A new study examined whether urinary biomarkers could predict future kidney complications in individuals with lupus nephritis (LN). Researchers found that non-invasive urinary biomarkers measured after approximately two years after a LN flare may help identify patients at higher risk for future flares and long-term kidney damage. Despite advancements in the management of LN, long-term renal outcomes remain suboptimal. 

The study, which recruited patients from the University of Toronto Lupus Cohort between January 2005 and June 2014, consisted of 69 people with LN who had preserved kidney function prior to a flare. Researchers measured urinary biomarkers including CD163, MCP-1, adiponectin, soluble VCAM-1, and PF4. 

A urinalysis was performed about two years after participants initial flares to assess biomarker levels, and each was followed for nearly 11 years. Among participants who achieved a primary efficacy renal response at 24 months, more than half (54%) experienced another flare, and 20% developed a decline in kidney function. Elevated urinary levels of MCP-1 and CD163 were associated with increased risk of future LN flares. Higher levels of CD163, MCP-1, adiponectin and PF4 predicted a sustained 30% decline in kidney function.

The study suggests that urinary biomarkers measured 24 months after an LN flare could serve as useful biomarkers to identify patients at a high risk for future disease activity and kidney function decline, even among those in clinical remission. However, despite clinical remission, many individuals with LN continue to experience kidney inflammation that’s not detected by proteinuria alone. Kidney biopsies remain the gold standard for routine checkups and assessing disease activity in LN. Learn more about lupus and the kidneys.

Read the study