When receiving a new diagnosis of immunoglobulin-A nephropathy (IgAN), it’s easy to become overwhelmed by the medical jargon and the myriad questions you’ll have concerning what it is, how you got it, how it affects you, and what you can do about it.* Here are some answers to those questions.

What is IgAN?

IgAN, also known as Berger’s disease, is a kidney disease that occurs when the antibody immunoglobulin-A (IgA) builds up in your kidneys. An antibody is a protein created by your immune system to fight infections. Over time, IgA build-up causes local inflammation that can damage your kidneys, hindering their ability to function properly.

What causes IgAN?

Patients with IgAN create high quantities of a poorly-folded and unstable form of the antibody IgA (IgA1) that circulates in your bloodstream. Your immune system identifies IgA1 as foreign and produces antibodies (anti-IgA1) to fight it. 

These large, warring groups of antibodies become deposited in your glomeruli, a network of tiny blood vessels in your kidneys that help filter wastes from your blood—causing inflammation and damage. Because your own body initiates this process, IgAN is considered an autoimmune disease. 

More research is necessary to fully understand this disease, but evidence suggests that genetics and environmental factors may contribute to the development of IgAN. 

What are the signs and symptoms of IgAN?

IgAN is often asymptomatic in its early stages. As the disease progress, indicators of IgAN can include:

• Dark and/or bloody urine, often after an upper respiratory infection 
• Edema (swelling), due to water retention
• Fatigue
• Low-grade fever
• Flu-like symptoms
• Muscle pain, such as dull aches or spasms

Patients with established IgAN may sometimes experience symptom flare-ups when they have infections or even after vigorous exercise. 

How is IgAN diagnosed?

If you have a family history of kidney disease and are experiencing symptoms, lab tests, and, in some cases, a kidney biopsy are necessary to make an accurate diagnosis. The tests will determine if there are abnormal levels of protein or blood in your urine, and abnormal levels of protein, cholesterol, and wastes in your blood. 

Based on your results, the doctor will calculate your glomerular filtration rate (GFR) to determine how well the kidneys are filtering wastes from your bloodstream. Your GFR is expressed as the percentage of functioning kidney matter you have. Thus, a GFR of 90 is better than a GFR of 60. 

What is the treatment for IgAN?

Until mid-2024, there were no FDA-approved targeted treatments IgAN. Therapies were largely supportive and included:

• Prednisone, a steroid to reduce inflammation (be aware of side effects)
• Dietary modifications, such as reduced sodium and increased omega-3 fish oil intake
• Statins, a lipid-lowering medication to lower cholesterol and reduce the risk of developing heart disease 

In August 2024, the FDA accelerated approval of Fabhalta (iptacopan), a first-in-class complement inhibitor, for treating proteinuria (too much protein in the urine) in adults with IgAN.

There are multiple active phase II (2) and phase III (3) clinical trials in the U.S. that are exploring a variety of potential new therapies that will hopefully continue to advance IgAN treatment in the next few years.

*IgA Nephropathy Foundation. (2021, Feb. 17). IgAN Basics. https://igan.org/igan-basics/