Decreased glucocorticoid receptor expression during critical illness

Area of Science:

• Endocrinology
• Critical Care Medicine
• Molecular Biology

Background:

• Critically ill patients often exhibit hypothalamic-pituitary-adrenal axis activation and variable cortisol levels.
• Sepsis can lead to relatively low cortisol concentrations despite severe illness.
• Understanding glucocorticoid receptor (GCR) expression is crucial for managing critical illness.

Purpose of the Study:

• To investigate the time course of GCR alpha and beta expression in polymorphonuclear cells of critically ill patients.
• To compare GCR expression patterns in septic versus nonseptic critically ill patients.
• To correlate GCR expression with illness severity and duration in the ICU.

Main Methods:

• Prospective observational study of 32 critically ill adults in an ICU.
• Blood samples collected within 24-48 hours of admission and at days 4, 8, and 13.
• Real-time PCR used to measure glucocorticoid receptor (GCR) alpha and beta mRNA expression.

Main Results:

• Both GCR-α and GCR-β mRNA levels significantly decreased over the ICU stay.
• GCR-α mRNA showed a fourfold decrease by day 4 and remained low for 2 weeks.
• GCR-β mRNA levels decreased threefold by week 2.

Conclusions:

• Critically ill patients exhibit highly variable GCR expression.
• GCR levels decline during ICU hospitalization.
• Decreased GCR expression may underlie differential patient responses to glucocorticoids.