MicroRNA fingerprints identify miR-150 as a plasma prognostic marker in patients with sepsis

The physiopathology of sepsis is still poorly understood and, despite recent advances in its management, this is a life threatening condition that represents the major cause of death among critically ill patients in Intensive Care Units (ICU). Therefore, there is a need for diagnostic markers related to pathogeny, useful for the development of new specific therapies. Since small non-coding RNAs named microRNAs (miRNAs) were recently linked to various human diseases, we aimed at the identification of miRNAs that could differentiate sepsis patients at early stages and eventually correlate with the ICU score. By genome-wide expression profiling in leukocytes and quantitative RT-PCR on plasma samples, we found that miR-150, miR-182, miR-342-5p and miR-486 expression could differentiate sepsis patients from healthy controls. In addition, we found that plasmatic level of miR-150 is significantly reduced in sepsis patients and correlates with the level of severity measured by the SOFA score. We also found that plasma levels of TNF-alpha, IL-10 and IL-18, genes with complementarity to miR-150 sequence, exhibited a negative correlation with plasma levels of this miRNA. Therefore, we propose that miR-150 levels in both leukocytes and plasma correlates with the aggressivity of sepsis after surgery and can be used as an early marker of sepsis.