At-Home Test for Lupus Nephritis Could Offer Alternative to Kidney Biopsy

In a preliminary cross-sectional study, the simple, easy-to-use test was 86% accurate in identifying active lupus nephritis in people with lupus.

Systemic Lupus Erythematosus (SLE) is an autoimmune disease that impacts an estimated 204,295 people in the U.S. However, because diagnosing the disease is challenging, that number may be higher.

Lupus can cause chronic inflammation in the joints, skin, and organs, including the heart, brain, and kidneys. This inflammation results from lupus autoantibodies attacking the body’s own cells.

When inflammation occurs in the kidneys, it can lead to lupus nephritis — one of the most serious complications of lupus. If not caught early and treated appropriately, lupus nephritis can lead to kidney failure.

That’s why rheumatologists — the specialists that diagnose and treat lupus — frequently order blood and urine tests to screen for kidney involvement in people with the disease.

However, these tests require a visit to the lab for a blood draw and urinalysis. And, if the lab results suggest lupus nephritis, the next step is undergoing a kidney biopsy — an invasive procedure.

Recently, a team of scientists from the University of Houston developed a new at-home test to diagnose lupus nephritis that uses a smart-phone based app and test kit to screen for urinary ALCAM (uALCAM) — a lupus nephritis biomarker. The easy-to use test is based on the same lateral flow assay (LFA) technology used in pregnancy tests and may eventually replace kidney biopsy to diagnose lupus nephritis.

The team’s research appears in the journal Frontiers in Immunology.

To test the new screening tool, the scientists conducted a preliminary cross-sectional study using 107 urine samples from 30 people with active lupus nephritis, 18 with active non-renal lupus, 29 individuals with inactive SLE, and 30 healthy controls. The samples came from patients from the Hopkins University School of Medicine in Baltimore, Maryland.

After testing the urine and analyzing the results, the scientists found that the new test was 86% accurate in identifying active lupus nephritis in people with lupus.

Although more research is needed, the team suggests this test could be a less expensive and less invasive method than kidney biopsy to diagnose lupus nephritis.

"Urine monitoring for disease biomarkers (such as uALCAM) at regular intervals could potentially be lifesaving because up to 60% of adults and 80% of children with SLE develop [lupus nephritis,] with 10–30% progressing to end-stage renal disease (ESRD) within 15 years of diagnosis, despite aggressive treatment," the study authors wrote.

The authors conclude that the new at-home test could help doctors adjust treatment early-on in active lupus nephritis without the risks associated with repeat kidney biopsies.