Performance characteristics of a new automated method for measurement of anti-cyclic citrullinated peptide

2015 ◽  
Vol 53 (7) ◽  
Author(s):  
Madelon Noordegraaf ◽  
Albert Wolthuis ◽  
Frans Peters ◽  
Monique de Groot ◽  
Rein Hoedemakers
Keyword(s):  
Clinical Manifestations ◽  
Method Comparison ◽  
Elisa Test ◽  
Performance Characteristics ◽  
Modular System ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Tests ◽  
Modular Systems ◽  
Siemens Healthcare ◽  
Automated Method

AbstractRheumatoid arthritis (RA) is a chronic inflammatory auto-immune disease affecting approximately 1%–2% of the population worldwide. RA is a potentially crippling disease since it results in malformation of the joints. RA is mostly diagnosed based on clinical manifestations but serological tests against autoantibodies, such as rheumatoid factor and anti-cyclic citrullinated peptides (aCCP), are available. The presence of aCCP antibodies is strongly associated with a more severe, destructive disease course. Recently, a new test for the measurement of aCCP antibodies on the IMMULITE 2000(XPi) platform was developed by Siemens Healthcare. In this study we investigated the performance characteristics of this new aCCP test in four different hospital laboratories and compared the new test with three different commercially available platforms.Samples were collected from patients presented to the hospital for aCCP measurement. Serum aCCP levels were determined by aCCP (Ig)G assay for IMMULITE 2000(XPi) systems (Siemens Healthcare), ImmunoScan RA enzyme-linked immunosorbent assay (ELISA) test (Eurodiagnostica), Immunocap 250 (Thermofisher) or aCCP IgG assay on the Modular system (Roche Diagnostics). The evaluation protocol consisted of within-run imprecision (20 sequential runs), between-run imprecision (16 workdays), comparison of serum and plasma measurement and method comparison.The within-run imprecision (n=20) for aCCP IgG assay on three different IMMULITE 2000(XPi) systems ranged from 3.0% to 6.9% at levels 3.2–171.2 U/mL. Between-run imprecision (n=16 days) ranged from 5.2% to 11% at levels of 3.2–106.9 U/mL. Method comparison showed good correlation when samples were measured on two different Immulite analyzers in two different hospital laboratories [0.21+0.96x (n=40)]. Method comparison of the IMMULITE 2000(XPi) aCCP test with aCCP on Immunoscan RA ELISA (n=112), Immunocap 250 (n=105) and the Modular system (n=289) resulted in a concordance of 90.2%, 93.3% and 94.8%, respectively. Correlation of serum versus heparin samples showed a correlation of 0.12+1.08x for the Immulite 2000(XPi) test.The aCCP assay on the IMMULITE 2000(XPi) has good performance characteristics and shows high level of concordance with the aCCP test on Immunoscan RA ELISA test, Immunocap 250 and the Modular systems.

scholarly journals Increased detection of schistosomiasis with Kato-Katz and SWAP-IgG-ELISA in a Northeastern Brazil low-intensity transmission area

2012 ◽  
Vol 45 (4) ◽  
pp. 510-513 ◽  
Author(s):  
Teiliane Rodrigues Carneiro ◽  
Marta Cristhiany Cunha Pinheiro ◽  
Sara Menezes de Oliveira ◽  
Ana Lúcia de Paula Hanemann ◽  
José Ajax Nogueira Queiroz ◽  
...  
Keyword(s):  
Serological Test ◽  
Laboratory Diagnosis ◽  
Elisa Test ◽  
Northeastern Brazil ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Tests ◽  
Predictive Values ◽  
Transmission Area ◽  
Elisa Technique ◽  
Endemic Areas

