Expression of Glucocorticoid Receptor Isoforms (a, β, γ, and p) in Egyptian Primary Immune Thrombocytopenia Patients

Glucocorticoid (GC) resistance has been demonstrated in nearly 30% of primary immune thrombocytopenia (ITP) patients even managed with high dosages GC. The biological effects of GC are mainly mediated through activation of glucocorticoid receptors (GR). An insight into the molecular mechanisms underlying GC resistance is important to avoid GC treatment in patients contraindicated from steroid use. We aimed at determining glucocorticoid receptor (GR) isoforms expression in adult ITP and its relation to glucocorticoid resistance. Thirty three ITP patients from the Hematology unit, Alexandria Main University Hospital were the subject of the study. They were subdivided into two groups (sensitive and resistant) according to their response to 4 weeks GC treatment. 15 healthy volunteers of matched age were also included. Glucocorticoid Receptor α, β, γ and p gene expression were measured in cases and controls by real time Polymerase Chain Reaction. The mean age value in GC sensitive, GC resistant and control group was 33.4±11.6, 38.1±12.3 and 31.7±5.8 years respectively. Statistically significant difference between GR alpha mRNA isoform and GRa/ GRβ ratio was detected between GC resistant and GC responsive group while GRb, GRγ and GRβ were insignificantly differed between groups. From this study, we concluded that study of GRa and GRa/ GRβ ratio is recommended early in ITP to avoid unnecessary glucocorticoid side effects.