Long-Term Kidney Outcome of Lupus Nephritis by Renal Response Status

Abstract

Introduction

Limited evidence exists that clinical trial treatment response criteria predict long-term outcomes in Asian patients with lupus nephritis (LN).

Methods

This retrospective analysis of prospectively collected data from the Hong Kong Queen Mary Hospital Cohort categorized adults with biopsy-proven LN (Class III, IV, V, or mixed [III ± V, IV ± V]) after standard treatment for 2 years postbiopsy and immunosuppression induction according to modified primary efficacy renal response (mPERR: estimated glomerular filtration rate [eGFR] ≥ 60 ml/min per 1.73 m² or ≤ 20% below biopsy value AND urine protein-to-creatinine ratio [uPCR] ≤ 0.7) and modified complete renal response (mCRR; eGFR ≥ 90 ml/min per 1.73 m² or ≤ 10% below biopsy value AND uPCR ≤ 0.5). Associations between 2-year mPERR/mCRR status and long-term kidney survival and mild chronic kidney disease (CKD) or worse (stage ≥ 3) were assessed.

Results

Of the 176 Chinese patients, 64.2% achieved mPERR and 43.8% achieved mCRR at 2 years postbiopsy. After mean follow-up of 15.3 years, significantly higher proportions of mPERR and mCRR responders versus nonresponders achieved long-term kidney survival (mPERR: 85.8% vs. 71.4%; P = 0.029; mCRR: 92.2% vs. 71.7%; P < 0.001). mPERR and mCRR achievement was associated with adjusted risk reductions for kidney nonsurvival of 60% (P = 0.034) and 86% (P < 0.001), respectively. Adjusted risk for mild CKD or worse (stage ≥ 3) was 82% (P = 0.013) and 87% (P = 0.012) lower for mPERR and mCRR responders, respectively, versus nonresponders.

Conclusion

In Chinese patients with LN, mPERR and mCRR at 2 years postbiopsy predict superior long-term kidney outcomes and lower CKD progression risk.