scholarly journals Autopsy-Controlled Prospective Evaluation of Serial Screening for Circulating Galactomannan by a Sandwich Enzyme-Linked Immunosorbent Assay for Hematological Patients at Risk for Invasive Aspergillosis

1999 ◽  
Vol 37 (10) ◽  
pp. 3223-3228 ◽  
Author(s):  
Johan Maertens ◽  
Jan Verhaegen ◽  
Hilde Demuynck ◽  
Penelope Brock ◽  
Gregor Verhoef ◽  
...  
Keyword(s):  
At Risk ◽  
Invasive Aspergillosis ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Sandwich Elisa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Hematological Patients ◽  
Increased Risk ◽  
Patients At Risk

Efforts to improve the diagnosis of invasive aspergillosis (IA) have been directed towards the detection of fungal antigens, including galactomannan (GM). However, previous evaluations of GM detection have been hampered by a lack of proven cases of IA and by a nonserial study design. This prospective study assessed the diagnostic value of serial screening for circulating GM by using a recently developed sandwich enzyme-linked immunosorbent assay (ELISA) for prolonged-neutropenic and/or steroid-treated patients with hematological disorders. Serum GM levels were monitored twice weekly for 186 consecutive patients at increased risk for IA. The patients were stratified according to the likelihood of IA (proven, probable, possible, and no evidence of IA) by using stringent criteria. Proven IA was defined by characteristic histopathological findings together with a positive culture forAspergillus species. Autopsy and culture from autopsy specimens was used to verify both positive and negative test results. A total of 2,172 serum samples were tested from 243 episodes (mean, 9 samples/episode). Based on the analysis of 71 patients with confirmed disease status (culture and histology), the sensitivity and specificity of serial GM monitoring were 92.6 and 95.4%, respectively. The positive predictive value was almost 93%, the negative predictive value was 95%, and the efficacy was 94%. False-positive reactions occurred at a rate of nearly 8%, although this figure might have been overestimated. Less than 1% of all tested sera were considered inconclusive. In more than half of the cases, antigenemia was detected before clinical suspicion of IA (median, 6 days before). Serial determination of serum GM by the sandwich ELISA technique is a sensitive tool for the diagnosis of IA in hematological patients at risk. This approach may substantially influence clinical management with regard to preemptive and empirical antifungal therapy.

scholarly journals Prevalence of feline coronavirus antibodies in cats in Bursa province, Turkey, by an enzyme-linked immunosorbent assay

2009 ◽  
Vol 11 (10) ◽  
pp. 881-884 ◽  
Author(s):  
Annamaria Pratelli ◽  
Kadir Yesilbag ◽  
Marcello Siniscalchi ◽  
Ebru Yalçm ◽  
Zeki Yilmaz
Keyword(s):  
Immunosorbent Assay ◽  
Predictive Value ◽  
Gold Standard ◽  
Population Based ◽  
Standard Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
High Association ◽  
Gold Standard Test ◽  
Feline Coronavirus

Feline sera from Bursa province (Turkey) were assayed for coronavirus antibody using an enzyme-linked immunosorbent assay (ELISA). The study was performed on 100 sera collected from cats belonging to catteries or community shelters and to households. The serum samples were initially tested with the virus neutralisation (VN) test and the results were then compared with the ELISA. The VN yielded 79 negative and 21 positive sera but the ELISA confirmed only 74 as negative. The ELISA-negative sera were also found to be free of feline coronoviruses-specific antibodies by Western blotting. Using the VN as the gold standard test, ELISA had a sensitivity of 100% and a specificity of 93.6%, with an overall agreement of 95%. The Kappa (κ) test indicated high association between the two tests (κ=0.86, 95% confidence interval (CI) 0.743–0.980). The positive predictive value (PPV) was 0.8, and the negative predictive value (NPV) was 0.93. The prevalence of FCoV II antibodies in the sampled population based on the gold standard was 62% (95% CI 0.44–0.77) among multi-cat environments, and 4% (95% CI 0.01–0.11) among single cat households.

scholarly journals Development of a double monoclonal antibody–based sandwich enzyme-linked immunosorbent assay for detecting canine distemper virus

2020 ◽  
Vol 104 (24) ◽  
pp. 10725-10735
Author(s):  
Yuan Zhang ◽  
Gang Xu ◽  
Lu Zhang ◽  
Jiakai Zhao ◽  
Pinpin Ji ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Immunosorbent Assay ◽  
Colloidal Gold ◽  
Canine Distemper Virus ◽  
Sandwich Elisa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Test Results ◽  
Canine Distemper ◽  
Serum Samples ◽  
Ideal Method

