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) lodges in your kidneys. This results in local inflammation that, over time, may hamper your kidneys' ability to filter wastes from your blood.
IgA nephropathy usually progresses slowly over many years, but the course of the disease in each person is uncertain. 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 disease progression.
IgA nephropathy usually doesn't cause symptoms in the early stages. The disease can go unnoticed for decades and is sometimes first 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 when kidney function is impaired include:
- Cola- or tea-colored urine (caused by red blood cells in the urine)
- Repeated episodes of cola- or tea-colored urine, sometimes even visible blood in your urine, usually during or after an upper respiratory or other type of infection
- Pain in the side(s) of your back below your ribs (flank)
- Swelling (edema) in your hands and feet
- High blood pressure
When to see a doctor
Make an appointment with your doctor if you notice blood in your urine. Urinary bleeding may be caused by strenuous exercise, some foods, medications or a urinary tract infection.
But prolonged or repeated bleeding may indicate a serious medical problem and should always be evaluated. Also see your doctor if you develop sudden swelling in your hands and feet.
Your kidneys are two bean-shaped, fist-sized organs located at the small of your back, one on each side of your spine. Each kidney contains tiny blood vessels (glomeruli) that filter waste, excess water and other substances from your blood as they pass through your kidneys. The filtered blood re-enters 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 these conditions or factors may be associated with the development of IgA nephropathy:
- Genes, because IgA nephropathy is more common in some families and in certain ethnic groups
- Liver diseases, including cirrhosis, a condition in which scar tissue replaces normal tissue within the liver, and chronic hepatitis B and C infections
- Celiac disease, a digestive condition triggered by eating gluten, a protein found in most grains
- Dermatitis herpetiformis, an itchy, blistering skin disease that stems from gluten intolerance
- Infections, including HIV infection and some bacterial infections
Although the exact cause of IgA nephropathy is unknown, these factors may 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 Caucasians and Asians than it is in blacks.
- Family history. In some cases, IgA nephropathy appears to run in families, indicating that genetic factors may contribute to the disease.
The course of IgA nephropathy varies from person to person. Some people have the disease for years with few problems. In fact, many cases may 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 may 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. In such cases, permanent dialysis or a kidney transplant is needed to sustain life.
- 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.
IgA nephropathy is often detected after you notice blood in your urine or when a routine test shows you have protein or blood in your urine. These could be signs of several types of kidney disease. To identify your problem, these tests may be performed:
- Urine test. Blood or protein in the urine may be the first sign of IgA nephropathy. This may be discovered as part of a routine checkup. If your doctor suspects that you have problems with your kidneys, you may need to collect your urine for a 24-hour period for additional kidney function tests.
- Blood tests. If you have kidney disease, such as IgA nephropathy, a blood test may show increased blood levels of the waste product creatinine.
- Kidney biopsy. The only way for your doctor to confirm a diagnosis of IgA nephropathy is with a kidney biopsy. This procedure involves using a special biopsy needle to extract small pieces of kidney tissue for microscopic examination to determine if there are IgA deposits in the glomeruli.
- Iothalamate clearance test. Your doctor may also recommend an iothalamate clearance 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 definitive way of knowing what course the disease will take. Some people experience complete remission and others live normal lives with low-grade blood or protein in their urine (hematuria or proteinuria).
Treatment with a number of medications can slow the progress of the disease and help you manage symptoms such as high blood pressure, protein in the urine (proteinuria), and swelling (edema) in your hands and feet.
Medications used to treat IgA nephropathy include:
- High blood pressure medications. A common complication of IgA nephropathy is high blood pressure. Taking angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) can lower your blood pressure and reduce the amount of protein (albumin) in your urine.
- Omega-3 fatty acids. These beneficial fats, available in dietary fish oil supplements, may reduce inflammation in the glomeruli without harmful side effects. Get advice from your doctor before you start using supplements.
- Immunosuppressants. In some cases, corticosteroid medications, such as prednisone, and other potent drugs that suppress the immune response (immunosuppressants) may be used to help protect kidney function. But these drugs can cause a range of serious side effects, such as high blood pressure or high blood sugar, so their benefits must be carefully weighed against the risks.
- Statin therapy. Cholesterol-lowering medications may help to slow damage to your kidneys.
- Mycophenolate mofetil (CellCept). Most studies so far have failed to show a benefit for using this medication, but it has been used successfully in some people who have persistent protein in their urine despite treatment with medications that lower blood pressure.
The ultimate goal is to avoid the need for kidney dialysis or kidney transplantation. But in more advanced cases, dialysis or transplantation may be necessary.
If you have signs and symptoms of IgA nephropathy, you're likely to start by seeing your primary care doctor. However, you may be referred to a doctor who specializes in treating kidney disorders (nephrologist).
What you can do
To get ready for your appointment:
- Ask about any pre-appointment restrictions, such as fasting for a blood test, when you make the appointment.
- Make a list of any symptoms you're experiencing, including any that seem unrelated to the reason for your appointment.
- Make a list of all medications and doses, including over-the-counter drugs, vitamins, herbs or other supplements that you're taking — or take the original bottles to your appointment.
- Ask a family member or friend to go with you to help you remember all of the information provided during your appointment.
- Prepare questions to ask your doctor.
Questions you might want to ask your doctor include:
- What tests do I need?
- What is a kidney biopsy and how is it done?
- Is this condition temporary or long lasting?
- What are the chances that I'll develop kidney failure? Is there any way to know?
- What's the best course of action? How long will I have to take medications?
- What are the alternatives to the primary approach that you're suggesting?
- Can this disease be managed with diet and lifestyle changes alone?
- I have other health conditions. How can I best manage these conditions together?
- I've had urinary tract infections in the past. Could these previous infections be a factor?
- Do you have any printed materials on this condition? Is there a website you can recommend where I can learn more?
What to expect from your doctor
Your doctor is likely to ask you several questions, such as:
- When did you begin experiencing symptoms?
- 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?
To help keep your kidneys healthier:
- Take steps to reduce your blood pressure. Keeping your blood pressure levels near normal may help slow kidney damage from IgA nephropathy. Your doctor may recommend healthy changes in your diet — including limiting your salt intake — losing excess weight, being physically active, using alcohol in moderation and remembering to take your blood pressure medications as ways to keep your blood pressure under control.
- Monitor your blood pressure levels 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 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 PEERS Lending Support, a national, telephone-based peer support program from NKF. Call 855-653-7337 to participate.
Because the cause of IgA nephropathy isn't known, it's not possible to prevent it. But if you have a family history of IgA nephropathy, talk with your doctor to find out what steps you can take to keep your kidneys healthy, such as reducing high blood pressure and keeping your cholesterol at healthy levels.