title: K2-EDTA and K3-EDTA Greiner Tubes for HbA1c Measurement.
abstract: OBJECTIVE
  To determine whether K2-ethylenediaminetetraacetic acid (EDTA) and K3-EDTA Greiner tubes could be used interchangeably for glycosylated hemoglobin, type A1C (HbA1c) measurement via the Abbott Laboratories ARCHITECT chemiluminescent microparticle HbA1c assay on the ARCHITECT i2000SR immunoanalyzer at our university hospital.
  
  
  METHODS
  We drew blood from a total of 45 outpatients into plastic Greiner Vacuette tubes, some of which were lined with K2-EDTA and others with K3-EDTA anticoagulant. Data are presented as median and interquartile range values. We used the Wilcoxon test and Passing-Bablok regression for tube comparison.
  
  
  RESULTS
  For K2-EDTA tubes median HbA1c concentration was 54 mmol/mol (41 to 71 mmol/mol) and for K3-EDTA tubes 56 mmol/mol (43 to 69 mmol/mol). There was no statistically significant difference between K2-EDTA and K3-EDTA (bias= -1.29 mmol/mol; P = 0.24). Passing-Bablok regression showed that there is no constant and proportional error: y = -0.23 (95% CI[-3.52 to 0.69]) + 1.00( 95% CI[0.98 to 1.06]) x.
  
  
  CONCLUSIONS
  In this study, we provide evidence for the lack of any clinically and statistically significant bias between K2-EDTA and K3-EDTA HbA1c measurements. Thus, Greiner tubes lined with K2-EDTA and those lined with K3-EDTA can safely be used interchangeably to measure HbA1c via the Abbott Laboratories ARCHITECT assay.
authors.affiliation: University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice, Zagreb, Croatia alenvrtaric@gmail.com.
authors.forename: Alen
authors.initials: A
authors.lastname: Vrtaric
authors.affiliation: University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice, Zagreb, Croatia.
authors.forename: Petra
authors.initials: P
authors.lastname: Filipi
authors.affiliation: University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice, Zagreb, Croatia.
authors.forename: Marina
authors.initials: M
authors.lastname: Hemar
authors.affiliation: University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice, Zagreb, Croatia.
authors.forename: Nora
authors.initials: N
authors.lastname: Nikolac
authors.affiliation: University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice, Zagreb, Croatia.
authors.forename: Ana-Maria
authors.initials: AM
authors.lastname: Simundic
mesh_terms: D000925:Anticoagulants / Q000494:pharmacology; D003920:Diabetes Mellitus / Q000175:diagnosis*; D003955:Diagnostic Tests, Routine / Q000379:methods*; D006442:Glycated Hemoglobin / Q000032:analysis*; D006785:Hospitals, University; D006801:Humans; D008163:Luminescent Measurements / Q000379:methods*; D013048:Specimen Handling / Q000379:methods*
chemical_list: D000925:Anticoagulants; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: HbA1c; K2-EDTA; K3-EDTA; method comparison; preanalytical phase; test tube comparison