Endocrine Abstracts

Summary: Objective: To evaluate the expression level and binding affinity of glucocorticoid receptors (GRs)in patients with endogenous Cushing’s syndrome(CS) and to determine whether there is partial glucocorticoid resistance.

Methods: Fifty-eight patients with CS and forty-one age- and sex-matched healthy volunteers were studied. The expression level and binding affinity of GRs in peripheral blood mononuclear cells (PBMLs) were examined by flow cytometry (FCM). The differences between the two groups were compared, and the correlations of GR level and affinity with serum cortisol concentrations and 24-h urinary free cortisol (UFC) were also analyzed.

Results: The expression level and binding affinity of GRs in CS patients were 11.9 ± 2.6 and 5.7 ± 2.0, while the values of normal controls were 21.5 ± 3.4 and 10.7 ± 2.4, respectively. There was a significant decrease in GR expression and binding affinity in the patients with CS. No correlation was observed between serum cortisol concentrations or 24-hour UFC and GR expression or binding affinity in CS patients.

Conclusion: The expression level and binding affinity of GRs are obviously decreased in patients with CS. To overcome glucocorticoid resistance and avoid glucocorticoid withdrawal syndrome after surgical resection of the causal tumor, a higher than physiological dose of glucocorticoid replacement should be given to CS patients after surgery.