title: Comparison of transferrin isoform analysis by capillary electrophoresis and HPLC for screening congenital disorders of glycosylation.
abstract: BACKGROUND
  Transferrin, a major glycoprotein has different isoforms depending on the number of sialic acid residues present on its oligosaccharide chain. Genetic variants of transferrin as well as the primary (CDG) & secondary glycosylation defects lead to an altered transferrin pattern. Isoform analysis methods are based on charge/mass variations. We aimed to compare the performance of commercially available capillary electrophoresis CDT kit for diagnosing congenital disorders of glycosylation with our in-house optimized HPLC method for transferrin isoform analysis.
  
  
  METHODS
  The isoform pattern of 30 healthy controls & 50 CDG-suspected patients was determined by CE using a Carbohydrate-Deficient Transferrin kit. The results were compared with in-house HPLC-based assay for transferrin isoforms.
  
  
  RESULTS
  Transferrin isoform pattern for healthy individuals showed a predominant tetrasialo transferrin fraction followed by pentasialo, trisialo, and disialotransferrin. Two of 50 CDG-suspected patients showed the presence of asialylated isoforms. The results were comparable with isoform pattern obtained by HPLC. The commercial controls showed a <20% CV for each isoform. Bland Altman plot showed the difference plot to be within +1.96 with no systemic bias in the test results by HPLC & CE.
  
  
  CONCLUSIONS
  The CE method is rapid, reproducible and comparable with HPLC and can be used for screening Glycosylation defects.
authors.affiliation: Research Department, P.D. Hinduja National Hospital & Medical Research Centre, Mumbai, Maharashtra, India.
authors.forename: Mihika B
authors.initials: MB
authors.lastname: Dave
authors.affiliation: Research Department, P.D. Hinduja National Hospital & Medical Research Centre, Mumbai, Maharashtra, India.|Biochemistry section, Department of Laboratory Medicine, P.D. Hinduja National Hospital & Medical Research Centre, Mumbai, Maharashtra, India.
authors.forename: Alpa J
authors.identifier: http://orcid.org/0000-0002-5574-3798
authors.initials: AJ
authors.lastname: Dherai
authors.affiliation: Department of Pediatric Neurology, P.D. Hinduja National Hospital & Medical Research Centre, Mumbai, Maharashtra, India.
authors.forename: Vrajesh P
authors.initials: VP
authors.lastname: Udani
authors.affiliation: Jaslok Hospital and Research Centre, Mumbai, Maharashtra, India.
authors.forename: Anaita U
authors.initials: AU
authors.lastname: Hegde
authors.affiliation: Department of Pediatric Neurology, P.D. Hinduja National Hospital & Medical Research Centre, Mumbai, Maharashtra, India.
authors.forename: Neelu A
authors.initials: NA
authors.lastname: Desai
authors.affiliation: Research Department, P.D. Hinduja National Hospital & Medical Research Centre, Mumbai, Maharashtra, India.|Biochemistry section, Department of Laboratory Medicine, P.D. Hinduja National Hospital & Medical Research Centre, Mumbai, Maharashtra, India.
authors.forename: Tester F
authors.initials: TF
authors.lastname: Ashavaid
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D018981:Congenital Disorders of Glycosylation / Q000175:diagnosis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D020033:Protein Isoforms / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D014168:Transferrin / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D020033:Protein Isoforms; D014168:Transferrin
keywords: 
  HPLC
  ; CDT kit; capillary electrophoresis; congenital disorders of glycosylation; transferrin isoforms