Performance of the EUROIMMUN Anti-SARS-CoV-2 ELISA Assay for detection of IgA and IgG antibodies in South Africa

Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) has been identified as the causative agent for causing the clinical syndrome of COVID -19. Accurate detection of SARS-CoV-2 infection is not only important for management of infected individuals but also to break the chain of transmission. South Africa is the current epicenter of SARS-CoV-2 infection in Africa. To optimize the diagnostic algorithm for SARS-CoV-2 in the South African setting, the study aims to evaluate the diagnostic performance of the EUROIMMUN Anti-SARS-CoV-2 assays. This study reported the performance of EUROIMMUN enzyme-linked immunosorbent assay (ELISA) for semi-quantitative detection of IgA and IgG antibodies in serum and plasma samples targeting the recombinant S1 domain of the SARS-CoV-2 spike protein as antigen. Samples were collected from 391 individuals who had tested positive for SARS-CoV-2 and 139 SARS CoV-2 negative controls. Samples were stratified by number of days’ post-PCR diagnosis and symptoms. The sensitivity of EUROIMMUN IgG was 64.1% (95% CI: 59.1–69.0%) and 74.3% (95% CI: 69.6–78.6%) for IgA and the specificity was lower for IgA [84.2% (95% CI: 77–89.2%)] than IgG [95.2% (95% CI: 90.8–98.4%)]. The EUROIMMUN Anti-SARS-CoV-2 ELISA Assay sensitivity was higher for IgA but low for IgG and improved for both assays in symptomatic individuals and at later timepoints post PCR diagnosis.

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Evaluation of the EUROIMMUN Anti-SARS-CoV-2 ELISA Assay for detection of IgA and IgG antibodies

10.1101/2020.05.11.089862 ◽

2020 ◽

Cited By ~ 2

Author(s):

Scott M. Matushek ◽

Kathleen G. Beavis ◽

Ana Abeleda ◽

Cindy Bethel ◽

Carlissa Hunt ◽

...

Keyword(s):

Clinical Microbiology ◽

Spike Protein ◽

Quantitative Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Elisa Assay ◽

Plasma Samples ◽

Igg Antibodies ◽

Human Coronavirus ◽

Human Coronaviruses ◽

The University

AbstractAs the Coronavirus 2019 (COVID-19) pandemic evolves, the development of immunoassays to help determine exposure and potentially predict immunity has become a pressing priority. In this report we present the performance of the EUROIMMUN enzyme-linked immunosorbent assay (ELISA) for semi-quantitative detection of IgA and IgG antibodies in serum and plasma samples using recombinant S1 domain of the SARS-CoV-2 spike protein as antigen. Specimens from patients, with and without COVID-19 infection, were tested at the University of Chicago Clinical Microbiology and Immunology Laboratory. Of 57 samples from COVID-19 PCR-negative patients, including 28 samples positive for common human coronavirus strains, 53 tested negative and 4 tested positive for IgA (93.0% agreement) while 56 tested negative and 1 tested positive for IgG (98.2% agreement). For COVID-19 PCR-positive patients, 29 of 30 (96.7%) samples collected ≥3 days after positive PCR were positive for IgA, and 28 of 28 samples collected ≥4 days after positive PCR were positive for IgG.The EUROIMMUN Anti-SARS-CoV-2 ELISA Assay demonstrates excellent sensitivity for detection of IgA and IgG antibodies from samples collected ≥3 days and ≥4 days, respectively, after COVID-19 diagnosis by PCR. This assay did not demonstrate cross reaction in any of the 28 samples from patients with common human coronaviruses, including types HKU1, NL63, CV229E, and OC43.

