EVALUATION OF ELEVEN IMMUNOCHROMATOGRAPHIC ASSAYS FOR SARS-CoV-2 DETECTION: INVESTIGATING DENGUE CROSS-REACTION

AbstractBackgroundCOVID-19 disease (Coronavirus disease 2019) caused by SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) is widespread worldwide, affecting more than 11 million people globally (July 6th, 2020). Diagnostic techniques have been studied in order to contain the pandemic. Immunochromatographic (IC) assays are feasible and low cost alternative for monitoring the spread of COVID-19 in the population.MethodsHere we evaluate the sensitivity and specificity of eleven different immunochromatographic tests in 98 serum samples from confirmed cases of COVID-19 through RT-PCR and 100 negative serum samples from blood donors collected in February 2019. Considering the endemic situation of Dengue in Brazil, we also evaluated the cross-reactivity with Dengue using 20 serum samples from patients with confirmed diagnosis for Dengue collected in early 2019 through four different tests.ResultsOur results demonstrated agreement between immunochromatographic assays and RT-PCR, especially after 10 days since the onset of symptoms. The evaluation of IgG and IgM antibodies combined demonstrated a strong level of agreement (0.85) of IC assays and RT-PCR. It was observed cross-reactivity between Dengue and COVID-19 using four different IC assays for COVID-19 diagnosis. The specificity of IC assays to detected COVID-19 IgM antibodies using Dengue serum samples varied from 80% to 85%; the specificity of IgG detection was 100% and total antibody was 95%.ConclusionsWe found high sensitivity, specificity and good agreement of IC assays, especially after 10 days onset of symptoms. However, we detected cross-reactivity between Dengue and COVID-19 mainly with IgM antibodies demonstrating the need for better studies about diagnostic techniques for these diseases.HighlightsImmunochromatographic assays demonstrated high sensitivity and specificity and good agreement with the gold-standard RT-PCR;Increase in sensitivity and specificity of assays using samples collected after the 10th day of symptoms;Cross-reaction with Dengue serology in evaluation of IgM.

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Development of in-house, indirect ELISAs for the detection of SARS-CoV-2 spike protein-associated serology in COVID-19 patients in Panama

PLoS ONE ◽

10.1371/journal.pone.0257351 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0257351

Author(s):

Carolina de la Guardia ◽

Giselle Rangel ◽

Alcibiades Villarreal ◽

Amador Goodridge ◽

Patricia L. Fernández ◽

...

Keyword(s):

Area Under The Curve ◽

High Sensitivity ◽

Cross Reactivity ◽

Spike Protein ◽

Close Relative ◽

Rt Pcr ◽

Characteristic Analysis ◽

Serum Samples ◽

Health Authorities ◽

Significant Difference

COVID-19 is the name of the acute respiratory disease caused by the new coronavirus SARS-CoV-2, a close relative of those that caused the severe outbreaks of SARS and MERS several years ago. Since first appearance on December of 2019, the COVID-19 pandemic has cause extremely high levels of mortality, morbidity, global economic breakdown, and the consequent human suffering. The main diagnostic test for the confirmation of symptomatic individuals is the detection of viral RNA by reverse transcriptase–quantitative real time PCR (RT-PCR). Additionally, serology techniques, such as ELISA are useful to measure the antibodies produced in humans after contact with the virus, as well as the direct presence of viral antigens. In this study we aim to assemble and evaluate four ELISA assays to measure the presence of IgG or IgM specific for the viral Spike protein in COVID-19 patients, using either the full recombinant SARS-CoV-2 Spike protein or the fragment corresponding to the receptor binding domain. As a control, we analyzed a group of pre-pandemic serum samples obtained before 2017. Strong reactivity was observed against both antigens. A few pre-pandemic samples displayed high OD values, suggesting the possibility of some cross reactivity. All four assays show very good repeatability, both intra- and inter-assay. Receiver operating characteristic analysis allowed the definition of cutoffs and evaluation of performance for each ELISA by estimation of the area under the curve. This performance parameter was high for all tests (AUC range: 0.98–0.99). Multiple comparisons between tests revealed no significant difference between each other (P values: 0.24–0.95). Our results show that both antigens are effective to detect both specific IgG and IgM antibodies, with high sensitivity (range 0.92–0.99), specificity (range 0.93–0.97) and congruence with the RT-PCR test (Cohen´s Kappa range 0.87–0.93). These assays will allow health authorities to have a new tool to estimate seroprevalence, in order to manage and improve the severe sanitary situation caused by this virus.

