What is IgA nephropathy (IgAN)?
Immunoglobulin A nephropathy, more commonly called IgA nephropathy or IgAN, is a chronic autoimmune disease. Although it’s often referred to as a kidney disease, it is actually thought to start in the gut.
And while it may not start in the kidneys, IgAN can lead to chronic kidney disease, end-stage kidney disease, and even kidney transplant. In fact, more than half of people with the disease may progress to end-stage kidney disease within 20 years of the initial diagnosis.
For many people, the first signs of IgAN include:
Bloody or frothy urine
Lower back pain
Swelling in the hands or feet
These are only some of the initial symptoms that may occur.
If IgAN is suspected, a kidney biopsy is needed in order to confirm the diagnosis.
Helpful questions to ask your doctor
How does IgAN happen?
Did you know?
Terms to know
When it comes to IgAN, a lot of the related terms can be challenging to pronounce, remember, or understand. With that in mind, we’ve listed some of the most important terms and what they mean below.
Antibodies are made by cells in the immune system called “B cells.” When the body recognizes something that does not belong, such as bacteria, viruses, or toxins, B cells make antibodies that attach to it and help the body remove it. Another name for antibody is immunoglobulin.
Peyer’s patches are areas of lymphoid tissue, like tonsils, lymph nodes, or the spleen, that play a large role in the immune system. They monitor for things that do not belong in the intestines and help destroy them if needed. Peyer’s patches are a main site of the immune cells that make the antibodies thought to contribute to IgA nephropathy.
Autoantibodies are antibodies that attack a person’s own body. Normally, the immune system, including antibodies, will ignore normal tissues. Autoantibodies will do the opposite and target a normal part of the body for destruction by the immune system. Some autoimmune diseases, such as IgA nephropathy, are caused by autoantibodies.
When there are increased levels of protein in the urine, this is called proteinuria. It can happen when the kidneys are inflamed or damaged. Measuring proteinuria levels in people with IgA nephropathy is a way to see if the kidneys show signs of potential damage. Typically, proteinuria is measured through a urinalysis.
Estimated glomerular filtration rate (eGFR)
Estimated glomerular filtration rate or eGFR is a measure of how well your kidneys are functioning and filtering blood. It is measured by a blood test.
The renin-angiotensin system (RAS) is used by the body to help control blood pressure. The body monitors for things like changes in blood pressure to the kidneys and salt content in the blood. Depending on these factors, the body can increase blood pressure.
Renin-angiotensin system inhibition (RASi)
When antibodies bind to their target, they form an immune complex. There can be more than one antibody or antigen in the complex. In diseases like IgA nephropathy, immune complexes can cause damage to the kidneys.
This is a test of the urine. It can check for many things, including color, odor, pH, blood, protein, glucose, bacteria, cells, and other substances. If you are living with IgA nephropathy your doctor will conduct this test on an ongoing basis to determine the best treatment plan for you.
Urine protein-to-creatinine ratio (UPCR)
This urine test is used to measure protein in the urine and can be used to monitor kidney function and detect kidney damage.