INTRODUCTION: The laboratory diagnosis of schistosomiasis is based mainly on the detection of parasite eggs in stool samples through the Kato-Katz (KK) technique, reading one slide by test. However, a widely known limitation of parasitological methods is reduced sensitivity, particularly in low endemic areas. METHODS: To increase sensitivity, we conducted further slide readings from the same stool sample using the parasitological method associated with a serological test. We used the KK method (three slides) and the IgG anti-Schistosoma mansoni-enzyme-linked immunosorbent assay (ELISA) technique to diagnose schistosomiasis in low endemic areas in the Brazilian State of Ceará. Fecal samples and sera from 250 individuals were analyzed. RESULTS: Sixteen percent and 47.2% of samples were positive in parasitological tests and serological tests, respectively. Parasitological methods showed that 32 (80%) individuals tested positive on the first slide, 6 (15%) on the second slide, and 2 (5%) on the third. The performance of the ELISA test in the diagnosis, using the KK method as diagnostic reference, showed a negative predictive value of 100%, with specificity and positive predictive values of 62.8% and 33.9%, respectively. CONCLUSIONS: In this study, the increase from one to three slides analyzed per sample using the KK technique was shown to be a useful procedure for increasing the diagnostic sensitivity of this technique.

Validation of a chemiluminescent assay for specific SARS-CoV-2 antibody

2020 ◽  
Vol 58 (8) ◽  
pp. 1357-1364 ◽  
Author(s):  
Marie Tré-Hardy ◽  
Alain Wilmet ◽  
Ingrid Beukinga ◽  
Jean-Michel Dogné ◽  
Jonathan Douxfils ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Elisa Test ◽  
Diagnostic Methods ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Elisa Method ◽  
Serological Tests ◽  
Economy Of Scale

AbstractObjectivesFaced with the COVID-19 pandemic and its impact on the availability and quality of both therapeutic and diagnostic methods, the Belgian authorities have decided to launch a procedure for additional evaluation of the performance of serological tests offered for sale on the national territory. This has been proposed with a double aim: (1) an in-depth verification of the analytical and clinical performances presented by the manufacturer and (2) an economy of scale in terms of centralized validation for all the laboratories using the tests subject to evaluation.MethodsA retrospective validation study was conducted including the serum of 125 patients in order to determine the analytical and clinical performances of the LIAISON®SARS-CoV-2 from DiaSorin® detecting anti-SARS-CoV-2 IgG and to compare its clinical performance with the enzyme-linked immunosorbent assay (ELISA) test from Euroimmun®, one of the first commercially available tests allowing the detection of anti-SARS-CoV-2 IgA and IgG.ResultsThe performances of the LIAISON®SARS-CoV-2 satisfied all the acceptance criteria and provided “real world” analytical and clinical performances very close to the ones reported by the manufacturer in its insert kit. Comparison between the LIAISON®SARS-CoV-2 and the ELISA method did not reveal any difference between the two techniques in terms of sensitivities and specificities regarding the determination of the IgG.ConclusionsThis study reports the validation of the LIAISON®SARS-CoV-2 allowing to detect IgG antibodies specifically directed against SARS-CoV-2. The analytical and clinical performances are excellent, and the automation of the test offers important rates, ideal for absorbing an extension of testing.

scholarly journals Seroprevalence of toxoplasmosis in sheep in South Africa

2007 ◽  
Vol 78 (3) ◽  
Author(s):  
N. Abu Samraa ◽  
C.M.E. McCrindle ◽  
B.L. Penzhorn ◽  
B. Cenci-Goga
Keyword(s):  
South Africa ◽  
Incidental Finding ◽  
Fluorescent Antibody ◽  
Elisa Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Published Data ◽  
Western Cape ◽  
Eastern Cape ◽  
Serum Samples ◽  
Serological Tests

