Multiplexed Antigen-Specific Antibody Fc Profiling on a Chip for Point-of-Care Diagnosis of TB in HIV-infected Children

摘要： 结核病是儿童死亡的主要原因，估计有100万儿童 每年有20多万儿童死于结核病。艾滋病毒合并感染一直是 据估计，在非洲与结核病有关的儿童死亡中， 艾滋病和结核病的冲突是迄今为止最致命的流行病之一。艾滋病毒感染以及 在接触艾滋病毒但未感染的儿童中，子宫内接触艾滋病毒与以下因素有关： 幼儿患结核病的风险更高。未能预防结核病， 灾难性的破坏被归咎于缺乏有效的疫苗，以及我们无法 诊断5岁以下的儿童，由于难以获得痰液和 在幼儿中疾病的少菌性。因此，一种廉价的基于生物标记的 使用非痰液样本为儿科结核病量身定制的诊断测试，可用于 在资源有限的情况下，定点治疗可以大大改善结核病治疗， 预防儿童死亡，特别是5岁以下儿童死亡。虽然结核分枝杆菌特异性 基于抗体滴度的诊断在过去表现不佳，这是由于无法 准确区分活动性结核病和潜伏性结核感染（LTBI）， 来自我们小组的研究表明，Mtb特异性抗体糖基化在不同的 疾病状态。此外，这种抗原特异性抗体糖基化方法可靠地分类了 不同地区的艾滋病毒感染状况， 甚至可以区分流行地区儿童中最近的伤寒感染。基于 根据这些观察，开发了一种简单的基于结合的测定法，其可以快速，灵敏， 并从小样品体积中特异性检测Mtb特异性抗体糖基化的变化 首次提供了开发抗原特异性抗体糖基化的机会， 从微升规模的样本中诊断儿科结核病。鉴于艾滋病毒阳性、高浓缩铀或 未暴露的儿童可能针对不同的结核分枝杆菌抗原，在这里，我们组装了一个多学科的 FASTER-Kids（儿童TubERbridium Fc抗体特征）团队和项目 这将：1）定义Mtb特异性抗体糖基化反应的景观， 2）开发一种即时检测方法，可以快速捕获这些特异性抗体 反应和糖基化的变化。最终，这一合作 结构将使迭代改进和发展这种简单，快速，廉价 诊断，以管理幼儿结核病感染。

Abstract: Tuberculosis (TB) is a leading cause of death in children, with an estimated 1 million children affected, and more than 200,000 deaths in children yearly due to TB. HIV coinfection has been estimated to contribute to more than 35% of TB-related deaths in children in Africa, making the collision of the HIV and TB epidemics one of the most lethal to date. Both HIV infection as well as HIV-exposure in utero, among HIV-exposed but uninfected (HEU) children, have been linked to higher risks for the development of TB among young children. Failures to prevent TB disease and devastation has been attributed to the lack of an effective vaccine as well as our inability to diagnose children under the age of 5 due to the difficulty in obtaining sputum and the paucibacillary nature of the disease in young children. Thus, an inexpensive biomarker-based diagnostic test tailored for pediatric TB using non-sputum samples that could be used at the point of care in resource-limited settings could profoundly improve TB treatment and prevent deaths in children, especially in those under 5 years of age. While Mtb-specific antibody titer-based diagnostics have performed poorly in the past, due to the inability of accurately distinguishing between active TB disease from latent TB infection (LTBI), recent data from our group has shown that Mtb-specific antibody glycosylation shifts significantly across disease states. Moreover, this antigen-specific antibody glycosylation approach reliably classifies individuals into active and latent disease states across HIV infection status, across geographies and can even distinguish recent Typhoid infection among children in endemic areas. Based on these observations, a simple binding-based assay was developed that can rapidly, sensitively, and specifically detect changes in Mtb-specific antibody glycosylation from a small sample volume offering an opportunity for the first time to develop an antigen-specific antibody glycosylation diagnostic for pediatric TB from a microliter-scale sample. Given that HIV+, HEU, or unexposed children may target distinct Mtb antigens, here we have assembled a multi-disciplinary team and program termed FASTER-Kids (Fc Antibody Signatures for TubERculosis in children) that will: 1) Define the landscape of Mtb-specific antibody glycosylation responses that distinguish children with TB, 2) Develop a point-of-care test that will rapidly capture these specific antibody responses and glycosylation changes from microliters of blood. Ultimately, this collaborative structure will enable the iterative improvement and development of this simple, rapid, inexpensive diagnostic to manage TB infection in young children.