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Development of a Bead-Based Multiplex Immunoassay for Simultaneous Quantitative Detection of IgG Serum Antibodies against Measles, Mumps, Rubella, and Varicella-Zoster Virus

Clinical and Vaccine Immunology ◽

10.1128/cvi.05537-11 ◽

2012 ◽

Vol 19 (3) ◽

pp. 396-400 ◽

Cited By ~ 59

Author(s):

Gaby P. Smits ◽

Pieter G. van Gageldonk ◽

Leo M. Schouls ◽

Fiona R. M. van der Klis ◽

Guy A. M. Berbers

Keyword(s):

Varicella Zoster Virus ◽

High Specificity ◽

Good Alternative ◽

Multiplex Assay ◽

Quantitative Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Igg Antibodies ◽

Multiplex Immunoassay ◽

Varicella Zoster ◽

Elisa Kit

ABSTRACTEnzyme-linked immunosorbent assay (ELISA) is normally used to quantify the amount of serum IgG antibodies against measles, mumps, rubella, and varicella-zoster virus (MMRV). However, this method is time- and material-consuming. Therefore, a multiplex immunoassay for the simultaneous quantitative detection of antibodies against MMRV was developed. In-house as well as commercially available antigens can be used, making the assay available for all laboratories. The multiplex assay is much more sensitive than the separate ELISAs and has a high specificity, and only 5 μl of serum is needed. Heterologous inhibition did not exceed 11.5%, while homologous inhibition varied between 91.3 and 97.9%. Good correlations with the in-house ELISAs for measles (R2= 0.98), mumps (R2= 0.97), and rubella (R2= 0.97) virus as well as with the ELISA kit for varicella-zoster virus (R2= 0.95) were obtained. In conclusion, the MMRV multiplex assay is a good alternative to the conventional ELISAs and suitable for use in serosurveillance and vaccine studies.

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A Quantitative ELISA Protocol for Detection of Specific Human IgG Against the SARS-CoV-2 Spike Protein

Vaccines ◽

10.3390/vaccines9070770 ◽

2021 ◽

Vol 9 (7) ◽

pp. 770

Author(s):

Rémi Vernet ◽

Emily Charrier ◽

Julien Grogg ◽

Nicolas Mach

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Immunosorbent Assay ◽

Spike Protein ◽

Quantitative Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Igg Antibodies ◽

Human Igg ◽

Microtiter Plates ◽

Global Priority ◽

Humoral Responses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a worldwide pandemic with at least 3.8 million deaths to date. For that reason, finding an efficient vaccine for this virus quickly became a global priority. The majority of vaccines now marketed are based on the SARS‑CoV‑2 spike protein that has been described as the keystone for optimal immunization. In order to monitor SARS‑CoV‑2 spike-specific humoral responses generated by immunization or infection, we have developed a robust and reproducible enzyme-linked immunosorbent assay (ELISA) protocol. This protocol describes a method for quantitative detection of IgG antibodies against the SARS‑CoV‑2 spike protein using antigen-coated microtiter plates. Results showed that antibodies could be quantified between the range of 1.953 ng/mL to 500 ng/mL with limited inter- and intra-assay variability.

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D-Dimer Determination to Exclude Pulmonary Embolism: a Two-Step Approach Using Latex Assay as a Screening Tool

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648817 ◽

1994 ◽

Vol 72 (01) ◽

pp. 089-091 ◽

Cited By ~ 21

Author(s):

P de Moerloose ◽

Ph Minazio ◽

G Reber ◽

A Perrier ◽

H Bounameaux

Keyword(s):

Pulmonary Embolism ◽

Screening Tool ◽

Screening Tests ◽

Enzyme Linked Immunosorbent Assay ◽

Elisa Assay ◽

Elisa Technique ◽

Diagnostic Step ◽

D Dimer ◽

Rule Out ◽

Latex Test

SummaryD-dimer (DD), when measured by a quantitative enzyme-linked immunosorbent assay (ELISA), is a valuable test to exclude venous thromboembolism (VTE). However, DD ELISA technique is not appropriate for emergency use and the available agglutination latex assays are not sensitive enough to be used as an alternative to rule out the diagnosis of VTE. Latex assays could still be used as screening tests. We tested this hypothesis by comparing DD levels measured by ELISA and latex assays in 334 patients suspected of pulmonary embolism. All but one patient with a positive (DD ≥500 ng/ml) latex assay had DD levels higher than 500 ng/ml with the ELISA assay. Accordingly, ELISA technique could be restricted to patients with a negative result in latex assay. This two-step approach would have spared about 50% of ELISA in our cohort. In conclusion, our data indicate that a latex test can be used as a first diagnostic step to rule out pulmonary embolism provided a negative result is confirmed by ELISA and the performance of the latex assay used has been assessed properly.

