Enzyme-linked immunosorbent assay to diagnose human leptospirosis: a meta-analysis of the published literature

2012 ◽  
Vol 141 (1) ◽  
pp. 22-32 ◽  
Author(s):  
M. L. SIGNORINI ◽  
J. LOTTERSBERGER ◽  
H. D. TARABLA ◽  
N. B. VANASCO
Keyword(s):  
Direct Method ◽  
Meta Analysis ◽  
False Negative ◽  
Area Under The Curve ◽  
Disease Stage ◽  
Enzyme Linked Immunosorbent Assay ◽  
Stage Of Disease ◽  
Negative Results ◽  
Igm Elisa ◽  
False Negative Results

SUMMARYWe report an evaluation of the accuracy of ELISA for the detection ofLeptospira-specific antibodies in humans. Eighty-eight studies published in 35 articles met all inclusion criteria and were submitted to meta-analysis. Pooled sensitivity and specificity were 0·779 (95% CI 0·770–0·789) and 0·913 (95% CI 0·908–0·917), respectively, and the area under the curve was 0·964. Heterogeneity across studies was statistically significant, but none of the sources of heterogeneity (disease stage, antigen used, antibody detected) could fully explain this finding. Although the convalescent stage of disease was significantly associated with higher diagnostic accuracy, IgM ELISA was the best choice, regardless of the stage of disease. Negative ELISAs (IgG or IgM) applied in the acute phase do not rule out leptospirosis due to the possibility of false-negative results. In this case it is advisable to request a second blood sample or to apply a direct method for leptospiral DNA.

Three highly sensitive "bedside" serum and urine tests for pregnancy compared

1990 ◽  
Vol 36 (9) ◽  
pp. 1686-1688 ◽  
Author(s):  
H Christensen ◽  
H H Thyssen ◽  
O Schebye ◽  
A Berget
Keyword(s):  
Paired Comparison ◽  
False Negative ◽  
Diagnostic Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Negative Results ◽  
False Negative Results ◽  
Significant Difference ◽  
Comparison Of The Results ◽  
Urine And Serum

Abstract We examined three enzyme-linked immunosorbent assay (ELISA) kits for human choriogonadotropin (hCG) (pregnancy tests) for use with urine and serum samples: the Tandem Icon II hCG Urine and Tandem Icon II hCG Serum, the NovoClone Target hCG Test, and the Abbott TestPacks hCG-urine and hCG-serum. Paired comparison of the results from each kit indicated that the NovoClone Target assay showed significantly lower diagnostic sensitivity (P less than 0.05) than did the Tandem Icon II or Abbott TestPack, both for urine and for serum samples. None of the products demonstrated any significant difference (P greater than 0.05) in diagnostic specificity, but the NovoClone Target kit showed several serious false-negative results with both urine and serum. Paired testing of urine kits vs serum kits also showed no significant differences (P greater than 0.05) in diagnostic sensitivity or specificity. We found the Abbott kits to be the most convenient to use and to read.

scholarly journals Assessment of the IgA Immunoassay Diagnostic Potential of the Mycobacterium tuberculosis MT10.3-MPT64 Fusion Protein in Tuberculous Pleural Fluid

2010 ◽  
Vol 17 (12) ◽  
pp. 1963-1969 ◽  
Author(s):  
Leonardo Silva Araujo ◽  
Renata Maciel Moraes ◽  
Anete Trajman ◽  
Maria Helena Féres Saad
Keyword(s):  
Pleural Fluid ◽  
Histopathological Examination ◽  
False Negative ◽  
High Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Negative Results ◽  
Diagnostic Potential ◽  
False Negative Results ◽  
Sds Page ◽  
Increased Sensitivity

