Circulating VEGF As a Biological Marker in Patients with Rheumatoid Arthritis? Preanalytical and Biological Variability in Healthy Persons and in Patients. Issue 1 (2008)

• Record Type: Journal Article
• Authors: Hetland, Merete Lund; Christensen, Ib Jarle; Lottenburger, Tine; Johansen, Julia Sidenius; Svendsen, Mads Nordahl; Hørslev-Petersen, Kim; Nielsen, Lone; Jørgen Nielsen, Hans
• Is Part Of: Disease markers. Volume 24:Issue 1(2008)
• Page Start: 1
• Page End: 10
• Publication Date: 2008
• Subjects: Diagnosis -- Periodicals; Biochemical markers -- Periodicals; Pathology -- Periodicals; 616
• DOI: 10.1155/2008/707864
• Languages: English
• ISSNs: 0278-0240

Abstract

Abstract : Background : Soluble vascular endothelial growth factor (VEGF) is a promising biomarker in monitoring rheumatoid arthritis (RA), but studies of pre-analytical and biologic variability are few. Methods : VEGF was measured by ELISA methods in serum and plasma from healthy persons and RA patients. Pre-analytical factors were investigated. A reference interval for VEGF was established in serum and plasma from 306 healthy persons. Diurnal, day-to-day, week-to-week, long-term variability, and impact of exercise were evaluated. Results : Delayed processing time, room temperature, low centrifugal force and contamination of plasma with cellular elements lead to significant increases in VEGF levels, whereas storage for up to 2 years at −80°C or up to 10 freeze/thaw cycles did not affect VEGF levels. Serum VEGF levels were 7–10 fold higher than plasma VEGF levels. Reference intervals for VEGF (plasma: 45 pg/ml (range: non-detectable to 352); serum: 328 pg/ml (53–1791)) were independent of gender and age. Short- and long-term biologic variability included diurnal variation (sampling should take place after 7 AM) and impact of exercise (increased VEGF immediately after bicycling normalised within 1 hour). Conclusions : Pre-analytical factors and biologic variability including diurnal variation and impact of exercise should be accounted for in future studies that include circulating VEGF as a biological marker.