Worldwide there are about 1.7 billion individuals with latent tuberculosis infection (LTBI) and only 5% to 15% will develop active tuberculosis (TB). It is recommended to treat only those most at risk of developing active TB to avoid problems of drug resistance. LTBI diagnosis involves reviewing the individual’s medical history, physical examination, and biological tests. Interferon gamma release assays (IGRA) can yield “undeterminate” or “uncertain” results, which makes clinical management decisions difficult. We assessed an ultra-sensitive immunoassay prototype based on single molecule array (SiMoA) technology to evaluate its overall performance, and in particular, its performance for indeterminate and uncertain positive or negative samples, as classified by the results from the current ELISA technique used for IFNγ quantification. We analyzed samples from hospitalized or consulting patients and healthcare workers from three hospitals in Paris, previously classified as negative (n = 30), positive (n = 35), uncertain negative (n = 25), uncertain positive (n = 31), or indeterminate (n = 30). We observed that with the SiMoA assay 83.3% of the indeterminate samples became interpretable and could be classified as negative, whereas 74% of uncertain positive samples were classified as positive. Most uncertain negative samples (72%) were reclassified as uncertain positive (68%) or positive (4%). The results suggest that the ultra-sensitive SiMoA IFNγ assay could represent a useful tool for the identification of true positive and negative samples among those giving indeterminate or uncertain results with the TB IGRA assay currently used.

中文翻译：

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评估潜伏性肺结核诊断的超灵敏IFNγ免疫分析原型。

在世界范围内，约有17亿人患有潜伏性结核感染（LTBI），只有5％至15％会发展为活动性结核（TB）。建议仅治疗那些最有可能发展为活动性结核病的人，以避免产生耐药性问题。LTBI诊断包括检查个人的病史，体格检查和生物学检查。干扰素γ释放测定（IGRA）可能产生“不确定”或“不确定”的结果，这使临床管理决策变得困难。我们评估了一种基于单分子阵列（SiMoA）技术的超灵敏免疫分析原型，以评估其整体性能，尤其是其对于不确定和不确定的阳性或阴性样品的性能，该性能按目前用于ELISA方法的结果分类IFNγ定量。n = 30），正数（n = 35），不确定的负数（n = 25），不确定的正数（n = 31）或不确定的（n = 30）。我们观察到，通过SiMoA分析，不确定的样品中有83.3％可以解释，可以归为阴性，而不确定的阳性样品中有74％被归为阳性。大多数不确定的阴性样品（72％）被重新分类为不确定的阳性（68％）或阳性（4％）。结果表明，超灵敏的SiMoAIFNγ测定法可以作为一种有用的工具，用于在使用当前使用的TB IGRA测定法得出不确定或不确定结果的样品中鉴定真实的阳性和阴性样品。