IgA nephropathy (Berger's disease)

Definition

IgA nephropathy — also called Berger's disease — is a common kidney disease that occurs when an antibody called IgA lodges in your kidneys. This hampers your kidneys' ability to filter waste and excess water from your blood. Over time, IgA nephropathy can lead to blood and protein in your urine, high blood pressure, and swollen hands and feet.

IgA nephropathy usually progresses slowly over many years, and although some people eventually achieve complete remission, 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, limiting protein in your diet and reducing your cholesterol levels also may help keep IgA nephropathy in check.

Symptoms
By Mayo Clinic staff

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 microscopic red blood cells in your urine.

The first visible sign is often cola- or tea-colored urine — the result of urinary blood that you can see.

Signs and symptoms of IgA nephropathy include:

■Repeated episodes of cola-colored or tea-colored urine, usually during or following an upper respiratory infection
■Pain in your side(s)
■Foam in the toilet water from protein in your urine
■Swelling (edema) in your hands and feet
■High blood pressure
■Low-grade fever
When to see a doctor
Make an appointment with your doctor if you have blood in your urine. Urinary bleeding often isn't serious and can result from strenuous exercise and some foods and medications. But prolonged bleeding may indicate a medical problem and should always be evaluated. Also see your doctor if your urine is foamy or you develop unaccustomed swelling in your hands and feet.

Causes
By Mayo Clinic staff

CLICK TO ENLARGE
Kidney cross section
Your kidneys are two bean-shaped, fist-sized organs located at the small of your back, one on either side of your spine. Each kidney contains approximately 1 million glomeruli — tiny blood vessels that filter waste and excess water from your blood as it passes 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. Every day about 2 quarts of water, along with waste products, leave your body as urine.

Immunoglobulin A (IgA) is an antibody that plays a key role in your immune system by attacking invading pathogens. But in IgA nephropathy, this antibody collects in the glomeruli, affecting their filtering ability.

Researchers don't know exactly what causes IgA deposits in the kidneys, although IgA nephropathy appears to have a genetic component in some people.

IgA nephropathy is also sometimes associated with other conditions, including:

■Cirrhosis, a condition in which scar tissue replaces normal tissue within the liver
■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 bacterial infections
■Henoch-Schonlein purpura, a condition that results from inflammation of the small blood vessels of the skin, joints, intestine and kidneys
Risk factors
By Mayo Clinic staff

Although the exact cause of IgA nephropathy is unknown, some factors may increase your risk of developing this condition:

■Age. IgA nephropathy can affect people of all ages, including children, but it's most likely to strike people in their 20s and 30s.
■Your sex. In the West, IgA nephropathy affects about 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.

Complications
By Mayo Clinic staff

The course of IgA nephropathy varies considerably from person to person. Some people have the disease for years with few problems; many cases, in fact, 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.
■Acute kidney failure. If your kidneys lose their filtering ability due to IgA deposits, waste products build up quickly in your blood. When this happens, you may need to undergo temporary hemodialysis — an artificial way of cleansing your blood when your kidneys aren't able to do so. During hemodialysis, a needle is inserted into your arm through a special access point. Your blood is then directed through the needle and tubing to a machine called a dialyzer, which filters your blood a few ounces at a time. The filtered blood returns to your body, through another needle.
■Chronic kidney failure. IgA nephropathy can cause your kidneys to gradually stop functioning. Kidney function at less than 10 to 15 percent of normal capacity is considered end-stage kidney disease. 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 (hypoalbuminemia), high cholesterol and swelling of your eyelids, feet and abdomen.