Serum samples from 600 sheep were collected from 5 different provinces randomly chosen in South Africa. Two sheep abattoirs (representing formal slaughter of sheep) and 1 rural location (representing informal slaughter of sheep) per province were also selected randomly. The serum samples were tested for anti-Toxoplasma gondii IgG antibodies using 2 different serological tests : an indirect fluorescent antibody (IFA) test and an enzyme-linked immunosorbent assay (ELISA) test available as a commercial kit. This study provides the first published data on seroprevalence of toxoplasmosis in sheep in South Africa, although positive titres have been found previously in wild felids, ferrets, chinchillas and a dog. Data on seroprevalence in sheep is considered important because consumption of mutton is universally considered to be a source of zoonotic transfer to humans. Seroprevalence in humans in South Africa was previously found to be 20% and it is postulated that this may be linked to the informal slaughter and consumption of mutton. During this study, the overall national seroprevalence per province in sheep was found to be 5.6 % (IFA) and 4.3 % (ELISA), respectively. This is lower than in other countries, possibly because South Africa has an arid climate. Differences in seroprevalence in different areas studied suggested an association with the climate and a significant correlation (P > 0.05) was detected between the prevalence of T. gondii and the minimum average temperature. The seroprevalence was found to be significantly higher (P < 0.01) in sheep originating from commercial farms (7.9 %) than in rural sheep in the informal sector (3.4 %). Also, sheep managed extensively had a seroprevalence of 1.8 %, which was significantly lower (P < 0.05) than the seroprevalence in sheep under semi-intensive or intensive management systems (5.3 %). An incidental finding of interest was the considerable movement of sheep to abattoirs and mutton after slaughter. The highest consumption of mutton was in the Western Cape Province (29.9 %) while the highest concentration of sheep is found in the Eastern Cape Province (30.1 %).

scholarly journals Helicobacter pylori and rosacea

2003 ◽  
Vol 9 (1-2) ◽  
pp. 167-171
Author(s):  
S. Zandi ◽  
S. Shamsaddini ◽  
M. J. Zahedi ◽  
M. Hyatbaksh
Keyword(s):  
Helicobacter Pylori ◽  
Method Comparison ◽  
Test Group ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Igg Antibody ◽  
Serological Tests ◽  
Serological Examination ◽  
Antibody Titres ◽  
H Pylori

Recent reports have suggested an increased prevalence of Helicobacter pylori infection in patients with rosacea, with some evidence of dermatological improvement in patients treated with antibiotics for this infection. Our study investigates the prevalence of H. pylori infection in rosacea patients in Kerman. Serological examination was done for 29 patients with classical identification of rosacea using the enzyme-linked immunosorbent assay IgG antibody method. Comparison of antibody titres with those of a control group revealed that the prevalence of positive serological tests for H. pylori was significantly higher in the test group. This supports the suggestion of some form of relationship between rosacea and H. pylori infection, though further investigations with larger sample sizes are required for a definite conclusion

scholarly journals Dengue pre-vaccination screening test evaluation for the use of dengue vaccine in an endemic area

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257182
Author(s):  
Umaporn Limothai ◽  
Sasipha Tachaboon ◽  
Janejira Dinhuzen ◽  
Taweewun Hunsawong ◽  
Prapapun Ong-ajchaowlerd ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Dengue Infection ◽  
Reference Method ◽  
Elisa Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dengue Vaccine ◽  
Serum Samples ◽  
Serological Tests ◽  
Low Sensitivity

Background The dengue vaccine (Dengvaxia) is only recommended for individuals with prior dengue infection (PDI). This study aimed to perform a serosurvey to inform decision-making for vaccine introduction and identify appropriate target populations. We also evaluated the performance of the serological tests using plaque reduction neutralization test (PRNT) as a reference test in identifying PDI to determine suitability for pre-vaccination screening. Methods We enrolled 115 healthy individuals between 10 and 22 years of age living in the Ratchaburi province of Thailand. The serum samples were tested by PRNT to measure the prevalence and concentration of serotype-specific neutralizing antibodies. The performance of the IgG rapid diagnostic test (RDT, SD Bioline, Korea) and IgG enzyme-linked immunosorbent assay (ELISA, EUROIMMUN, Germany) in identifying PDI were evaluated by using PRNT as a reference method. Results Ninety-four (81.7%) individuals neutralized one or more dengue serotypes at a titer threshold greater than or equal to 10. Multitypic profiles were observed in 70.4% of the samples which increased to 91.9% in subjects aged 19–22. Among monotypic samples, the highest proportion was reactive against DENV-1 followed by DENV-2, DENV-3, and DENV-4. The highest anti-dengue antibody titers were recorded against DENV-1 and increased with age to a geometric mean NT50 titer (GMT) of 188.6 in the 19–22 age group. While both RDT and ELISA exhibited 100% specificity, RDT demonstrated low sensitivity (35%) with ELISA displaying much greater sensitivity (87%). Conclusions Almost 80% of adolescents and youth in Ratchaburi province had already been exposed to one or more of the dengue virus serotypes. The dengue IgG RDT displayed low sensitivity and is likely not be suitable for dengue pre-vaccination screening. These results support the use of IgG ELISA test for dengue vaccination in endemic areas.