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Severe Inherited “Homozygous” Protein C Deficiency in a Newborn Infant

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661136 ◽

1984 ◽

Vol 52 (01) ◽

pp. 053-056 ◽

Cited By ~ 77

Author(s):

A Estellés ◽

I Garcia-Plaza ◽

A Dasí ◽

J Aznar ◽

M Duart ◽

...

Keyword(s):

Newborn Infant ◽

Protein C ◽

Skin Lesions ◽

Fresh Frozen Plasma ◽

Clinical Syndrome ◽

Assay Method ◽

Enzyme Linked Immunosorbent Assay ◽

Protein C Deficiency ◽

Fresh Frozen ◽

Frozen Plasma

SummaryA relapsing clinical syndrome of skin lesions and disseminated intravascular coagulation (DIC) that showed remission with the infusion of fresh frozen plasma is described in a newborn infant with homozygous deficiency of protein C antigen.This patient presented since birth a recurrent clinical picture of DIC and ecchymotic skin lesions that resembled typical ecchymosis except for the fact that they showed immediate improvement with the administration of fresh frozen plasma. Using an enzyme linked immunosorbent assay method, the determination of protein C antigen levels in the patient, without ingestion of coumarin drugs, showed very low values (<1%).No other deficiencies in the vitamin-K-dependent factors or in anti thrombin III, antiplasmin, and plasminogen were found. Seven relatives of the infant had heterozygous deficiency in protein C antigen (values between 40-55%), without clinical history of venous thrombosis. The pedigree analysis of this family suggests an autosomal recessive pattern of inheritance for the clinical phenotype, although an autosomal dominant pattern has been postulated until now in other reported families.We conclude that our patient has a homozygous deficiency in protein C and this homozygous state may be compatible with survival beyond the neonatal period.

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Etiology, clinical characteristics and coinfection status of bronchiolitis in Suzhou

BMC Infectious Diseases ◽

10.1186/s12879-021-05772-x ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Jiahong Tan ◽

Jinfeng Wu ◽

Wujun Jiang ◽

Li Huang ◽

Wei Ji ◽

...

Keyword(s):

Virus Infection ◽

Clinical Characteristics ◽

Immunofluorescence Assay ◽

Clinical Syndrome ◽

Enzyme Linked Immunosorbent Assay ◽

Direct Immunofluorescence ◽

Increased Risk ◽

Syncytial Virus ◽

Direct Immunofluorescence Assay ◽

Mixed Virus Infection

Abstract Background Bronchiolitis is a clinical syndrome commonly encountered in practice, particularly among infants and young children. To investigate the prevalence of pathogens in hospitalized children with bronchiolitis and study the clinical characteristics of bronchiolitis with or without coinfections. Methods We investigated the respiratory specimens and clinical data of 1012 children with bronchiolitis who were treated at the Children’s Hospital of Soochow University between November 2011 and December 2018. The nasopharyngeal aspirates were examined to detect viruses by direct immunofluorescence assay or polymerase chain reaction (PCR). Mycoplasma pneumoniae (MP) was tested by PCR and enzyme-linked immunosorbent assay. Results Of the 1134 children less than 2 years with bronchiolitis, 122 were excluded by exclusion criteria. Causative pathogen was detected in 83.2% (842 of 1012). The majority of these (614 [72.9%] of 842) were single virus infection. The most common pathogens detected were respiratory syncytial virus (RSV) (44.4%), MP (15.6%), and human rhinovirus (HRV) (14.4%). Coinfection was identified in 13.5% (137 of 1012) of the patients. Coinfection included mixed virus infection and virus infection with MP infection. Children with single virus infection had a higher rate of oxygen therapy compared with single MP infection. Conclusions The most common pathogen detected in children with bronchiolitis is RSV, followed by MP and HRV. Coinfection leads to a longer period of illness, increased severity of the symptoms and increased risk of hypoxemia.

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Safety and immunogenicity of an mRNA-lipid nanoparticle vaccine candidate against SARS-CoV-2

Wiener klinische Wochenschrift ◽

10.1007/s00508-021-01922-y ◽

2021 ◽

Author(s):

Peter G. Kremsner ◽

Philipp Mann ◽

Arne Kroidl ◽

Isabel Leroux-Roels ◽

Christoph Schindler ◽

...

