Egg yolk immunoglobulin Y as a promising tool to detect immune complexes in neurocysticercosis serum samples

2020 ◽  
Vol 114 (8) ◽  
pp. 585-592
Author(s):  
Gabriela B da Silva ◽  
Lucas S da Faria ◽  
Camila A Lopes ◽  
Daniela S Nunes ◽  
Vanessa S Ribeiro ◽  
...  

Abstract Background Neurocysticercosis (NCC) is a neglected tropical disease and its diagnosis is still a challenge due to non-specific manifestations. Neuroimaging techniques are used in the diagnosis of NCC, however, due to the high cost of these methods and the advantages presented in the use of immunological tests, such as ease of performance and satisfactory results, immunoassays are commonly used to detect antibodies against Taenia sp. antigens. The aim of the present study was to produce, characterize and apply specific polyclonal immunoglobulin Y (IgY) anti-Taenia crassiceps extracted from egg yolk of hens immunized with T. crassiceps metacestodes. Methods Indirect enzyme-linked immunosorbent assay (ELISA), avidity ELISA, immunoblotting and indirect immunofluorescence tests were performed for characterization of IgY antibodies. Diagnostic performance was verified by ELISA for immune complex detection testing 90 serum samples. Results Values of sensitivity, specificity, positive and negative likelihood ratios (LR+/LR−) and area under the curve (AUC) were calculated and presented the following results: sensitivity 83.3%, specificity 96.7%, AUC 0.966, LR+ 25.0 and LR− 0.17. Conclusions Results of this pioneering and innovative study demonstrate that anti-T. crassiceps IgY antibodies present potential applicability and can be used as an efficient tool in human NCC serodiagnosis.

Diagnostics ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 109 ◽  
Author(s):  
Ukweh ◽  
Ugbem ◽  
Okeke ◽  
Ekpo

Background: Ultrasound is operator-dependent, and its value and efficacy in fetal morphology assessment in a low-resource setting is poorly understood. We assessed the value and efficacy of fetal morphology ultrasound assessment in a Nigerian setting. Materials and Methods: We surveyed fetal morphology ultrasound performed across five facilities and followed-up each fetus to ascertain the outcome. Fetuses were surveyed in the second trimester (18th–22nd weeks) using the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) guideline. Clinical and surgical reports were used as references to assess the diagnostic efficacy of ultrasound in livebirths, and autopsy reports to confirm anomalies in terminated pregnancies, spontaneous abortions, intrauterine fetal deaths, and still births. We calculated sensitivity, specificity, positive and negative predictive values, Area under the curve (AUC), Youden index, likelihood ratios, and post-test probabilities. Results: In total, 6520 fetuses of women aged 15–46 years (mean = 31.7 years) were surveyed. The overall sensitivity, specificity, and AUC were 77.1 (95% CI: 68–84.6), 99.5 (95% CI: 99.3–99.7), and 88.3 (95% CI: 83.7–92.2), respectively. Other performance metrics were: positive predictive value, 72.4 (95% CI: 64.7–79.0), negative predictive value, 99.6 (95% CI: 99.5–99.7), and Youden index (77.1%). Abnormality prevalence was 1.67% (95% CI: 1.37–2.01), and the positive and negative likelihood ratios were 254 (95% CI: 107.7–221.4) and 0.23 (95% CI: 0.16–0.33), respectively. The post-test probability for positive test was 72% (95% CI: 65–79). Conclusion: Fetal morphology assessment is valuable in a poor economics setting, however, the variation in the diagnostic efficacy across facilities and the limitations associated with the detection of circulatory system anomalies need to be addressed.


2014 ◽  
Vol 51 (3) ◽  
pp. 181-189 ◽  
Author(s):  
F. Jing ◽  
J. Cui ◽  
R. Liu ◽  
L. Liu ◽  
P. Jiang ◽  
...  

