- stop therapy. A subgroup of patients (estimated to be 100) will undergo pharmacogenetic and pharmacodynamic studies. The pharmacogenetic study will evaluate the presence of gene polymorphisms that modifies the numbers of functioning receptors and their affinity for steroids (genes studied are showed in Tab 3). The pharmacodynamic study will evaluate the in vitro response to steroids on blood mononuclear cells: individual sensibility to steroids will be detected before and during steroid treatment and compared with the clinical response, in order to tailor treatment in the future.