Novel therapies in vasculitis.

The vasculitides comprise various clinical and pathological entities which pose a therapeutic challenge in terms of disease control versus drug toxicity. Glucocorticoids are important in most regimens; duration of exposure and dosages can be minimised by the use of cytotoxic drugs and transplant immunosuppressives such as cyclosporin, tacrolimus and mycophenolate mofetil. Among alkylating agents, cyclophosphamide has proven to be highly effective; switching to less toxic antimetabolites, typically methotrexate, for maintenance after achieving disease control is an effective strategy. Plasmapheresis may be considered when pharmacological options are maximised. IVIG infusions are of proven benefit in Kawasaki disease and possible benefit in other vasculitides. Targeting infective aetiologies is the basis of therapies such as lamivudine and vidarabine for hepatitis B associated polyarteritis nodosa as well as ribavarin and IFN-alpha for hepatitis C associated cryoglobinaemic vasculitis. IFN-alpha also has immunomodulatory effect even in non-hepatitis C-associated vasculitis. Trimethoprim-sulphamethoxazole has been used in limited Wegener's granulomatosis. Thalidomide, colchicine and dapsone are miscellaneous agents that have been used in Behcet's disease and cutaneous vasculitis. Anti-lymphocytic monoclonal antibodies have been employed for induction therapy in Wegener's granulomatosis. The tumour necrosis factor inhibitor etanercept is just being explored as a therapeutic agent. Bone marrow and stem cell transplantation may find a role in refractory disease.