A case of a 16 year old girl with Takayasu’s arteritis is described; the girl was treated with oral prednisone and methotrexate, with a very poor clinical response and, after 1 year’s treatment with high dose steroids, no sign of exogenous Cushing’s syndrome was evident. The whole cell [3H]dexamethasone binding assay revealed a reduced number of receptors per cell in the patient’s PBMCs in comparison with ten patients, treated with GCs and responsive to treatment, and six healthy controls. Binding affinity (Kd) was, on the contrary, not modified. No mutation in the glucocorticoid receptor gene was identified, however an increased expression of hsp90 mRNA in the patient’s PBMCs was evident, which could give a molecular explanation for the GC resistance.