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Evaluation of in-house ELISA and 11 commercial ELISA kits in the serological diagnosis of COVID-19

Medycyna Doświadczalna i Mikrobiologia ◽

10.32394/mdm.73.04 ◽

2021 ◽

pp. 39-52

Author(s):

Waldemar Rastawicki ◽

Klaudia Płaza ◽

Adam Pietrusiński

Keyword(s):

Viral Infections ◽

Clinical Symptoms ◽

High Sensitivity ◽

Diagnostic Methods ◽

Molecular Diagnostic ◽

Rt Pcr ◽

Serum Samples ◽

Serological Tests ◽

Igm Antibodies ◽

Epidemiological Surveys

Introduction: ELISA-Immunoassays can complement the molecular diagnostic methods, and can be one of the important tools of sero-surveillance and vaccine evaluation. The aim of the presented study was to develop in-house ELISA and evaluate 11 commercial ELISA tests for detection of anti-SARS-CoV-2 antibodies in serum samples collected from COVID patients. Methods: In total, 237 serum samples obtained from 165 people with COVID-19 with RT-PCR confirmed SARS-CoV-2 virus infection were used for the study. The specificity of the developed in-house ELISA kit was tested using 170 serum samples obtained from patients with various bacterial and viral infections. The study used an in-house ELISA and 11 commercial ELISA kits developed by various manufacturers. Results: The presented study showed high sensitivity (81.0%) and specificity (97.2%) of the developed in-house kit in relation to the RT-PCR method. The sensitivity of the inhouse test significantly increased (98.1%) when only convalescents - persons at least 3 weeks after COVID-19 were examined. Commercial ELISA kits most frequently detected IgG antibodies (from 44.9% to 89.4%), especially in samples obtained later in the disease, and the least frequent detection of IgM antibodies (from 4.2% to 42.4%). Conclusions: All the presented ELISA kits may be used in serodiagnosis of COVID-19 however the detection of antibodies in individual tests differed quite significantly and was dependent on the period of the disease, on the class of immunoglobulins and the type of antigen used. The sensitivity of serological tests in the IgG class is clearly higher when examining samples obtained at least 2-3 weeks from the onset of clinical symptoms. Searching for IgA antibodies may be useful mainly in the early phase of the disease while IgM antibodies does not provide significant additional information. In the case of asymptomatic or mild infection, the level of antibodies is low which may be the cause problems with the correct interpretation of epidemiological surveys

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Diagnosis of west Nile neuroinvasive disease in humans

Archives of Veterinary Medicine ◽

10.46784/e-avm.v11i1.19 ◽

2018 ◽

Vol 11 (1) ◽

pp. 79-90

Author(s):

Ivana Hrnjaković Cvjetković ◽

Vesna Milošević ◽

Tamaš Petrović ◽

Dušan Petrić ◽

Gordana Kovačević ◽

...

Keyword(s):

