antibody detection and 95.74% and 96.3% for gB IgG antibody detection by dual-FMIA.Conclusion We provide a new method for monitoring PRV protective antibody in vaccinated pigs and differentiating wild-type-PRV-infected from vaccinated pigs

Abstract 15928: Relative Sparing of Apical Longitudinal Strain for Detection of Cardiac Amyloidosis: Intervendor Variation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Julia M Simkowski ◽  
Michael Jiang ◽  
NADIA El HANGOUCHE ◽  
Jeesoo Lee ◽  
Milica Marion ◽  
...  
Keyword(s):  
Cardiac Amyloidosis ◽  
Longitudinal Strain ◽  
Global Longitudinal Strain ◽  
High Sensitivity ◽  
High Specificity ◽  
Left Ventricular ◽  
Control Group ◽  
Lower Sensitivity ◽  
Medical Systems ◽  
Roc Curve Analysis

Introduction: Relative apical longitudinal strain (RALS) is defined as (average apical LS/(average basal & mid-ventricular LS)). A threshold of 2 has been found to have high sensitivity and specificity for differentiating cardiac amyloidosis (CA) from other causes of left ventricular hypertrophy (LVH). This threshold was developed using General Electric (GE) software, and its reproducibility among different software vendors is unknown. Hypothesis: In patients with CA, regional segmental LS patterns and relative apical longitudinal strain will vary among software vendors. Methods: Speckle-tracking echocardiography was retroactively performed by an experienced technician on two patient cohorts, CA (n=52) and LVH (n=52), using software from two independent vendors: EchoPAC (GE Medical Systems) and TomTEC (TOMTEC Imaging Systems GMBH). For each vendor and patient, strain values for the basal, mid, and apical segments were averaged to obtain three regional LS values which were then used to calculate global longitudinal strain (GLS) and RALS. Results: EchoPAC demonstrated greater average apical LS (-16.5±5.7 vs -13.1±6.6, p<0.001) and RALS (2.1±0.9 vs 1.7±0.7, p<0.001) compared to TomTEC. Bland-Altman analysis yielded a mean bias of -0.4 with limit of agreement 2.2 (p<0.001) in RALS between the two vendors. ROC curve analysis using a RALS cutoff of 2 to differentiate CA from the overall control group showed similarly high specificity (EchoPAC 85%, TomTEC 83%) between vendors but lower sensitivity for TomTEC (23% vs 45%) (Figure 1). LVH subgroup analysis showed similar comparisons. Overall difference in area-under-curve (AUC) was significant (AUC = 0.78 EchoPAC vs AUC = 0.52 TomTEC, p < 0.001). Conclusions: Software measurements of regional LS and thus RALS vary between vendors. Further efforts are needed for intervendor regional strain fidelity. For now, different RALS thresholds to diagnose CA may be needed for various vendors.

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