CT-02 Kidney biopsy findings of lupus nephritis patients in remission and renal flare after withdrawal of maintenance therapy: a prospective observational cohort study

Background One of the most difficult management issues in lupus nephritis (LN) is duration of maintenance immunosuppression after patients are in clinical remission. Most patients receive immunosuppression for years, based mainly on expert opinion. Prospective data are unavailable. Complicating this issue are data that patients in clinical remission can still have histologically active LN, however the implications of this are unknown. The Lupus Flares and Histological Renal Activity at the end of Treatment (LuFla) study was designed to examine whether residual histologic activity predisposes to LN flares in class III and IV LN. Methods Patients in complete clinical remission for at least 12 months who had received at least 36 months of immunosuppression were eligible. Patients consented to a second kidney biopsy and were then tapered off maintenance immunosuppression. The patients were followed prospectively for LN flares over 24 months. Results LuFla enrolled 44 patients and 36 completed the study. LN flares occurred in 11 patients (30.5%) and 10 (90.9%) of these had residual histologic activity on biopsy 2 (figure 1). All patients with an NIH activity index (AI)>2 flared (figure 1). Endocapillary proliferation, a component of the AI and duration of SLE at biopsy 2 were independent predictors of flare. A predictive equation based on these variables discriminated between flare and no-flare with a sensitivity of 100%, specificity of 92%, and a misclassification rate of 5.6%. Conclusions These data suggest a repeat kidney biopsy is useful in managing maintenance immunosuppression in LN, and patients in histologic remission are candidates for withdrawal of therapy. Trial registration ClinicalTrial. gov, NCT02313974