scholarly journals Multiple-bead assay for the differential serodiagnosis of neglected human cestodiases: Neurocysticercosis and cystic echinococcosis

2022 ◽  
Vol 16 (1) ◽  
pp. e0010109
Author(s):  
Ana Hernández-González ◽  
Belén González-Bertolín ◽  
Laura Urrea ◽  
Agnes Fleury ◽  
Elizabeth Ferrer ◽  
...  

Background Neurocysticercosis (NCC), and cystic echinococcosis (CE) are two neglected diseases caused by cestodes, co-endemic in many areas of the world. Imaging studies and serological tests are used in the diagnosis of both parasitic diseases, but cross-reactions may confound the results of the latter. The novel multiplex bead-based assay with recombinant antigens has been reported to increases the diagnostic accuracy of serological techniques. Methodology We set-up an immunoassay based on the multiplex bead-based platform (MBA), using the rT24H (against Cysticercus cellulosae, causing cysticercosis) and r2B2t (against Echinococcus granulosus sensu lato, causing CE) recombinant antigens, for simultaneous and differential diagnosis of these infections. The antigens were tested on 356 sera from 151 patients with CE, 126 patients with NCC, and 79 individuals negative for both diseases. Specificity was calculated including sera from healthy donors, other neurological diseases and the respective NCC or CE sera counterpart. The diagnostic accuracy of this assay was compared with two commercial ELISA tests, Novalisa and Ridascreen, widely used in the routine diagnosis of cysticercosis and CE, respectively. Main findings For the diagnosis of NCC, sensitivity ranged from 57.94–63.49% for the rT24H-MBA, and 40.48–46.03% for Novalisa ELISA depending on exclusion or inclusion of sera having equivocal results on ELISA from the analysis; specificities ranged from 90.87–91.30% and 70.43–76.96%, respectively. AUC values of the ROC curve were 0.783 (rT24H) and 0.619 (Novalisa) (p-value < 0.001). For the diagnosis of CE, the sensitivity of the r2B2t-MBA ranged from 68.87–69.77% and of Ridascreen ELISA from 50.00–57.62%; specificities from 92.47–92.68% and from 74.15–80.98%, respectively. AUC values were 0.717 and 0.760, respectively. Conclusions/Significance Overall, the recombinant antigens tested with the bead-based technology showed better diagnostic accuracy than the commercial assays, particularly for the diagnosis of NCC. The possibility of testing the same serum sample simultaneously for the presence of antibodies against both antigens is an added value particularly in seroprevalence studies for cysticercosis linked to control programs in endemic areas where these two parasites coexist.

2019 ◽  
Vol 52 (4) ◽  
pp. 229-236
Author(s):  
Rui Tiago Gil ◽  
Teresa Margarida Cunha ◽  
Mariana Horta ◽  
Ines Alves

Abstract Objective: To evaluate the added value of diffusion-weighted imaging (DWI) in the preoperative assessment of myometrial invasion in endometrial cancer, in comparison with T2-weighted imaging (T2WI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Materials and Methods: This was a retrospective study involving 44 women with endometrial cancer who underwent preoperative 1.5 T MRI. Two radiologists, both of whom were blinded to the histopathology reports, performed a consensus interpretation of the depth of myometrial invasion and of the stage of the cancer, considering three sets of sequences: T2WI, DCE-MRI+T2WI, and DWI+T2WI. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each set. The accuracy was compared with p-value adjustment by the Benjamini-Hochberg procedure. Results: Among the 44 patients evaluated, DWI+T2WI demonstrated better diagnostic performance in assessing deep myometrial invasion and correctly staged more patients (n = 41) than did DCE-MRI+T2WI (n = 34) and T2WI (n = 22). The superior diagnostic accuracy of DWI+T2WI was statistically significant in comparison with T2WI (p < 0.05) but not in comparison with DCE-MRI+T2WI (p > 0.05). Conclusion: The addition of DWI apparently improves the diagnostic accuracy of MRI in the preoperative assessment of the depth of myometrial invasion in endometrial cancer, which may be particularly helpful in patients for whom contrast agents are contraindicated.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Francesca Tamarozzi ◽  
Silvia Stefania Longoni ◽  
Cristina Mazzi ◽  
Sofia Pettene ◽  
Antonio Montresor ◽  
...  