Cerebrospinal Fluid ◽

Real Time ◽

Cross Reactivity ◽

Igg Antibodies ◽

Rt Pcr ◽

Serum Samples ◽

West Nile ◽

Igm Antibodies ◽

Neuroinvasive Disease ◽

Viremia Level

West Nile virus (WNV) is arbovirus distributed all around the world. In humans, 80% of infection cases are asymptomatic. In 20% of infected people, a febrile self-limiting illness is reported. WNV has the potential for fatal neuroinvasive disease. In 1% of cases, the infection may result in neuroinvasive disease with permanent neurological consequences or death outcome. Neurological forms may vary presenting with encephalitis, meningitis, meningoencephalitis or acute flaccid paralysis. Outbreaks with neurological forms of WNV infection were recorded in different areas of Greece, Italy, Romania, Hungary and Serbia. During the period from 2013 to 2016, 114 samples of cerebrospinal fluid and 107 serum samples were taken from 114 patients suspected of WNV neuroinvasive disease (WNND). The presence of specific anti-WNV IgM and IgG antibodies in cerebrospinal fluid (CSF) and sera samples were tested by WNV IgM and IgG ELISA (Euroimmun, Germany). In addition, 48 samples of CSF or/and serum of people with suspected WNV infection were examined by commercial molecular tests - real time RT-PCR (WNV Real-TM, Sacace biotechnologies, Italy). The IgM antibodies against WNV were present in 25.4% (29/114) of CSF samples, and in 31.8% (34/107) of serum samples tested from 114 patients suspected of WNND. The IgG antibodies against WNV were detected in 3.5% (4/114) of CSF samples, and in 11.2% (12/107) of serum samples. The WNV RNA was detected by real time RT-PCR test in 7 out of 48 (14.6%) CSF or/and serum samples. In this study, detection of IgM antibodies in CSF is more frequent than detection of WNV RNA in CSF or serum samples. WNV RNA detection in CSF is confirmatory diagnostic test but has limited utility in the diagnosis of WNV neuroinvasive disease due to low viremia level at the time of clinical presentation of the disease. The limitations in the use of ELISA IgM test are linked to cross - reactivity among flaviviruses and long persistence of IgM antibodies in the serum and CSF.

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Detection of a novel bunyavirus associated with fever, thrombocytopenia and leukopenia syndrome in Henan Province, China, using real-time reverse transcription PCR

Journal of Medical Microbiology ◽

10.1099/jmm.0.049577-0 ◽

2013 ◽

Vol 62 (7) ◽

pp. 1060-1064 ◽

Cited By ~ 8

Author(s):

Xueyong Huang ◽

Licheng Liu ◽

Yanhua Du ◽

Hongxia Ma ◽

Yujiao Mu ◽

...

Keyword(s):

Real Time ◽

Reverse Transcription ◽

High Sensitivity ◽

Cross Reactivity ◽

Henan Province ◽

Clinical Samples ◽

Rt Pcr ◽

Pcr Assay ◽

Serum Samples ◽

Reverse Transcription Pcr

A novel bunyavirus associated with fever, thrombocytopenia and leukopenia syndrome (FTLS) was discovered in Henan Province, China. Here, we report the development of an assay for this novel bunyavirus based on real-time reverse transcription PCR (RT-PCR). The assay exhibited high sensitivity and specificity without cross-reactivity towards 13 other viruses that cause similar symptoms. To evaluate the performance of this assay in detecting clinical samples, we analysed 261 serum samples from patients in Henan Province between 2007 and 2010. Of these samples, 91.95 % were bunyavirus positive. Compared with serological assays, the real-time PCR assay was much more sensitive in identifying infected patients 1 to 7 days after the onset of symptoms.

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Evaluation of the performance of the COVID-19 rapid antigen tests in a tertiary level hospital in Bangladesh.

10.21203/rs.3.rs-1056525/v1 ◽

2021 ◽

Author(s):

Mohammad Jahidur Rahman Khan ◽

Md. Shahadat Hossain ◽

Samshad Jahan Shumu ◽

Md. Selim Reza ◽

Farzana Mim ◽

...

