In a new study, researchers found low glomerular filtration rate (eGFR, a measure used to assess how well the kidneys filter blood) and chronic histologic damage predicted eGFR loss in people with lupus nephritis, (LN, lupus-related kidney disease), suggesting that these measures may have potential as a long-term predictive biomarkers for kidney survival. Although treatments for lupus have improved, LN remains a serious and common complication that causes significant illness and death. 

Researchers analyzed time-to-event associations between clinical, centrally scored histologic, and serologic factors and kidney function loss in 172 people with LN over a median 4.6-year follow-up. They found kidney function loss occurred in 33% of participants. Lower baseline eGFR, repeat kidney biopsy, and higher NIH Chronicity Index (CI) scores predicted eGFR decline in LN, highlighting chronic damage as central to prognosis. In contrast, the NIH Activity Index, International Society of Nephrology class, and serologic responses generally lacked predictive value, though very high anti-dsDNA levels at 12 months were associated with increased risk in a small subset of patients. While lower 12 month proteinuria correlated with better outcomes, no single threshold fully predicted outcomes, and participants achieving deeper remission (a urine protein-to-creatinine ratio below 0.25g/g at one year) did better. These results suggest reinterpreting proteinuria and eGFR stability as prognostic markers rather than treatment targets. 

This study refines understanding of prognostic factors and underscores the limitations of threshold-based markers, which serve better as long-term prognostic tools than short-term response measures. The findings highlight the need for biomarkers or repeat biopsies that more accurately assess intrarenal disease activity and treatment response in LN. Learn more about lupus nephritis. 

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