IgA Nephropathy
IgA nephropathy is a kidney disease where a specific protein builds up in the kidneys, causing inflammation and damage over time. While it often progresses slowly and may go unnoticed for years, it is one of the most common kidney diseases worldwide and can eventually lead to kidney failure if not properly managed.
Table of contents
- What is IgA Nephropathy?
- Other Names for the Disease
- How Common is IgA Nephropathy?
- Associated Anatomy
- What Causes IgA Nephropathy?
- Who is More Likely to Have IgA Nephropathy?
- Signs and Symptoms
- Complications
- How is IgA Nephropathy Diagnosed?
- Treatment Options
- Lifestyle Changes and Self-Care
- What to Expect After Diagnosis
What is IgA Nephropathy?
IgA nephropathy is a kidney disease that happens when a protein called immunoglobulin A (IgA) builds up in the kidneys[2]. IgA is an antibody, which is a protein your immune system makes to protect you from germs like bacteria and viruses[4].
This buildup causes inflammation, which is a type of swelling, in tiny blood vessels inside your kidneys called glomeruli[2]. These glomeruli are the filtering units of your kidneys that clean waste from your blood[4]. When they become damaged, the kidneys may leak blood and protein into your urine. Over time, this damage can make it harder for the kidneys to filter waste from the blood[2].
IgA nephropathy is an autoimmune disease, which means your immune system mistakenly attacks your own body—in this case, your kidneys[3].
Berger’s disease, Berger disease, IgAN, synpharyngitic glomerulonephritis
Other Names for the Disease
IgA nephropathy is also commonly known as Berger’s disease or Berger disease[2]. The condition was discovered in the late 1960s by two French doctors, Jean Berger and Nicole Hinglais[4].
Other names you might hear include IgAN (a shortened form), IgAN disease, or immunoglobulin A nephropathy[4].
How Common is IgA Nephropathy?
IgA nephropathy is a common kidney disease and an important cause of chronic kidney disease and kidney failure[3]. It is the most common type of glomerulonephritis, which is inflammation of the kidney’s filtering units, worldwide[5].
About 1 in 10 kidney biopsies in the United States show IgA nephropathy[3]. The disease appears more frequently in certain parts of the world. In East Asian countries, IgA nephropathy appears in about 4 out of every 10 kidney biopsies. In European countries, it appears in between 2 and 3 out of every 10 kidney biopsies[4].
IgA nephropathy can affect people at any age, but most people are diagnosed as young and middle-aged adults[13]. Although the disease can affect anyone, men are more likely to have it than women[4].
- Kidneys
- Glomeruli (tiny blood vessels in the kidneys)
- Nephrons (filtering units of the kidneys)
Associated Anatomy
IgA nephropathy affects the kidneys, specifically the glomeruli. The glomeruli are sets of tiny, looping blood vessels located in structures called nephrons, which are the working units of your kidneys that filter wastes and remove extra fluids from your blood[3].
When IgA antibodies and other antibodies form clumps and get stuck in the glomeruli, they cause inflammation and damage[3]. This damage may also lead to scarring of the nephrons[3].
What Causes IgA Nephropathy?
Medical experts believe IgA nephropathy is an autoimmune disease, which means your immune system attacks your kidneys[4]. The exact cause of IgA nephropathy remains largely a mystery, though some researchers believe a problem with how the immune system works can cause it[14].
People with IgA nephropathy have a higher level of IgA with less galactose than is typical. Galactose is a type of sugar. Your immune system considers these low-galactose IgA to be foreign invaders[4]. As a result, other antibodies in your body attach to the low-galactose IgA, and the IgA forms masses or clusters called immune complexes. These immune complexes get stuck in your glomeruli, causing inflammation and damage that result in kidney disease[4].
IgA immune complexes circulate in your body more when you have a cold or upper respiratory infection. Some of these complexes end up in your kidneys, which is why some people have symptoms of IgA nephropathy after a cold[4].
Who is More Likely to Have IgA Nephropathy?
Several factors can increase your risk of developing IgA nephropathy. Risk factors include a genetic family history of IgA nephropathy or IgA vasculitis (formerly known as Henoch-Schönlein purpura)[4]. Some people with IgA nephropathy have a family history of the disease, which suggests there may be a genetic link[14].
Although IgA nephropathy can affect anyone, you may be more likely to have it if you are male, in your late teens to late 30s, or of Asian or European descent[4].
Signs and Symptoms
IgA nephropathy often doesn’t cause symptoms early on. You might not notice any health effects for 10 years or more[2]. Up to 40% of people living with IgAN show no recognizable symptoms at initial diagnosis[13]. Sometimes, routine medical tests find signs of the disease, such as protein and red blood cells in the urine that are seen under a microscope[2].
When IgA nephropathy causes symptoms, they might include[2][13]:
- Blood in the urine (hematuria), which may make urine appear cola-colored or tea-colored
- Protein in the urine (proteinuria), which can make urine appear foamy
- Dark or “cola” colored urine after a viral infection, such as a cold, sore throat, or respiratory illness
- Swelling (edema), especially in the face, eyes, legs, ankles, or abdominal area
- High blood pressure
- Flank pain (pain in the sides of your body near your kidneys)
- Fatigue
- Joint pain
- High cholesterol
The classic presentation of the disease, which happens in 40–50% of cases, is episodic hematuria that usually starts within a day or two of a non-specific upper respiratory tract infection. This is different from post-streptococcal glomerulonephritis, which occurs some time (weeks) after initial infection[5].
Complications
IgA nephropathy often becomes worse slowly over years, but the course of the disease varies from person to person[2]. Some people leak blood into their urine without having other problems. Others might have complications such as losing kidney function and spilling protein into the urine. Still others develop kidney failure, which means the kidneys stop working well enough to filter the body’s waste on their own[2].
