scholarly journals Laboratory Evaluation of a Point-of-Care Downward-Flow Assay for Simultaneous Detection of Antibodies to Treponema pallidum and Human Immunodeficiency Virus

2016 ◽  
Vol 54 (7) ◽  
pp. 1922-1924 ◽  
Author(s):  
S. Herbst de Cortina ◽  
C. C. Bristow ◽  
S. K. Vargas ◽  
D. G. Perez ◽  
K. A. Konda ◽  
...  

Combining the detection of syphilis and HIV antibodies into one point-of-care test integrates syphilis screening into already existing HIV screening programs, which may be particularly beneficial in settings such as antenatal care. Using the INSTI Multiplex downward-flow immunoassay, we tested 200 stored serum samples from high-risk patients enrolled in a longitudinal study on HIV infection and syphilis in Peruvian men who have sex with men and transgender women. This rapid assay detected HIV andTreponema pallidumserum antibodies with sensitivities of 100% (95% confidence interval [CI], 95.9% to 100%) and 87.4% (95% CI, 81.4% to 92.0%), respectively, and specificities of 95.5% (95% CI, 89.9% to 98.5%) and 97.0% (95% CI, 84.2% to 99.9%), respectively (n= 200). The sensitivity for syphilis antibody detection was higher in patients with a rapid plasma reagin titer of ≥1:8 (97.3%) than in those with a titer of ≤1:4 (90%) or a nonreactive titer (66.7%).

2015 ◽  
Vol 54 (2) ◽  
pp. 492-494 ◽  
Author(s):  
S. R. Leon ◽  
L. B. Ramos ◽  
S. K. Vargas ◽  
N. Kojima ◽  
D. G. Perez ◽  
...  

We assessed the laboratory performance of the Chembio dual-path platform HIV-syphilis rapid immunodiagnostic test and electronic reader for detection of HIV andTreponema pallidumantibodies in 450 previously characterized serum specimens. For visual or electronic reader HIV antibody detection, the sensitivity was 100% and the specificity was 98.7%. For visualT. pallidumantibody detection, the test sensitivity was 94.7% and the specificity was 100.0%; with the electronic reader, the sensitivity was 94.7% and the specificity was 99.7%.


2016 ◽  
Vol 54 (12) ◽  
pp. 3034-3042 ◽  
Author(s):  
O. Villard ◽  
B. Cimon ◽  
C. L'Ollivier ◽  
H. Fricker-Hidalgo ◽  
N. Godineau ◽  
...  

Toxoplasmosis, a benign infection, is asymptomatic or paucisymptomatic in over 80% of cases, except in immunocompetent patients suffering from ocular toxoplasmosis or in immunocompromised patients with opportunistic or congenital toxoplasmosis. Diagnosis is based mainly on serology testing. Thus, we compared the performance of the nine most commonly used commercial automated or semiautomated immunoassays for IgG and IgMToxoplasma gondiiantibody detection, that is, the Advia Centaur, Architect, AxSYM, Elecsys, Enzygnost, Liaison, Platelia, VIDAS, and VIDIA assays. The assays were conducted on four panels of serum samples derived during routine testing from patients with an interfering disease and who exhibited a low IgG antibody level in one of two clinical settings, namely, acute or chronic toxoplasmosis. As a result, IgG sensitivities ranged from 97.1% to 100%, and IgG specificities ranged from 99.5% to 100%. For IgG quantification, strong differences in IgG titers (expressed in IU/ml) were noted depending on the assay used. IgM sensitivities ranged from 65% to 97.9%, and IgM specificities ranged from 92.6% to 100%. For defining the best serological strategies to be implemented, it appears crucial to compare the diagnostic performance of the different tests with respect to their specificity and sensitivity in detecting the presence of IgG and IgM antibodies.


2018 ◽  
Vol 56 (8) ◽  
Author(s):  
Phornpun Phokrai ◽  
Wisansanee Karoonboonyanan ◽  
Nida Thanapattarapairoj ◽  
Chidchanok Promkong ◽  
Adul Dulsuk ◽  
...  

