title: Determination of total homocysteine in dried blood spots using high performance liquid chromatography for homocystinuria newborn screening.
abstract: BACKGROUND
  The most widely used method for newborn screening for homocystinuria (HCU) is a semi-quantitative bacterial inhibition assay for measuring methionine concentration in dried blood spots (DBS). Because this method has resulted in a number of missed cases due to many factors, we developed a high performance liquid chromatography (HPLC) method with fluorescence detection to measure total homocysteine (tHcy) in DBS which might be useful for newborn screening for HCU.
  
  
  METHODS
  One disk of DBS 3 mm in diameter was sonicated in 10 min. The extract was reduced with dithioerythritol and was derivatized with 4-aminosulfonyl-7fluoro-2,1,3-benzoxadiazole before injection into HPLC.
  
  
  RESULTS
  This method showed good linearity (r = 0.996), precision (coefficient of variation range 2.7-5%), and excellent correlation coefficient between DBS and serum tHcy, both in control (r = 0.932) and patient samples (r = 0.952). By this method, the mean tHcy concentration in DBS of preterm newborns, full-term newborns, and adults was 1.4 +/- 1.0, 2.5 +/- 1.6, and 4.9 +/- 1.5 micro mol/L, respectively. The mean tHcy DBS concentration in two cases of cystathionine-beta-synthase deficiency and one case of 5,10-methylentetrahydrofolate reductase deficiency was 22.7 +/- 2.88, 29.3 +/- 1.90, and 41.3 micro mol/L, respectively.
  
  
  CONCLUSIONS
  The present method, which is rapid, user friendly and reliable, seems applicable to newborn screening of HCU in place of methionine measurement.
authors.affiliation: Department of Pediatrics, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan. afebriani@hotmail.com
authors.forename: Andi Dwi Bahagia
authors.initials: AD
authors.lastname: Febriani
authors.forename: Akiko
authors.initials: A
authors.lastname: Sakamoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ono
authors.forename: Nobuo
authors.initials: N
authors.lastname: Sakura
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ueda
authors.forename: Chiyoko
authors.initials: C
authors.lastname: Yoshii
authors.forename: Miho
authors.initials: M
authors.lastname: Kubota
authors.forename: Junko
authors.initials: J
authors.lastname: Yanagawa
mesh_terms: D000704:Analysis of Variance; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005453:Fluorescence; D006710:Homocysteine / Q000097:blood*; D006712:Homocystinuria / Q000097:blood / Q000517:prevention & control*; D006801:Humans; D007231:Infant, Newborn; D016014:Linear Models; D015997:Neonatal Screening / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D006710:Homocysteine