scholarly journals Evaluation of IgG, IgA and IgM against Mycobacterial Antigen in Patients with Extrapulmonary Tuberculosis

2021 ◽  
Vol 6 (1) ◽  
pp. 6-12
Author(s):  
Ngangom. Arunkumar Singh ◽  
Tina Das ◽  
Sungdirenla Jamir
Keyword(s):  
Immunosorbent Assay ◽  
Extrapulmonary Tuberculosis ◽  
Radiological Finding ◽  
Elisa Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mycobacterial Antigen ◽  
Diagnostic Significance ◽  
Serological Tests ◽  
Cross Sectional ◽  
Acid Fast Bacilli

Tuberculosis (TB) is a specific infectious disease usually caused by the tubercle bacillus, Mycobacterium tuberculosis (MBT). It primarily affects the lungs and causes pulmonary tuberculosis (PTB) and when it affects other organs it is known as extrapulmonary tuberculosis (EPTB). The diagnosis of TB largely depends on case history, clinical examination, radiological finding and subsequent laboratory confirmation by bacteriological examination. But the radiological findings are not specific and the sensitivity of AFB (acid fast bacilli) smear is poor. To overcome this difficulty, various serological tests have been tried. A novel antigen namely A60 antigen was found to be highly immunogenic and this present study was carried out to see the diagnostic significance of the ELISA test for A60 antigen in diagnosing extrapulmonary tuberculosis. The study was designed as a cross-sectional study involving both extrapulmonary TB patients and controls. Their serum immunoglobulins (IgG, IgA and IgM) specific toA60 antigen were measured by enzyme linked immunosorbent assay (ELISA) technique. In this study, IgG, IgA and IgM was significantly elevated among the EPTB patients as compared to the controls and the IgA and IgM ELISA test combinations was most ideal in diagnosing EPTB. Keywords: Tuberculosis, Extrapulmonary tuberculosis, AFB (acid fast bacilli), A60 antigen, ELISA (enzyme linked immunosorbent assay), Immunoglobulin.

scholarly journals Detection of H. pylori IgG by Using ELISA

2020 ◽  
pp. 102-106
Author(s):  
Malabika Mahato
Keyword(s):  
Antimicrobial Agents ◽  
Elisa Test ◽  
Endoscopic Examination ◽  
Endometrial Biopsy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Tests ◽  
Medical College ◽  
Arterial Blood ◽  
H Pylori ◽  
Acting Agent

Background: Helicobacter pylori is a Gram-negative, winding, microaerophilic human pathogen and have indicated solid relationship with different gastroduodenal illnesses. Its contagion is one of the most widely recognized interminable diseases in humans since the isolation of the pathogen (1–3). Aim and Objectives: This examination was directed to discover the affectability and particularity of ELISA in distinguishing H. pylori. Materials and Methods: The investigation was completed in the Department of Pathology, Sri Balaji Medical College and Hospital, Chennai for a period from November 2016 to October 2018. The research was planned as Prospective study. The study recruited two population of respondents comprising of 50 symptomatic clinicians and 50 infection populations of either sex, over 18 years of age. Patients with signs identified with the upper gastrointestinal tract prompted by endoscopic examination and identified as having gastritis, peptic ulcer (PU) and those patients were recalled for this investigation. Patients who took treatment of pylori destruction and use of antimicrobial agents, neutron siphon agonists, bismuth containing mixtures during the month prior to endometrial biopsy were removed from the inquiry. All essential history, clinical breakthroughs and research facility records of each subject were methodically documented in Microsoft windows sensitive Excel sheet for the consequent examination. Arterial blood samples were collected for the Enzyme Linked Immunosorbent Assay (ELISA) test. For this, 50 people of either sex matured over 18 years of age were considered. Results: It was observed that, the normal age of the patient was 40 to 60 years, 56% of them were male and 44% female. In this examination, serology tests to recognize IgG counter acting agent demonstrated the affectability of (60%). By and large, low precision and affectability of IgG serological tests is because of the failure to separate among present and past disease. Conclusion: These examinations show that H. pylori contamination is a typical issue among individuals in tamilnadu, India. The titer of IgG antibodies to H. pylori in serum can be utilized as non-intrusive tests for the presence of gastritis.