Keyword(s):

Immune Responses ◽

Vaccine Candidate ◽

Phase 1 ◽

Lipid Nanoparticles ◽

Enzyme Linked Immunosorbent Assay ◽

Receptor Binding Domain ◽

Igg Antibodies ◽

Phase 1 Study ◽

S Protein ◽

Dosage Escalation

Summary Background We used the RNActive® technology platform (CureVac N.V., Tübingen, Germany) to prepare CVnCoV, a COVID-19 vaccine containing sequence-optimized mRNA coding for a stabilized form of SARS-CoV‑2 spike (S) protein encapsulated in lipid nanoparticles (LNP). Methods This is an interim analysis of a dosage escalation phase 1 study in healthy 18–60-year-old volunteers in Hannover, Munich and Tübingen, Germany, and Ghent, Belgium. After giving 2 intramuscular doses of CVnCoV or placebo 28 days apart we assessed solicited local and systemic adverse events (AE) for 7 days and unsolicited AEs for 28 days after each vaccination. Immunogenicity was measured as enzyme-linked immunosorbent assay (ELISA) IgG antibodies to SARS-CoV‑2 S‑protein and receptor binding domain (RBD), and SARS-CoV‑2 neutralizing titers (MN50). Results In 245 volunteers who received 2 CVnCoV vaccinations (2 μg, n = 47, 4 μg, n = 48, 6 μg, n = 46, 8 μg, n = 44, 12 μg, n = 28) or placebo (n = 32) there were no vaccine-related serious AEs. Dosage-dependent increases in frequency and severity of solicited systemic AEs, and to a lesser extent local AEs, were mainly mild or moderate and transient in duration. Dosage-dependent increases in IgG antibodies to S‑protein and RBD and MN50 were evident in all groups 2 weeks after the second dose when 100% (23/23) seroconverted to S‑protein or RBD, and 83% (19/23) seroconverted for MN50 in the 12 μg group. Responses to 12 μg were comparable to those observed in convalescent sera from known COVID-19 patients. Conclusion In this study 2 CVnCoV doses were safe, with acceptable reactogenicity and 12 μg dosages elicited levels of immune responses that overlapped those observed in convalescent sera.

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Risk factors associated with toxoplasmosis and toxocariasis in populations of children from nine cities in southern Brazil

Journal of Helminthology ◽

10.1017/s0022149x14000212 ◽

2014 ◽

Vol 89 (4) ◽

pp. 428-432 ◽

Cited By ~ 11

Author(s):

A.A. Marchioro ◽

C.M. Colli ◽

É.C. Ferreira ◽

B.M. Viol ◽

S.M. Araújo ◽

...

Keyword(s):

Risk Factors ◽

Preventive Measures ◽

Enzyme Linked Immunosorbent Assay ◽

Multiple Logistic Regression ◽

Southern Brazil ◽

Parasite Control ◽

Igg Antibodies ◽

Positive Serology ◽

Factors Associated ◽

Epidemiological Factors

AbstractThis study investigated the epidemiological factors that contribute to the seroprevalence of Toxoplasma gondii and Toxocara spp. in children from Paraná state, Brazil. Immunoglobulin G (IgG) antibodies to T. gondii were detected using indirect immunofluorescence, and IgG antibodies to Toxocara were detected using an enzyme-linked immunosorbent assay. For each individual, a questionnaire was completed that contained epidemiological and clinical data. The data analysis was performed using multiple logistic regression. Of the 544 children investigated, 3.2% presented co-infection with T. gondii and Toxocara spp. Of this total, 7.4% were positive for antibodies to T. gondii, and 25% were positive for antibodies to Toxocara spp. The presence of antibodies to Toxocara spp. increased the risk of T. gondii infection (P= 0.029). Children who were 1–8 years of age were less infected by T. gondii than those who were 9–12 years of age. The variables that influenced positivity for anti-Toxocara spp. were the origin of the children and contact with sand. Children with positive serology for Toxocara spp. presented more eosinophilia compared with those with non-reactive serology. Infection with both parasites reveals the need for preventive measures, such as guidance about modes of infection, parasite control and monitoring recreational areas.

