Proteomic analysis of supernatants of stored red blood cell products

BACKGROUND: The development of the red blood cell (RBC) storage lesion remains incompletely understood. To gain a greater insight into the mechanisms involved, a proteomics analysis was used to identify proteins that accumulate in supernatants of standard nonleukoreduced RBC products (S-RBCs) and prestorage leukofiltered RBC products (LF-RBCs) during storage. STUDY DESIGN AND METHODS: S-RBCs and LF-RBCs were collected and stored in accordance with standard blood bank procedures. Supernatant samples were collected at fortnightly intervals until product expiry (at Day 42). Maps of supernatant proteins were generated by two-dimensional (2D)-gel electrophoresis and selected proteins were identified by mass spectrometry. RESULTS: 2D-gel mapping revealed that greater numbers of proteins accumulated in supernatants of S-RBCs compared to LF-RBCs. Abundant plasma proteins were strongly represented in both products. Several potentially bioactive proteins were found to predominantly accumulate in supernatant of S-RBCs. Among these, a promoter of neutrophil adhesion and an acute-phase scavenger protein were identified. In contrast, proteins found to accumulate predominantly in supernatant of LF-RBCs were RBC-regulatory proteins. CONCLUSION: Proteomics provides a valuable approach to examine storage-related effects on RBCs. Such analytical approaches may help to elucidate the mechanisms involved in the RBC storage lesion and provide insights into the biologic consequences of transfusion of stored RBC products.