What is IgA Nephropathy?

Learning all you can about the disease can keep you moving in the right direction.

Let’s start with the kidneys

Understanding IgA nephropathy begins with understanding your kidneys.  

Two kidneys, the organs affected by IgA nephropathy

Most people have 2 kidneys1

Computer mouse to show relative size of a human kidney

Most kidneys are the size of a computer mouse2

Kidneys and their position in the human body

Kidneys are situated below your ribs toward the middle of your back1

Kidneys are your body’s filtering system, and each one contains about a million tiny filtering units, called glomeruli. Kidneys remove waste products from your blood and extra fluid from your body through your urine, and let proteins and other nutrients return to your bloodstream. In just one day, your kidneys filter about 150 quarts of blood!3

Filtering units

If your glomeruli  (kidney’s filtering units) don’t work properly, you may experience:



Increased level of protein spills into urine1



Blood spills into urine4

Proteinuria is nephrotoxic.5-7

Damaging or destructive to the kidneys

Lowering proteinuria may lower the risk of your disease progressing (getting worse).8

How does IgAN affect the kidneys?


For those with IgA nephropathy, a specific antibody—immunoglobulin A (IgA)—is made incorrectly by the body and circulates in the blood.9

Another word for antibody is immunoglobulin


Other antibodies are attracted to this misshapen IgA and stick to it, together attracting immune molecules to the kidneys.9


Once these groups of antibodies build up in the kidneys, several harmful events take place. Two molecules in particular, endothelin-1 (ET-1) and angiotensin II (Ang II), can worsen damage to the kidneys’ filters, gradually decreasing kidney function and possibly leading to kidney failure.10-13

Everyone has ET-1 and Ang II in their bodies. But in people with IgA nephropathy, these molecules are more active and promote several destructive processes in the kidneys, such as:

  • Inflammation
  • Tissue scarring
  • Multiplication of—or damage to—important cells
  • Changes in blood pressure and blood flow


The damage done to the kidneys’ filters results in increased proteinuria levels.14,15 Proteinuria then further increases levels of ET-1 and Ang II in the body, creating a harmful cycle.16-18

Increased level of protein spills into urine

Proteinuria can be both a sign of current kidney damage and a cause of future damage.5-7, 14,15

Explore a treatment option that blocks both ET-1 and Ang II.

Who is affected?

IgA nephropathy is a rare kidney disease that is19:

  • Most commonly found in Caucasians and people with ancestry from East Asia, including people from China, Japan, Korea, and Singapore. It can also be found in people with Hispanic heritage9,19
  • 2x more likely to develop in men than women (in North America and Europe)20
  • Known to occur at any age, but tends to appear between one’s teens and late 30s20
Cross section of a kidney, the human organ affected by IgA nephropathy


of IgA nephropathy

You may not experience any symptoms with IgA nephropathy at first.1 In fact, 40% of people living with IgA nephropathy have no recognizable symptoms when their disease is first suspected.21

People can have this disease for years without knowing it, as it continues to progress.1

If you do have symptoms, here are the most common to look for:

Liquid droplet with one half the droplet darker than the other half, to symbolize hematuria, or blood in the urine

Hematuria (blood in your urine) that can make it appear dark brown or cola colored1

If you see blood in your urine, reach out to your doctor immediately as this could be a sign of kidney inflammation.8

Yellow liquid droplet and small white circles symbolizing foamy urine, a sign of large amounts of protein in your urine, or proteinuria

Foamy urine caused by proteinuria (large amounts of protein spilling into your urine)1

Swollen human foot

Edema (swelling) in your legs, feet, or ankles1

Heart symbol to represent high blood pressure

High blood pressure1

View of the inside of a blood vessel, with bumps on the vessel's inside walls symbolizing cholesterol deposits

High cholesterol14

Person placing their hand on their lower back, symbolizing pain in that area

Pain in one or both sides of your back below your ribs1

Person leaning forward and snoring, symbolizing unusual tiredness

Unusual tiredness20 

Do any of these
sound familiar?

A mountain reflected both in daylight and moonlight, symbolizing time passing, and the possibility that IgA nephropathy can get worse over time

IgA nephropathy can get worse over time1

IgA nephropathy can lead to kidney failure. It is important to stay on top of your disease.1 The sooner you take action to lower your proteinuria, the sooner you'll be working to slow your disease progression.22

Increased level of protein spills into urine

The path forward

Progression can be hard to predict because IgA nephropathy varies from person to person.1 But, if you continue to see your doctor, follow your treatment plan, and keep track of numbers like your proteinuria, blood pressure, and eGFR, you and your doctor will have a better idea of how to manage your disease.

