Objective: To evaluate responses to mycophenolate mofetil (MMF) and intravenous cyclophosphamide (CYC) in lupus nephritis in a multiethnic population.
Methods: This was a retrospective study of all patients with systemic lupus erythematosus (SLE) that underwent kidney biopsy at New York University Medical Center. Patients with followup of at least 6 months were included. Clinical response was defined as complete (return to +/- 10% of normal) or partial (improvement of 50% in abnormal renal measurements).
Results: Ninety-nine patients were included in the study: 86% females, 86% non-Caucasian, age 34.2 +/- 1.1 years, 62% with proliferative nephritis (PN; ISN/RPS-III and IV), and 32% with membranous nephritis (MN; ISN/RPS-V). Of the 70 patients with PN, 37 were treated with CYC and 33 with MMF. The baseline characteristics of the 2 treatment groups were different in the incidence of ISN/RPS-IV, values of serum creatinine and serum albumin, and type of insurance (p < 0.05). The response rate was greater in the MMF than in the CYC group (70% vs 41%). Responses to MMF were different in Asians (11/11), Caucasians (4/5), African Americans (3/5), and Hispanics (5/11). Responses to CYC had a similar distribution (Asians 6/10, Caucasians 4/5, African Americans 4/9, Hispanics 1/11). In the MN group (N = 23) responses were similar to the PN group (73% MMF and 38% CYC). After adjusting for race, serum creatinine, serum albumin, type of insurance, and class of nephritis, in a logistic regression model, response to MMF was superior to CYC: OR 6.2 (95% CI 1.9-20.2). Hispanics had worse outcome than Caucasians (OR 0.17). Longterm followup suggested no difference in maintenance with MMF or CYC.
Conclusion: After controlling for the fact that less severe nephritis is preferentially treated with MMF, we found overall that response to MMF was superior to CYC. In this US population, ethnicity was observed to have an influence on response.