Lupus nephritis: induction therapy in severe lupus nephritis--should MMF be considered the drug of choice?

Severe lupus nephritis is an aggressive disease that requires an aggressive approach to treatment. Recent randomized clinical trials showed that mycophenolate mofetil compared favorably with cyclophosphamide (traditional approach) for remission induction. Consequently, mycophenolate mofetil is now commonly recommended as first-line therapy. Nevertheless, the role of mycophenolate mofetil in treating severe lupus nephritis is unclear, because such patients were excluded from these trials. With this limitation as background, this work addresses the question of mycophenolate mofetil for induction therapy for severe lupus nephritis. We performed a systematic review of the outcomes of treating severe lupus nephritis with mycophenolate mofetil or cyclophosphamide. Because no studies directly addressed this question, these data were extracted from the published literature or obtained by personal communications from investigators. There is no universally accepted definition, and therefore, severe lupus nephritis was arbitrarily defined by renal histology, resistance to therapy, or level of kidney function at presentation. For each trial analyzed, we determined the partial and complete remission rates. Long-term outcomes were compared when available. The pooled results suggest that mycophenolate mofetil and cyclophosphamide are equally effective in inducing remission of severe lupus nephritis. However, relapse rates and risk of developing ESRD were higher for mycophenolate mofetil compared with cyclophosphamide. In conclusion, in the short term, mycophenolate mofetil and cyclophosphamide are about equal in inducing remission. However, long-term outcomes suggest better preservation of kidney function and fewer relapses with cyclophosphamide therapy. Therefore, mycophenolate mofetil should not yet be considered the induction drug of choice for severe lupus nephritis.