e-ISSN 2329-0072




Analytical problems in the measurement of tumor type Pyruvate Kinase (Tumor M2-PK)

Christina Gutjahr, Christiane Hansen, Hildegund Sauer-Eppel, Gerhard M Oremek

Med Sci Tech 2009; 50(2): RA77-80

ID: 881668

Available online:

Published: 2009-03-22

Introduction: Tumor M2-PK is an isoform of the glycolytic enzyme pyruvate kinase. This isoform exists in an active tetrameric and less active dimeric form. The dimeric form is expressed by various tumor cells and can be measured in blood by a specific ELISA. Material and methods: We included 500 healthy persons, 30 patients with an acute rheumatic disease (high CRP), and 50 patients with a nephropathy and proteinuria with more than 20 mg/dl. We measured Tumor M2-PK in each of these groups in different specimen of EDTA-plasma, serum, heparine-, citrate-, fluoride- and oxalateplasma. Results: We found different concentration of Tumor M2-PK in healthy persons depending on the kind of specimen. The normal range of Tumor M2-PK concentration was higher in serum than in plasma with 35 U/l compared to 15 U/l. In haemolytic material we found concentrations up to 80 U/l in healthy persons. Lipaemic or icteric serum material showed higher concentration of Tumor M2-PK as well. In patients with triglycerid concentration higher than 300mg/dl the normal range for Tumor M2-PK was measured between 30-50U/l. Similar results were found in patients with icteric serum. Patients with an active rheumatic disease and elevated CRP concentration showed Tumor M2-PK concentration between 40-60 U/l. Patients with a nephropathy and proteinuria over 20 mg/dl have elevated Tumor M2-PK concentration from 25-60 U/l. Conclusions: We conclude that different materials seem to be suitable for measurement of Tumor M2-PK concentration as far as attention is payed to different normal ranges. Haemolytic material should not be used as it offers false positive results. Some diseases as rheumatic disease, hyperlipidaemia and nephropathy have a non- neglectable influence on Tumor M2-PK concentration. (Clin Exp Med Lett 2009; 50(2):77-80)

Keywords: Tumor M2-PK, lipaemic, icteric or haemolytic material, nephropathy and proteinuria, rheumatic disease