Identification of Apolipoprotein AI as a serum biomarker of chronic kidney disease in liver transplant recipients, using proteomic techniques

• Published in: Proteomics. Clinical applications 2008-09, Vol.2 (9), p.1338-1348
• Main Authors: O'Riordan, Aisling, Johnston, Olwyn, McMorrow, Tara, Wynne, Kieran, Maguire, Patricia, Hegarty, John E., McCormick, Aidan, Watson, Alan J., Cagney, Gerard, Gallagher, William M., Ryan, Michael P.
• Format: Article
• Language: English
• Subjects: Chronic kidney disease; ESI-LC-MS/MS; Orthotopic liver transplantation; SELDI-TOF-MS; Serum biomarkers
• ISSN: 1862-8346; 1862-8354
• DOI: 10.1002/prca.200780167

Chronic kidney disease (CKD) is a common complication post‐orthotopic liver transplantation (OLT). Development of CKD is detected by monitoring serum urea and creatinine, however disease can occasionally be at an advanced stage before they become abnormal. Therefore, more accurate parameters are required. In order to identify novel biomarkers of CKD, serum was obtained from 47 OLT recipients with CKD (glomerular filtration rate 90 mL/min). Using the proteomic technique SELDI‐TOF‐MS, three protein biomarkers (55.6 kDa, 9.5 kDa and 11.4 kDa) were identified that, together, could stratify patients into cases or controls with a sensitivity and specificity of 93.6 and 91.3%, respectively. The area under the curve was 0.94. The primary splitter of the groups at 55.6 kDa was an alternative version of a molecule at 27.8 kDa, which was subsequently identified by 1‐D SDS‐PAGE and LC‐ESI‐MS/MS to be Apolipoprotein AI. Protein expression was shown to be reduced in CKD, by both ELISA (p = 0.057) and Western blot analysis (p = 0.003). Apolipoprotein AI is a novel, accurate marker of CKD post‐OLT. It does require further validation in a large, more diverse patient population but could potentially improve detection of CKD.