- 作者：Valé ; rie Pennemans ; Liesbeth M. De Winter ; Christel Faes ; Emmy Van Kerkhove ; Carmen Reynders ; Jean-Michel Rigo ; Quirine Swennen ; Joris Penders
- 关键词：Kidney Injury Molecule 1 (KIM-1) ; pH ; Stability ; Urine ; Biomarker ; Kidney
- 刊名：Clinica Chimica Acta
- 出版年：2010
- 出版时间：14 December 2010
- 年：2010
- 卷：411
- 期：23-24
- 页码：2083-2086
- 全文大小：294 K
BackgroundUrinary KIM-1 is a novel biomarker for tubular kidney damage, however little is known about its stability. The goal of this study is to examine the effect of urinary pH on the stability of KIM-1.Methods
Urine samples were collected from 45 volunteers. Samples were aliquoted, adapted to different pH values (range 4 to 9) and stored at −80 °C. After thawing, each aliquot was divided into two, of which one was used to measure KIM-1 (human tim-1/kim-1/Havcr Elisa kit; R&D systems) at the same pH at which it was stored, while the other was readapted to pH 7 before measurement.
Results
KIM-1 values of aliquots of the same sample are stable when stored at pH 6, 7 and 8 whereas at lower and higher storage pH, KIM-1 levels decrease significantly. When samples are readjusted to a neutral pH just before KIM-1 measurement, there are no longer significant differences between KIM-1 in aliquots stored at different pH values.
Conclusions
No effect of urinary pH on the stability of KIM-1 was seen. However, the only commercially available human tim-1/kim-1/Havcr Elisa kit of RD systems is pH dependent and we therefore suggest samples should be adjusted to neutral pH before measurement.