Etiology and clinical features of epididymo-orchitis: A single-center study in Tehran, Iran

2020 ◽  
Vol 20 ◽  
Author(s):  
Sara Abolghasemi ◽  
Mohammad Alizadeh ◽  
Ali Hashemi ◽  
Shabnam Tehrani
Keyword(s):  
Chlamydia Trachomatis ◽  
Clinical Symptoms ◽  
Urine Culture ◽  
Clinical Manifestations ◽  
Urinary Frequency ◽  
Serological Tests ◽  
Duration Of Symptoms ◽  
Two Samples ◽  
History Of ◽  
Tract Infections

Introduction: Epididymo-orchitis is a common urological disease among men. Little is known about the clinical and epidemiological aspects of the disease in Iran. Thus, the present study was aimed to investigate the etiology, clinical sequelae and risk factors of patients with epididymo-orchitis in Tehran, Iran. Materials and Methods: Patients presenting with epididymo-orchitis were prospectively analyzed in order to study the etiology and pattern of the disease. Bacteriological, molecular and serological tests were undertaken to look for Chlamydia trachomatis, Neisseria gonorrhoeae, Brucella spp., Mycoplasma spp, and other bacteria. Results: Fifty patients with epididymo-orchitis were evaluated according to their clinical symptoms, duration of symptoms, physical examination, and laboratory studies. The mean age of the patients was 53 years. Fever, dysuria, pain in the flanks, urinary frequency and discharges occurred in 58.0%, 50.0%, 50.0%, 28.0% and 6.0%, respectively. Bacterial pathogen was identified in 26% (13/50) of patients by urine culture. Escherichia coli was the etiological agent in 11/13 patients (84.6%). Two out of 50 patients (4.0%) were also positive for Chlamydia trachomatis. Two samples were serologically positive for Brucella spp. High Mean age, fever, urinary frequency, history of the underlying disease and history of urinary tract infections were found to have a significant association with the positive bacteriologic urine culture (P<0.05). Conclusions: The most common clinical manifestations were fever, dysuria, and abdominal pain. E. coli and C. trachomatis were the major causative agents. Use of a set of diagnostic approaches including clinical symptoms, urine culture and more precise techniques such as PCR should be taken into consideration for the definitive diagnosis.

scholarly journals Validation of a Novel Commercial ELISA Test for the Detection of Antibodies against Coxiella burnetii

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1075
Author(s):  
Salvatore Ledda ◽  
Cinzia Santucciu ◽  
Valentina Chisu ◽  
Giovanna Masala
Keyword(s):  
Diagnostic Accuracy ◽  
Phase Ii ◽  
Coxiella Burnetii ◽  
Q Fever ◽  
Animal Health ◽  
Elisa Test ◽  
Clinical Diagnostics ◽  
Complex Life Cycle ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specificity And Sensitivity

