Abstract:
Red blood cells (RBCs) become sickle-shaped and stiff under hypoxia as a consequence of hemoglobin (Hb) polymerization in sickle cell anemia. Distinguishing between sickle cell disease and trait is crucial during the diagnosis of sickle cell disease. While genetic analysis or high-performance liquid chromatography (HPLC) can accurately differentiate between these two genotypes, these tests are unsuitable for field use. Here, we report a novel microscopy-based diagnostic test called ShapeDx™ to distinguish between disease and trait blood in less than 1 h. This is achieved by mixing an unknown blood sample with low and high concentrations of a chemical oxygen scavenger and thereby subjecting the blood to slow and fast hypoxia, respectively. The different rates of Hb polymerization resulting from slow and fast hypoxia lead to two distinct RBC shape distributions in the same blood sample, which allows us to identify it as healthy, trait, or disease. The controlled hypoxic environment necessary for differential Hb polymerization is generated using an imaging microchamber, which also reduces the sickling time of trait blood from several hours to just 30 min. In a single-blinded proof-of-concept study conducted on a small cohort of clinical samples, the results of the ShapeDx™ test were 100% concordant with HPLC results. Additionally, our field studies have demonstrated that ShapeDx™ is the first reported microscopy test capable of distinguishing between sickle cell disease and trait samples in resource-limited settings with the same accuracy as a gold standard test.
摘要:
在镰状细胞性贫血中,由于血红蛋白(Hb)聚合,红细胞(RBC)在缺氧下会变成镰状和僵硬。在镰状细胞病的诊断过程中,区分镰状细胞病和性状至关重要。虽然基因分析或高效液相色谱(HPLC)可以准确区分这两种基因型,这些测试不适合现场使用。这里,我们报告了一种名为ShapeDx™的新型基于显微镜的诊断测试,可在不到1小时的时间内区分疾病和特征血液。这是通过将未知的血液样本与低浓度和高浓度的化学氧清除剂混合,从而使血液经受缓慢和快速的缺氧来实现的。分别。缓慢和快速缺氧导致的Hb聚合速率不同导致相同血液样本中两种不同的红细胞形状分布。这让我们认为它是健康的,性状,或疾病。使用成像微室产生差分Hb聚合所需的受控低氧环境,这也将性状血液的腌制时间从几个小时缩短到30分钟。在对一小部分临床样本进行的单盲概念验证研究中,ShapeDx™测试的结果与HPLC结果100%一致。此外,我们的现场研究表明,ShapeDx™是第一个报道的显微镜测试,能够在资源有限的环境中区分镰状细胞病和性状样本,其准确性与黄金标准测试相同.