Abstract Canine distemper virus (CDV) infection causes mass mortality in diverse carnivore species. For effective virus surveillance, rapid and sensitive assays are needed to detect CDV in field samples. In this study, after BABL/c mice were immunized with recombinant CDV-fusion (F) protein, monoclonal antibodies (mAbs) against recombinant CDV-F protein (designated 1A5, 1A6, and 7D5) were produced using traditional hybridoma cell technology. Next, capture antibody (1A6, 800 ng/well) and horseradish peroxidase (HRP)–conjugated detection antibody (HRP-7D5, 1:100, 500 ng/well) were used in a double monoclonal antibody–based sandwich enzyme-linked immunosorbent assay (ELISA) for CDV detection after optimization of both mAb amounts per well using a checkerboard titration test. Based on sandwich ELISA test results for 120 known CDV-negative samples, the cutoff value for a positive result was set to an OD450 nm value ≥ 0.196. As compared with test results obtained from commercial immune colloidal gold test strips, the low limits of detection for the two assays were revealed to be 100 TCID50 per 100 μL. In addition, the sandwich ELISA agreed 100% and 96.4% with commercial immune colloidal gold test strips when testing serum and stool samples. The sandwich ELISA assay provided statistically similar CDV detection. Thus, the sandwich ELISA developed here to detect CDV in fecal and serum samples provided good sensitivity, high specificity, and good reproducibility and should serve as an ideal method for large-scale surveillance of CDV infections in carnivores. Key points • Three CDV mAbs that recognized different epitopes and bound to virion were generated. • The sandwich ELISA based mAbs to detect CDV in fecal and serum samples was developed. • The sandwich ELISA is an ideal method for detecting CDV infections in the field.

scholarly journals Development of an Enzyme-Linked Immunosorbent Assay for Serodiagnosis of Ringworm Infection in Cattle

2013 ◽  
Vol 20 (8) ◽  
pp. 1150-1154 ◽  
Author(s):  
Elena Tatiana Băguţ ◽  
Ludivine Cambier ◽  
Marie-Pierre Heinen ◽  
Vasile Cozma ◽  
Michel Monod ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Skin Lesions ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Predictive Values ◽  
Content Type ◽  
Ringworm Infection

ABSTRACTThe aim of this study was to develop an in-house enzyme-linked immunosorbent assay (ELISA) for the serological diagnosis of ringworm infection in cattle. We used available recombinant forms ofTrichophyton rubrumdipeptidyl peptidase V (TruDppV) andT. rubrumleucin aminopeptidase 2 (TruLap2), which are 98% identical toTrichophyton verrucosumorthologues. Field serum samples from 135 cattle with ringworm infection, as confirmed by direct microscopy, fluorescence microscopy, and PCR, and from 55 cattle without any apparent skin lesions or history of ringworm infection that served as negative controls were used. Sensitivities, specificities, and positive and negative predictive values were determined to evaluate the diagnostic value of our ELISA. Overall, the ELISAs based on recombinant TruDppV and TruLap2 discriminated well between infected animals and healthy controls. Highly significant differences (P< 0.0001, Mann-Whitney U test) were noted between optical density values obtained when sera from infected versus control cattle were tested. The ELISA developed for the detection of specific antibodies against DppV gave 89.6% sensitivity, 92.7% specificity, a 96.8% positive predictive value, and a 78.4% negative predictive value. The recombinant TruLap2-based ELISA displayed 88.1% sensitivity, 90.9% specificity, a 95.9% positive predictive value, and a 75.7% negative predictive value. To the best of our knowledge, this is the first ELISA based on recombinant antigens for assessing immune responses to ringworm infection in cattle; it is particularly suitable for epidemiological studies and also for the evaluation of vaccines and/or vaccination procedures.

