Background and aims To explore predictors of renal remission, insufficiency and damage in lupus nephritis (LN).

Methods We retrospectively analysed our lupus cohort and studied LN patients with at least one renal biopsy since 1990 until 2016. Follow-up ended at last patient visit. Complete renal remission (CRR) was defined as proteinuria <0.5 g/day and normal serum creatinine (SCr); partial remission as proteinuria <3.5 g/day with normal SCr; renal failure as SCr ≥2 mg/dl; renal flare as an increase in proteinuria >0.5 g/day and/or requirement for treatment modifications. Damage was measured by SLICC damage index (SDI).

Results 81 patients were studied (Table) who underwent 110 biopies. Forty patients (49.3%) went into CRR by the end of follow-up. Thirty-six (44.5%) had 2 renal flares while 21≥3 (26%). Six patients developed renal failure preceded by ≥3 flares in 5. One case of ESRD was reported. By the end of follow-up 30 patients (37%) had SDI≥2. At univariate analysis, increased proteinuria at 12 and 24 months from first biopsy and higher flare number were inversely associated with CRR, while long-lasting hypertension, abnormal SCr, decreased GFR and C4 at time of first biopsy were associated with renal failure. At multivariate analysis 24h-proteinuria at 24 months independently predicted lack of CRR (OR 3.7), while a higher number of renal flares (OR 5.27), higher SCr at 6 months from renal biopsy (OR 5.01) and a longer disease duration (OR 6.34) were independently associated with damage accrual.

Conclusions Increased proteinuria and abnormal baseline renal function make CRR unlikely. Suboptimal control of LN activity and longer disease duration are associated with severe damage accrual.