Objective Kidney survival is the ultimate goal in lupus nephritis (LN) management, but long‐term predictors remain inadequately studied, requiring long‐term follow‐up. This study aimed to identify baseline and early longitudinal predictors of kidney survival in the Accelerating Medicines Partnership LN longitudinal cohort. Methods We performed time‐to‐event analyses of clinical, centrally scored histological, and serological predictors of kidney function loss (sustained ≥ 40% eGFR decline or progression to end‐stage kidney disease) in 172 LN patients with a median follow‐up of 4.6 years (range 0.5‐7.8). Results Kidney function loss occurred in 57/172 (33%) patients. Baseline lower eGFR, non‐first kidney biopsy, and higher NIH Chronicity Index (CI) were associated with eGFR loss. CI was the strongest predictor, but no clear threshold defined higher risk. NIH Activity Index and International Society of Nephrology (ISN) class were not predictive. Proteinuria at 12 months was prognostic, with urine protein to creatinine ratio <0.7 g/g associated with lower risk, though no single threshold ensured protection, and lower levels had better outcomes. Lack of complete clinical response at 3, 6, or 12 months predicted future eGFR loss, while partial response conferred intermediate risk. Serological markers were not associated with eGFR loss. Conclusion Low baseline eGFR and chronic histologic damage, but not activity or ISN class, predicted eGFR loss. Proteinuria <0.7 g/g at 1 year was associated with better outcomes but did not ensure protection. Since proteinuria does not reflect intrarenal inflammation, these results suggest current response definitions serve better as prognostic indicators than true measures of treatment efficacy, and better biomarkers are needed.
Zhang et al. (Tue,) studied this question.