Noninvasive Test Helps Identify Cause of Specific Kidney Disease

The first test that can help determine a specific type of kidney disease, called membranous glomerulonephritis (MGN) has been authorized for marketing.

Membranous glomerulonephritis (MGN) is a chronic kidney disease that causes damage to the glomeruli, which are the cluster of tiny tufts of capillary blood vessels in the kidney that filter the blood and begin the process to remove waste and excess fluid from the blood.

The US Food and Drug Administration (Silver Springs, MD, USA) reviewed a clinical study of 560 blood samples of which 275 samples were obtained from patients with presumed primary MGN (pMGN), while 285 samples were obtained from patients diagnosed with other kidney diseases including secondary MGN (sMGM) and autoimmune diseases, not including pMGN, that can damage the kidney, like lupus erythematosus.

The EUROIMMUN Anti- PLA2R IFA blood test (Euroimmun US Inc.; Morris Plains, NJ, USA) detects if a patient has an antibody, a protein molecule the body’s immune system produces, that is specific to pMGN. The test was able to detect pMGN in 77% of the presumed pMGN samples, and gave a false positive result in less than 1% of the other disease samples. Notably, the test was helpful in distinguishing between pMGN from sMGN in most of the patients. The test should not be used alone to diagnose pMGN. Additional information, including patient symptoms and other laboratory tests, should always be considered when making a diagnosis of pMGN. A biopsy of the kidney is needed to confirm the diagnosis of pMGN. A negative result from the test does not rule out a diagnosis of pMGN.

Alberto Gutierrez, PhD, director of the Office of In Vitro Diagnostics at the FDA, said, “Treatment of MGN depends on the underlying cause of the disease. This test can help patients get a timely diagnosis for their MGN and aid with earlier treatment.” The FDA reviewed the EUROIMMUN Anti- PLA2R IFA blood test through its de novo classification process, a regulatory pathway for some novel low- to moderate-risk medical devices that are first-of-a-kind. The test should not be used to monitor the stage of disease or the response to treatment.

Symptoms of MGN include swelling, high cholesterol, high blood pressure and increased predisposition to blood clots. Over time, usually 10 to 20 years, some people with MGN proceed to kidney failure and require a kidney transplant. MGN affects mostly adult, Caucasian men. About 85% of MGN cases are caused by the body’s immune system mistakenly attacking healthy kidney tissue, which is one of the leading causes of kidney disease in adults.

Related Links:
US Food and Drug Administration
Euroimmun US Inc.