Abstract Background The diagnosis of strongyloidiasis is challenging. Serological tests are acknowledged to have high sensitivity, but issues due to cross-reactions with other parasites, native parasite antigen supply and intrinsic test variability do occur. Assays based on recombinant antigens could represent an improvement. The aim of this study was to assess the sensitivity and specificity of two novel immunoglobulin (Ig)G and IgG4 enzyme-linked immunosorbent assays (ELISAs) based on the recombinant antigens NIE/SsIR for the diagnosis of strongyloidiasis. Methods This was a retrospective diagnostic accuracy study. We included serum samples collected from immigrants from strongyloidiasis endemic areas for whom there was a matched result for Strongyloides stercoralis on agar plate culture and/or PCR assay, or a positive microscopy for S. stercoralis larvae. For the included samples, results were also available from an in-house indirect fluorescent antibody test (IFAT) and a commercial (Bordier ELISA; Bordier Affinity Products SA) ELISA. We excluded: (i) samples with insufficient serum volume; (ii) samples from patients treated with ivermectin in the previous 6 months; and (iii) sera from patients for whom only routine coproparasitology was performed after formol–ether concentration, if negative for S. stercoralis larvae. The performance of the novel assays was assessed against: (i) a primary reference standard, with samples classified as negative/positive on the basis of the results of fecal tests; (ii) a composite reference standard (CRS), which also considered patients to be positive who had concordant positive results for the IFAT and Bordier ELISA or with a single “high titer” positive result for the IFAT or Bordier ELISA. Samples with a single positive test, either for the IFAT or Bordier ELISA, at low titer, were considered to be “indeterminate,” and analyses were carried out with and without their inclusion. Results When assessed against the primary reference standard, the sensitivities of the IgG and IgG4 ELISAs were 92% (95% confidence interval [CI]: 88–97%) and 81% (95% CI: 74–87%), respectively, and the specificities were 91% (95% CI: 88–95%) and 94% (95% CI: 91–97%), respectively. When tested against the CRS, the IgG ELISA performed best, with 78% sensitivity (95% CI: 72–83%) and 98% specificity (95% CI: 96–100%), when a cut-off of 0.675 was applied and the indeterminate samples were excluded from the analysis. Conclusion The NIE-SsIR IgG ELISA demonstrated better accuracy than the IgG4 assay and was deemed promising particularly for serosurveys in endemic areas. Graphical abstract


Author(s):  
Mahmoud Ahmed Ebada ◽  
Notila Fayed ◽  
Souad Alkanj ◽  
Ahmed Wadaa Allah

: Enterovirus D68 (EV-D68) is a single-stranded positive-sense RNA virus, and it is one of the family Picornaviridae. Except for EV-D68, the family Picornaviridae has been illustrated in literature. EV-D68 was first discovered and isolated in California, USA, in 1962. EV-D68 has resulted in respiratory disorders’ outbreaks among children worldwide, and it has been detected in cases of various neurological diseases such as acute flaccid myelitis (AFM). A recent study documented a higher number of EV-D68 cases associated with AFM in Europe in 2016 compared to the 2014 outbreak. EV-D68 is mainly diagnosed by quantitative PCR, and there is an affirmative strategy for EV-D68 detection by using pan-EV PCR on the untranslated region and/or the VP1 or VP2, followed by sequencing of the PCR products. Serological tests are limited due to cross-reactivity of the antigens between the different serotypes. Many antiviral drugs for EV-D68 have been evaluated, and showed promising results. In our review, we discuss the current knowledge about EV-D68 and its role in the development of AFM.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Selim M’rad ◽  
Raja Chaâbane-Banaoues ◽  
Massaouda Ghrab ◽  
Hamouda Babba ◽  
Myriam Oudni-M’rad

Abstract Background Cystic echinococcosis (CE) has a worldwide distribution and is especially prevalent in North African countries. With a mean annual surgical incidence (ASI) of CE of 12.7 per 100,000 inhabitants, Tunisia is one of the most CE endemic countries in the Mediterranean area. Tataouine governorate is considered to be the most CE hypoendemic region in Tunisia (ASI = 0.92) despite favourable socioeconomic conditions that enable maintenance of the Echinococcus granulosussensu lato (s.l.) life-cycle and a significant environmental contamination with E. granulosuss.l. eggs. The aim of this study was to assess human CE seroprevalence, prevalence of CE in food animals and environmental contamination by E. granulosus s.l. eggs in different districts of Tataouine governorate. Methods This study was conducted from January to December 2018. A total of 374 human sera samples were tested for the presence of immunoglobulin G antibodies against E. granulosus using a commercial ELISA kit. Specimens were also collected from animals slaughtered at the Tataouine abattoir (n = 8609) and examined for the presence of hydatid cysts; 111 hydatid cysts were genotyped. Eggs of E. granulosuss.l. were identified by PCR and DNA sequencing from dog faecal samples (n = 288). Results Serological tests showed that 8.5% of the sera samples tested were positive for E. granulosus-specific antibodies. The average prevalence of hydatidosis in livestock was 1.6%, and CE infection was more prevalent in cattle than in sheep, goats and dromedaries. The contamination rate of dog faeces by E. granulosus sensu stricto eggs varied significantly from 0 to 23.5% depending on the collection area. Molecular analyses only revealed the presence of the G1 genotype for cysts and eggs. Conclusions Based on our findings, CE is likely to be more endemic in the Tataouine governorate than previously described. Thus, to implement an effective control programme against CE, a national survey should be carried out to determine human CE prevalence in the different Tunisian governorates. Graphic Abstract