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A Case for Regular Aflatoxin Monitoring in Peanut Butter in Sub-Saharan Africa: Lessons from a 3-Year Survey in Zambia

Journal of Food Protection ◽

10.4315/0362-028x.jfp-15-542 ◽

2016 ◽

Vol 79 (5) ◽

pp. 795-800 ◽

Cited By ~ 17

Author(s):

SAMUEL M. C. NJOROGE ◽

LIMBIKANI MATUMBA ◽

KENNEDY KANENGA ◽

MOSES SIAMBI ◽

FARID WALIYAR ◽

...

Keyword(s):

South Africa ◽

Aflatoxin B1 ◽

Peanut Butter ◽

Aflatoxin Contamination ◽

Comprehensive Analysis ◽

Sub Saharan Africa ◽

Enzyme Linked Immunosorbent Assay ◽

Contamination Level ◽

Batch Number ◽

Sub Saharan

ABSTRACT A 3-year comprehensive analysis of aflatoxin contamination in peanut butter was conducted in Zambia, sub-Saharan Africa. The study analyzed 954 containers of 24 local and imported peanut butter brands collected from shops in Chipata, Mambwe, Petauke, Katete, and Nyimba districts and also in Lusaka from 2012 to 2014. For analysis, a sample included six containers of a single brand, from the same processing batch number and the same shop. Each container was quantitatively analyzed for aflatoxin B1 (AFB1) in six replicates by using competitive enzyme-linked immunosorbent assay; thus, aflatoxin contamination level of a given sample was derived from an average of 36 test values. Results showed that 73% of the brands tested in 2012 were contaminated with AFB1 levels >20 μg/kg and ranged up to 130 μg/kg. In 2013, 80% of the brands were contaminated with AFB1 levels >20 μg/kg and ranged up to 10,740 μg/kg. Compared with brand data from 2012 and 2013, fewer brands in 2014, i.e., 53%, had aflatoxin B1 levels >20 μg/kg and ranged up to 1,000 μg/kg. Of the eight brands tested repeatedly across the 3-year period, none consistently averaged ≤20 μg/kg. Our survey clearly demonstrates the regular occurrence of high levels of AF B1 in peanut butter in Zambia. Considering that some of the brands tested originated from neighboring countries such as Malawi, Zimbabwe, and South Africa, the current findings provide a sub-Saharan regional perspective regarding the safety of peanut butter.

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A comparison between enzyme immunoassay and HPLC for ochratoxin A detection in green, roasted and instant coffee

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132007000200020 ◽

2007 ◽

Vol 50 (2) ◽

pp. 349-359 ◽

Cited By ~ 21

Author(s):

Simone Fujii ◽

Elisabete Yurie Sataque Ono ◽

Ricardo Marcelo Reche Ribeiro ◽

Fernanda Garcia Algarte Assunção ◽

Cássia Reika Takabayashi ◽

...

Keyword(s):

Monoclonal Antibody ◽

Ochratoxin A ◽

High Performance ◽

Screening Tool ◽

Correlation Coefficients ◽

Enzyme Linked Immunosorbent Assay ◽

Elisa Assay ◽

Quality And Safety ◽

Green Coffee ◽

Instant Coffee

An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for ochratoxin A (OTA) detection in green, roasted and instant coffees was developed using anti-OTA monoclonal antibody. Immunological reagents prepared were OTA-BSA (4.76 mg/mL), anti-OTA.7 MAb (2x10³-fold dilution) and HRP-anti IgG (10³-fold dilution). The detection limit was 3.73 ng OTA/g and correlation coefficients (r) between this immunoassay and high performance liquid chromatography were 0.98 for green coffee, 0.98 for roasted and 0.86 for instant. OTA levels detected by ic-ELISA were higher than by HPLC, with ELISA/HPLC ratio of 0.66 - 1.46 (green coffee), 0.96 - 1.11 (roasted) and 0.93 - 1.82 (instant). ELISA recoveries for OTA added to coffee (5 - 70 ng/g) were 81.53 % for green coffee, 46.73 % for roasted and 64.35 % for instant, while recoveries by HPLC were 80.54 %, 45.91 % and 55.15 %, respectively. Matrices interferences were minimized by samples dilution before carrying out the ELISA assay. The results indicate that MAb-based ic-ELISA could be a simple, sensitive and specific screening tool for OTA detection, contributing to quality and safety of coffee products.

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