Mycophenolate mofetil as maintenance therapy in patients with vasculitis and renal involvement

Cytotoxic drugs have reduced the mortality in patients with ANCA-associated vasculitis (AASV) but their use carries a substantial risk of toxicity. Efforts are made to switch from cytotoxic drugs to less toxic maintenance regimens. In this study we aimed to assess the efficacy of mycophenolate mofetil (MMF) as maintenance therapy in patients with AASV and renal involvement.

22 patients with newly diagnosed AASV, microscopic polyangiitis (MPA) (n = 16), Wegener's granulomatosis (WG, n = 4), renal limited vasculitis (RLV, n = 1) and Churg-Strauss syndrome (CSS, n = 1) and renal involvement were followed for a median of 42 months (range 24 - 101). After 6 months of standard induction therapy, patients were switched to MMF monotherapy for 18 months. Renal parameters i.e. serum creatinine, proteinuria and urine sediment, BVAS scores and ANCA titers were assessed at baseline, after induction and after 18 months with MMF.

After the end of induction, 3 of the 4 patients who were initially hemodialysis (HD) dependent, remained on HD and were withdrawn from further analysis. In the remaining 19 patients, the improvement in renal function (p < 0.001), hematuria (p = 0.011), proteinuria (p = 0.007) and BVAS scores (p < 0.001) after induction was sustained after 18 months maintenance with MMF and no patient relapsing during this period. Until the end of the follow up, 31.58% of patients relapsed, at a median of 21.5 months (range: 18 - 60). Side effects were transient and infrequent.

In patients with AASV and renal involvement, MMF seems to be an effective and well tolerated option in sustaining short- and medium-term remission.