2011 ◽  
Vol 20 (3) ◽  
pp. 202-206 ◽  
Author(s):  
Nicolle Fridlund Plugge ◽  
Fabiano Montiani Ferreira ◽  
Rosária Regina Tesoni de Barros Richartz ◽  
Adriana de Siqueira ◽  
Rosangela Locatelli Dittrich

This study aimed to evaluate occurrences of antibodies against Neospora caninum and Toxoplasma gondii in dogs with neurological signs. Blood samples from 147 dogs were collected: 127 from owned dogs (attended at the Veterinary Teaching Hospital of the Federal University of Paraná (HV-UFPR) and at private veterinary clinics in the city of Curitiba), and 20 from stray dogs found in Curitiba's metropolitan region. The dogs presented one or more of the following neurological signs: seizures, paresis or paralysis, ataxia, behavioral abnormalities, sensory and somatic disorders and chorioretinitis. The samples were analyzed by means of the indirect fluorescent antibody test (IFAT), at a cutoff dilution of 1:50. Out of the 147 samples obtained, 17 (11.56%) were seropositive for N. caninum, 31 (21.08%) for T. gondii and four (2.72%) for both protozoa. Serum titration on the positive animals showed that 54.83% (17/31) and 41.18% (7/17) had titers > 1:200 against T. gondii and N. caninum, respectively. A significant difference in seropositivity for T. gondii (P = 0.021; OR = 2.87; CI = 1.1 > 2.8 > 7.4) was observed between owned dogs (18.11%) and stray dogs (40%). Inclusion of serological tests for neosporosis and toxoplasmosis is recommended in diagnosing neurological diseases in dogs.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Cécile Beck ◽  
Philippe Desprès ◽  
Sylvie Paulous ◽  
Jessica Vanhomwegen ◽  
Steeve Lowenski ◽  
...  

West Nile virus (WNV), Japanese encephalitis virus (JEV), and tick-borne encephalitis virus (TBEV) are flaviviruses responsible for severe neuroinvasive infections in humans and horses. The confirmation of flavivirus infections is mostly based on rapid serological tests such as enzyme-linked immunosorbent assays (ELISAs). These tests suffer from poor specificity, mainly due to antigenic cross-reactivity among flavivirus members. Robust diagnosis therefore needs to be validated through virus neutralisation tests (VNTs) which are time-consuming and require BSL3 facilities. The flavivirus envelope (E) glycoprotein ectodomain is composed of three domains (D) named DI, DII, and DIII, with EDIII containing virus-specific epitopes. In order to improve the serological differentiation of flavivirus infections, the recombinant soluble ectodomain of WNV E (WNV.sE) and EDIIIs (rEDIIIs) of WNV, JEV, and TBEV were synthesised using theDrosophilaS2 expression system. Purified antigens were covalently bonded to fluorescent beads. The microspheres coupled to WNV.sE or rEDIIIs were assayed with about 300 equine immune sera from natural and experimental flavivirus infections and 172 nonimmune equine sera as negative controls. rEDIII-coupled microspheres captured specific antibodies against WNV, TBEV, or JEV in positive horse sera. This innovative multiplex immunoassay is a powerful alternative to ELISAs and VNTs for veterinary diagnosis of flavivirus-related diseases.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Emily R. Adams ◽  
Inge Versteeg ◽  
Mariska M. G. Leeflang

Identification of post-kala-azar dermal leishmaniasis (PKDL) is important due to the long and toxic treatment and the fact that PKDL patients may serve as a reservoir for visceral leishmaniasis (VL). We summarized the published literature about the accuracy of diagnostic tests for PKDL. We searched Medline for eligible studies investigating the diagnostic accuracy of any test for PKDL. Study quality was assessed using QUADAS-2. Data were extracted from 21 articles including 43 separate studies. Twenty-seven studies evaluated serological tests (rK39 dipstick, ELISA, DAT, and leishmanin tests), six studies molecular tests, eight microscopy, and two cultures. Only a few of these studies reported a valid estimate of diagnostic accuracy, as most were case-control designs or used a reference standard with low sensitivity. The included studies were very heterogeneous, for example, due to a large variety of reference standards used. Hence, no summary estimates of sensitivity or specificity could be made. We recommend well-designed diagnostic accuracy trials that evaluate, side-by-side, all currently available diagnostics, including clinical symptoms, serological, antigen, molecular, and parasitological tests and possible use of statistical modelling to evaluate diagnostics when there is no suitable gold standard.


