Dos Santos Emily Ferreira, Silva Ângelo Antônio Oliveira, Freitas Natália Erdens Maron, Leony Leonardo Maia, Daltro Ramona Tavares, Santos Carlos Antônio de Souza Teles, de Almeida Maria da Conceição Chagas, de Araújo Fernando Luiz Vieira, Celedon Paola Alejandra Fiorani, Krieger Marco Aurélio, Zanchin Nilson Ivo Tonin, Dos Reis Mitermayer Galvão, Santos Fred Luciano Neves
Advanced Health Public Laboratory, Gonçalo Moniz Institute, Oswaldo Cruz Foundation - Bahia (FIOCRUZ-BA), Salvador, Brazil.
Center for Integration of Data and Health Knowledge (CIDACS), Gonçalo Moniz Institute, Oswaldo Cruz Foundation - Bahia (FIOCRUZ-BA), Salvador, Brazil.
Front Med (Lausanne). 2022 Mar 7;9:852864. doi: 10.3389/fmed.2022.852864. eCollection 2022.
Chagas disease (CD) is among the top 10 causes of inability to blood donation. Blood donation centers screen for anti- 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- 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 -negative and 21 (0.42%) as -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 transmission.
恰加斯病（CD）是导致无法献血的十大原因之一。献血中心使用高灵敏度免疫酶法（ELISA）或化学发光法筛查抗体，这可能导致假阳性结果。由于阳性样本不能使用，为避免宝贵的献血流失，有必要在不降低用于血液筛查测试灵敏度的情况下提高其特异性。为此，我们团队开发了四种嵌合蛋白（IBMP - 8.1、IBMP - 8.2、IBMP - 8.3和IBMP - 8.4），这些蛋白已在I期和II期研究中进行了评估，表现出高性能和低交叉反应率。该研究纳入了从巴西巴伊亚州血液学和血液治疗基金会的志愿献血者中收集的5014份血清样本。由于没有用于此目的的金标准测试，所以使用所有四种IBMP抗原单独检测抗体，并以潜在类别分析（LCA）作为参考测试。考虑到所分析的样本量，LCA将4993份（99.6%）样本分类为抗体阴性，21份（0.42%）样本分类为抗体阳性。灵敏度值范围为：IBMP - 8.1为85.71%，IBMP - 8.2为90.48%，IBMP - 8.3为95.24%，IBMP - 8.4为100%；而特异性范围为：IBMP - 8.3和IBMP - 8.4为99.98%，IBMP - 8.1和IBMP - 8.2为100%。准确性值范围为99.4%至99.98%。这些分子的预测试概率为0.42，而所有抗原的阳性测试后概率范围为95.24%至99.95%，阴性测试后概率范围为0.00001%至0.0006%。发现IBMP - 8.4的诊断优势比更高，它已被证明是用于血液样本中CD血清学筛查的一种安全单一抗原。使用嵌合IBMP抗原是减少因假阳性结果而废弃血袋数量的一种替代方法。这些分子具有高诊断性能，被证明适用于血库中CD的筛查，单独使用（IBMP - 8.4）或联合使用；并且它们在血库中的使用可以显著减少血袋的不必要丢弃或传播风险。