ABSTRACTMelioidosis is a fatal infectious disease caused by the environmental bacteriumBurkholderia pseudomallei. It is highly endemic in Asia and northern Australia but neglected in many other tropical countries. Melioidosis patients have a wide range of clinical manifestations, and definitive diagnosis requires bacterial culture, which can be time-consuming. A reliable rapid serological tool is greatly needed for disease surveillance and diagnosis. We previously demonstrated by enzyme-linked immunosorbent assay (ELISA) that a hemolysin-coregulated protein (Hcp1) is a promising target for serodiagnosis of melioidosis. In this study, we developed a rapid immunochromatography test (ICT) using Hcp1 as the target antigen (Hcp1-ICT). We evaluated this test for specific antibody detection using serum samples obtained from 4 groups of human subjects, including the following: (i) 487 culture-confirmed melioidosis patients from four hospitals in northeast Thailand; (ii) 202 healthy donors from northeast Thailand; (iii) 90 U.S. healthy donors; and (iv) 207 patients infected with other organisms. Compared to culture results as a gold standard, the sensitivity of ICT for all hospitals was 88.3%. The specificities for Thai donors and U.S. donors were 86.1% and 100%, respectively, and the specificity for other infections was 91.8%. The results of the Hcp1-ICT demonstrated 92.4% agreement with the Hcp1-ELISA results with a kappa value of 0.829, indicating that the method is much improved compared with the current serological method, the indirect hemagglutination assay (IHA) (69.5% sensitivity and 67.6% specificity for Thais). The Hcp1-ICT represents a potential point-of-care (POC) test and may be used to replace the IHA for screening of melioidosis in hospitals as well as in resource-limited areas.


2013 ◽  
Vol 20 (6) ◽  
pp. 907-911 ◽  
Author(s):  
Konstantin P. Lyashchenko ◽  
Rena Greenwald ◽  
Javan Esfandiari ◽  
Daniel J. O'Brien ◽  
Stephen M. Schmitt ◽  
...  

ABSTRACTBovine tuberculosis (TB) in cervids remains a significant problem affecting farmed herds and wild populations. Traditional skin testing has serious limitations in certain species, whereas emerging serological assays showed promising diagnostic performance. The recently developed immunochromatographic dual-path platform (DPP) VetTB assay has two antigen bands, T1 (MPB83 protein) and T2 (CFP10/ESAT-6 fusion protein), for antibody detection. We evaluated the diagnostic accuracy of this test by using serum samples collected from groups of white-tailed deer experimentally inoculated withMycobacterium bovis,M. aviumsubsp.paratuberculosis, orM. bovisBCG Pasteur. In addition, we used serum samples from farmed white-tailed deer in herds with no history of TB, as well as from free-ranging white-tailed deer culled during field surveillance studies performed in Michigan known to have bovine TB in the wild deer population. The DPP VetTB assay detected antibody responses in 58.1% of experimentally infected animals within 8 to 16 weeks postinoculation and in 71.9% of naturally infected deer, resulting in an estimated test sensitivity of 65.1% and a specificity of 97.8%. The higher seroreactivity found in deer with naturally acquiredM. bovisinfection was associated with an increased frequency of antibody responses to the ESAT-6 and CFP10 proteins, resulting in a greater contribution of these antigens, in addition to MPB83, to the detection of seropositive animals, compared with experimentalM. bovisinfection. Deer experimentally inoculated with eitherM. aviumsubsp.paratuberculosisorM. bovisBCG Pasteur did not produce cross-reactive antibodies that could be detected by the DPP VetTB assay. The present findings demonstrate the relatively high diagnostic accuracy of the DPP VetTB test for white-tailed deer, especially in the detection of naturally infected animals.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e22019-e22019
Author(s):  
R. Lastra ◽  
A. Monasterio ◽  
I. Alvarez-Busto ◽  
J. Mayordomo ◽  
J. Algorta ◽  
...  

