Impact of Hydrocortisone Administration on White Blood Cell Gene Expression in Patients With Severe Sepsis

Relative Adrenal Insufficiency, Sepsis

Sepsis, Adrenal Insufficiency, Hydrocortisone, Gene Expression, Microarray, RNA, Critically Ill

The purpose of this pilot study is to (1) examine the changes in gene expression in patients who suffer from severe sepsis and whose shock (inadequate oxygen delivery to vital organs) state does not respond to fluid and vasopressor administration, (2) to show that our sampling method of isolating RNA provides reliable and consistent data, (3) provide a basis for future gene expression studies in critically ill patients

Severe sepsis is characterized by inadequate perfusion of vital organs due to infection. More than 750,000 cases of severe sepsis occur each year in the United States. Mortality among patients with severe sepsis ranges from 7% to 50%. Initiation of antibiotic therapy within the first hour of diagnosis as well as fluid resuscitation and hemodynamic stabilization are primary goals of therapy. Steroid administration has been shown to improve outcome in the subset of severe sepsis patients suffering from relative adrenal insufficiency. Although initial studies using high dose short course steroid therapy did not demonstrate efficacy, more recent studies of low dose longer duration hydrocortisone administration demonstrated a significant reduction in mortality at 28 days. The mechanism by which steroid administration affords protection is unclear. We hypothesize that steroid administration changes white blood cell gene and protein expression in severe sepsis patients from an immuno-inflammatory profile to a pattern consistent with healing. Our first specific aim is to obtain plasma and total cellular RNA from leukocytes in the blood of ten patients admitted to Stanford Medical Center with the diagnosis of severe sepsis and adrenal insufficiency. Significant and distinct variations in whole blood leukocyte gene expression patterns occur depending upon the method of RNA isolation. We will attempt to demonstrate that our sampling method provides reliable and consistent data. Our second specific aim is to begin an analysis of gene expression patterns in white blood cells before and after steroid administration in patients suffering from severe sepsis with relative adrenal insufficiency. We will use a protocol for assessment of gene expression that was developed by members of our research team.

No related papers found yet.

United States