title: Erythrocyte transketolase activity, markers of cardiac dysfunction and the diagnosis of infantile beriberi.
abstract: BACKGROUND
  Infantile beriberi is a potentially lethal manifestation of thiamin deficiency, associated with traditional post-partum maternal food avoidance, which persists in the Lao PDR (Laos). There are few data on biochemical markers of infantile thiamin deficiency or indices of cardiac dysfunction as potential surrogate markers.
  
  
  RESULTS
  A case control study of 47 infants with beriberi and age-matched afebrile and febrile controls was conducted in Vientiane, Laos. Basal and activated erythrocyte transketolase activities (ETK) and activation (α) coefficients were assayed along with plasma brain natriuretic peptide, N-terminal pro-brain natriuretic peptide and troponin T. Basal ETK (and to a lesser extent activated ETK) and plasma troponin T were the only infant biochemical markers that predicted infantile beriberi. A basal ETK ≤ 0.59 micromoles/min/gHb gave a sensitivity (95%CI) of 75.0 (47.6 to 92.7)% and specificity (95%CI) of 85.2 (66.3 to 95.8)% for predicting infantile beriberi (OR (95%CI) 15.9 (2.03-124.2); p = 0.008) (area under ROC curve = 0.80). In contrast, the α coefficient did not discriminate between cases and controls. Maternal basal ETK was linearly correlated with infant basal ETK (Pearson's r = 0.66, p < 0.001). The odds of beriberi in infants with detectable plasma troponin T was 3.4 times higher in comparison to infants without detectable troponin T (OR 3.4, 95%CI 1.22-9.73, p = 0.019). Detectable troponin T had a sensitivity (95%CI) of 78.6 (59.0 to 91.7) % and specificity (95%CI) of 56.1 (39.7 to 71.5) % for predicting infantile beriberi.
  
  
  CONCLUSIONS
  Basal ETK is a more accurate biochemical marker of infantile beriberi than the activation coefficient. Raised plasma troponin T may be a useful indicator of infantile beriberi in infants at risk and in the absence of other evident causes.
authors.affiliation: Wellcome Trust-Mahosot Hospital-Oxford Tropical Medicine Collaboration, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao People's Democratic Republic.
authors.forename: Douangdao
authors.initials: D
authors.lastname: Soukaloun
authors.forename: Sue J
authors.initials: SJ
authors.lastname: Lee
authors.forename: Karen
authors.initials: K
authors.lastname: Chamberlain
authors.forename: Ann M
authors.initials: AM
authors.lastname: Taylor
authors.forename: Mayfong
authors.initials: M
authors.lastname: Mayxay
authors.forename: Kongkham
authors.initials: K
authors.lastname: Sisouk
authors.forename: Bandit
authors.initials: B
authors.lastname: Soumphonphakdy
authors.forename: Khaysy
authors.initials: K
authors.lastname: Latsavong
authors.forename: Kongsin
authors.initials: K
authors.lastname: Akkhavong
authors.forename: Douangkham
authors.initials: D
authors.lastname: Phommachanh
authors.forename: Vanmaly
authors.initials: V
authors.lastname: Sengmeuang
authors.forename: Khonsavanh
authors.initials: K
authors.lastname: Luangxay
authors.forename: Theresa
authors.initials: T
authors.lastname: McDonagh
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: White
authors.forename: Paul N
authors.initials: PN
authors.lastname: Newton
mesh_terms: D001602:Beriberi / Q000150:complications / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D019411:Clinical Laboratory Techniques / Q000379:methods*; D004912:Erythrocytes / Q000201:enzymology*; D005260:Female; D006331:Heart Diseases / Q000175:diagnosis; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007812:Laos; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood; D012680:Sensitivity and Specificity; D014174:Transketolase / Q000378:metabolism*; D020107:Troponin T / Q000097:blood
chemical_list: D015415:Biomarkers; D020107:Troponin T; D020097:Natriuretic Peptide, Brain; D014174:Transketolase