Role of Routine Laboratory Tests in Assessing Risk of Recurrent Venous Thrombosis: Results from the MEGA Follow-Up Study

2018 ◽  
Vol 118 (11) ◽  
pp. 1918-1929
Author(s):  
Vânia Morelli ◽  
Willem Lijfering ◽  
Suely Rezende ◽  
Astrid Vlieg ◽  
Frits Rosendaal ◽  
...  
Keyword(s):  
At Risk ◽  
Venous Thrombosis ◽  
Renal Dysfunction ◽  
Kidney Function ◽  
Predictive Value ◽  
Hazard Ratio ◽  
Risk Of Recurrence ◽  
Glucose Levels ◽  
Increased Risk ◽  
Patients At Risk

Background Kidney function, measured as estimated glomerular filtration rate (eGFR), glucose levels and haematologic variables (blood cell count) are easily obtainable tests, and have been associated with increased risk of first venous thrombosis (VT). Whether these routine tests can identify patients at risk of recurrence is unclear. Aim Our aim was to investigate the predictive value of serum glucose levels, eGFR and haematologic variables in patients at risk of recurrent VT. Methods Patients with a first VT were followed from discontinuation of anticoagulant treatment. Percentile categories of eGFR, glucose levels and haematologic variables were established. Crude incidence rates with 95% confidence intervals (CIs) of recurrence were estimated in each percentile category. Cox regression models were used to compare groups, adjusted for age and sex. Results Of 2,106 patients followed for a median of 6.9 years, 326 developed recurrence (incidence rate, 2.7/100 patient-years; 95% CI, 2.5–3.1). The adjusted hazard ratio for recurrence was 1.5 (95% CI, 0.9–2.4) in the lowest eGFR percentile category (< 59 mL/min/1.73 m2) versus the reference (≥86 mL/min/1.73 m2). Stratification by unprovoked or provoked first events yielded similar results. The combination of a first unprovoked VT with renal dysfunction was associated with a threefold increased risk of recurrence compared with those with first provoked VT and normal kidney function (hazard ratio, 3.1, 95% CI, 1.6–5.9). Glucose levels and haematologic variables were not associated with increased recurrence risk. Conclusion Testing glucose levels and haematologic variables did not identify patients at increased risk of recurrent VT. Renal dysfunction tests may have some predictive value, particularly in combination with other variables.

scholarly journals Development and Application of a Double-Antigen Sandwich Enzyme-Linked Immunosorbent Assay for Detection of Antibodies to Porcine Circovirus 2

2012 ◽  
Vol 19 (9) ◽  
pp. 1480-1486 ◽  
Author(s):  
Meng Ge ◽  
Wei Luo ◽  
Daliang Jiang ◽  
Runcheng Li ◽  
Wenwei Zhao ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Immunosorbent Assay ◽  
Sandwich Elisa ◽  
Test Procedure ◽  
Porcine Circovirus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Swine Industry ◽  
Elisa Kit ◽  
Porcine Circovirus 2

ABSTRACTA double-antigen sandwich enzyme-linked immunosorbent assay (ELISA) is described for detection of porcine circovirus 2 (PCV2) antibodies using the well-characterized recombinant PCV2 capsid protein. In a comparative test of 394 pig sera against an indirect immunofluorescence (IIF) test and a commercial ELISA kit (also based on the recombinant PCV2 capsid protein), the results showed that the diagnostic sensitivity, specificity, and accuracy of the assay were, respectively, 90.61, 94.02, and 91.62% compared with IIF and 94.38, 95.28, and 94.67% compared with the commercial ELISA kit. Assay of 12 PCV-free pigs over a 5-week period produced only PCV2-negative titers by all 3 methods. These results and the seroprofiles of 4 pig farms obtained by both the commercial ELISA kit and the double-antigen sandwich ELISA indicate that the sandwich ELISA is a reliable method for detection of antibodies to PCV2. Additionally, the method described here permits the use of undiluted test serum samples simultaneously loaded with horseradish peroxidase (HRP)-conjugated antigen into the test well, and the complete test procedure can be performed in less than 90 min. This double-antigen sandwich ELISA should be a useful tool to aid swine industry professionals in deciding the intervention strategies for the control of PCV2-associated diseases.

scholarly journals Immunoglobulin A-Specific Capture Enzyme-Linked Immunosorbent Assay for Diagnosis of Dengue Fever

1998 ◽  
Vol 36 (5) ◽  
pp. 1189-1192 ◽  
Author(s):  
Antoine Talarmin ◽  
Bhety Labeau ◽  
Josiane Lelarge ◽  
Jean-Louis Sarthou
Keyword(s):  
Dengue Virus ◽  
Dengue Fever ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Immunoglobulin A ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Simple Method ◽  
Previous Infection

