Thalidomide: rationale for renewed use in immunological disorders.

Despite its inherent teratogenic risk, thalidomide has over the years proven to be of clinical use in a small number of mainly immunological diseases (e.g. erythema nodosum leprosum, Behçet's syndrome and rheumatoid arthritis). The mode of action of thalidomide is still poorly understood. Recent research has shown a decrease in tumour necrosis factor-alpha (TNF alpha) during thalidomide treatment in several settings. Others have found altered expression of adhesion molecules. Currently, the most interesting new fields of application are the prevention and treatment of graft-versus-host disease in allogeneic bone marrow transplantation and the treatment of aphthous ulceration in HIV-positive patients. Contraceptive measures must be instituted in women receiving thalidomide, and careful monitoring for neurological adverse effects is required in all patients.