Dexamethasone-Induced FKBP51 Expression in Peripheral Blood Mononuclear Cells Could Play a Role in Predicting the Response of Asthmatics to Treatment with Corticosteroids

Corticosteroids (CSs) are the preferred anti-inflammatory therapy for the treatment of asthma, but the responses of asthmatics to CSs are known to vary. It has thus become important to discover reliable markers in predicting responses to CSs. We performed time-series microarrays using a murine model of asthma after a single dose of dexamethasone, based on the assumption that the gene showing a greater change in response to CSs can also be a potential marker for that finding. We then evaluated the clinical meaning of the gene discovered in the microarray experiments. We found that the expression of FK506 binding protein 51 gene (FKBP51) in lung tissue markedly increased after dexamethasone treatment in a murine model of asthma. We then measured dexamethasone-induced FKBP51 expression in peripheral blood mononuclear cells (PBMCs) in asthmatics. Dexamethasone-induced FKBP51 expression in PBMCs was significantly higher in severe asthmatics compared with mild-to-moderate asthmatics treated with inhaled CSs. In addition, we found that dexamethasone-induced FKBP51 expression in PBMCs was inversely correlated with improvement in lung function after treatment with orally administered prednisolone in six steroid-naive asthmatics. Dexamethasone-induced FKBP51 expression in PBMCs may be a reliable and practical biomarker in predicting the response to CSs in asthmatics.