Thumbnail of the Doctor Discussion Guide to indicate that the PDF is downloadable

Partner with your doctor

Use this guide to help you have proactive conversations with your doctor and monitor your kidney health, together.

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How is IgAN

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      1. Mayo Clinic. IgA nephropathy (Berger’s disease). Accessed August 2023. https://www.mayoclinic.org/diseasesconditions/iga-nephropathy/symptoms-causes/syc-20352268. 2. University of Pittsburgh Medical Center. Chronic kidney disease. Accessed August 2023. https://www.wmhs.com/upmc-westernmaryland-march-2020-population-healthinitiative-chronic-kidneydisease/. 3. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Your kidneys & how they work. Accessed August 2023. https://www.niddk.nih.gov/health-information/kidneydisease/kidneys-how-they-work. 4. Mayo Clinic. Blood in urine (hematuria). Accessed August 2023. https://www.mayoclinic.org/diseasesconditions/blood-in-urine/symptoms-causes/syc-20353432. 5. Remuzzi G, Bertani T. Pathophysiology of progressive nephropathies. N Engl J Med. 1998;339(20):1448-1456. 6. Dhaun N, Webb DJ, Kluth DC. Endothelin-1 and the kidney—beyond BP. Br J Pharmacol. 2012;167(4):720-731. 7. Cravedi P, Remuzzi G. Pathophysiology of proteinuria and its value as an outcome measure in chronic kidney disease. Br J Clin Pharmacol. 2013;76(4):516-523. 8. Kidney Disease: Improving Global Outcomes (KDIGO) Glomerular Diseases Work Group. KDIGO 2021 Clinical practice guideline for the management of glomerular diseases. Kidney Int. 2021;100(4S):S1-S276. 9. Lai KN, Tang SC, Schena FP, et al. IgA nephropathy. Nat Rev Dis Primers 2. 2016;16001. 10. Floege J, Barratt J, Coppo R, et al. International physicians Delphi survey: managing patients with IgA nephropathy. Kidney Int Rep. 2022;7(9):2076-2080. 11. Komers R, Plotkin H. Dual inhibition of reninangiotensin-aldosterone system and endothelin-1 in treatment of chronic kidney disease. Am J Physiol Regul Integr Comp Physiol. 2016;310(10):R877-R884. 12. Kohan DE, Barton M. Endothelin and endothelin antagonists in chronic kidney disease. Kidney Int. 2014;86(5):896-904. 13. Wyatt RJ, Julian BA. IgA nephropathy. N Engl J Med. 2013;368(25): 2402-2414. 14. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). IgA nephropathy. Accessed August 2023. https://www.niddk.nih.gov/health-information/kidney-disease/iga-nephropathy. 15. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Glomerular disease primer. Accessed August 2023. https://www.niddk.nih.gov/research-funding/at-niddk/labsbranches/kidney-diseases-branch/kidney-disease-section/glomerulardisease-primer/normal-kidney. 16. Zoja C, Morigi M, Figliuzzi M, et al. Proximal tubular cell synthesis and secretion of endothelin-1 on challenge with albumin and other proteins. Am J Kidney Dis. 1995;26(6):934-941. 17. Morigi M, Buelli S, Angioletti S, et al. In response to protein load podocytes reorganize cytoskeleton and modulate endothelin-1 gene: implication for permselective dysfunction of chronic nephropathies. Am J Pathol. 2005;166(5):1309-1320. 18. Tejera N, Gómez-Garre D, Lázaro A, et al. Persistent proteinuria up-regulates angiotensin II type 2 receptor and induces apoptosis in proximal tubular cells. Am J Pathol. 2004;164(5):1817-1826. 19. Kwon CS, Daniele P, Forsythe A, et al. A systematic literature review of the epidemiology, health-related quality of life impact, and economic burden of immunoglobulin A nephropathy. JHEOR. 2021;8(2)36-45. 20. National Organization for Rare Disorders (NORD). IgA nephropathy. Accessed August 2023. https://rarediseases.org/rare-diseases/iga-nephropathy/. 21. Barratt J, Feehally J. IgA nephropathy. J Am Soc Nephrol. 2005;16(7):2088-2097. 22. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Slow progression and reduce complications. Accessed August 2023. https://www.niddk.nih.gov/healthinformation/professionals/clinical-tools-patient-management/kidney-disease/identify-manage-patients/manage-ckd/slow-progression-reduce-complications.

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