Stability Assessment of Four Chimeric Proteins for Human Chagas Disease Immunodiagnosis

Celedón, Paola Alejandra Fiorani; Leony, Leonardo Maia; Oliveira, Ueriton Dias de; Freitas, Natália Erdens Maron; Silva, Ângelo Antônio Oliveira; Daltro, Ramona Tavares; Santos, Emily Ferreira dos; Krieger, Marco Aurélio; Zanchin, Nilson Ivo Tonin; Santos, Fred Luciano Neves

doi:10.3390/bios11080289

Cited by 10 publications

(7 citation statements)

References 28 publications

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“…In November 2011, the Abbott ESA Chagas was approved by the US FDA for the confirmation of blood donors who are repeatedly reactive in Chagas screening tests. The diagnostic performance obtained here using WB corroborates our previous findings obtained using a variety of diagnostic platforms [ 16 – 22 , 55 – 58 ]. Indeed, all four chimeric proteins achieved 100% sensitivity and specificity, with the exception of IBMP-8.3 (95% sensitivity).…”

Section: Discussionsupporting

confidence: 89%

Western blot using Trypanosoma cruzi chimeric recombinant proteins for the serodiagnosis of chronic Chagas disease: A proof-of-concept study

et al. 2022

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Background Chagas disease (CD) is caused by Trypanosoma cruzi. The chronic phase of CD is characterized by the presence of IgG anti-T. cruzi antibodies; and diagnosis is performed by serological methods. Because there is no realible test that can be used as a reference test, WHO recommends the parallel use of two different tests for CD serodiagnosis. If results are inconclusive, samples should be subjected to a confirmatory test, e.g., Western blot (WB) or PCR. PCR offers low sensitivity in the chronic phase, whereas few confirmatory tests based on the WB method are commercially available worldwide. Therefore, new diagnostic tools should be evaluated to fill the gap in confirmatory tests CD. In recent years, four chimeric recombinant antigens (IBMP-8.1, IBMP-8.2, IBMP-8.3 and IBMP-8.4) have been evaluated in phase I, II and III studies using ELISA, liquid microarray and immunochromatography with 95–100% accuracy. Given the high diagnostic performance of these antigens, the present study investigated the ability of these molecules to diagnose chronic CD using a WB testing platform. Methodology/Principal findings In this study, we analyzed the diagnostic potential of four chimeric antigens using 40 T. cruzi-positive, 24-negative, and three additional samples positive for visceral leishmaniasis (i.e., potentially cross-reactive) using WB as the diagnostic platform. Checkerboard titration with different dilutions of antigens, conjugated antigens, and serum samples was performed to standardize all assays. All IBMP antigens achieved 100% sensitivity, specificity, and accuracy, with the exception of IBMP-8.3, which had 100% specificity despite lack of significance, but lower sensitivity (95%) and accuracy (96.9%). No cross-reactivity was observed in samples positive for leishmaniasis. Conclusions/Significance The present phase I (proof-of-concept) study demonstrated the high diagnostic potential of these four IBMP antigens to discriminate between T. cruzi-positive and -negative samples, making them candidates for phase II and confirmatory testing with WB.

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Section: Discussionsupporting

confidence: 89%

Western blot using Trypanosoma cruzi chimeric recombinant proteins for the serodiagnosis of chronic Chagas disease: A proof-of-concept study

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“…The antigen IBMP-8.4 had the highest sensitivity value in the present study as well as in the previously performed studies, regardless of the population studied and the methodology used. This is due to the nature of the molecule, as it comprises a larger repertoire of epitopes compared to the others, making it responsive to a greater diversity of anti- T. cruzi antibodies ( 25 , 30 , 34 , 35 ). In contrast to the IBMP-8.4 protein, identification of anti- T. cruzi was less efficient in blood donors with IBMP-8.1, probably due to its limited repertoire of antigens.…”

Section: Discussionmentioning

confidence: 99%

“…High accuracy and low cross-reactivity rates have been observed in several infectious and parasitic diseases, including leishmaniasis ( 30 , 33 ). In addition, all antigens have been shown to maintain their functional and structural stability under adverse conditions ( 34 ), making them robust and reliable candidates for future in vitro diagnostic assays that can be used for various models of point-of-care devices, including advanced biosensors. The performance of these antigens was evaluated using latent class analysis (LCA), a statistical tool used to evaluate new assays in the absence of a gold standard ( 35 ).…”

