title: Is automated kinetic measurement superior to end-point for advanced oxidation protein product?
abstract: BACKGROUND
  Advanced oxidation protein product (AOPP) was first described as an oxidative protein marker in chronic uremic patients and measured with a semi-automatic end-point method. Subsequently, the kinetic method was introduced for AOPP assay. We aimed to compare these two methods by adapting them to a chemistry analyzer and to investigate the correlation between AOPP and fibrinogen, the key molecule responsible for human plasma AOPP reactivity, microalbumin, and HbA1c in patients with type II diabetes mellitus (DM II). The effects of EDTA and citrate-anticogulated tubes on these two methods were incorporated into the study.
  
  
  METHODS
  This study included 93 DM II patients (36 women, 57 men) with HbA1c levels > or = 7%, who were admitted to the diabetes and nephrology clinics. The samples were collected in EDTA and in citrate-anticoagulated tubes. Both methods were adapted to a chemistry analyzer and the samples were studied in parallel.
  
  
  RESULTS
  In both types of samples, we found a moderate correlation between the kinetic and the endpoint methods (r = 0.611 for citrate-anticoagulated, r = 0.636 for EDTA-anticoagulated, p = 0.0001 for both). We found a moderate correlation between fibrinogen-AOPP and microalbumin-AOPP levels only in the kinetic method (r = 0.644 and 0.520 for citrate-anticoagulated; r = 0.581 and 0.490 for EDTA-anticoagulated, p = 0.0001).
  
  
  CONCLUSIONS
  We conclude that adaptation of the end-point method to automation is more difficult and it has higher between-run CV% while application of the kinetic method is easier and it may be used in oxidative stress studies.
authors.forename: Osman
authors.initials: O
authors.lastname: Oguz
authors.forename: Berrin Bercik
authors.initials: BB
authors.lastname: Inal
authors.forename: Turker
authors.initials: T
authors.lastname: Emre
authors.forename: Oguzhan
authors.initials: O
authors.lastname: Ozcan
authors.forename: Esma
authors.initials: E
authors.lastname: Altunoglu
authors.forename: Gokce
authors.initials: G
authors.lastname: Oguz
authors.forename: Cigdem
authors.initials: C
authors.lastname: Topkaya
authors.forename: Guvenc
authors.initials: G
authors.lastname: Guvenen
mesh_terms: D000328:Adult; D062107:Advanced Oxidation Protein Products / Q000097:blood*; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001774:Blood Chemical Analysis / Q000379:methods* / Q000592:standards*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D005260:Female; D006801:Humans; D007700:Kinetics; D016014:Linear Models; D008297:Male; D008875:Middle Aged
chemical_list: D062107:Advanced Oxidation Protein Products; D015415:Biomarkers