1Lao Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR.
2Centre for Tropical Medicine and Global Health, Churchill Hospital, University of Oxford, Oxford, United Kingdom.
Am J Trop Med Hyg. 2020 Dec;103(6):2600-2604. doi: 10.4269/ajtmh.20-0479. Epub 2020 Sep 24.
Thiamin deficiency, or beriberi, is an increasingly re-recognized cause of morbidity and mortality in the developing world. Thiamin status has traditionally been measured through the erythrocyte activation assay (ETKA) or basal transketolase activity (ETK), which indirectly measure thiamin diphosphate (TDP). Thiamin diphosphate can also be measured directly by high-performance liquid chromatography (HPLC), which may allow a more precise estimation of thiamin status. We compared the direct measurement of TDP by HPLC with basal ETK activity and ETKA in 230 patients with malaria in rural southern Laos without overt clinical beriberi, as part of a trial of thiamin supplementation. Admission thiamin status measured by basal ETK activity and ETKA (α) were compared with thiamin status assessed by the measurement of TDP by HPLC. 55% of 230 included patients were male, and the median age was 10 (range 0.5-73) years. Using α ≥ 25% as the gold standard of thiamin deficiency, the sensitivity of TDP < 275 ng/gHb as a measure of thiamin deficiency was 68.5% (95% CI: 54.4-80.5%), with specificity of 60.8 (95% CI: 53.2-68.1%). There was a significant inverse correlation between the results of the two tests (Kendall's tau = -0.212, < 0.001). Basal ETK activity was also significantly positively correlated with TDP levels (Kendall's tau = 0.576, < 0.001). Thiamin diphosphate measurement may have a role in measuring thiamin levels in clinical settings. Further studies evaluating TDP concentration in erythrocytes with basal ETK activity and ETKA (α) in beriberi patients would help establish comparative values of these assays.
硫胺素缺乏症，或脚气病，是发展中国家发病率和死亡率日益增加的原因。硫胺素状况传统上通过红细胞激活测定法（ETKA）或基础转酮醇酶活性（ETK）来衡量，这两种方法间接测量硫胺素二磷酸（TDP）。也可以通过高效液相色谱法（HPLC）直接测量 TDP，这可能更准确地估计硫胺素状况。我们在老挝南部农村地区对 230 名无明显临床脚气病的疟疾患者进行了研究，将 HPLC 直接测量 TDP 与基础 ETK 活性和 ETKA 进行了比较，这是一项硫胺素补充试验的一部分。根据基础 ETK 活性和 ETKA（α）测量的入院硫胺素状况与通过 HPLC 测量 TDP 评估的硫胺素状况进行了比较。230 名纳入患者中 55%为男性，中位年龄为 10 岁（范围 0.5-73 岁）。使用 α≥25%作为硫胺素缺乏的金标准，TDP＜275ng/gHb 作为衡量硫胺素缺乏的指标的灵敏度为 68.5%（95%CI：54.4-80.5%），特异性为 60.8%（95%CI：53.2-68.1%）。两种检测结果之间存在显著的负相关关系（Kendall tau=-0.212，<0.001）。基础 ETK 活性与 TDP 水平也呈显著正相关（Kendall tau=0.576，<0.001）。TDP 测量可能在临床环境中测量硫胺素水平方面发挥作用。进一步研究评估脚气病患者中基础 ETK 活性和 ETKA（α）的红细胞 TDP 浓度将有助于确定这些检测方法的比较值。