Q fever is a zoonosis caused by Coxiella burnetii, a Gram-negative pathogen with a complex life cycle and a high impact on public and animal health all over the world. The symptoms are indistinguishable from those belonging to other diseases, and the disease could be symptomless. For these reasons, reliable laboratory tests are essential for an accurate diagnosis. The aim of this study was to validate a novel enzyme-linked immunosorbent assay (ELISA) test, named the Chorus Q Fever Phase II IgG and IgM Kit (DIESSE, Diagnostica Senese S.p.A), which is performed by an instrument named Chorus, a new device in medical diagnostics. This diagnostic test is employed for the detection of antibodies against C. burnetii Phase II antigens in acute disease. Our validation protocol was performed according to the Italian Accreditation Body (ACCREDIA) (Regulation UNI CEI EN ISO/IEC 17025:2018 and 17043:2010), OIE (World Organization for Animal Health), and Statement for Reporting Studies of Diagnostic Accuracy (STARD). Operator performance was evaluated along with the analytical specificity and sensitivity (ASp and ASe) and diagnostic accuracy of the kit, with parameters such as diagnostic specificity and sensitivity (DSp and DSe) and positive and negative predictive values (PPV and NPV), in addition to the repeatability. According to the evaluated parameters, the diagnostic ELISA test was shown to be suitable for validation and commercialization as a screening method in human sera and a valid support for clinical diagnostics.

scholarly journals 753. Performance Characteristics of Diagnostic Assays in Blastomycosis

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S424-S424
Author(s):  
Timothy O’Dowd ◽  
Jack McHugh ◽  
Nancy Wengenack ◽  
Elitza Theel ◽  
Paschalis Vergidis
Keyword(s):  
Granulomatous Inflammation ◽  
Cross Reactivity ◽  
Performance Characteristics ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fungal Culture ◽  
Noninvasive Test ◽  
Serum Antigen ◽  
Urine Antigen ◽  
Antigen Tests ◽  
Urine And Serum

Abstract Background Blastomycosis has historically been a difficult diagnosis to establish, often initially misdiagnosed as bacterial pneumonia. Serologic assays and polymerase chain reaction (PCR) tests are available, but their performance is not well defined. The objective of this study was to characterize their performance. Methods Subjects were identified via chart review of patients diagnosed with blastomycosis from 2005 to 2020. A definitive diagnosis was based on fungal culture, histopathology, or cytology. Performance characteristics of the Blastomyces antibody enzyme linked immunosorbent assay (ELISA), immunodiffusion (ID), complement fixation (CF), urine and serum antigen ELISAs, and PCR were evaluated in patients with confirmed blastomycosis. Data on patient demographics, location of disease, and mortality was also collected. Results We identified 193 patients with blastomycosis. The mean age was 51.8 years (range, 11-84) and 73.6% of patients were male. 42.5% resided in Minnesota, 18.1% in Wisconsin, and 12.9% in Iowa. Diagnosis was based on culture in 142 (73.2%) or histopathology/cytology in 67 (34.7%) patients. Granulomatous inflammation was present in 73.1% (38/52) while 21.2% (41/193) had evidence of extrapulmonary dissemination. The antibody, ID, and CF assays were positive in 43.5% (37/85), 35.1% (33/94) and 20.5% (8/39) of patients, respectively. Sensitivity of Blastomyces PCR was 40% (4/10) in sputum and 75% (21/28) in bronchoalveolar lavage (BAL) fluid. Blastomyces urine and serum antigen tests were positive in 68% (34/50) and 50% (9/18) of cases, respectively, while the urine antigen was positive in 63.6% (7/11) of disseminated cases. Patients had a positive Histoplasma urine antigen test in 54.1% (20/37) and Aspergillus galactomannan in BAL in 34.8% (8/23) of cases. Serum beta-D-glucan test was positive in 16.7% (2/12). 90-day mortality was 21/193 (10.9%) and median time from diagnosis to death was 18 days. Conclusion In this cohort, Blastomyces urine antigen was the most sensitive noninvasive test, with similar performance in pulmonary and disseminated disease. However, its utility is limited by poor specificity due to cross-reactivity. Blastomyces PCR from BAL fluid demonstrated the highest sensitivity. Blastomyces antibody, ID, and CF had poor sensitivity. Disclosures All Authors: No reported disclosures

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