Development and validation of a prediction score system in lupus nephritis

The risk assessment for developing end-stage renal disease (ESRD) remains unclear in patients with lupus nephritis (LN). The purpose of this study was to develop and validate a prediction rule for estimating the individual risk of ESRD in patients with LN using clinical and pathological data. A total of 599 patients with LN diagnosed by renal biopsy between June 2009 and June 2014 in West China Hospital of Sichuan University were retrospectively followed. Patients were randomly divided into derivation cohort (n = 379) and validation cohort (n = 220). The SLEDAI score was used to evaluate the clinical disease activity. Pathological lesions according to the International Society of Nephrology and the Renal Pathology Society (ISN/RPS) systems were meticulously evaluated. The risk factors for developing ESRD were evaluated using a Cox proportional hazard model with a stepwise backward elimination method. In the derivation cohort, 100 patients (26.5%) developed ESRD during the average 46.0 ± 21.1 months’ follow-up. The final prediction model included cellular crescents, active index >20, glomerular sclerosis, fibrous crescents, interstitial fibrosis, chronic index >5, nephrotic syndrome, and eGFR <45 mL/min as independent risk factors for developing ESRD. To create a prediction rule, the score for each variable was weighted by the regression coefficients calculated using the relevant Cox model. The prediction rule was validated in the validation cohort. During the follow-up period, 45 patients (21.5%) in validation cohort progressed to ESRD. This study developed and validated a new prediction rule using clinical measures and pathological changes for developing ESRD in patients with LN.