What is IgA nephropathy (IgAN)?

A rare autoimmune condition where abnormal antibody proteins build up in the kidney's tiny filters (glomeruli), IgAN causes dangerous inflammation, scarring, and long-term organ damage.

IgA nephropathy (also known as Berger's disease) is a chronic kidney disease caused by deposits of abnormal immunoglobulin A (IgA), a protein that normally helps the body's immune system fight infections, accumulating inside the filters of the kidneys (glomeruli).1

When IgA proteins do not form correctly, they build up in these filters, causing localised inflammation, swelling, and progressive scarring. Over time, this damage impairs the kidneys' ability to filter waste, leading to key signs such as blood (hematuria) and protein (proteinuria) leaking into the urine.1,2

Kidney failure occurs when almost all (over 85%) kidney function is lost.3 When the kidneys fail, dialysis or a kidney transplant is needed to survive.

Key Facts About IgA Nephropathy (IgAN):⁴

Condition Type: Chronic (long-term) autoimmune kidney disorder.
Primary Cause: Abnormal IgA protein accumulation causing renal inflammation and scarring.
Common Symptoms: Blood in the urine (hematuria), protein in the urine (proteinuria), and elevated blood pressure.
Curability: There is currently no cure for IgA nephropathy; clinical management focuses on slowing disease progression and preserving kidney function.

Who does IgAN affect?

At least 25 adults per million worldwide each year.5

Leads to end-stage kidney disease in up to 50% of patients within 20 years of diagnosis.6

Living with IgAN can affect many aspects of life. Daily activities may become more challenging, mental wellbeing can be impacted, and the condition may stand in the way of important goals, such as careers or family planning.6,7,8

What are the signs and symptoms?

Signs and symptoms may include:9

Brown urine caused by red blood cells

Foamy urine caused by protein

High blood pressure

Swelling in the hands, face, feet, belly, or around the eyes

By applying our long-standing expertise in immunology, we want to deliver meaningful innovation that addresses the needs of people with IgAN, and prevent or delay progression to kidney failure.

References

Lai KN, et al. IgA nephropathy. Nat Rev Dis Primers. 2016;2:16001.
Suzuki, Hitoshi et al. “The pathophysiology of IgA nephropathy.” Journal of the American Society of Nephrology : JASN vol. 22,10 (2011): 1795-803. doi:10.1681/ASN.2011050464
KDIGO2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. 2024;105(4S):S117-S314.
KDIGO 2025 Clinical Practice Guideline for the Management of Immunoglobulin A Nephropathy (IgAN) and Immunoglobulin A Vasculitis (IgAV) . Kidney Int. 2025;108(4S):S1-S71.
McGrogan A, et al. The incidence of primary glomerulonephritis worldwide: a systematic review of the literature. Nephrol Dial Transplant. 2011;26:414-430. doi:10.1093/ndt/gfq665
Caster DJ, et al. Clinicopathological characteristics of adult IgA nephropathy in the United States. Kidney Int Rep. 2023;8:1792-1800. doi:10.1016/j.ekir.2023.06.016
Kwon, Christina Soeun et al. “A Systematic Literature Review of the Epidemiology, Health-Related Quality of Life Impact, and Economic Burden of Immunoglobulin A Nephropathy.” Journal of health economics and outcomes research vol. 8,2 36-45. 1 Sep. 2021, doi:10.36469/001c.26129 .
Jarrick, Simon et al. “Pregnancy outcomes in women with immunoglobulin A nephropathy: a nationwide population-based cohort study.” Journal of nephrology vol. 34,5 (2021): 1591-1598. doi:10.1007/s40620-021-00979-2
National Kidney Foundation. IgA nephropathy. [Internet, cited September 2026]. Available from: https://www.kidney.org/kidney-topics/iga-nephropathy.

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