ABSTRACT Pleural tuberculosis (PL-TB) remains difficult to diagnose. An enzyme-linked immunosorbent assay (ELISA) was developed based on a construction containing the fusion of the Rv3019c (MT10.3) and Rv1980c (MPT64) gene sequences, and its performance was evaluated in an area where TB is endemic. A total of 92 pleural fluid (PF) samples at serial dilutions of 1:50 to 1:800 were included in the ELISA IgA MT10.3-MPT64 evaluation: 70 from TB patients and 22 from patients with other pleurisies. Confirmation of the expression and subsequent purification of the protein was made by SDS-PAGE and Western blot assays, resulting in a 36-kDa protein. ELISA IgA MT10.3-MPT64 showed sensitivities of 61.4%, 58.6%, 62.9%, 67.1%, and 70% at each PF dilution, respectively. The cumulative results of all dilutions increased sensitivity to 81.4% without jeopardizing specificity. Similar results were also obtained at the combined dilutions of 1:50, 1:200, and 1:800 or 1:50 plus 1:800 dilutions (80%). The overall sensitivity of the reference test, i.e., histopathological examination, was 74%. But, via the ELISA IgA MT10.3-MPT64 test, sensitivity was high for specimens with a negative culture (23/27; 85.2%) or nonspecific histopathology (17/18; 94.4%). Our findings demonstrated the promising use of this test as an adjunct in PL-TB diagnoses, particularly in cases with lower bacterial loads and false-negative results in the reference tests, since the new test includes such important features as quick and easy application, high sensitivity and, perhaps most importantly, affordability, which is so crucial for its widespread use in developing countries.

scholarly journals Diagnostic Value of Endoscopic Ultrasound after Neoadjuvant Chemotherapy for Gastric Cancer Restaging: A Meta-Analysis of Diagnostic Test

Diagnostics ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 100
Author(s):  
Victor Mihai Sacerdotianu ◽  
Bogdan Silviu Ungureanu ◽  
Sevastita Iordache ◽  
Adina Turcu-Stiolica ◽  
Antonio Facciorusso ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Diagnostic Test ◽  
Endoscopic Ultrasound ◽  
Meta Analysis ◽  
False Negative ◽  
Diagnostic Value ◽  
Significant Heterogeneity ◽  
True Negative ◽  
Negative Results ◽  
False Negative Results

This study aimed to evaluate the diagnostic value of endoscopic ultrasound (EUS) after neoadjuvant therapy (NT) for gastric cancer restaging by meta-analysis. We conducted a systematic search of studies published on PubMed and Web of Science up to 30th August 2021. Assessing the risk of bias in the included studies was done with the QUADAS-2 tool. We used R and Review Manager 5.4.1 for calculations and statistical analysis. To evaluate the diagnostic value of EUS after NT for gastric cancer restaging, we performed a meta-analysis on six studies, with a total of 283 patients, including true-positive, true-negative, false-positive, and false-negative results for T1-T4, N0. EUS as a diagnostic test for GC patients after chemotherapy has a relatively low DOR for the T2 (3.96) and T4 stages (4.79) and a relatively high partial AUC for the T2 (0.85) and T4 (0.71) stages. Our results reveal that the pooled sensitivity for T stages after chemotherapy is rather low (29–56%), except for the T3 stage (71%). A potential limitation of our study was the small number of included studies, but no significant heterogeneity was found between them. Our meta-analysis concludes that EUS is not recommended or is still under debate for GC restaging after NT.

scholarly journals Negative Immunodiffusion Test Results Obtained with Sera of Paracoccidioidomycosis Patients May Be Related to Low-Avidity Immunoglobulin G2 Antibodies Directed against Carbohydrate Epitopes

2003 ◽  
Vol 10 (5) ◽  
pp. 802-807 ◽  
Author(s):  
Andréia R. Neves ◽  
Ronei L. Mamoni ◽  
Cláudio L. Rossi ◽  
Zoilo P. de Camargo ◽  
Maria Heloísa S. L. Blotta
Keyword(s):  
Paracoccidioides Brasiliensis ◽  
False Negative ◽  
Enzyme Linked Immunosorbent Assay ◽  
Test Results ◽  
Sodium Metaperiodate ◽  
Negative Results ◽  
Carbohydrate Epitopes ◽  
False Negative Results ◽  
Specific Igg

ABSTRACT Immunodiffusion (ID) is the serologic test most frequently used for the diagnosis and posttherapy follow-up of patients with paracoccidioidomycosis (PCM). The ID test is highly specific (100%), but its sensitivity is relatively low (90%), leading to false-negative results. The aim of this study was to determine the profiles of antibodies in sera from patients with proven PCM and with negative results in the ID test (IDneg) versus positive results in the ID test (IDpos). We analyzed 46 sera from patients with active PCM for total immunoglobulin G (IgG) and IgG subclass responses to Paracoccidioides brasiliensis gp43 antigen (treated or not treated with sodium metaperiodate) by enzyme-linked immunosorbent assay and immunoblotting. Immunoblotting showed that both IDneg and IDpos sera recognized predominantly the gp43 fraction of the P. brasiliensis antigen used in the ID test. IDneg sera contain low-avidity antibodies, low levels of specific IgG (total) and IgG1, and high levels of IgG2 compared with IDpos sera. The antibodies present in IDneg sera were predominantly directed against carbohydrate epitopes, since treatment with sodium metaperiodate resulted in a significant decrease in antibody reactivity. These data suggest that the lack of reactivity of sera from PCM patients in the ID test may be related to the production of low-avidity IgG2 antibodies directed against carbohydrate epitopes.