2007 ◽  
Vol 15 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Olga Sánchez Negrette ◽  
Fernando J. Sánchez Valdéz ◽  
Carlos D. Lacunza ◽  
María Fernanda García Bustos ◽  
María Celia Mora ◽  
...  

ABSTRACT Serological tests are the main laboratory procedures used for diagnosis during the indeterminate and chronic stages of Chagas' disease. A serological regression to negativity is the main criterion used to define parasitological cure in treated patients. The aim of this work was to monitor the individual specificities of antibody levels for 3 years posttreatment in 18 adult patients. Conventional serological techniques (hemagglutination assays and enzyme-linked immunosorbent assay [ELISA]) were modified by using recombinant antigens to detect early markers of treatment effectiveness. For this purpose, serum samples were taken before and during treatment and every 6 months after treatment for at least 3 years. When hemagglutination assays were used, a decrease in antibody levels was observed in only one patient. When ELISA with serum dilutions was used, antibody clearance became much more apparent: in 77.7% (14/18) of the patients, antibody titers became negative with time. This was observed at serum dilutions of 1/320 and occurred between the 6th and the 30th months posttreatment. The immune response and the interval for a serological regression to negativity were different for each patient. For some of the recombinant antigens, only 50% (9/18) of the patients reached the serological regression to negativity. Recombinant antigen 13 might be a good marker of treatment effectiveness, since 66.6% (six of nine) of the patients presented with an early regression to negativity for specific antibodies to this antigen (P = 0.002).


2009 ◽  
Vol 48 (04) ◽  
pp. 173-178 ◽  
Author(s):  
H. Ham ◽  
A. Dobbeleir ◽  
P. Santens ◽  
Y. D'Asseler ◽  
I. Goethals

SummaryThe aim of our study was to evaluate the value of a pictorial atlas of 123I FP-CIT SPECT images for aid in the visual diagnosis. Patients, materials, methods: Sixty patients, of whom 20 were clinically diagnosed as ‘non-parkinsonian’ and 40 as having Parkinson's disease or any related disorder, were included in the study. An atlas consisting of 12 123I FP-CIT SPECT images was constructed first. Validity of the atlas was investigated by performing a receiver operating characteristic (ROC) analysis with the clinical diagnosis as the gold standard. The remaining 48 SPECT images were visually assessed twice by 5 observers, first with and secondly without consulting the atlas, or vice versa. The added value of the atlas was investigated by comparing the diagnostic accuracy and the interobserver variability for both methods. Results: ROC analysis performed on the atlas yielded an area under the curve of 1 for a threshold discriminating between clinically non-parkinsonian and parkinsonian patients that was situated between image 4 and 5 of the atlas. For the diagnostic accuracy, we found that the area under the ROC curve was systematically higher if observers had access to the atlas compared to when they had not (Wilcoxon's test, p<0.05). Also, the interobserver variability was significantly lower when observers used the atlas when compared to when they did not (p = 0.05). Conclusion: Diagnostic accuracy was significantly higher and interobserver variability significantly lower if observers had access to the atlas compared to when they had not. Hence, having a pictorial atlas available may facilitate the visual assessment of 123I FP-CIT SPECT scans.


2019 ◽  
Vol 13 (2) ◽  
pp. 10-16
Author(s):  
Haitham Ahmed ◽  
Tagreed A. Al-Sadoon ◽  
Khudhair A. Khudhair

Objective: To investigate the influence of obesity on disease activity in rheumatoid arthritis patients and to determine a probable connection with the acute phase response.                                          Materials and methods: The recruited patients satisfied the criteria from the American College of Rheumatology (ACR). To evaluate the body mass index (BMI), anthropometric tests were carried out at the Rheumatology Department at Baquba Teaching Hospital, which has a consultation unit. The serum levels of anti-cyclic citrullinated peptide antibodies (anti-CCP) were measured from blood samples taken through the particle-enhanced (latex) immunonephelometry assays on the genius analyser (CO, Ltd. China) and test kits from IMTEC-CCP-Antibodies. RF screen and serological tests (latex) were carried out to determine the C-reactive protein (CRP), measure Hb and the total WBCs count, the erythrocyte sedimentation rate (ESR) was also carried out.                                                                                                                                                                        Results: The current study findings from the sample of RA patients showed that the proportion of patients falling into the overweight classification (BMI 25-29) was 80.6% while the obese classification (BMI 30-35) was 33.33%. Among the RF and ACCP-positive cases, a marginally stronger relationship between the development of RA and the history of obesity was found. Additionally, a significant correlation between acute phase response and free mass was found in RA patients (anti-CCP p-value≤ 0.00021 ESR p≤ 0.00072 Hb p≤ 0.00054, and W.B.C p =≤ 0.000.94, CRP p≤1).                                                                                                     Conclusion: The present study’s findings show an elevated prevalence of high body mass among the RA patients. Furthermore, a linear association existed between the fat free mass and the acute phase response.


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