Comparison of thiamin diphosphate high-performance liquid chromatography and erythrocyte transketolase assays for evaluating thiamin status in malaria patients without beriberi

Abstract

Copyright © 2020 by The American Society of Tropical Medicine and Hygiene. 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 Plasmodium falciparum 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 (a) 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 a ≥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 twotests (Kendall's tau=-0.212, P < 0.001).Basal ETK activitywas also significantly positively correlatedwith TDP levels (Kendall's tau = 0.576, P < 0.001). Thiamin diphosphate measurement may have a role inmeasuring thiamin levels in clinical settings. Further studies evaluating TDP concentration in erythrocytes with basal ETK activity and ETKA (a) in beriberi patients would help establish comparative values of these assays.