Keyword(s):

Viral Load ◽

Real Time ◽

Sensitivity And Specificity ◽

Detection Rate ◽

High Sensitivity ◽

Rt Pcr ◽

College Hospital ◽

Medical College ◽

Qrt Pcr ◽

Antigen Tests

Abstract Background: While the COVID-19 pandemic is a worldwide crisis, tests with high sensitivity and specificity are essential for identifying and managing COVID-19 patients. Globally, several rapid antigen tests RATs for COVID-19 have been developed, but their clinical efficacy has not been well established. This study aimed to evaluate the performance of several rapid antigen tests (RATs) to diagnose SARS-CoV-2 infection.Methods: This prospective observational study was conducted at Shaheed Suhrawardy Medical College hospital from February 2021 to April 2021 in Dhaka, Bangladesh. This study included the patients admitted in this hospital at the COVID-19 isolation unit or referred from the triage facility of the outdoor department of this hospital suspected as COVID-19 case. Two nasopharyngeal samples were collected simultaneously. one sample was used on the spot for the RAT. The other was sent to the adjacent Shaheed Suhrawardy Medical College COVID-19 RT-PCR laboratory for real-time reverse transcription-polymerase chain reaction (qRT-PCR). The performance of the RAT was evaluated using the results of qRT-PCR as a reference.Results: A total of 223 patients were included in this study, and the real-time RT-PCR detected SARS-CoV-2 in 84 (37.7%) patients. Of these 84 patients, 9 (10.7%) were asymptomatic. The overall sensitivity and specificity of RATs were 78.6% and 99.3%, respectively. The sensitivity was 81.3% in symptomatic cases and 55.6% in asymptomatic cases. False-negatives were observed in 18 patients, 3 of whom were asymptomatic and had a low viral load (cycle threshold (Ct) > 30). The detection rate of RATs was 100% when the Ct value was up to 24. The detection rate was 42.3% when the Ct was >29. The detection rate of RATs was 92.3% when the onset of symptoms was within three days. The detection rate was 33.3% when the onset of symptoms was >7 days.Conclusions: RATs for COVID-19 used in this study delivered an acceptable performance in patients with high viral load and within the first week of the onset of symptoms. They can be used as a supplementary method to RT-PCR for the diagnosis of COVID-19 patients.

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Novel Blood Biomarkers for an Earlier Diagnosis of Alzheimer’s Disease: A Literature Review

International Journal of Medical Students ◽

10.5195/ijms.2020.452 ◽

2020 ◽

Author(s):

Shiavax Rao ◽

Andrew J. Boileau

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Literature Review ◽

Clinical Diagnosis ◽

Sensitivity And Specificity ◽

Memory Loss ◽

High Sensitivity ◽

Diagnostic Techniques ◽

Pubmed Database ◽

Diagnostic Approaches

Alzheimer’s disease is a neurodegenerative condition associated with neurofibrillary tangles and cortical deposition of amyloid plaques. Clinical presentation of the disease involves manifestations such as memory loss, cognitive decline and dementia with some of the earliest reported deficits being episodic memory impairment and olfactory dysfunction. Current diagnostic approaches rely on autopsy characterization of gross brain pathology, or brain imaging of biomarkers late in the disease course. The aim of this literature review is to identify and compare newly emerging and novel CSF, serum and mucosal biomarkers, with the potential of making an earlier clinical diagnosis of Alzheimer’s disease. Utilizing such techniques may allow for earlier therapeutic intervention, reduction of disability and enhancement of quality of life. Literature review and analysis was performed by screening the PubMed database for relevant studies within the past 5 years. All studies showed statistically significant (P < 0.05) differences in testing between AD patients and controls. Two categories of serum biomarkers (redox-reactive antiphospholipid antibodies and microRNAs) and an olfactory mucosal marker (microRNA-206) could discriminate between early AD patients and controls with high sensitivity and specificity. In conclusion, certain studies have shown promising results with high sensitivity and specificity, high discriminative potential for Alzheimer’s disease early in its progression, and statistically significant results in larger study samples. Utilization of such diagnostic techniques should increase the efficacy of making an earlier clinical diagnosis of Alzheimer’s disease.

