LUPUS NEPHRITIS AND HISTOLOGY RESULTS AS PREDICTORS OF KIDNEY OUTCOMES: A SYSTEMATIC REVIEW

Abstract Background: In lupus nephritis (LN), glomerular class alone incompletely predicts renal outcomes. Contemporary frameworks emphasize semiquantitative activity/chronicity indices and tubulointerstitial (TI) lesions as stronger prognosticators. Objective: To synthesize original evidence on histologic predictors of kidney outcomes in LN and contextualize findings with recent guidelines and methodology updates. Methods: Following PRISMA principles, we screened the user-supplied corpus of original LN studies and performed a narrative synthesis focused on biopsy-based predictors (modified NIH activity/chronicity indices, TI inflammation/fibrosis, repeat biopsy) and clinically actionable targets (proteinuria thresholds). Results: Across cohorts, a higher modified NIH chronicity index independently predicted eGFR decline or composite renal endpoints (per-point HR =1.3). Severe TI inflammation conferred substantially higher risks of CKD/ESRD versus mild TI change, while glomerular activity alone correlated poorly with long-term failure. Repeat-biopsy cohorts showed frequent histologic non-response despite apparent clinical response, and a higher chronicity burden on follow-up biopsy tracked with worse long-term function. In membranous LN, achieving complete remission or reducing proteinuria to <1 g/g by 1 year was associated with markedly lower risk of doubling of serum creatinine. Conclusions: Histology-derived chronicity and TI metrics consistently outperform glomerular class for prognostication; structured use of repeat biopsy and proteinuria targets can refine risk and guide therapy.