TREATMENT OF SMALL VESSEL VASCULITIS AFFECTING THE KIDNEYS

Treatment of vasculitis can be divided into two phases: (i) an inducti on phase to achieve remission, abate destructive inflammation and mini mize scarring; and (ii) the maintenance phase to sustain patients in r emission with minimal treatment-related side-effects. A combination of corticosteroids and cytotoxic agents is commonly used as induction th erapy. The dose and route of administration of corticosteroids have no t been studied adequately, but intravenous (i.v.) bolus doses of methy lprednisolone are often administered to patients with severe disease. It has the advantage of fewer side-effects compared to prolonged high dose oral corticosteroids, and the immediate immuno-modulatory effects of the steroid boluses may confer additional therapeutic benefits. It is the general impression that cyclophosphamide is more effective tha n azathioprine in the acute phase of patients with severe disease. The use of cyclophosphamide by i.v. pulse rather than orally is contentio us, and some recent studies have demonstrated its failure to induce su stained remission. Azathioprine with low dose corticosteroids is often employed as long-term maintenance immunosuppression, although low dos e cyclophosphamide has also been used for such purpose, which should b e withdrawn after 1 year of remission because of its potential side-ef fects. Clinical and serologic parameters are useful monitors during ma intenance therapy. Although serial levels of antineutrophil cytoplasm antibodies (ANCA) correlate with disease activity, some patients remai n well despite positive or increasing levels of ANCA. Consequently, wh ether immunosuppressive therapy should be escalated based on increasin g ANCA levels alone remains controversial.