Worse long-term renal outcome of lupus nephritis patients of African descent living in Europe.

INTRODUCTION: Prognosis of lupus nephritis (LN) among patients of African descent living in Europe has been understudied. METHODS: In a retrospective study performed in two European university hospitals, we compared the prognosis of LN in patients of African descent or Caucasians. Remission was defined as a urine protein to creatinine (uP/C) ratio<0.5 g/g and a serum creatinine value<120% of baseline. Renal relapse was defined as the reappearance of a uP/C>1 g/g, leading to a repeat kidney biopsy and/or immunosuppressive treatment change. Chronic kidney disease (CKD) was defined as estimated glomerular filtration rate≤60 mL/min/1.73 m2. Adherence was retrospectively assessed through medical files and/or hydroxychloroquine level measurements. RESULTS: 52 patients of African descent and 85 Caucasian patients were included in this analysis. Class III and isolated class V LN were more common among patients of African descent. Time to first renal remission did not differ between ethnic subgroups. By contrast, patients of African descent suffered from earlier renal flares, CKD was more common and time to CKD was shorter after a flare. In a multivariate analysis, African ancestry was an independent risk factor for progression to CKD. We observed no significant difference in non-adherence to treatment between the two groups. CONCLUSION: LN patients of African descent have worse renal outcomes, mainly explained by a higher rate of renal flare.

Absence of renal remission portends poor long-term kidney outcome in lupus nephritis.

BACKGROUND: The very long-term consequences of absence of remission in lupus nephritis (LN) remain understudied. METHODS: In this retrospective analysis, we studied a selected cohort of 128 patients with biopsy-proven class III, IV or V incident LN followed for a median period of 134 months (minimum 25). Remission was defined as a urine protein to creatinine (uP:C) ratio <0.5 g/g and a serum creatinine value <120% of baseline. Renal relapse was defined as the reappearance of a uP:C >1 g/g, leading to a repeat kidney biopsy and treatment change. Poor long-term renal outcome was defined as the presence of chronic kidney disease (CKD). RESULTS: Twenty per cent of patients never achieved renal remission. Their baseline characteristics did not differ from those who did. Absence of renal remission was associated with a threefold higher risk of CKD (48% vs 16%) and a 10-fold higher risk of end-stage renal disease (20% vs 2%). Patients achieving early remission had significantly higher estimated glomerular filtration rate (eGFR) at last follow-up compared with late remitters. Accordingly, patients with CKD at last follow-up had statistically longer time to remission. Among patients who achieved remission, 32% relapsed, with a negative impact on renal outcome, that is, lower eGFR values and higher proportion of CKD (33% vs 8%). CONCLUSION: Early remission should be achieved to better preserve long-term renal function.