IgA nephropathy overview
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Immunoglobulin A nephropathy, or IgA nephropathy, is a chronic (long-term) kidney condition characterized by the accumulation of an antibody called immunoglobulin A (IgA) inside the kidney’s filtration units (glomeruli).
The disease is a leading cause of kidney inflammation and kidney failure.
What is IgA nephropathy?
IgA nephropathy, also called Berger disease or IgAN, is a chronic, autoimmune kidney condition that causes abnormal deposits of the immune protein IgA inside the kidneys’ filtration units. This accumulation can damage the kidneys and lead to chronic kidney disease or eventually renal (kidney) failure. Although IgA nephropathy is a relatively rare condition, the illness remains one of the leading causes of kidney disease and renal failure.
How IgA nephropathy affects the kidneys
Inside the kidneys are many small structures called glomeruli (singular: glomerulus), composed of clusters of capillaries (tiny blood vessels) and specialized cells. Glomeruli help remove waste and excess fluid from the blood, which is later excreted as urine. They also prevent non-waste substances, like large proteins and blood cells, from entering the urine.
In IgA nephropathy, the body begins to produce an abnormal form of the IgA protein, which causes the immune system to produce antibodies against it. Complexes (clusters) of abnormal IgA and other antibodies can accumulate within the glomeruli. These complexes irritate the glomeruli, causing inflammation, damage, and overgrowth of certain cell types. Altogether, these changes impair the glomeruli’s ability to filter, leading to poor kidney function or failure over time.
What causes IgA nephropathy?
Doctors are still trying to understand IgA nephropathy causes. The condition is most commonly diagnosed in young adults (teens-30s) and can affect people of all racial and ethnic backgrounds, although the disease appears more common and sometimes more severe in people from East Asia.
Two types of IgA kidney disease have been identified: primary and secondary IgA nephropathy. Most cases (about 90%) of primary IgA nephropathy are sporadic, meaning medical experts have identified no known cause. The illness often develops after an infection, yet it isn’t infectious or caused by a specific type of illness. Less than 10% of IgA nephropathy cases are genetic, and several different genes may influence disease development.
Secondary IgA nephropathy develops as a consequence of another condition. Many different conditions, including liver disease, inflammatory bowel disease, celiac disease, psoriasis, some lung diseases, and certain cancers, are associated with IgA nephropathy. Specific medications can also cause the condition, though this is relatively rare.
Common signs and symptoms
IgA nephropathy is often asymptomatic (doesn’t cause symptoms), or causes only mild and non-specific symptoms. IgA nephropathy symptoms can include the following:
- Episodes of bloody urine: The urine may look red or pink, or sometimes “cola colored.” These episodes usually last only a few days and are more common during illness, especially respiratory or gastrointestinal infections. Bleeding may also happen after intense exercise or without a clear trigger.
- Frothy urine: This issue stems from having excess protein in the urine.
- Microscopic hematuria or proteinuria: Blood or protein in the urine remains invisible to the naked eye but can be detected by a urine test.
- High blood pressure: If the kidneys aren’t filtering blood properly, high blood pressure (hypertension) can develop.
- Gastrointestinal symptoms: Some patients experience non-renal symptoms like abdominal pain, cramping, or diarrhea.
Because the symptoms of IgA nephropathy can be so mild, it often isn’t detected until routine urine or kidney function tests detect the condition. Occasionally, clinicians unfamiliar with the disease misdiagnose blood in the urine as a urinary tract infection. However, urinary tract infections rarely feature significant blood or protein in the urine and typically present with symptoms such as burning or pain during urination.
How IgA nephropathy is diagnosed
If a doctor suspects IgA nephropathy, they may test the urine for blood and protein. They may also run blood tests to check kidney function. A definitive IgA nephropathy diagnosis requires a kidney biopsy, a procedure in which a doctor takes a small sample of kidney tissue to look for IgA deposits.
How doctors assess the risk of disease progression
Doctors use several factors to assess the risk of IgA nephropathy progression and recommend treatment. These include the following criteria:
- Current kidney function
- Blood pressure levels
- Microscopic appearance of kidney tissue, including signs of cellular overgrowth (hypercellularity), tissue scarring, wasting (atrophy), or “crescent” formation within the glomeruli
- The amount of protein in the urine
Treatment and monitoring
IgA nephropathy doesn’t always require treatment right away. If the kidneys are still functioning well and have minimal damage, a doctor may recommend periodic monitoring rather than active treatment. People with kidney conditions often have no symptoms at all until they reach advanced kidney failure, so routine follow-up with a physician is very important.
If kidney function is affected, IgA nephropathy treatment often includes blood pressure medications such as angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, which lower blood pressure, reduce proteinuria, and slow disease progression. In addition, a number of treatments designed to preserve kidney function by targeting molecules thought to contribute to IgA nephropathy are approved for people with the disease.
Some studies also suggest that omega-3 supplements can be beneficial. Lifestyle changes, such as quitting smoking and following a low-salt or low-protein diet, may also be helpful. In severe cases, immunosuppressive medications may be necessary, and individuals with severe disease or kidney failure may require a kidney transplant
Can IgA nephropathy lead to kidney failure?
IgA nephropathy can sometimes progress to kidney failure, though estimates about its prevalence vary widely. Up to 50% of patients never experience progression or complications, and many individuals maintain good health through conservative management, such as blood pressure medication. While IgA nephropathy can recur after a kidney transplant, the condition usually doesn’t progress to end-stage renal disease (kidney failure) a second time, and continued treatment can slow disease progression in the new kidney.
Living well with IgA nephropathy
Overall, the IgA nephropathy prognosis (outcome) is often positive, and individuals can live for many years with the condition. Attending regular medical appointments for kidney function monitoring, taking prescribed medications consistently, and following recommended dietary or lifestyle guidelines can help slow or prevent kidney damage, allowing people with IgA nephropathy to live full lives.
IgA Nephropathy News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