AbstractIn the present study, a sandwich ELISA based on IgY (egg yolk immunoglobulin) was developed for detection of circulating antigens (CAg) in sere of mice experimentally infected with Trichinella spiralis. The IgY-sandwich ELISA assay involved the use of chicken antibody IgY against excretory-secretory (ES) antigens of Trichinella spiralis muscle larvae as a capture antibody and mouse polyclonal antibody IgG to ES antigens as a detecting antibody. This method was able to detect as little as 3 ng/ml of ES antigens added to normal mouse serum. A group of sixteen mice was orally inoculated with 500 T. spiralis muscle larvae per animal. The serum samples from the infected mice were taken during 1–35 days post-infection (dpi). The CAg was detectable as early as 8 dpi in the sera of infected mice. The level of CAg increased dramatically during 13–15 dpi and reached a peak at 22 dpi and remained a plateau for 3 days, then declined gradually. Another peak of CAg occurred at 31 dpi. The anti-Trichinella antibodies was first detected in 14.3 % of the infected mice at 2 weeks post-infection (wpi), and reached a peak positive rate of 100 % at 5 wpi. Moreover, the infected mice were treated with abendazole at 5 wpi and the serum CAg levels increased significantly during 2–6 days posttreatment (dpt) and then declined rapidly during 8–14 dpt. By 42 dpt, the CAg levels decreased to the undetected level, but the detection rate of antibodies was still 100 %. The IgY-sandwich ELISA appears to be a sensitive for detection of antigenemia of T. spiralis and valuable to judge the efficacy of chemotherapy in trichinellosis.


Author(s):  
Hong-Chao Liu ◽  
Yu-Lu Gao ◽  
Dan-Feng Li ◽  
Xi-Yi Zhao ◽  
Yuan-Qing Pan ◽  
...  

Background: The performance of Xpert MTB/RIF using bronchoalveolar lavage fluid (BAL) for the diagnosis of pulmonary tuberculosis (PTB) remains unclear. Therefore, a systematic review/meta-analysis was conducted. Methods: Studies published before December 31, 2019, were retrieved from the PubMed, Embase, and Web of Science databases using the keywords “pulmonary tuberculosis,” “Xpert MTB/RIF,” and “BAL.” Two independent evaluators extracted the data and assessed the bias risk of the included studies. A random-effects model was used to calculate the overall sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR, respectively), diagnostic odds ratio (DOR), and the area under the curve (AUC), as well as the respective 95% confidence intervals (CIs). Results: Nineteen trials involving 3019 participants met the inclusion criteria. Compared to the culture method, the pooled sensitivity, specificity, PLR, NLR, DOR, and the AUC with 95% CIs of Xpert MTB/RIF were 0.87 (0.84–0.90), 0.92 (0.91–0.93), 10.21 (5.78–18.02), 0.16 (0.12–0.22), 78.95 (38.59–161.53), and 0.9467 (0.9462-0.9472), respectively. Relative to the composite reference standard, the observed values were 0.69 (0.65–0.72), 0.98 (0.98–0.99), 37.50 (18.59–75.62), 0.30 (0.21–0.43), 171.98 (80.82–365.96), and 0.9691 (0.9683–0.9699), respectively. All subgroups, except children, showed high sensitivity and specificity. Conclusions: The use of Xpert MTB/RIF in the context of BAL samples has a high diagnostic performance for PTB (except for children) and may serve as an alternative rapid diagnostic tool.


2020 ◽  
Vol 243 ◽  
pp. 108642
Author(s):  
Dehong Yang ◽  
Kaijie Mai ◽  
Qi Zhou ◽  
Yuanjun Zhu ◽  
Juanjuan Xing ◽  
...  

2012 ◽  
Vol 93 (1) ◽  
pp. 154-159 ◽  
Author(s):  
Junlin Wen ◽  
Suqing Zhao ◽  
Daigui He ◽  
Yuane Yang ◽  
Yueming Li ◽  
...  

Parasitology ◽  
2012 ◽  
Vol 139 (7) ◽  
pp. 956-961 ◽  
Author(s):  
A. L. R. GONÇALVES ◽  
D. S. NUNES ◽  
M. R. F. GONÇALVES-PIRES ◽  
M. T. UETA ◽  
J. M. COSTA-CRUZ

SUMMARYThe aim of this study was to use larval, parasitic female and egg antigens fromStrongyloides venezuelensisto detect parasite-specific IgG and immune complexes in human serum samples by enzyme-linked immunosorbent assay (ELISA). In total, 95 serum samples were analysed, consisting of 30 patients harbouringS. stercoralislarvae, 30 healthy subjects and 35 patients with other parasites. Sensitivity, specificity and diagnostic efficiency were calculated. A significant statistical difference was found in the detection of immune complexes and antibodies in patients harbouringS. stercoralislarvae from larval and eggs antigens, with higher positivity using larval antigen. The larval antigen showed the highest values for sensitivity, specificity and diagnostic efficiency in ELISA from detection of immune complexes. For the first time we used IgG anti-larvae, IgG anti-parasitic females or IgG anti-eggs for immune complex detection. We concluded that the association of antibody and immune complex detection could be used in the diagnosis of human strongyloidiasis.


