IgA Nephropathy

What is iga nephropathy?

IgA nephropathy, sometimes called Berger’s disease, is a kidney disease that occurs when a protein called immunoglobulin A (IgA) builds up inside the kidneys. Immunoglobulin A is an antibody, a protein the immune system normally makes to fight infections. In IgA nephropathy, abnormal forms of this antibody collect in the glomeruli, which are the tiny filtering units inside each kidney. Over time, these deposits cause inflammation (swelling and irritation) that can damage the filters and reduce how well the kidneys clean the blood.

To understand what IgA nephropathy means for your health, it helps to know what the kidneys do. Healthy kidneys filter waste products and extra fluid from the blood while keeping useful substances, such as protein and red blood cells, inside the body. When the glomeruli are inflamed, blood and protein can leak into the urine, and the kidneys may slowly lose their filtering ability.

IgA nephropathy is one of the most common forms of glomerulonephritis, the general medical term for inflammation of the kidney’s filtering units. It can affect people of any age but is most often diagnosed in older children, teenagers, and young to middle-aged adults. It appears to be more common in people of Asian and European ancestry, and men are diagnosed somewhat more often than women in many populations. The disease usually progresses slowly over many years, and its course varies widely: some people keep normal kidney function for life, while others gradually develop chronic kidney disease.

Symptoms of iga nephropathy

Many people with IgA nephropathy have no symptoms at all, especially in the early stages. The condition is often discovered by chance when a routine urine test finds blood or protein that cannot be seen with the naked eye. When iga nephropathy symptoms do appear, they may include:

• Visible blood in the urine (gross hematuria): urine that looks pink, red, or cola-colored, often appearing during or shortly after a cold, sore throat, or other infection.
• Microscopic blood in the urine: blood detectable only with a laboratory test, which may be present continuously for years.
• Foamy urine: persistent foam or bubbles in the toilet, which can be a sign of protein leaking into the urine (proteinuria).
• Swelling (edema): puffiness in the hands, feet, ankles, or around the eyes, caused by fluid retention.
• High blood pressure (hypertension): often found during a routine check rather than felt directly.
• Pain in the side or lower back: a dull ache in the flank area, below the ribs, in some cases.
• Fatigue and general tiredness: more common when kidney function has declined.

Symptoms often differ by how far the disease has progressed. In early or mild disease, episodes of visible blood in the urine linked to infections are a classic pattern, particularly in younger people, and kidney function may remain normal between episodes. In more advanced disease, symptoms of chronic kidney disease may develop, such as ongoing fatigue, poor appetite, nausea, itching, difficulty concentrating, and worsening swelling. A smaller number of people develop heavy protein loss in the urine (a pattern doctors call nephrotic syndrome), which typically causes more noticeable swelling and foamy urine. Rarely, IgA nephropathy can progress quickly, with a fast decline in kidney function that needs urgent treatment.

Because symptoms can be absent for a long time, regular check-ups that include blood pressure measurement and urine testing are important for anyone who has been told they may have this condition.

Causes and risk factors

The exact iga nephropathy causes are not fully understood, but researchers believe the disease develops in several steps. First, the body produces an abnormal form of the IgA antibody that is missing part of its usual sugar coating (doctors call this galactose-deficient IgA1). The immune system then treats this abnormal IgA as foreign and makes other antibodies against it. These antibodies bind to the abnormal IgA, forming clumps called immune complexes. The complexes travel through the bloodstream and become trapped in the glomeruli, where they trigger inflammation and scarring.

Why some people produce this abnormal IgA is not entirely clear, but several factors seem to play a role:

• Genetics: IgA nephropathy sometimes runs in families, and certain inherited gene variations appear to increase the risk. However, most cases occur without any family history.
• Ancestry: the condition is diagnosed more often in people of East Asian and European descent and less often in people of African descent, although it can occur in anyone.
• Age and sex: diagnosis is most common between the teenage years and the forties, and men are affected somewhat more often in many regions.
• Infections: respiratory infections (such as colds and tonsillitis) and, less often, gastrointestinal infections frequently trigger episodes of visible blood in the urine. Infections do not cause the underlying disease but may provoke flares.
• Associated conditions: IgA nephropathy is sometimes seen alongside other conditions, including celiac disease (an immune reaction to gluten), chronic liver disease, and certain other immune-related disorders. It is also closely related to IgA vasculitis (Henoch-Schönlein purpura), a condition that inflames small blood vessels, especially in children.

It is important to know that IgA nephropathy is not caused by anything a person did or failed to do. It is not contagious, and it cannot be prevented by lifestyle choices, although healthy habits can help protect kidney function once the condition is present.

