Article Text
Abstract
Background and aims To determine: 1-the predictive ability of proteinuria, urinary sediment (uRBCs) and serum creatinine (Cr) at 1 year to predict good long-term outcomes, and 2- the best proteinuria cut-off at 1 year to predict good long-term outcomes.
Methods Retrospective analysis on 1849 patients. Patients with lupus nephritis (LN) (24 hour proteinuria [24H-P]>0.5 g/d) with at least 7 years’ follow-up were identified and baseline was defined as the onset of LN. Good renal outcome was defined as Cr <100 mmol/L and renal transplant/dialysis-free at 7 years.
ROC curves examined the predictive power of Cr, 24H-P, and uRBCs at 1 year post-LN diagnosis with respect to good renal outcome. AUC were analysed for: a) 24H-P at year 1, b) absolute change in 24H-P between year 1 and 7, and c) percent change in 24H-P between year 1 and 7. The proteinuria cutoff was identified by optimising sensitivity/specificity.
Results 101 LN patients were analysed with baseline 24H-P of 2.36±2.31 g/d. 24H-P of 0.6 g/d at 1 year after LN diagnosis best predicted good long-term renal outcome, with sensitivity 62%/specificity 70% (Figure 1).
AUC analysis confirmed that 24H-P at 1 year, but not absolute/percent change, is a predictor of good long-term renal outcomes (Figures 1 and 2). uRBCs did not provide any predictive benefit while Cr at 1 year predicted long-term renal outcome with an AUC of 0.82 (Figure 2).
Conclusions Proteinuria of 0.6 g/d at 1 year and Cr at 1 year post-LN diagnosis best predicted good long-term renal outcome. uRBCs did not offer any prognostic benefit.