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.

Keywords: chronic kidney disease; end-stage kidney disease; lupus erythematosus, systemic; lupus nephritis; renal response.

Figure 1

Study design. CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; LN, lupus nephritis; mCRR, modified complete renal response; mPERR, modified primary efficacy renal response. ^aDefined as survival without progression to severe and end-stage CKD (eGFR < 30 ml/min per 1.73 m² [CKD stage 4 or 5]) or dialysis or transplant or death; ^bdefined as new occurrence of eGFR < 60 ml/min per 1.73 m² on at least 2 consecutive measurement occasions ≥3 months apart (GFR level equivalent to CKD stage 3a [GFR: 45–59 ml/min per 1.73 m²], 3b [GFR: 30–44 ml/min per 1.73 m²], 4 [GFR: 15–29 ml/min per 1.73 m²], or 5 [GFR: < 15 ml/min per 1.73 m²]).

Figure 2

Flow diagram of patient populations. CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; LN, lupus nephritis; SLE, systemic lupus erythematosus.

Figure 3

Kaplan–Meier plots comparing the proportion of patients with long-term kidney survival by (a) mPERR status and (b) mCRR status at 2 years postbiopsy. mCRR, modified complete renal response; mPERR, modified primary efficacy renal response.

Figure 4

Kaplan–Meier plot comparing the incidence of mild CKD or worse (stage ≥ 3) by (a) mPERR status and (b) mCRR status at 2 years postbiopsy. CKD, chronic kidney disease; mCRR, modified complete renal response; mPERR, modified primary efficacy renal response. ^aProportion of patients without CKD progression.