IgA Nephropathy

Built by in-house doctors

What Is IgA Nephropathy?

IgA nephropathy, or IgAN, is a long-term kidney disease in which an antibody called immunoglobulin A builds up in the kidneys. These deposits cause inflammation and can damage the glomeruli—the tiny filters that remove waste and extra fluid from the blood. IgAN is also known as Berger’s disease.

‍

What Causes IgA Nephropathy?

The exact cause is not fully understood. Researchers believe that differences in the immune system cause unusual forms of IgA to collect in the kidneys. Genetics, environmental factors and infections may all play a role. Some people first notice blood in their urine during or shortly after a cold, sore throat or respiratory infection.

‍

Types of IgA Nephropathy

Primary IgAN occurs when IgA nephropathy is the main disease affecting the kidneys. Secondary IgAN is associated with another condition, such as certain liver diseases, celiac disease, inflammatory bowel disease or some infections. Identifying an associated condition may influence how the disease is managed.

IgA nephropathy is different from IgA vasculitis. Both involve IgA deposits, but IgA vasculitis affects small blood vessels throughout the body and may also cause a purple rash, joint pain and abdominal symptoms.

‍

How Is IgA Nephropathy Treated?

Treatment aims to reduce protein loss, control blood pressure and protect kidney function. Medicines such as ACE inhibitors or ARBs are commonly used to lower blood pressure and reduce protein in the urine.

Depending on the person’s risk and kidney function, treatment may also include SGLT2 inhibitors, targeted immune treatments, corticosteroids or other medicines that act on the disease process. Treatment availability varies, and the benefits and possible side effects should be discussed with a kidney specialist.

Risks

Anyone can develop IgAN, although it is often identified in children, teenagers and younger adults. Having a family history of IgAN or IgA vasculitis may increase the likelihood of developing it.

IgAN is also associated with conditions such as celiac disease, inflammatory bowel disease, chronic liver disease and certain infections. Having one of these risk factors does not mean that someone will necessarily develop IgAN, and there is currently no established way to prevent it.

‍

Symptoms

Many people have no noticeable symptoms at first. Early signs may only be found during routine blood or urine tests.

Possible symptoms include pink, red, brown or cola-colored urine caused by blood, foamy urine caused by protein, swelling around the eyes or in the legs and feet, and high blood pressure. These symptoms can also occur with other conditions and do not confirm IgAN on their own.

‍

Diagnosis

Diagnosis usually begins with urine tests, blood tests, blood-pressure measurements and a review of symptoms and family history. These tests can identify blood or protein in the urine and show how well the kidneys are working.

A kidney biopsy is normally needed to confirm IgAN. During a biopsy, a small sample of kidney tissue is examined for IgA deposits and signs of inflammation or scarring.