Biological markers of injury-induced immunosuppression

Severe injuries such as severe sepsis, burn, trauma and major surgery lead to an overlapping development of pro- and anti- inflammatory responses. It is now well established that these injuries are associated with the secondary development of immune suppression, which results in significant morbidity and mortality. Recent data suggest that immunostimulatory drugs might prevent these complications. However, intensive care patients are heterogeneous, making patient stratification essential for a targeted treatment. In the present review, we discuss potential biomarkers of injury-induced immunoparalysis, mainly focusing on these that have been associated with poor outcome in various clinical settings. We namely present clinical data on monocyte human leukocyte antigen DR, lymphopenia, PD-1/PD-L1 and transcriptomic approach.