About IgA Nephropathy

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.

Symptoms

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

Causes

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.