Shining a light on IgA nephropathy (IgAN)
Chee Kay Cheung is a consultant nephrologist and honorary associate professor at University Hospitals of Leicester. His research focuses on glomerular diseases, especially IgAN. Here he provides his expert insights into some of the most frequently asked questions around IgAN
This article has been sponsored by CSL Vifor and is drawn from a Q&A session which was organised and funded by CSL Vifor.
IgAN, previously known as Berger’s disease, is a rare immune-mediated disease and the most common type of glomerular disease—a condition that affects the kidney’s filters, known as glomeruli.1–4 What sets IgAN apart is the buildup of a specific antibody called immunoglobulin A subtype 1 (IgA1) in these filters, leading to inflammation and potential kidney damage over time.2
IgAN is a complex, often silent condition that can vary widely in how it presents and progresses.2,5,6 Thanks to ongoing research, more is being discovered about the causative role of the immune system and the significant risk of kidney damage, which is paving the way for better diagnosis and treatment.2,5
How common is IgAN?
While IgAN is the most common glomerular disease, it’s still considered rare.1,2,6 Globally, its prevalence varies—it’s more common in East Asia and less so in Western countries.2,7 Interestingly, in North America and Europe, men are more frequently affected than women, with a ratio of about 2 to 3 men for every woman diagnosed.6,8
Why is it sometimes hard to detect?
One of the challenges with IgAN is that it often goes undiagnosed and many people may live with the condition without knowing it. This happens as patients can be asymptomatic and do not experience symptoms until the disease is advanced.5,9
What are the symptoms of IgAN?
IgAN is highly variable. Some people may not notice any symptoms for years, while others might experience:2,5,10
- headaches
- pain around the kidneys
- swelling in the legs
- blood in the urine
Why symptoms appear early in some people and not in others remains unclear.
What causes IgAN?
Recent advances have shed light on the underlying mechanisms. People with IgAN tend to have higher levels of a form of IgA1, a type of antibody, that lacks sugar molecules called galactose. This makes the IgA1 “stickier,” allowing it to clump with other proteins and antibodies. These immune complexes get trapped in the kidney filters, triggering inflammation and damage.2,11
There’s also growing evidence that this problematic IgA1 may originate from the mucosal immune system—especially the gut. This connection is opening new doors for research and potential treatments.2,11,12
Is IgAN genetic?
IgAN isn’t caused by a single gene, but genetics do play a role. Several genes have been linked to the condition, many of which are involved in immune function, IgA production and the gut’s mucosal barrier. These genetic factors may influence both the risk of developing IgAN and how quickly it progresses.2,11
How is IgAN usually diagnosed?
Many people don’t have symptoms until the disease is advanced.5 But routine tests can offer early hints:13
- Urine tests may show blood or protein—even if you feel fine
- Blood tests might reveal reduced kidney function
That said, a kidney biopsy is the only way to diagnose IgAN.2 It’s not just about confirming the condition—it’s about understanding how severe it is.2,11 The biopsy reveals whether there’s inflammation in the kidney affecting the filters and whether there’s a lot of scarring in the kidneys.2,11
What should someone expect when they are undergoing a kidney biopsy?
In many clinics, a kidney biopsy is done as a day case procedure but in other units you may need to be admitted into hospital. You have a pre-assessment where you discuss the procedure, and the risks will be outlined to you. You’ll have a local anaesthetic to numb the area and then a biopsy needle is inserted to take small pieces of kidney out, usually two small cores of kidney which are sent off to be analysed for any underlying disease process. You’ll be mandated around six hours of bed rest to lower the risk of bleeding complications. And then afterwards, when you’re discharged home, it’ll be important to avoid strenuous physical activity.14
How is IgAN managed clinically?