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Performance evaluation of the Simtomax® CoronaCheck rapid diagnostic test

10.1101/2020.10.28.20219667 ◽

2020 ◽

Author(s):

P. J. Ducrest ◽

A. Freymond ◽

J.-M. Segura

Keyword(s):

Diagnostic Test ◽

Rapid Diagnostic Test ◽

Diagnostic Performance ◽

High Sensitivity ◽

High Specificity ◽

Negative Control ◽

List Type ◽

Plasma Samples ◽

Rt Pcr ◽

Two Samples

AbstractThe aim of this study was to evaluate the diagnostic performance of Simtomax® CoronaCheck, a serology rapid diagnostic test (RDT) for the detection of IgG and IgM against SARS-CoV-2. 48 plasma samples positive for SARS-CoV-2 based on RT-PCR and 98 negative control samples were studied. Diagnostic performance of the IgG/IgM RDT was assessed against RT-PCR and the electro-chemiluminescence immunoassay (ECLIA) Elecsys® Anti-SARS-CoV-2 total Ig. Overall, the RDT sensitivity was 92% (95% confidence interval [95%CI]: 79-97), specificity 97% (95% CI: 91-99%), PPV 94% (95% CI: 81-98) and the NPV 96% (95% CI: 89-99). When considering only samples collected ≥ 15 days post-symptoms (DPS), the sensitivity increased to 98% (95%CI: 86-100) and the specificity was 97% (95% CI: 91-99%). Two samples with 180 DPS were still positive for IgG. Globally, this IgG/IgM RDT displayed a high diagnostic accuracy for SARS-CoV-2 IgG/IgM detection in plasma samples in high COVID-19 prevalence settings. It could be effectively used, in absence of facilities for routine diagnostic serology, for samples with a DPS between 15 and 180 days.Highlights–The rapid diagnostic test Simtomax CoronaCheck displays a high sensitivity of 98% and a high specificity of 97% for SARS-CoV-2 IgG/IgM detection in plasma samples after 15 days post-symptoms.–The rapid diagnostic test Simtomax CoronaCheck can detect SARS-CoV-2 antibodies in plasma up to 180 days after symptom onset.–The rapid diagnostic test Simtomax CoronaCheck could be effectively used as an alternative to serological analysis using laboratory facilities.

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Comparison of Coombs Gel Test with ELISA and Standard Tube Agglutination Tests Used in Serological Diagnosis of Brucellosis

Infectious Diseases and Clinical Microbiology ◽

10.36519/idcm.2019.0024 ◽

2020 ◽

Vol 2 (1) ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Cigdem Akalan Kuyumcu ◽

Serpil Erol ◽

Rıza Adaleti ◽

Seniha Senbayrak ◽

Secil Deniz ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Diagnostic Tests ◽

Serological Test ◽

High Sensitivity ◽

Serological Diagnosis ◽

Control Groups ◽

Serum Samples ◽

Serological Tests ◽

Reliable Test ◽

And Control

Objective: Serological tests are the most commonly used tests in the diagnosis of brucellosis; however, each serological test has some drawbacks. In this study, we aimed to determine the value of the Brucella Coombs gel test (BCGT) in the serological diagnosis of brucellosis in comparison with Standard tube agglutination (STA) and ELISA tests. Materials and Methods: The study included 42 patients who were considered to have brucellosis as a preliminary diagnosis. BCGT, Brucella-IgM/IgG ELISA, and STA tests were performed from serum samples of the patients. The correlation of the diagnostic tests was analyzed using Cohen’s Kappa Analysis. Results: Twenty-seven (64.2%) of 42 patients were diagnosed with brucellosis according to their medical history and clinical and serological tests. The sensitivity and specificity of BCGT to diagnose brucellosis was 96.2%, and 100%, respectively. The sensitivity and specificity for the diagnosis of brucellosis 62.9% and 100% for STA, respectively; 33.3% and 66.6% for Brucella-IgM; and 66.6% and 100% for Brucella-IgG. BCGT was significantly correlated with STA (κ= 0.590) and Brucella-IgG (κ=0.539) Conclusion: BCGT can be utilized as a simple and reliable test in the diagnosis of brucellosis with high sensitivity and specificity. Nevertheless, the sensitivity and specificity of BCGT should be demonstrated by comprehensive studies, including culture-confirmed cases and control groups.