Without treatment, IgA nephropathy may gradually get worse and cause kidney failure, also called renal failure. Kidney failure is fatal without treatment[4]. In traditional cases, there is a slow progression to chronic kidney failure in 25–30% of cases during 20 years[5].
High blood pressure is a common complication that puts you at risk for stroke, heart attack, eye damage, and further kidney damage[4]. Other health problems that can develop from worsening kidney disease include anemia and fluid buildup[8].
How is IgA Nephropathy Diagnosed?
IgA nephropathy is often found after you notice blood in your urine. Or a routine test might show that you have protein or blood in your urine[9].
Diagnostic tests may include[9]:
Urine tests: A lab can check a sample of your urine under a microscope. This is done to find out how well your kidneys are working and how much protein the kidneys are spilling. With IgA nephropathy, the lab exam shows blood in the urine or other signs that could hint at inflammation of the tiny filters in the kidneys, called glomeruli.
Blood tests: If you have kidney disease, blood tests might show higher levels of the waste product creatinine or the protein cystatin C.
Kidney biopsy: This procedure is the only way to confirm whether you have IgA nephropathy[9]. A special needle is used to take out small pieces of kidney tissue. Then the tissue is checked under a microscope.
Your doctor also may recommend an iothalamate clearance test. It uses a special contrast agent to track how well your kidneys are filtering wastes[9].
Treatment Options
There’s no cure for IgA nephropathy, but medicines can slow how quickly it becomes worse[2]. For the first time, there are multiple FDA-approved treatment options to specifically treat IgAN. Starting these treatments as early on in your diagnosis as possible can help preserve your kidney function[13].
Treatment must be individualized because the clinical presentation and prognosis in IgA nephropathy varies widely[10]. Your treatment plan should be tailored to you and will depend on factors such as your current stage of kidney disease, other treatments you’ve tried before, any related health issues, other health conditions you have, and your personal goals and preferences[8].
All patients should be given supportive therapy to control hypertension and proteinuria, including medications that block a system called the renin-angiotensin system and dietary sodium restriction[10]. Keeping blood pressure under control and lowering cholesterol also slow the disease[2].
Medicines to treat IgA nephropathy include[9][8]:
High blood pressure drugs: Most people with kidney disease are started on an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB), which help lower blood pressure and protein in the urine.
Medications specifically for IgAN: For some adults with high levels of protein in the urine whose disease is likely to get worse quickly, there are now medications specifically for IgAN that help to lower the amount of protein in the urine. The US FDA has approved several agents to reduce proteinuria in adults with IgA nephropathy who are at risk of rapid disease progression[10]:
- Budesonide (Tarpeyo), a targeted-release formulation of a corticosteroid
- Sparsentan (Filspari), a dual angiotensin II and endothelin-1 receptor antagonist
- Atrasentan (Vanrafia), an endothelin-1 receptor antagonist
- Iptacopan (Fabhalta), a complement inhibitor
Corticosteroids are the option with the most convincing evidence to support their use, but if used, they should be administered only to carefully selected patients, and preferably should not be given for more than 6 months[10].
Some people need treatment to lower inflammation, reduce the spilling of protein into the urine, and prevent the kidneys from failing. Such treatments may help the disease become not active, a state called remission[2].
At later stages of kidney disease, you may need to consider dialysis or getting a new kidney[8].
Lifestyle Changes and Self-Care
Even if you are feeling well, it’s important to keep up with a healthy lifestyle and take your medications as prescribed. IgA Nephropathy is a lifelong condition that needs to be closely followed and managed[8].
Certain lifestyle habits can help support your physical and mental well-being while living with IgA nephropathy[12]. Additional supportive care measures include[10]:
- Dietary sodium restriction
- Smoking cessation
- Weight control
- Exercise
- Address cardiovascular risk
Your doctor might encourage you to make dietary changes to help manage IgAN, reduce your risk of complications, or support your overall health[12]. Consider asking your doctor for a referral to a registered dietitian who can help you develop a kidney-friendly eating plan.
The two golden rules of eating for kidney health are to keep your sodium low and load up on nutrient-rich, whole foods[15]. Reducing sodium intake may help lower your blood pressure and reduce protein in your urine. Managing blood pressure is important for limiting kidney damage and reducing your risk of certain complications, including kidney failure[15].
Your doctor may encourage you to lower your intake of calories if you have overweight or obesity. Some research suggests that obesity may cause IgAN to worsen more quickly[12].
Prioritizing mental health is also important. Implementing coping strategies and practicing self-care are essential components in effectively managing illness and promoting overall health and well-being[1].
What to Expect After Diagnosis
Receiving an IgA nephropathy diagnosis can make many people feel worried about the impact the disease will have on their day-to-day life as well as their future[14]. While IgA nephropathy can have a serious impact on your kidneys, it’s not always life-threatening[14].
The progression of the disease can vary from person to person, depending on their overall health and how well they manage the condition. Some people may experience a gradual loss of kidney function over decades, while others may be able to avoid significant progression and maintain stable kidney function[14].
Statistically, many people living with IgA nephropathy can have a normal life expectancy, especially if they detect IgA nephropathy at an early stage and maintain their kidney health with a combination of treatment and lifestyle changes[14].
The best way to live a full, high-quality life with IgA nephropathy is to be proactive and take good care of yourself. This includes regular urine tests, making sure your overall health like your blood pressure is managed, and working closely with your healthcare team[14].
Take charge of your health and act now—recent advancements in research and drug development offer new opportunities that can help you stop disease progression[13].
