OBJECTIVE: To identify the relationship between the expression of α and β-isoforms of glucocorticoid receptors (GR) in peripheral blood mononuclear cells (PBMC) and glucocorticoid resistance in children with idiopathic thrombocytopenia purpura (ITP). METHODS: Real-time PCR was used to detect the expression of GRα and GRβ mRNA in PBMC from 30 children with ITP (glucocorticoid-sensitive, n=18; glucocorticoid-resistant, n=12) and 10 healthy children (control group). Enzyme immunoassay was used to measure plasma levels of total glucocoticoits. RESULTS: There were no significant differences in PBMC GRα mRNA levels among the glucocorticoid sensitive, the glucocorticoid-resistant and the control groups. Compared with the glucocorticoid-sensitive and the control groups, the expression of GRβ mRNA in the glucocorticoid-resistant group was significantly up-regulated (P<0.01). Plasma total glucocoticoits level in the glucocorticoid-resistant group was found to be much higher than that in the glucocorticoid-sensitive and the control groups (P<0.01). CONCLUSIONS: The up-regulated expression of GRβ mRNA may associated with glucocorticoid resistance in children with ITP.［Chin J Contemp Pediatr, 2009, 11 (9):714-716］