e22019 Background: Conventionals serum biomarkets have a low sensibility in breast cancer diagnosis. Proteomic is a promising tool to identify new proteins profiles to be used in screening and early diagnosed. Methods: 1)Biomarker identification: Serum proteins from 114 women were separated and analysed by bidimensional gel electrophoresis; data from 72 patients (p) were compared with those from 42 control women to search for differentially expressed proteins. Several comparisons were performed between controls and p regarding clinical parameters such as histological type, tumour stage and lymph node affection (-/+). A total of 53 spots were found to be differentially expressed and identified by mass spectrometry (MS) as potential breast cancer biomarkers.2) Protein Chip development: A Protein Chip was developed with antibodies against six biomarkers and three control proteins (an antibody for the detection of a spiked control, for data normalization and two proteins as positive and negative controls). An antibody against CA15–3 antigen was also included as a reference breast tumour marker to be compared with our biomarker panel. 3) Clinical validation of the Protein Chip: A clinical validation study was carried out with 75 healthy women and 125 breast cancer p. After multivariate statistical analysis of the biomarker data, CA15–3 was discarded due to its low significance while a panel of 5 biomarkers was obtained as the best predictive model to discriminate p from healthy subjects. Results: 53 diferentially expressed proteins have been identified as potential breast cancer serum biomarkers after analysing 114 serum samples by 2DE Technology. A Protein Chip has been developed for the simultaneous detection of five serum biomarkers and three control proteins. After clinical validation with 200 p and healthy women, the sensitivity of the Protein Chip to detect breast cancer was 95% and its specificity was 27%. Conclusions: The high sensitivity of the Protein Chip suggests that it could be a valid tool to complement mammography (sensitivity < 80%) in breast cancer screening programs, specially when its sensitivity tends to decrease, as it happens in young women and dense breast cases. Larger clinical validation trials are being developed. This work is supported by INDAS BIOTECH. No significant financial relationships to disclose.


2017 ◽  
Vol 55 (3) ◽  
pp. 893-901 ◽  
Author(s):  
Joshua Malo ◽  
Eric Holbrook ◽  
Tirdad Zangeneh ◽  
Chris Strawter ◽  
Eyal Oren ◽  
...  

ABSTRACT Coccidioidomycosis is a common cause of community-acquired pneumonia in areas of the southwestern United States in which the disease is endemic. Clinical presentations range from self-limited disease to severe disseminated disease. Therefore, early and accurate diagnosis is essential to ensure appropriate treatment and monitoring. Currently available diagnostic tests have variable accuracy, particularly in certain patient populations, and new tests may offer improved accuracy for the diagnosis of coccidioidomycosis. Serum samples from 103 cases of coccidioidomycosis and 373 controls were tested for IgG and IgM antibodies using the MVista anti- Coccidioides antibody enzyme immunoassay. Serum specimens from 170 controls from areas in which the disease is endemic and 44 cases were tested by immunodiffusion at MiraVista Diagnostics. The sensitivity of the MVista antibody assay was 88.3%, and the specificity was 90%. The sensitivity was maintained in the presence of immunocompromising conditions or immunosuppressive therapies. The sensitivity of immunodiffusion was 60.2%, and the specificity was 98.8%. The sensitivity of complement fixation (62 cases) was 66.1%, but the specificity could not be determined. The MVista anti- Coccidioides antibody enzyme immunoassay offers improved sensitivity, compared with immunodiffusion and complement fixation, is not impaired in immunocompromised patients, and permits highly reproducible semiquantification.


2021 ◽  
Vol 25 (8) ◽  
pp. 626-631
Author(s):  
K. Sharma ◽  
M. Sharma ◽  
M. Modi ◽  
N. Singla ◽  
A. Sharma ◽  
...  

BACKGROUND: Diagnostic delay and drug resistance not only worsen the outcomes of tuberculous meningitis (TBM), but are also important impediments to TB elimination efforts. Given the need for a near point-of-care test suitable for primary healthcare centres and simultaneous detection of resistance, Truenat™ MTB Plus assay was evaluated on a large cohort of TBM patients.METHODS: Truenat assay was performed on 148 cerebrospinal fluid specimens (76 definite TBM, 32 probable TBM and 40 non-TBM controls) and its performance was compared with Xpert® Ultra.RESULTS: The overall sensitivity of Truenat and Ultra was respectively 78.7% and 67.6% in diagnosing TBM, and respectively 85.5% and 96% in diagnosing definite TBM. Twenty-three additional cases were detected using Truenat and 11 using Ultra. Truenat missed seven cases of rifampicin (RIF) resistance and indicated false RIF resistance in four cases.CONCLUSION: Performance of Truenat was comparable to that of Ultra in diagnosing TBM and inferior to Xpert Ultra in determining RIF resistance.


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