2012 ◽  
Vol 19 (9) ◽  
pp. 1452-1456 ◽  
Author(s):  
Sabine C. de Greeff ◽  
Peter Teunis ◽  
Hester E. de Melker ◽  
Frits R. Mooi ◽  
Daan W. Notermans ◽  
...  

ABSTRACTMeasuring IgG antibodies against pertussis toxin (IgG-Ptx) with an enzyme-linked immunosorbent assay (ELISA) can be used to diagnose pertussis infection; however, the cutoff points are not unanimously defined. To determine the diagnostic specificity of increases of IgG-Ptx in paired sera and of absolute values in single serum samples, we applied a two-component cluster analysis to serum samples of patients suspected for pertussis, whose sera had been submitted to a routine diagnostic laboratory between 2003 and 2009, and had been assayed with an in-house IgG-Ptx ELISA calibrated with the international FDA lot 3 IgG-Ptx reference serum. Children eligible for the acellular pertussis vaccination were excluded to avoid interference from a vaccine-induced IgG-Ptx rise. Binary distribution mixtures were fitted to the data. Receiver operating characteristic (ROC) curves were calculated for absolute values in single samples (n= 14,452) and increases in paired samples (n= 2,455). For both parameters, two subpopulations could be identified: a population with high reactivity (persons with pertussis infection) and a population with low reactivity (persons without pertussis infection). For absolute values in single samples, the area under the curve (AUC) of the ROC curve was 0.993 and the optimum cutoff (with the highest cumulative value of specificity plus sensitivity) was 67.7 IU/ml (95% confidence interval, 63.9 to 74.1; sensitivity, 96.4%; specificity, 95.7%). A previously determined diagnostic cutoff of 125 IU/ml was associated with a sensitivity of 88.1% and a specificity of 98.8%. For increases in paired sera, the AUC was 0.999 and the optimum cutoff was 3.1-fold (95% CI, 2.8 to 3.4; sensitivity, 99.6%; specificity, 99.2%). Given the methodology of this study, estimates of sensitivity probably are overrated (because pertussis patients without IgG-Ptx response are not detected), but estimates of specificities can be considered very accurate.


Lupus ◽  
2016 ◽  
Vol 26 (6) ◽  
pp. 606-615 ◽  
Author(s):  
Y Zuo ◽  
R Willis ◽  
E Papalardo ◽  
M Petri ◽  
E N Harris ◽  
...  

Background While essential for the classification of antiphospholipid syndrome (APS), anticardiolipin (aCL) assays lack specificity and anti-β2glycoproteinI (anti-β2GPI) assays lack sensitivity in this regard. Our aim was to perform a comparative analysis of the APhL ELISA assay (IgG/IgM) and criteria antiphospholipid (aPL) immunoassays in identifying APS-related clinical manifestations in a large group of patients with systemic lupus erythematosus (SLE). Methods Serum samples from 1178 patients from the Hopkins ( n = 543), LUMINA ( n = 588) and Jamaican SLE cohorts ( n = 47) were examined for IgG/IgM positivity in aCL (in-house), anti-β2GPI (two commercial kits) and APhL (Louisville APL) ELISA assays. Correlation of assay positivity with clinical manifestations and sensitivity, specificity, positive and negative predictive values and likelihood ratios were evaluated. A case series analysis was also performed in patients for whom there was isolated positivity in the specific aPL assays. Results The prevalence of aCL positivity was 34.9%, anti-β2GPI kit A was 22.6%, APhL was 11.5% and anti-β2GPI kit B was 7.6% in the study population. Anti-β2GPI kit B, aCL and APhL assays were correlated with venous thrombosis, while only APhL was significantly correlated with arterial thrombosis and consistently correlated with pregnancy-related morbidity. No significant correlations were noted for anti-β2GPI kit A. Sensitivity was greatest for aCL assays followed by anti-β2GPI kit A, APhL and anti-β2GPI kit B, while specificity was greatest and equal for anti-β2GPI kit B and APhL assays. Conclusions Overall, APhL antibodies, especially IgG, represent a promising biomarker for the classification of APS patients in the context of autoimmunity and in risk assessment with regards to pregnancy morbidity and thrombotic manifestations.


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