IgA nephropathy (nuh-FROP-uh-thee), also known as Berger's disease, is a kidney disease that occurs when an antibody called immunoglobulin A (IgA) builds up in your kidneys. This results in local inflammation that, over time, can hamper your kidneys' ability to filter waste from your blood.
IgA nephropathy usually progresses slowly over years, but the course of the disease varies from person to person. Some people leak blood in their urine without developing problems, some eventually achieve complete remission and others develop end-stage kidney failure.
No cure exists for IgA nephropathy, but certain medications can slow its course. Keeping your blood pressure under control and reducing your cholesterol levels also slow the disease.
IgA nephropathy care at Mayo Clinic
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IgA nephropathy usually doesn't cause symptoms in the early stages, so the disease can go unnoticed for years or decades. It's sometimes suspected when routine tests reveal protein and red blood cells in your urine that can't be seen without a microscope (microscopic hematuria).
Signs and symptoms of IgA nephropathy include:
- Cola- or tea-colored urine (caused by red blood cells in the urine)
- Repeated episodes of cola- or tea-colored urine, and sometimes visible blood in your urine, usually during or after an upper respiratory or other infection and sometimes after strenuous exercise
- Foamy urine from protein leaking into your urine (proteinuria)
- Pain in the one or both sides of your back below your ribs
- Swelling (edema) in your hands and feet
- High blood pressure
When to see a doctor
Make an appointment with your doctor if you see blood in your urine. Urinary bleeding can have a number of causes, but prolonged or repeated bleeding might indicate a serious medical problem. Also see your doctor if you develop sudden swelling in your hands and feet.
Kidney cross section
Kidney cross section
The kidneys remove waste and excess fluid from your blood through filtering units called nephrons. Each nephron contains a filter (glomerulus) that has a network of tiny blood vessels called capillaries. When blood flows into a glomerulus, tiny molecules — water, essential minerals and nutrients, and wastes — pass through the capillary walls. Large molecules, such as proteins and red blood cells, do not. The filtered solution then passes into another part of the nephron called the tubule. The water, nutrients and minerals your body needs are transferred back to the bloodstream. The excess water and waste become urine that flows to the bladder.
Your kidneys are two bean-shaped, fist-sized organs situated at the small of your back, one on each side of your spine. Each kidney contains tiny blood vessels that filter waste, excess water and other substances from your blood as they pass through your kidneys. The filtered blood reenters your bloodstream, while the waste material passes into your bladder and out of your body when you urinate.
Immunoglobulin A (IgA) is an antibody that plays a key role in your immune system by attacking invading pathogens and fighting infections. But in IgA nephropathy, this antibody collects in the glomeruli, causing inflammation (glomerulonephritis) and gradually affecting their filtering ability.
Researchers don't know exactly what causes IgA deposits in the kidneys, but the following might be associated:
- Genes. IgA nephropathy is more common in some families and in certain ethnic groups.
- Liver diseases. These include cirrhosis, a condition in which scar tissue replaces normal tissue within the liver, and chronic hepatitis B and C infections.
- Celiac disease. Eating gluten, a protein found in most grains, triggers this digestive condition.
- Infections. These include HIV and some bacterial infections.
Although the exact cause of IgA nephropathy is unknown, these factors might increase your risk of developing this condition:
- Sex. In North America and Western Europe, IgA nephropathy affects at least twice as many men as it does women.
- Ethnicity. IgA nephropathy is more common in whites and Asians than it is in blacks.
- Age. IgA nephropathy most often develops between the late teens and late 30s.
- Family history. In some cases, IgA nephropathy appears to run in families, indicating that genetic factors contribute to the disease.
The course of IgA nephropathy varies from person to person. Some people have the disease for years with few or no problems. In fact, many cases go undiagnosed. Other people develop one or more of the following complications:
- High blood pressure. Damage to your kidneys from IgA deposits can raise your blood pressure, and high blood pressure can cause further damage to your kidneys.
- High cholesterol. High levels of cholesterol can increase your risk of a heart attack.
- Acute kidney failure. If your kidneys lose their filtering ability due to IgA deposits, waste products build up quickly in your blood.
- Chronic kidney disease. IgA nephropathy can cause your kidneys to gradually stop functioning. Then permanent dialysis or a kidney transplant is needed to live.
- Nephrotic syndrome. This is a group of problems that can be caused by damage to the glomeruli, including high urine protein levels, low blood protein levels, high cholesterol and lipids, and swelling of your eyelids, feet and abdomen.
You can't prevent IgA nephropathy. If you have a family history of the disease, talk with your doctor about what you can do to keep your kidneys healthy, such as reducing high blood pressure and keeping your cholesterol at healthy levels.