Urine Test Could Replace Painful Kidney Biopsies for Lupus Patients

Lupus is an autoimmune disorder that causes the immune system to attack the body’s own tissues and organs. Among the five million people living with lupus globally, nearly half develop lupus nephritis, a severe kidney inflammation that is a leading cause of death. Between 5% and 25% of patients with lupus nephritis die from kidney-related complications within five years of onset. Currently, monitoring kidney health relies on renal biopsies—painful, invasive procedures with risks of bleeding and infection, as well as subjectivity in interpretation. Now, monitoring kidney damage in lupus patients may soon become far less invasive.

A new study from the University of Houston (Houston, TX, USA) has found that urine samples can reveal the severity and progression of lupus nephritis—a major complication of systemic lupus erythematosus (SLE)—without requiring repeat renal biopsies. The discovery could transform disease management for millions worldwide. The new study aimed to identify noninvasive biomarkers capable of predicting kidney inflammation and scarring by analyzing urinary proteins through a large-scale proteomics approach.

Image: Urine samples can indicate lupus nephritis without the need for repeat and painful renal biopsies (Photo courtesy of Shutterstock)

Using 1,317 urine samples collected at the time of biopsy from patients with lupus nephritis, the researchers identified 57 proteins that were significantly elevated in individuals whose kidney tissue showed active damage. These elevated proteins were linked to microscopic signs such as vascular swelling, tissue necrosis, and clusters of injured cells—hallmarks of ongoing inflammation.

Further analysis revealed that some urinary proteins were also associated with chronic scarring, suggesting they could help clinicians distinguish between active disease and long-term damage. These findings, published in The Journal of Clinical Investigation, demonstrate that urine-based biomarkers could provide a reliable, repeatable, and noninvasive way to assess kidney disease activity and progression in lupus patients.

“Overall, the results indicate that by measuring certain proteins in urine, doctors might be able to tell how active or long-lasting someone’s lupus-related kidney disease is, and they could check kidney health without having to do another biopsy,” said Dr. Chandra Mohan, an international expert and pioneer in lupus research at the University of Houston.

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