Updated on November 11, 2026.
Immunoglobulin A nephropathy (IgAN) is a type of kidney disease that occurs as a result of an underlying problem with the immune system. It involves an antibody protein called immunoglobulin A.
Normally, immunoglobulin A circulates in the blood and helps the body fight off infections. When a person has IgAN, the body produces abnormal versions of immunoglobulin A.
The immune system attacks the abnormal immunoglobulin A. This results in the formation of large immune complexes, clumps of proteins that circulate in the bloodstream.
As these immune complexes move through the kidneys, they become stuck inside the glomeruli. Glomeruli are networks of delicate blood vessels that act as filtering units, removing waste and excess fluid from the blood.
The immune system goes to work clearing away these clogs, but glomeruli become inflamed and damaged in the process. This reduces the kidneys’ ability to filter the blood.
The loss of kidney function is typically gradual, but IgAN can progress quickly in some cases. IgAN can progress to end-stage renal disease, or kidney failure, where the kidneys are no longer functioning well enough to keep a person alive.
What are the goals of treating IgAN?
There is no cure for IgAN. A treatment plan for IgAN will typically focus on addressing specific markers of kidney health, including blood pressure, proteinuria (protein in the urine), and estimated glomerular filtration rate. These specific goals support the larger goals of protecting kidney function and preventing complications.
Blood pressure
Blood pressure is the force that blood exerts on the inner walls of the blood vessels as it moves through the body. Controlling blood pressure is extremely important to the management of any kidney disease.
IgAN often causes high blood pressure, or hypertension. As the kidneys’ filtering units are damaged, blood and protein end up in urine, while sodium and excess fluid remain in the bloodstream.
Excess fluid and sodium contribute to high blood pressure. High blood pressure can damage blood vessels inside the kidneys, accelerating the loss of kidney function. High blood pressure is also a major risk factor for heart failure and other types of cardiovascular disease.
Most treatment plans for IgAN include medications to control blood pressure.
Proteinuria
Blood and protein in the urine are common symptoms of IgAN. In the early stages, blood and protein may not be visible but can be detected with a urine test during a routine medical exam. As the disease progresses, urine may be foamy or appear pink, reddish, dark brown, or tea-colored due to blood and protein content.
Lower proteinuria is associated with better treatment outcomes. Treatment for IgAN can include medications to reduce proteinuria, and some medications that reduce proteinuria also lower blood pressure.
Glomerular filtration rate (GFR)
Glomerular filtration rate (GFR) is how much blood the kidneys filter in a minute. A healthy kidney will filter about half a cup of blood per minute, though this number varies with age. When there is damage to the kidneys, the kidneys cannot filter blood as quickly or as effectively. Measuring GFR shows how well the kidneys are functioning.
This is most commonly done with a blood test called an estimated glomerular filtration rate (eFGR). While this test does not measure GFR directly, it does not require specialized equipment, is less expensive, and less time consuming. A direct measurement of GFR requires specialized equipment, but it is more accurate and may also be recommended.
GFR or eGFR will be used to diagnose and monitor IgAN. Medications for IgAN can help stabilize and protect GFR.
What else should you know about treatment?
Treatment for IgAN will vary from person to person and will depend on the severity of the condition and overall health. IgAN affects different people in different ways. Some experience only mild symptoms, while others experience significant progression that leads to kidney failure. Even in cases where IgAN symptoms are mild or minimal, the disease can progress.
Different people also have different health concerns and needs. Treatment plans often include medications to lower cholesterol levels. Limiting salt, quitting smoking (for anyone who smokes), and other changes to diet and lifestyle are also important to treatment.
Your healthcare provider will be your best source of information about your diagnosis, test results, risk of complications, and treatment options.
