PREDICTIVE VALUE OF CHRONIC HISTOLOGIC CHANGES IN LUPUS NEPHRITIS

O041 / #709 Topic: AS15 - Lupus Nephritis-Clinical ABSTRACT CONCURRENT SESSION 06: LUPUS NEPHRITIS – CLINICAL OUTCOMES, PREDICTION AND THERAPY 23-05-2025 1:40 PM - 2:40 PM Background/Purpose The Mayo Clinic Chronicity Score (MCCS) is a tool to assess the chronicity of renal histology in glomerulopathies. This tool includes arteriosclerosis (AE), a chronic vascular lesion, and has not been evaluated in lupus nephritis (LN). Our objective was to evaluate the predictive value of the individual components of the International Society of Nephrology/Renal Pathology Society and MCCS in LN. Methods LN patients from Mayo Clinic between 1992 and 2023 were included. The earliest kidney biopsy was index date. Follow-up was until July 2023, death or loss follow-up. Biopsy reports were reviewed by a nephropathologist and chronic lesions reclassified (glomerulosclerosis [GS], interstitial fibrosis [IF], tubular atrophy [TA], arteriosclerosis [AE], and fibrous crescents [FC]). The outcomes were proteinuria <500 mg/day and complete renal response (CRR) within 1-year, end-stage kidney disease (ESKD), and death. We used stratified multivariable proportional hazards regression adjusted for sex and age. P-values <0.05 were statistically significant. Results We included 307 patients (median age, 34 years; 75% female; median follow-up, 11 years). The majority had class III, IV. FC were in 4.9%, AE in 12%. Table shows hazard ratios of proteinuria<500 mg/day, CRR, ESRD, and death for different variables of interest. At one year, 47.5% had proteinuria <500 mg/day and 43.4% CRR. Those with grade 2-3 of GS (HR 0.21 [0.09, 0.48]) and grade 2-3 IFTA (HR 0.14 [0.05, 0.39]) were less likely to achieve proteinuria <500 mg/day. Grade 2-3 of GS (HR 0.19 [0.08, 0.48]) and grade 2-3 IFTA (HR 0.16 [0.06, 0.44]) were also less likely to achieve CRR. (Figure 1) shows increasing grades of GS is associated with a lower chance of CRR. Similarly, AE (HR 0.44 [0.21, 0.91], for proteinuria <500 mg/day, HR 0.37 [0.16, 0.84], for CRR) was associated with a reduced likelihood of achieving the outcomes. During follow-up, 33 patients died, and 60 developed ESKD. No variables were associated with mortality. Grade 2-3 GS (HR 9.28 [4.91, 17.54], grade 2-3 IFTA (HR 20.10 [10.08, 40.08]), and the presence of AE (HR 3.56 [1.87, 6.78]) were associated with an increased ESKD. (Figure 2) shows increasing grades of GS is associated with a greater chance of ESKD. Table. Hazard ratios of proteinuria <500 mg/day, CRR, ESKD, and death for variables. Figure 1: Kaplan Meier curve for complete renal response (CRR) for glomerulosclerosis (GS) score. Black line: GS grade 0, red: GS grade 1, green: GS grades 2-3. Increasing GS is associated with a lower chance of CRR. Figure 2: Kaplan Meier curve for end stage kidney disease (ESKD) for glomerulosclerosis (GS) score. Black line: GS grade 0, red: GS grade 1, green: GS grades 2-3. Increasing GS is associated with greater hazard of ESKD Conclusions GS, IFTA, AE are independently associated with outcomes in LN. FC is rare finding. The MCCS included all the chronic histologic elements associated with outcomes in LN.