Aim: The optimal maintenance therapy for active diffuse lupus nephritis remains to be established. In this study, we explored the efficacy and safety of tacrolimus for maintaining remission of active lupus nephritis compared to that of azathioprine.
Methods: Seventy patients with biopsy-proven lupus nephritis who achieved remission were enrolled in nine nephrology centers in China from 2006 to 2008. Patients were randomized either to tacrolimus plus prednisone (n = 34) or azathioprine plus prednisone (n = 36) for six months. Tacrolimus was titrated to achieve a trough blood concentration of 4-6 ng/mL, and the dosage of azathioprine was 2 mg/kg/d. Prednisone was administered at a dose of 10 mg/d to both groups. The primary outcome was incidence of relapse. Response, clinical parameters and adverse effects were secondary endpoints.
Results: After six months of therapy, two of the azathioprine-treated patients developed renal relapse compared to none of the tacrolimus-treated patients (p = 0.49; odds ratio, 1.06; 95% CI (0.98, 1.15)). Leucopenia (defined as < 2000 cells per cubic millimeter) was significantly more frequent in the azathioprine group than the tacrolimus group (47% vs. 9%, p < .001).
Conclusion: In conjunction with prednisone, maintenance therapy with tacrolimus and azathioprine has a similar low rate of renal relapse, and the tacrolimus regimen has a more favorable safety profile, with less leucopenia. However, since our study lacked sufficient power, longer follow-up is needed to draw final conclusions.