Dengue fever (DF) is usually diagnosed by testing for dengue virus immunoglobulin M (IgM) by a capture enzyme-linked immunosorbent assay (ELISA) (MAC-ELISA). However, IgM can last for months, and its presence might reflect a previous infection. We have tested the use of anti-dengue virus IgA capture ELISA (AAC-ELISA) for the diagnosis of DF by comparing the results of MAC-ELISAs and AAC-ELISAs for 178 serum samples taken from patients with confirmed cases of DF. IgM appears more rapidly (mean delay of positivity, 3.8 days after the onset of DF) than IgA (4.6 days) but lasts longer; the peak IgA titer is obtained on day 8. The specificity and the positive predictive value of AAC-ELISA are 100%; its sensitivity and negative predictive value (NPV) are also 100% between days 6 and 25 after the onset of DF, but they decrease drastically when data for tests conducted with specimens from the first days of infection are included, because the IgA titers, like the IgM titers, have not yet risen. AAC-ELISA is a simple method that can be performed together with MAC-ELISA and that can help in interprating DF serology.

scholarly journals Anti-Protective Antigen IgG Enzyme-Linked Immunosorbent Assay for Diagnosis of Cutaneous Anthrax in India

2012 ◽  
Vol 19 (8) ◽  
pp. 1238-1242 ◽  
Author(s):  
N. Ghosh ◽  
A. K. Goel
Keyword(s):  
Bacillus Anthracis ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Protective Antigen ◽  
Public Health Problem ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Animal Products ◽  
Content Type ◽  
Cutaneous Anthrax

ABSTRACTAnthrax caused byBacillus anthracisis a public health problem in several developing countries whose main source of income is farming. Anthrax is a disease of herbivorous animals, and humans can be infected by handling infected animals or contaminated animal products. Specific diagnostic tests are unavailable in India for the detection and confirmation of cutaneous anthrax in humans. Here, we describe the development of an enzyme-linked immunosorbent assay (ELISA) for detection of serum antibodies againstBacillus anthracisprotective antigen in the Indian population. A total of 405 serum samples collected from different groups were tested by the developed ELISA. The assay provided a specificity of 99.41% (95% confidence interval [CI], 97.89 to 99.93) and a sensitivity of 100% (CI, 94.4 to 100) using a cutoff value of 0.29 ELISA unit (EU). The positive predictive value (PPV) and negative predictive value (NPV) of the assay were 97% and 100%, respectively. The efficiency and J index for the reliability of the assay were 99.5% and 0.994, respectively. The assay can be a very useful tool for surveillance as well as for diagnosis of cutaneous anthrax cases in India.

scholarly journals Evaluation of a NovelAspergillusAntigen Enzyme-Linked Immunosorbent Assay

2019 ◽  
Vol 57 (7) ◽  
Author(s):  
Karl Dichtl ◽  
Ulrich Seybold ◽  
Steffen Ormanns ◽  
Heidi Horns ◽  
Johannes Wagener
Keyword(s):  
Sensitivity And Specificity ◽  
Immunosorbent Assay ◽  
Fungal Infections ◽  
Time Frame ◽  
Enzyme Linked Immunosorbent Assay ◽  
The Novel ◽  
Serum Samples ◽  
European Organization ◽  
Content Type ◽  
Patients At Risk

ABSTRACTInvasive aspergillosis (IA) is a life-threatening infection that mainly occurs in immunocompromised patients. Here, we compared the novelAspergillus-specific galactomannoprotein (GP) enzyme-linked immunosorbent assay (ELISA) (Euroimmun Medizinische Labordiagnostika AG) to the established PlateliaAspergillusgalactomannan (GM) ELISA (Bio-Rad Laboratories) for the detection of IA. A total of 267 serum samples from 45 cases of proven and 4 episodes of probable IA (according to European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group [EORTC/MSG] criteria) and 156 sera from patients without evidence of IA were tested. Pearson’s correlation statistics, as well as sensitivity and specificity, were calculated using manufacturer-recommended (GM) or optimized (GP) cutoff levels.Aspergillus fumigatuswas found in 88% of culture-positive infections. When we analyzed all 423 serum samples, GM and GP tests correlated strongly (r = 0.82,P < 0.0001). Among proven IA cases using samples obtained as closely as possible to the day of proven diagnosis, the sensitivity for both tests was 40%. All cases of probable IA (defined by positive GM testing) were also GP positive. Concordant results of the two ELISAs were obtained in 43 of 49 samples (88%). Extending measurements to all sera available in the time frame of 7 days prior to 7 days after the day of proven diagnosis, 47% and 56% of the cases were detected by the GM and GP tests, respectively. Specificity was 99% for GM and 96% for GP testing. For the diagnosis of IA, sensitivity and specificity of the novel GP ELISA are similar to those of the Platelia GM ELISA. The low sensitivities of both tests underline the need for serial testing in patients at risk for IA.

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