Association of low-grade proteinuria with changes of lupus nephritis in kidney biopsy in SLE patients.

This article focuses on the histopathological findings in systemic lupus erythematosus (SLE) patients with low-level proteinuria (urine protein-to-creatinine ratio [UPCR] ≤500 mg/g) who underwent kidney biopsy at Johns Hopkins University. Among 27 patients studied, 85.1% showed evidence of lupus nephritis (LN), predominantly class III and V, despite many having normal or low proteinuria and some lacking typical serological markers such as anti-dsDNA antibodies or low complement levels. Kidney biopsy findings led to significant changes in immunosuppressive treatment, highlighting that current guidelines excluding biopsy for low proteinuria may miss early LN. The study suggests the need for improved biomarkers to better identify SLE patients who would benefit from early kidney biopsy to prevent progression of kidney damage.