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.