scholarly journals Early Detection of Maedi-Visna (Ovine Progressive Pneumonia) Virus Seroconversion in Field Sheep Samples

2001 ◽  
Vol 13 (4) ◽  
pp. 301-307 ◽  
Author(s):  
R. Varea ◽  
E. Monleón ◽  
C. Pacheco ◽  
L. Luján ◽  
R. Bolea ◽  
...  
Keyword(s):  
Early Detection ◽  
False Negative ◽  
Field Conditions ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Negative Results ◽  
Visna Virus ◽  
False Negative Results ◽  
Ovine Progressive Pneumonia ◽  
Antibody Levels

The aim of this work was to investigate whether an enzyme-linked immunosorbent assay (ELISA) was useful for early detection of maedi-visna virus (MVV) infection in sheep under field conditions. An ELISA based on p25 recombinant protein and a gp46 synthetic peptide was used. Sequentially obtained serum samples ( n = 1,941) were studied for 4 years. ELISA results were compared with those of the agar gel immunodiffusion (AGID) test, and results of both tests were compared with a reference result established using consensus scores for at least 2 of 3 serologic techniques (AGID, ELISA, and western blotting, which was used to resolve result discrepancies between the other 2 techniques). A total of 247 discrepancies were observed between ELISA and AGID. Of these, 131 were due to an earlier detection of 120 sera by the ELISA and 11 sera by AGID. The remaining discrepancies (116) were due to the presence of false reactions in both tests. Fewer false-negative results were found by ELISA than with AGID (6 vs. 69 sera, respectively), whereas the number of false-positive results was virtually the same for ELISA and AGID (21 vs. 20, respectively). In relation to the reference result, ELISA sensitivity and specificity were 97.8% and 98.2%, respectively, whereas values for AGID were 76.3% and 98.3%, respectively. The agreement between ELISA and the reference result was higher than that between AGID and the reference result (κ value: 0.96 and 0.77, respectively). A variation in the ELISA signal (based on optical density) was observed during the study period, suggesting different antibody levels throughout the animal's life. The ELISA was useful for detecting MVV-infected sheep in field conditions and has potential for use in control and eradication programs.

scholarly journals Diagnostic Accuracy of Rapid Antigen Test Kits for Detecting SARS-CoV-2: A Systematic Review and Meta-Analysis of 17,171 Suspected COVID-19 Patients

2021 ◽  
Vol 10 (16) ◽  
pp. 3493
Author(s):  
Shahad Saif Khandker ◽  
Nik Haszroel Hysham Nik Hashim ◽  
Zakuan Zainy Deris ◽  
Rafidah Hanim Shueb ◽  
Md Asiful Islam
Keyword(s):  
Rural Areas ◽  
Meta Analysis ◽  
False Negative ◽  
Antigen Test ◽  
Rt Pcr ◽  
Negative Results ◽  
Specificity And Sensitivity ◽  
Online Databases ◽  
False Negative Results ◽  
Set Up

Early diagnosis is still as crucial as the initial stage of the COVID-19 pandemic. As RT-PCR sometimes is not feasible in developing nations or rural areas, health professionals may use a rapid antigen test (RAT) to lessen the load of diagnosis. However, the efficacy of RAT is yet to be investigated thoroughly. Hence, we tried to evaluate the overall performance of RAT in SARS-CoV-2 diagnosis. Based on our PROSPERO registered protocol (CRD42021231432), we searched online databases (i.e., PubMed, Google Scholar, Scopus, and Web of Science) and analysed overall pooled specificity and sensitivity of RAT along with study quality, publication bias, heterogeneity and more. The overall pooled specificity and sensitivity of RAT were detected as 99.4% (95% CI: 99.1–99.8; I2 = 90%) and 68.4% (95% CI: 60.8–75.9; I2 = 98%), respectively. In subgroup analyses, nasopharyngeal specimens and symptomatic patient’s samples were more sensitive in RAT, while cycle threshold (Ct) values were found to have an inverse relationship with sensitivity. In the European and American populations, RAT showed better performance. Although the sensitivity of RAT is yet to be improved, it could still be an alternative in places with poor laboratory set up. Nevertheless, the negative samples of RAT can be re-tested using RT-PCR to reduce false negative results.