Section: Introductionmentioning

confidence: 99%

Performance of Chimeric Trypanosoma cruzi Antigens in Serological Screening for Chagas Disease in Blood Banks

et al. 2022

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Chagas disease (CD) is among the top 10 causes of inability to blood donation. Blood donation centers screen for anti-Trypanosoma cruzi antibodies using highly sensitive immunoenzymatic (ELISA) or chemiluminescent methods, which can lead to false positive results. Since positive samples cannot be used, to avoid the loss of valuable blood donations, it is necessary to improve specificity without reducing the sensitivity of the tests used for blood screening. For this purpose, our group has developed four chimeric proteins (IBMP-8.1, IBMP-8.2, IBMP-8.3, and IBMP-8.4) that have been evaluated in phase I and II studies with high performance and low cross-reactivity rates. The study included a panel of 5,014 serum samples collected from volunteer blood donors at the Hematology and Hemotherapy Foundation of the State of Bahia (Brazil). They were subjected to the detection of anti-T. cruzi antibodies, using all four IBMP antigens individually and latent class analysis (LCA) as a reference test, since there is no gold standard test for this purpose. Considering the sample size analyzed, LCA classified 4,993 (99.6%) samples as T. cruzi-negative and 21 (0.42%) as T. cruzi-positive. Sensitivity values ranged from 85.71% for IBMP-8.1 and 90.48% for IBMP-8.2–95.24% for IBMP-8.3 and 100% for IBMP-8.4, while specificity ranged from 99.98% for IBMP-8.3 and IBMP-8.4–100% for IBMP-8.1 and IBMP-8.2. Accuracy values ranged from 99.4 to 99.98%. The pretest probability for the molecules was 0.42, whereas the positive posttest probability ranged from 95.24 to 99.95% and the negative posttest probability ranged from 0.00001 to 0.0006% for all antigens. The higher odds ratio diagnosis was found for IBMP-8.4, which has been shown to be a safe single antigen for serological screening of CD in blood samples. The use of chimeric IBMP antigens is an alternative to reduce the number of bags discarded due to false-positive results. These molecules have high diagnostic performance and were shown to be suitable for use in screening CD in blood banks, isolated (IBMP-8.4) or in combination; and their use in blood banks could significantly reduce unnecessary disposal of blood bags or the risk of T. cruzi transmission.

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“…In 2020, this device was licensed by the Brazilian Health Regulatory Agency to form the portfolio of diagnostic products of the Brazilian Ministry of Health for use in the Unified Health System: the TR-Chagas Bio-Manguinhos (Oswaldo Cruz Foundation, Rio de Fig. 8 Constitution of the IBMP chimeric recombinant proteins [156,159,166] Janeiro, RJ, Brazil) [169]. Recently, all four IBMP antigens have shown promising results in a phase 3 study with more than 5000 samples from a Brazilian blood bank, especially the IBMP-8.3 and IBMP-8.4 antigens [161].…”

Section: Diagnostic Methodsmentioning

confidence: 99%

“…IBMP antigens are composed of different epitopes of several T. cruzi proteins, as described in Fig. 8 [ 156 , 159 , 166 ]. In general, this diversity of antigenic determinants is responsible for their high reactivity to anti- T. cruzi antibodies.…”

Section: Introductionmentioning

confidence: 99%

Technological advances in the serological diagnosis of Chagas disease in dogs and cats: a systematic review

et al. 2022

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Background Chagas disease (CD) is caused by Trypanosoma cruzi, which is transmitted mainly through the feces/urine of infected triatomine bugs. The acute phase lasts 2–3 months and is characterized by high parasitemia and nonspecific symptoms, whereas the lifelong chronic phase features symptoms affecting the heart and/or digestive tract occurring in 30–40% of infected individuals. As in humans, cardiac abnormalities are observed in T. cruzi-infected dogs and cats. We reviewed the technological advances in the serological diagnosis of CD in dogs and cats. Methods A review of the published literature during the last 54 years (1968–2022) on the epidemiology, clinical features, diagnosis, treatment and prevention of CD in dogs and cats was conducted. Results Using predefined eligibility criteria for a search of the published literature, we retrieved and screened 436 publications. Of these, 84 original studies were considered for inclusion in this review. Dogs and cats are considered as sentinels, potentially indicating an active T. cruzi transmission and thus the risk for human infection. Although dogs and cats are reputed to be important for maintaining the T. cruzi domestic transmission cycle, there are no commercial tests to detect past or active infections in these animals. Most published research on CD in dogs and cats have used in-house serological tests prepared with native and/or full-length recombinant antigens, resulting in variable diagnostic performance. In recent years, chimeric antigens have been used to improve the diagnosis of chronic CD in humans with encouraging results. Some of them have high performance values (> 95%) and extremely low cross-reactivity rates for Leishmania spp., especially the antigens IBMP-8.1 to IBMP-8.4. The diagnostic performance of IBMP antigens was also investigated in dogs, showing high diagnostic performance with negligible cross-reactivity with anti-Leishmania infantum antibodies. Conclusions The development of a commercial immunodiagnostic tool to identify past or active T. cruzi infections in dogs and cats is urgently needed. The use of chimeric recombinant T. cruzi antigens may help to fill this gap and is discussed in this review. Graphical Abstract

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Stability Assessment of Four Chimeric Proteins for Human Chagas Disease Immunodiagnosis

Cited by 10 publications

References 28 publications

Western blot using Trypanosoma cruzi chimeric recombinant proteins for the serodiagnosis of chronic Chagas disease: A proof-of-concept study

Western blot using Trypanosoma cruzi chimeric recombinant proteins for the serodiagnosis of chronic Chagas disease: A proof-of-concept study

Performance of Chimeric Trypanosoma cruzi Antigens in Serological Screening for Chagas Disease in Blood Banks

Technological advances in the serological diagnosis of Chagas disease in dogs and cats: a systematic review

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