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Serum metabolomics reveals dysregulation and diagnostic potential of oxylipins in tumor-induced osteomalacia

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/clinem/dgab885 ◽

2021 ◽

Author(s):

Yiyi Gong ◽

Xiaolin Ni ◽

Chenxi Jin ◽

Xiang Li ◽

Yujie Wang ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Fibroblast Growth Factor 23 ◽

Tumor Resection ◽

High Sensitivity ◽

Leukotriene B4 ◽

Arachidonic Acid Metabolism ◽

Serum Samples ◽

Diagnostic Potential ◽

Liquid Chromatography Tandem Mass ◽

Diagnostic Panel

Abstract Context Excessive production of fibroblast growth factor 23 (FGF23) by tumor was considered as the main pathogenesis in tumor-induced osteomalacia (TIO). Despite its importance to comprehensive understanding of pathogenesis and diagnosis, the regulation of systemic metabolism in TIO remains unclear. Objectives We aimed to systematically characterize the metabolome alteration associated with TIO. Methods By means of liquid chromatography-tandem mass spectrometry (LC-MS) based metabolomics, we analyzed the metabolic profile from 96 serum samples (32 initial diagnosis TIO patients, pairwise samples after tumor resection and 32 matched healthy control subjects). In order to screen and evaluate potential biomarkers, statistical analyses, pathway enrichment and receiver operating characteristic (ROC) were performed. Results Metabolomic profiling revealed distinct alterations between TIO and HC cohort. Differential metabolites were screened and conducted to functional clustering and annotation. Significantly enriched pathway was found involved in arachidonic acid metabolism. A combination of 5 oxylipins, 4-HDoHE, leukotriene B4, 5-HETE, 17-HETE and 9,10,13-TriHOME, demonstrated a high sensitivity and specificity panel for TIO prediction screened by random forest (RF) algorithm (AUC=0.951, 95% confidence interval, CI 0.827-1). Supported vector machine (SVM) model and partial least-squares (PLS) model were conducted to validate the predictive capabilities of the diagnostic panel. Conclusions Metabolite profiling of TIO altered significant compared with HC. A high sensitivity and specificity panel with 5 oxylipins were tested as diagnostic predictor. For the first time, we provide the global profile of metabolomes and identify potential diagnostic biomarkers of TIO. The present work may offer novel insights into the pathogenesis of TIO.

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A rapid, sensitive enzyme-linked immunoassay for human thyrotropin.

Clinical Chemistry ◽

10.1093/clinchem/31.7.1131 ◽

1985 ◽

Vol 31 (7) ◽

pp. 1131-1134 ◽

Cited By ~ 11

Author(s):

Y C Tseng ◽

K D Burman ◽

J R Baker ◽

L Wartofsky

Keyword(s):

Color Change ◽

Clinical Laboratory ◽

High Sensitivity ◽

Normal Subjects ◽

Turnaround Time ◽

Cross Reactivity ◽

Serum Samples ◽

Assay Sensitivity ◽

Nitrophenyl Phosphate ◽

Set Up

Abstract In this enzyme-linked immunoassay for human thyrotropin (TSH) in unextracted serum we use 96-well immunoenzymometric assay plates, first coated with polyclonal antibody to TSH, then incubated with the serum samples and reacted with mouse monoclonal antibody to human TSH. After incubation with alkaline phosphatase-labeled antibody against mouse IgG, disodium p-nitrophenyl phosphate is added and the color change is measured spectrophotometrically. Assay sensitivity is 0.1 milli-int. unit/L. Cross reactivity with lutropin, follitropin, or choriogonadotropin was negligible. TSH concentrations ranged from 0.4 to 4.1 milli-int. units/L in 43 normal subjects (mean 2.0, SD 1.0), and were uniformly less than 0.3 milli-int. unit/L in 23 patients with hyperthyroidism. Features which make this assay advantageous to the clinical laboratory include ease of set-up, ability to assay many samples at a time, high sensitivity, rapid turnaround time (8 h), and absence of requirements for radioactive materials.

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