Steroid Responsiveness in Duchenne Muscular Dystrophy Epigenetic Regulator Histone Deacetylase 2.

OBJECTIVE: To find the role of an epigenetic regulator histone deacetylase (HDAC-2) in predicting steroid responsiveness in patients with Duchenne muscular dystrophy (DMD). METHODS: Peripheral blood mononuclear cells were isolated from three milliliters of venous blood sample of patients with DMD for estimation of HDAC-2 levels. The patients were then given prednisolone at 0.75 mg/kg/d and followed up for response. Improvement in muscle power and timed function tests were evaluated 2 monthly for 6 mo. Side- effects of steroids were also noted. RESULTS: HDAC-2 values showed a linear correlation with improvement in muscle power at 6 mo as reflected in direct assessment and in various functional tests. When >/=3 point change from baseline was considered in power of various muscle groups at 6 mo as cut off to distinguish good responders (GR) from poor responders (PR) of steroid, a HDAC-2 value of >/=4.40 seemed to be 92.6% sensitive and 100% specific to distinguish GRs. CONCLUSIONS: The degree of improvement in power and various timed function tests at 6 mo could be predicted from the HDAC-2 value of the individual patient recorded at baseline. HDAC-2 levels at baseline might be a good biomarker for predicting steroid response in patients with DMD.