1 / 34

Svårigheter att bestämma HbA1c

Svårigheter att bestämma HbA1c. Jan-Olof Jeppsson Klinisk Kemi Universitetssjukhuset MAS Malmo. HbA1c + Glukos. Pre-HbA1c. HbA1c. Glykering av Hemoglobin. Maillard reaction. Agenda. Kortfattad biokemisk bakgrund IFCC referenssystem Internationella jämförelser.

xenon
Télécharger la présentation

Svårigheter att bestämma HbA1c

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Svårigheter att bestämma HbA1c Jan-Olof Jeppsson Klinisk Kemi Universitetssjukhuset MAS Malmo

  2. HbA1c + Glukos Pre-HbA1c HbA1c Glykering av Hemoglobin Maillard reaction

  3. Agenda • Kortfattad biokemisk bakgrund • IFCC referenssystem • Internationella jämförelser

  4. Glycation sites of Hemoglobin N-terminal valinered HbA1c Lysinegreen Glycated Hemoglobin Glutathione HbA3 or HbA1d

  5. Importtant landmarks • Diabetes Control and Complications Trial (DCCT)NEJM 1993;329:977-86 • UK Prospective Diabetes Study Group (UKPDS)BMJ 2000;321:405-11

  6. HbA1c och risk för komplikationer % HbA1c (IFCC)

  7. Harmonisation of HbA1cDesignated Comparison Methods (DCM) • National Glycohemoglobin Standardization Program(NGSP) for DCCT in USA • Mono S ion exchange chromatography (EQUALIS) in Sweden

  8. BioRex 70 Ion Exchange Chromatography HbA1c HbA0 HbA1c HbA0 Reference interval 4-6% Goldstein et al in Clark WL,Larner J, Pohl SL eds Methods of Diabetes Research Vol 2; 1986:475-504

  9. Ion Exchange Chromatography of HbA1c • Mono S chromatography • Reference interval3.6 - 5.0 % < 50 years4.0 - 5.3 % > 50 years HbA0 HbA1c

  10. Contents of the HbA1c peak ( Mono S) 99

  11. Correlation between HbA1c and MPG Rohlfing C et alDiabets Care 2002;25:S33-49

  12. Correlation between HbA1c och fB-Glucose 20-88 years, n=255 <50 y >50y fB-Glucose mmol/l % HbA1c Bäck S-E et al CCLM 1999;37:573-92

  13. Biological Variation of HbA1cIntra- and inter individual variation at non-diabetes Rohlfing C et al Clin Chem 2002;48:111618

  14. Årstidsvariation av HbA1c Data från Dr Bent Lind KPLL, Köpenhamn

  15. Hb A1c response over time Tamara Y, Shima K. Diabetes Care 1995;18:440-7

  16. 70-årig kvinna med diabetes % HbA1c Socialstyrelsens rekommenderade behandlingsmål Icke diabetiker Månader

  17. Filter paper for HbA1c produced in SwedenDiabetes Care 1996; 19(2):142-45

  18. Referenssystem för HbA1cIFCC arbetsgrupp • Definition av analyt • Preparation av rent HbA1c och HbA0 • Utveckling av referensmetod • Etablering av nätverk, 14 internationella laboratorier • Jämförande studier mellan USA, Sverige och Japan samt alla tillverkare av reagenser

  19. Major Glycation sites of Hemoglobin b-Chains: Yellow a-Chains: Blue N-terminal Valine: Red Hexapeptide Red/Green

  20. Electrospray ionisation mass spectrometry of HbA1c 15126 Da Non-glycated a-chain 16028 Da Mono-glycated b-chain Finke et al Clin Chem Lab Med. 1998;36(5):299-308

  21. Electrospray ionisation mass spectrometry of HbA0 15125 Da Non-glycated a-chain 15866 Da Non-glycated b-chain

  22. Hemolysate EnzymaticCleavage HPLC-Capillary Electrophoresis HPLC-Mass Spectrometry Flow Chart for Reference Methods Clin Chem Lab Med 2002;40:78-89 Accepted by Scientific Division, IFCC, July 2001

  23. Proteolytic Cleavage of b-chainby Endoproteinase Glu-C VHLTPE E KSAVTALWGKVNVDE VGGE ALGRLLVVYPWTQRFFE SFGDLSTPDAVMGNPKVKAHGKKVLGAFS DGLAHLDNLKGTFATLSE LHCDKLHVDPE NFRLLGNVLVCVLAHHFGKE FTPPVQAAYQKVVAGVANALAHKYH

  24. Proteolytic cleavage of b-chain (146 amino acids) Glu-C HbAo-peptide ……... Val His Leu Thr Pro Glu Glu Lys Ser HbA1c-peptide ……... Glc Val His Leu Thr Pro Glu Glu Lys Ser The Analytical Challenge

  25. Photometric detection of peptides

  26. Two-dimensional separation ofN-terminal hexapeptides of hemoglobin Capillary Electrophoresis C 18 Chromatography Non-glycated hexapeptide Glycated hexapeptide

  27. IFCC Working group for standardization of HbA1c

  28. Comparison between the IFCC reference method and three designated comparison methods 12,00 NGSP = 0,92xIFCC + 2,15 10,00 8,00 NGSP Mono-S DSM JDS 6,00 Mono S = 0,989xIFCC+0.88 4,00 JDS = 0,927xIFCC+1,73 2,00 0,00 0,00 2,00 4,00 6,00 8,00 10,00 12,00 % HbA1c IFCC method Hölzel et al Clin Chem 2004;50:166-74

  29. Kvalitetssäkring av HbA1c i USACollage of American Pathologist

  30. IFCC Monitoring Program for HbA1c Year 2006

  31. Sammanfattning • IFCC systemet utgör en ny global HbA1c standard för tillverkare av reagenser • DCM nätverken NGSP och EQUALIS ska vara spårbara till IFCC nätverkslaboratorier • Tillverkare och användare behåller sina nuvarande enheter tills studien - sambandet mellan HbA1c och MBG är utvärderad

  32. Acknowledgements Clinical Chemistry, UMAS Malmö Anna Arnetorp, Benny Larsson Ann-Christin Mårtensson, May-Lill Svensson EQUALIS, Uppsala Marie Lundberg Arne Mårtensson Gunnar Nordin

More Related