A Serological Assay for Neutralizing Antitoxin Response in Patients with Clostridioides difficile Infection (Phase II)

摘要 该SBIR第二阶段项目将支持体外诊断血液测试的开发，以确定 一个感染艰难梭菌的人是否有足够的中和抗毒素抗体， 他们不太可能复发。抗生素抗性C. difficile造成超过29，000人死亡 美国每年有1000人死亡，这种感染对全世界的公共卫生构成紧迫威胁。当前 抗生素的标准治疗破坏了肠道微生物群，并导致高复发率，这是 这是疾病临床管理中最重要的问题。C.艰难梭菌感染（CDI）主要由两种 主要的外毒素和毒素中和抗体负责有效的免疫。但目前的 测量患者抗毒素应答的测定基于细胞培养物中和生物测定， 消耗、费力且难以标准化，因此这种生物测定在研究实验室中受到限制。在我们 在SBIR I期（R43 AI 136176）研究中，我们成功建立了一种简单快速的血清学ELISA， 命名为BB-ELISA，并证明BB-ELISA能够测量抗毒素中和 CDI血液样本中的活性。基于这些有希望的结果，我们建议标准化这种新的BB- 通过经验丰富的CRO Corgenix进行ELISA，并与默克合作评估用于预测的测定方法 CDI疾病复发和结局。第二阶段SBIR的完成不仅将验证这一新的 ELISA用于测量CDI患者的中和抗体应答和预测疾病结局，但 也为这种新型ELISA测定的未来商业化铺平了道路。

Abstract This SBIR Phase II project will support the development of an in vitro diagnostic blood test to determine whether a person infected with Clostridioides difficile has mounted enough neutralizing antitoxin antibodies so that they are unlikely to suffer recurrence. Antibiotic-resistant C. difficile is responsible for more than 29,000 deaths in the US each year and the infection is an urgent threat to public health worldwide. The current standard treatment with antibiotics disrupts gut microbiota and induces high rates of recurrence, which is the most significant issue in clinical management of the disease. C. difficile infection (CDI) is mainly caused by two major exotoxins, and toxin-neutralizing antibodies are responsible for effective immunity. However, current assays to measure patient antitoxin responses are based on cell-culture neutralizing bioassay that is time consuming, laborious, and difficult to standardize, thus such bioassay is limited in research laboratories. In our SBIR Phase I (R43AI136176) study, we successfully established a simple and rapid serological ELISA, designated as BB-ELISA, and demonstrated that the BB-ELISA was able to measure antitoxin neutralizing activities in CDI blood samples. Based on these promising results, we propose to standardize this novel BB- ELISA through an experience CRO Corgenix and to collaborate with Merck to evaluate the assay for predicting CDI disease recurrence and outcomes. The completion of this Phase II SBIR will not only validate this novel ELISA for measuring neutralizing antibody responses in CDI patients and predicting disease outcomes, but also pave the way toward future commercialization of this novel ELISA assay.