Monocyte HLA-DR in sepsis: shall we stop following the flow?

The best marker for the monitoring of immune alterations in critically ill patients (sepsis, trauma, pancreatitis, surgery, burns) so far remains decreased HLA-DR expression on monocytes measured by flow cytometry as it regularly provides valuable information in terms of mortality prediction or evaluation of risk for secondary infections. As shown by Cajander and colleagues in a recent issue of Critical Care, some promising tools-based molecular biology may circumvent some drawbacks related to flow cytometry. Herein, issues and perspectives about this alternative are discussed.