Hypoxia Inducible Factor 1 Alpha as a Novel Biomarker in Septic Shock

Sepsis is one of the most significant challenges in critical care. Septic shock (SS) is the most severe form of sepsis and is associated with higher mortality, significant financial expenses and longer lengths of stay. Pathophysiological mechanisms of SS include 3 key components: 1) bacterial overgrowth, 2) spill of bacterial product into the blood causing hemodynamic insufficiency, and 3) both lead to tissue hypoxia (TH). To date the biomarkers of sepsis/SS are limited to hemodynamic parameters. However, aggressive fluid resuscitation does not fully prevent development of tissue hypoxia (TH). To date the investigators are limited in appreciating TH by measurement of lactic acid (LA), which is neither an early nor an accurate marker. Unfortunately, LA has limited predictive value in SS due to its complex metabolism. Thus, there is an acute need for biomarkers that would aid diagnosis and prognosis of sepsis/septic shock. Cellular responses/adaptations to hypoxia rely on the transcription hypoxia-inducible factor HIF, a heterodimeric protein composed of a constitutively expressed subunit and an inducible (types 1, 2, and 3) subunit. More recently HIF was identified in diverse tissues including blood; it has been also shown that HIF expression in blood cells is representative of systemic tissues in hypoxic conditions.