Center for Advanced Biomolecular Recognition, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea.
Department of Pediatrics, CHA Bundang Medical Center, Gyeonggi-do 13496, Republic of Korea.
Clin Chim Acta. 2024 Aug 15;562:119886. doi: 10.1016/j.cca.2024.119886. Epub 2024 Jul 23.
Sitosterolemia is a rare inherited lipid metabolic disorder characterized by increased levels of plant sterols and accelerated atherosclerosis. Although early detection is beneficial for the prevention of disease progression, it is largely underdiagnosed by routine screening based on conventional lipid profiles.
A gas chromatography-mass spectrometry (GC-MS)-based profiling has been developed and validated to measure the levels of biologically active free sterols, including five endogenous sterols and three plant sterols (sitosterol, campesterol, and stigmasterol) in dried blood spot (DBS).
Within- and between-run precisions were 1.4-11.1 % and 2.2-14.1 %, respectively, while the accuracies were all 86.3 ∼ 121.9 % with the correlation coefficients (r) > 0.988 for all the sterols. In the patients (four girls and two boys, 6.5 ± 2.8 years), sitosterol levels were significantly increased, with an optimal cut-off value of 2.5 µg/mL distinguishing them from ninety-three age-matched healthy children. A cut-off value of 31.9 µg/mL differentiated the patients from six ABCG5/ABCG8 heterozygous carriers. In addition, the molecular ratios of sitosterol to cholesterol, desmosterol, and 7-dehydrocholesterol provided excellent cut-off values of 26.3, 67.6, and 21.6, respectively, to distinguish patients from both healthy controls and heterozygous carriers.
The novel DBS-based GC-MS profiling of free sterols accurately identified patients with sitosterolemia, with a performance comparable to that of a serum assay. The DBS profiling could be more feasible method in clinical practice as well as population screening programs, and it can provide diagnostic cut-off values for individual plant sterols.
植物固醇血症是一种罕见的遗传性脂代谢紊乱疾病，其特征是植物固醇水平升高和动脉粥样硬化加速。尽管早期发现有利于疾病进展的预防，但基于常规脂质谱的常规筛查，这种疾病的漏诊率很高。
开发并验证了一种基于气相色谱-质谱（GC-MS）的分析方法，用于测量干血斑（DBS）中生物活性游离固醇的水平，包括五种内源性固醇和三种植物固醇（植物固醇、菜油固醇和豆固醇）。
在 DBS 中，五种内源性固醇和三种植物固醇（植物固醇、菜油固醇和豆固醇）的日内和日间精密度分别为 1.4-11.1%和 2.2-14.1%，准确度均为 86.3∼121.9%，相关系数（r）均>0.988。在患者（四名女孩和两名男孩，6.5±2.8 岁）中，植物固醇水平显著升高，最佳截断值为 2.5μg/mL，可将其与 93 名年龄匹配的健康儿童区分开来。31.9μg/mL 的截断值可将患者与六名 ABCG5/ABCG8 杂合子携带者区分开来。此外，植物固醇与胆固醇、去甲胆固醇和 7-脱氢胆固醇的分子比值提供了出色的截断值，分别为 26.3、67.6 和 21.6，可分别将患者与健康对照者和杂合子携带者区分开来。
新型基于 DBS 的游离固醇 GC-MS 分析准确地鉴定了植物固醇血症患者，其性能与血清检测相当。与血清检测相比，DBS 分析更适合临床实践和人群筛查项目，并且可以为个体植物固醇提供诊断截断值。
