Two Studies Show Potential for Novel Biomarkers to Replace Surgical Biopsy in Detecting and Monitoring Lupus Kidney Disease

Lupus Research Institute-Funded Scientists Show Positive Results With Non-invasive Alternatives

Studies funded by the Lupus Research Institute (LRI) show the potential for two novel and non-invasive tests using biomarkers to assess kidney disease in lupus without the need for biopsy, an invasive procedure. Measurable substances that increase or decrease according to the degree of disease, biomarkers are looked at more and more in diagnosis and treatment.

Results just published in the October 1 issue of Kidney International show that a novel investigational contrast agent developed by Dr. Joshua Thurman at University of Colorado, when used with magnetic resonance imaging (MRI), can detect proteins in the kidney that indicate disease. Similarly, research by Chaim Putterman, MD at Albert Einstein College of Medicine in New York and Chandra Mohan, MD at University of Texas Southwestern Medical Center in Dallas shows potential for a non-invasive test to monitor kidney disease by measuring levels of specific proteins in urine. Both studies, performed in mice, are now moving to investigations in the human disease.

Affecting at least one third of lupus patients, kidney disease can cause irreversible damage. While several tests can be done to assess kidney function, biopsy is typically needed if kidney disease is suspected. Performed in the hospital, biopsy is an invasive procedure, removing a small sample of kidney tissue with the potential for complications.

Novel Agent with MRI to Detect Kidney Damage

With funding from the LRI, Joshua Thurman, MD and his colleagues developed a novel diagnostic tool, known as an MRI contrast agent, that makes it possible to see lupus kidney damage using MRI. The agent detects proteins deposited in the kidneys as part of the immune system's attack, which then serves as a biomarker for disease. MRI scans of lupus mice injected with the agent showed a correlation between the amount of these proteins and the severity of kidney inflammation in early and mid-stages of disease. Using a biomarker to monitor disease may substitute for biopsy.

Dr. Thurman noted, "In addition to being potentially safer, the MRI approach should be more sensitive than biopsy by looking at the entire kidney rather than just a small sampling. MRI also could be used to track a patient's disease over time and to measure response to treatment in a clinical trial. Based on these encouraging results, we plan to investigate the agent in lupus patients."

Urine Testing for Kidney Disease

Working collaboratively under a consortium grant from the Lupus Research Institute, Drs. Putterman and Mohan have also been investigating biomarkers to develop non-invasive tests to diagnose and monitor kidney damage from lupus. Their animal study identified four proteins that show up in urine in increasing quantities as kidney damage progresses. Each of these proteins is either present in humans or has a human equivalent. Based on the success in these studies, the researchers currently are studying whether an increase in the levels of these proteins also indicates an increase in disease among lupus patients.

"With LRI funding, we are now conducting tests in humans, using the urine of people with lupus to determine the value of these proteins as biomarkers or indicators of disease severity," commented Dr. Putterman. "If we can predict flares when patients' symptoms suddenly worsen and monitor their response to treatment, we can better manage their disease."

Recognizing the need for continued novel research to understand the physiologic, biologic, molecular and genetic basis of human lupus, the Lupus Research Institute has expanded this pioneering work through its Human Lupus Biology Initiative launched just three years ago. Innovative human studies now comprise more than half of the LRI's research portfolio.

About Lupus

Lupus is a chronic, complex and prevalent autoimmune disease that affects more than 1.5-million Americans. More than 90% of lupus sufferers are women, mostly young women between the ages of 15 to 44. Women of color are especially at risk. In lupus, the immune system, which is designed to protect against infection, creates antibodies that attack the body's own tissues and organs -- the kidneys, brain, heart, lungs, blood, skin, and joints. Lupus is difficult to diagnose, difficult to treat, and is a leading cause of premature cardiovascular disease, kidney disease and stroke among young women. While there is no known cause or cure, the progress of recent discoveries is highly promising. For more information about lupus and kidney disease, visit the website of the service arm of the Lupus Research Institute, the S.L.E. Lupus Foundation, at: http://www.lupusny.org/about-lupus/fight-lupus-body-and-mind/lupus-and-your-kidneys.

About the Lupus Research Institute

The Lupus Research Institute (LRI), the world's leading private supporter of innovative research in lupus, pioneers discovery and champions scientific creativity in the hunt for solutions to this complex and dangerous autoimmune disease. Founded by families and shaped by leading scientists, the LRI mandates sound science and rigorous peer review to uncover and support only the highest ranked novel research to prevent, treat and cure lupus.

With its National Coalition of state and local lupus organizations, the LRI is dedicated to finding new and safer options for treating the disease by improving the design of clinical studies and promoting broad participation in clinical trials.