Background: Standard therapy with corticosteroids and cyclophosphamide followed by azathioprine has improved renal and patient survival in renal vasculitis. However, this regimen is associated with high toxicity. Mycophenolate mofetil (MMF), a less toxic immunosuppressive drug, has been proposed as a therapeutic alternative.
Methods: We report 12 patients (4 males, 8 females, aged 65.6 A+/- 12.1 years) with anti-MPO renal vasculitis who were switched from standard therapy to MMF because of drug-related adverse effects: leukopenia, toxic hepatitis, nausea, hair loss or appearance of carcinoma. MMF was introduced at a dose of 500 mg/8 h, after 83 A+/- 56 days under standard therapy.
Results: After 354 A+/- 195 days of MMF therapy, all patients maintained clinical remission. Mean values of serum anti-MPO, disease activity markers and serum creatinine decreased when these values were compared from pre-therapy to the time of switching to MMF, and then to the end of the study anti-MPO: 204 A+/- 144 U, 54 A+/- 85 U and 12 A+/- 5 U. Serum-reactive C protein 97 A+/- 82 mg/l, 13 A+/- 10 mg/l and 4 A+/- 2 mg/l. Erythrocyte sedimentation rate 88 A+/- 40, 41 A+/- 28 and 26 A+/- 15 mm. Serum creatinine 415 A+/- 238, 202 A+/- 93 and 169 A+/- 104 micromol/l. In one case there was a relapse of vasculitis under MMF and a low dose of prednisone after 9 months of therapy. Side effects were herpes infection in four cases and chickenpox in one. Neither leukopenia nor anemia was observed.
Conclusions: These results indicate that MMF could be an alternative therapy for anti-MPO renal vasculitis associated with cyclophosphamide or azathioprine-related toxicity.