There’s no cure for IgAN—yet. But there’s good news: treatments have come a long way. Just a decade ago, options were limited. Today, innovative therapies might help to slow the progression of kidney disease and improve patient outcomes.15,16 The earlier we can make the diagnosis of IgAN the more chance there is to intervene and to help slow the progression of kidney disease.16 If we diagnose it too late, there can be irreversible scarring, which may mean that people can progress to reaching kidney failure.2,17
Managing IgAN isn’t a solo journey: a multi-disciplinary team that may include a nephrologist (kidney specialist), your GP or primary care doctor, a specialist nurse and potentially a dietitian, pharmacist or psychologist, depending on need. This team works together to tailor a care plan that fits an individual’s life.
Also, important to note are patient support groups. These can be important sources of information and connection for people living with this condition.
Is there a potential for patients to need dialysis or a kidney transplant?
Unfortunately, in some people with IgAN, the kidney disease will progress to reaching kidney failure.2 When that happens, there are options. People can go on to dialysis treatment and this could be haemodialysis. This is where the blood is cleaned through a machine. Or it could be peritoneal dialysis, where fluid is flushed in and out of the abdomen to clean the blood.18
The other option is a kidney transplant. This is generally considered a favorable treatment option. We do know that unfortunately in some people the aberrant IgA can come back in the kidney transplant and that’s because the disease is happening outside of the kidney, within the immune system, and IgA can get stuck in the filters of the newly transplanted kidney.19,20
Can IgAN affect blood pressure?
Many people with IgAN experience high blood pressure.13 We think that’s because when the IgA is deposited within the kidneys, it releases signals from the kidney cells.2 These include angiotensin II and endothelin 1 which are small peptides or hormones that cause blood pressure to increase.21,22
Not only is high blood pressure a common feature, but it can actually worsen the kidney disease itself.2,23 So it’s really important that we keep blood pressure under control, because that’s one of the key factors that can help slow down the rate of progression of kidney disease in people with IgAN.13,15,20,24
How should patients respond if they notice worsening symptoms?
If you do develop more symptoms, for example, increased swelling of your legs or fatigue and you’re worried about them, it’s really important that you discuss these with your doctor and with your medical team, because it could indicate that something is going on with your kidneys or with your underlying condition, and you may need further tests to diagnose that.
What resources are available for people living with IgAN?
Patient support groups, such asIgAN Friends,which has members from across Europe, are a great resource for people living with this condition. You can also visit theMyKidneyHouse,a CSL Vifor owned website, where you’ll find plenty of information, including a brochure to download, Living with IgA Nephropathy, which has been developed to provide high quality information to people living with IgAN or people newly diagnosed with this condition.
This article has been sponsored by CSL Vifor and is drawn from a filmed question and answer session which took place with honorary associate professor Chee Kay Cheung in London, UK, on 19th June 2025. The Q&A session was organised and funded by CSL Vifor and is intended to provide information about IgA nephropathy to the readership of RARE Revolution Magazine and the wider IgA nephropathy community.
Abbreviations
IgA, immunoglobulin A; IgA1, immunoglobulin A subtype 1; IgAN, immunoglobulin A nephropathy
References
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[13] National Kidney Foundation (2024). IgA Nephropathy (IgAN). https://www.kidney.org/kidney-topics/iga-nephropathy. Date Accessed: October 2025.
[14] NHS Hull Teaching Hospitals (2020). Having a kidney biopsy. Available at: https://www.hey.nhs.uk/patient-leaflet/having-a-kidney-biopsy/. Date Accessed: October 2025.
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[18] National Health Service (NHS) (2021). Overview Dialysis. Available at: https://www.nhs.uk/tests-and-treatments/dialysis/. Date Accessed: October 2025.
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[22] Kohan D, et al. Clin Sci. 2024;138:645‒62.
[23] National Kidney Foundation. High Blood Pressure and Chronic Kidney Disease. Available at: https://www.kidney.org/high-blood-pressure-and-chronic-kidney-disease. Date Accessed: October 2025.
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UK-SPT-2500227 | October 2025
