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 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.
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.
IgA nephropathy is often detected after you notice blood in your urine or when a routine test shows that you have protein or blood in your urine. These tests can help identify which kidney disease you have:
- Urine tests. Blood or protein in the urine, a possible first sign of IgA nephropathy, might be discovered during a routine checkup. If your doctor suspects that you have problems with your kidneys, you might be asked to collect your urine for 24 hours for additional kidney function tests.
- Blood tests. If you have kidney disease, a blood test might show increased blood levels of the waste product creatinine.
- Kidney biopsy. This procedure is the only way for your doctor to confirm a diagnosis of IgA nephropathy. It involves using a special biopsy needle to extract small pieces of kidney tissue for microscopic examination.
- Iothalamate clearance test. Your doctor may also recommend this test, which uses a special contrast agent to track how well your kidneys are filtering wastes.
There's no cure for IgA nephropathy and no sure way of knowing what course your disease will take. Some people need only monitoring to determine whether the disease is getting worse.
For others, a number of medications can slow disease progress and help manage symptoms.
Medications to treat IgA nephropathy include:
- High blood pressure medications. Taking angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) can lower your blood pressure and reduce protein loss.
- Omega-3 fatty acids. These fats, available in dietary fish oil supplements, might reduce inflammation in the glomeruli without harmful side effects. Talk to your doctor before you start supplements.
- Immunosuppressants. In some cases, corticosteroid medications, such as prednisone, and other potent drugs that suppress the immune response (immunosuppressants) might keep your immune system from attacking your glomeruli. These drugs can cause serious side effects, such as high blood pressure, high blood sugar and increased risk of infection.
- Statin therapy. If you have high cholesterol, cholesterol-lowering medications can help control it and slow the progression of kidney damage.
- Diuretics. These help remove extra fluid from your blood. Removing extra fluid can help improve blood pressure control.
The ultimate goal is to avoid the need for kidney dialysis or kidney transplantation. But in some cases, dialysis or transplantation is necessary.
Lifestyle and home remedies
To help keep your kidneys healthier:
- Take steps to reduce your blood pressure. Keeping your blood pressure levels near normal can help slow kidney damage from IgA nephropathy. Healthy changes in your lifestyle — including limiting your salt intake, losing excess weight, being physically active, using alcohol in moderation and taking your blood pressure medications as prescribed — are ways to keep your blood pressure under control.
- Monitor your blood pressure at home. Note each reading and bring this record with you to your doctor's appointments.
- Eat less protein. Reducing the amount of protein you eat and taking steps to decrease your cholesterol levels may help slow the progression of IgA nephropathy and protect your kidneys.
Coping and support
Coping with severe forms of IgA nephropathy can be challenging. But you don't have to do it alone. If you have questions or need guidance, talk with a member of your health care team.
You might also benefit from joining a support group, which can provide both empathetic listening and helpful information. To find out about support groups in your area that deal with kidney disease, ask your doctor. Or contact the National Kidney Foundation (NKF) to learn about NKF Peers, a national, telephone-based peer support program. Call 855-NKF-PEER (855-653-7337) to participate.
Preparing for an appointment
You're likely to start by seeing your primary care doctor. However, you might be referred to a doctor who specializes in treating kidney disorders (nephrologist). Here are some tips for getting ready for your appointment.
What you can do
Ask about pre-appointment restrictions, such as fasting for a blood test, when you make the appointment.
Make a list of:
- Your symptoms, including any that seem unrelated to the reason for your appointment, and when they began
- All medications and doses, including over-the-counter drugs, vitamins, herbs or other supplements you take
- Questions to ask your doctor
Ask a family member or friend to go with you to help you remember the information you receive.
Questions to ask your doctor include:
- What tests do I need?
- What's the best course of action? How long will I need medications?
- Can I manage this disease with diet and lifestyle changes?
- I have other health conditions. How can I best manage these conditions together?
- Do you have printed materials on this condition I can have? What websites do you recommend?
What to expect from your doctor
Your doctor is likely to ask you questions, such as:
- Have your symptoms been continuous or occasional?
- How severe are your symptoms?
- Does anything seem to improve your symptoms?
- What, if anything, appears to worsen your symptoms?