scholarly journals The T2-FLAIR Mismatch Sign as an Imaging Indicator of IDH-Mutant, 1p/19q Non-Codeleted Lower Grade Gliomas: A Systematic Review and Diagnostic Accuracy Meta-Analysis

Diagnostics ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1620
Author(s):  
Antonis Adamou ◽  
Eleftherios T. Beltsios ◽  
Panagiotis Papanagiotou
Keyword(s):  
Diagnostic Accuracy ◽  
Meta Analysis ◽  
False Negative ◽  
Diagnostic Odds Ratio ◽  
Lower Grade ◽  
Mri Scan ◽  
Negative Results ◽  
False Negative Results ◽  
The Brain

The study’s objective was the evaluation of the diagnostic accuracy of the T2-FLAIR mismatch sign in terms of diagnosing IDH-mutant non-codeleted (IDHmut-Noncodel) lower grade gliomas (LGG) of the brain. We searched the MEDLINE, Scopus and Cochrane Central databases. The last database search was performed on 12 April 2021. Studies that met the following were included: MRI scan assessing the presence of T2-FLAIR mismatch sign, and available IDH mutation and 1p/19q codeletion status. The quality of studies was assessed using the QUADAS-2 tool. Twelve studies involving 14 cohorts were included in the quantitative analysis. The diagnostic odds ratio [DOR (95% confidence interval; CI)] was estimated at 34.42 (20.95, 56.56), Pz < 0.01. Pooled sensitivity and specificity (95% CI) were estimated at 40% (31–50%; Pz = 0.05) and 97% (93–99%; Pz < 0.01), respectively. The likelihood ratio (LR; 95% CI) for a positive test was 11.39 (6.10, 21.29; Pz < 0.01) and the LR (95% CI) for a negative test was 0.40 (0.24, 0.65; Pz < 0.01).The T2-FLAIR mismatch sign is a highly specific biomarker for the diagnosis of IDHmut-Noncodel LGGs. However, the test was found positive in some other tumors and had a high number of false negative results. The diagnostic accuracy of the mismatch sign might be improved when combined with further imaging parameters.

Extraction of Staphylococcal Enterotoxins (SE) From Minced Meat and Subsequent Detection of SE with Enzyme-Linked Immunosorbent Assay (ELISA)

1983 ◽  
Vol 46 (3) ◽  
pp. 238-241 ◽  
Author(s):  
S. NOTERMANS ◽  
R. BOOT ◽  
P. D. TIPS ◽  
M. P. DE NOOIJ
Keyword(s):  
Immunosorbent Assay ◽  
False Negative ◽  
Extraction Procedure ◽  
Enzyme Linked Immunosorbent Assay ◽  
Distilled Water ◽  
Elisa System ◽  
Staphylococcal Enterotoxins ◽  
Negative Results ◽  
False Negative Results ◽  
Minced Meat

ELISA (enzyme-linked immunosorbent assay) was employed to demonstrate staphylococcal enterotoxins A, B, C and E (SEA, SEB, SEC and SEE) in minced meat (50% beef/50% pork). For unheated minced meat, extraction of the sample with an equal amount of distilled water at pH 4.5 and a subsequent concentration (10-fold) of the extract, readjusted to pH 7.2, was sufficient to detect less than 0.5 μg of SE per 100 g of product. The extraction procedure gave 40–80% recovery of the toxin, and using the ELISA system neither false-positive nor false-negative results were obeserved. Using the just mentioned extraction procedure, recovery of SE that had been heated in minced meat was low (0.14% for SEB). It was demonstrated that components extracted by heating (among others, gelatin) present in minced meat caused immunological inactivation of SEB, SEC and SEE during heating. From monkey-feeding tests it became clear that the immunological inactivation of SEB in gelatin by heating was accompanied by biological inactivation.

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