Simultaneous measurement of mouse and human albumin in chimeric mice with humanized livers.

The degree of human hepatocyte replacement in chimeric mice with humanized liver has previously been shown to correlate with human plasma albumin measurements. However, there are no reports that directly compare the remaining endogenous mouse albumin with the newly expressed human albumin following engraftment. To better understand the disposition of serum albumin in PXB-mice, we developed a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to simultaneously quantitate both human and mouse albumin from plasma. A robust correlation was observed between the serum human albumin levels measured by LC-MS/MS and the estimated replacement index of PXB-mice. All data were shown to be specific and suitable to accurately quantify both human and mouse albumin from plasma of chimeric mice with humanized livers.