title: Point-of-Care Quantitative Measure of Glucose-6-Phosphate Dehydrogenase Enzyme Deficiency.
abstract: OBJECTIVE
  Widespread newborn screening on a point-of-care basis could prevent bilirubin neurotoxicity in newborns with glucose-6-phosphate dehydrogenase (G6PD) deficiency. We evaluated a quantitative G6PD assay on a digital microfluidic platform by comparing its performance with standard clinical methods.
  
  
  METHODS
  G6PD activity was measured quantitatively by using digital microfluidic fluorescence and the gold standard fluorescence biochemical test on a convenience sample of 98 discarded blood samples. Twenty-four samples were designated as G6PD deficient.
  
  
  RESULTS
  Mean ± SD G6PD activity for normal samples using the digital microfluidic method and the standard method, respectively, was 9.7 ± 2.8 and 11.1 ± 3.0 U/g hemoglobin (Hb), respectively; for G6PD-deficient samples, it was 0.8 ± 0.7 and 1.4 ± 0.9 U/g Hb. Bland-Altman analysis determined a mean difference of -0.96 ± 1.8 U/g Hb between the digital microfluidic fluorescence results and the standard biochemical test results. The lower and upper limits for the digital microfluidic platform were 4.5 to 19.5 U/g Hb for normal samples and 0.2 to 3.7 U/g Hb for G6PD-deficient samples. The lower and upper limits for the Stanford method were 5.5 to 20.7 U/g Hb for normal samples and 0.1 to 2.8 U/g Hb for G6PD-deficient samples. The measured activity discriminated between G6PD-deficient samples and normal samples with no overlap.
  
  
  CONCLUSIONS
  Pending further validation, a digital microfluidics platform could be an accurate point-of-care screening tool for rapid newborn G6PD screening.
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, California; bhutani@stanford.edu.
authors.forename: Vinod K
authors.initials: VK
authors.lastname: Bhutani
authors.affiliation: Faculty of Medicine of the Hebrew University, Jerusalem, Israel;
authors.forename: Michael
authors.initials: M
authors.lastname: Kaplan
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, California;
authors.forename: Bertil
authors.initials: B
authors.lastname: Glader
authors.affiliation: Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina;
authors.forename: Michael
authors.initials: M
authors.lastname: Cotten
authors.affiliation: Advanced Liquid Logic, Durham, North Carolina; and.
authors.forename: Jairus
authors.initials: J
authors.lastname: Kleinert
authors.affiliation: Baebies, Inc, Durham, North Carolina.
authors.forename: Vamsee
authors.initials: V
authors.lastname: Pamula
mesh_terms: D000328:Adult; D002648:Child; D005260:Female; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000175:diagnosis*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D000067716:Point-of-Care Testing