Hypoxia-inducible factor (HIF1α) gene expression in human shock states

INTRODUCTION Hypoxia-inducible factor-1 (HIF1) controls the expression of genes involved in the cellular response to hypoxia. No information is available on its expression in critically ill patients. Thus, we designed the first clinical study in order to evaluate the role of HIF1α as a prognosis marker in patients with shock. METHODS 50 consecutive adult patients with shock and 11 healthy volunteers were prospectively included. RNA was extracted from whole blood samples and expression of HIF1α was assessed over the first 4 hours of shock. The primary objective was to assess HIF1α as a prognostic marker in shock. Secondary objectives were to evaluate the role of HIF1α as a diagnostic and follow-up marker. Patient survival was evaluated at day 28. RESULTS The causes of shock were sepsis (78%), hemorrhage (18%), and cardiac dysfunction (4%). The HIF1α expression was significantly higher in the shock patients than in the healthy volunteers (121 [72-168] vs. 48 [38-54] normalized copies, p < 0.01), whatever the measured isoforms. It was similar in non-survivors and survivors (108 [range 84-183] vs. 121 [range 72-185] normalized copies, p = 0.92), and did not significantly change within the study period. CONCLUSIONS The present study is the first to demonstrate the increased expression of HIF1α in patients with shock. Further studies are needed to clarify the potential association with outcome. Our findings reinforce the value of monitoring plasma lactate levels to guide the treatment of shock.