Background/Purpose: Advanced chronic kidney disease (CKD) carries an increased risk for progression to end-stage renal disease (ESRD) and renal replacement therapy. However, the rate of progression and the predictors that drive the decline of renal function in lupus nephritis (LN) are not known. The aim of the present study is to define such factors in patients with LN and advanced CKD.

Methods: Patients with advanced LN-related CKD for two consecutive clinic visits were retrieved from our long-term longitudinal lupus cohort. Advanced CKD was defined according to the Kidney Disease Improving Global Outcomes as CKD stage 3b (eGFR=30-44ml/min/1.73m²) and stage 4 (eGFR=15-29ml/min/1.73m²), while ESRD was defined as eGFR<15ml/min/1.73m² or initiation of dialysis. All individuals were followed until the progression to ESRD or the last visit and were divided into two groups (“progressors” and “non-progressors”). Demographic, clinical, immunological and therapeutic variables were compared at baseline (the second visit of advanced CKD). Multivariable Cox regression analysis was performed for the identification of predictors for transition to ESRD. Statistical analysis was performed with SAS 9.4; p<0.05 was considered significant.

Results: One hundred eighteen patients (74 with CKD 3b and 44 with CKD 4) were included. Mean time from LN to advanced CKD was 5.6 years. There were no differences between groups at baseline, concerning demographic, clinical and immunological variables. Patients with CKD 4 more often had a proliferative LN (class III or IV) (50% vs. 29.7%, p=0.053). Rates of and time to progression are shown in Table 1.

Patients who did not progress (n=73, 61.9%) had a mean follow-up of 5.8 years (range 0-26.7). Their eGFR remained unaltered (from a median of 38.6 at baseline to 37.1ml/min/1.73m² at the last visit). Multivariable analysis for predictors of progression to ESRD is shown in Table 2.

Conclusion: Only 24.6% of our patients developed ESRD, while another 21.6% of the CKD 3b patients progressed to CKD 4. Risk factors for ESRD included abnormal anti-dsDNA antibodies at the time of CKD as well as treatment with glucocorticosteroids and higher cumulative dose (for the treatment of LN). Immunosuppressive treatment at the time of CKD was protective. Renal function remained stable in approximately 73% of the CKD 3b and 43% of the CKD 4 patients over 6 years of follow-up.