Diagnosis

An iga nephropathy diagnosis usually begins when a doctor notices blood or protein in the urine, either because of symptoms or during a routine test. Because several kidney conditions can cause similar findings, doctors use a series of tests to narrow down the cause:

• Urine tests (urinalysis): a dipstick and microscopic examination check for blood, protein, and red blood cell casts (tiny clumps of cells that suggest the bleeding comes from the kidney filters). A urine protein-to-creatinine ratio or a 24-hour urine collection measures how much protein is being lost.
• Blood tests: serum creatinine and the estimated glomerular filtration rate (eGFR), a calculation of how well the kidneys are filtering, show current kidney function. Doctors may also test blood IgA levels, although these are not reliable enough on their own to confirm or rule out the disease. Other blood tests help exclude different causes of kidney inflammation.
• Blood pressure measurement: high blood pressure is both a sign of kidney involvement and a factor that can speed up kidney damage, so it is checked carefully.
• Imaging: an ultrasound of the kidneys is often performed to look at kidney size and structure and to rule out other causes of blood in the urine, such as stones or growths. Imaging cannot confirm IgA nephropathy itself.
• Kidney biopsy: the only way to confirm the diagnosis with certainty. In this procedure, a doctor uses a thin needle, guided by ultrasound and performed under local anesthesia, to remove a very small sample of kidney tissue. A pathologist examines the sample under special microscopes and uses staining techniques to detect IgA deposits in the glomeruli. The biopsy also shows how much inflammation and scarring is present, which helps predict the likely course of the disease and guide treatment.

Not everyone with suspected IgA nephropathy needs a biopsy. When findings are very mild, such as microscopic blood in the urine with normal kidney function, little or no protein loss, and normal blood pressure, doctors may choose to monitor instead, because the biopsy result would not change treatment. A biopsy is more likely to be recommended when there is significant protein in the urine, declining kidney function, or diagnostic uncertainty.

Treatment options for iga nephropathy

There is currently no cure that removes IgA deposits from the kidneys, so iga nephropathy treatment focuses on protecting kidney function, reducing protein loss in the urine, controlling blood pressure, and slowing or preventing progression to kidney failure. Care is usually led by a nephrologist, a doctor who specializes in kidney disease. Within the Acibadem hospital group, this condition is managed by the Nephrology Department. Treatment is tailored to each person and often includes several of the following approaches.

Watchful waiting and supportive care

For people with very mild disease, no significant protein in the urine, normal blood pressure, and normal kidney function, doctors may recommend regular monitoring rather than medication. This typically involves periodic urine tests, blood tests, and blood pressure checks. Monitoring is an active strategy: it allows treatment to start promptly if the disease shows signs of progressing.

Blood pressure and kidney-protective medications

Medications called ACE inhibitors (angiotensin-converting enzyme inhibitors) and ARBs (angiotensin receptor blockers) are a cornerstone of treatment for most people with protein in the urine or high blood pressure. These drugs lower blood pressure and also reduce pressure inside the glomeruli, which decreases protein leakage and helps slow kidney damage. Your doctor may adjust the dose gradually to reach the maximum tolerated level. In recent years, another class of medication called SGLT2 inhibitors, originally developed for diabetes, has been shown to help protect the kidneys in many people with chronic kidney disease, including some with IgA nephropathy, and your nephrologist may consider adding one.

Immunosuppressive and disease-targeted therapy

When the disease remains active despite supportive treatment, for example when significant protein loss continues or kidney function is declining, doctors may consider medications that calm the immune system. Corticosteroids (such as prednisone or newer targeted-release formulations designed to act in the gut, where much IgA is produced) are the most commonly used option in selected patients. Because steroids and other immunosuppressive drugs can have meaningful side effects, including infections, weight gain, high blood sugar, and bone changes, the decision to use them involves weighing potential benefits against risks for each individual. In rapidly progressive cases, stronger immunosuppressive regimens may be needed. Newer targeted therapies for IgA nephropathy are being developed and studied, and options continue to evolve; your nephrologist can explain what is currently appropriate in your situation.

Lifestyle and dietary measures

Supportive measures apply to nearly everyone with the condition. These often include limiting salt intake to help control blood pressure and swelling, avoiding smoking, maintaining a healthy weight, staying physically active as advised, and avoiding medications that can harm the kidneys, such as regular use of certain over-the-counter anti-inflammatory painkillers (NSAIDs), unless a doctor approves them. Some people with reduced kidney function may be advised to moderate protein intake; this should only be done under medical or dietitian guidance. In some cases, doctors also prescribe medications to manage cholesterol or fluid retention.

Treatment for advanced kidney disease

If IgA nephropathy progresses to kidney failure, meaning the kidneys can no longer keep the body healthy on their own, treatment options include dialysis (a procedure that filters waste from the blood using a machine or the lining of the abdomen) and kidney transplantation. Transplantation is often a good option for suitable candidates, although IgA deposits can sometimes recur in the transplanted kidney over time; this recurrence does not always cause significant damage. Surgery is not otherwise a treatment for IgA nephropathy itself, although removal of the tonsils (tonsillectomy) has been used in some countries for selected patients with frequent infection-related flares; its benefit remains debated and it is not a standard recommendation everywhere.

Living with iga nephropathy and outlook

The outlook for IgA nephropathy varies widely from person to person, and honest uncertainty is part of the picture. Many people, likely a substantial proportion, maintain good kidney function for decades, especially when protein loss is minimal and blood pressure is well controlled. In some people the disease remains completely stable, and occasional cases even show spontaneous improvement in urine findings. However, a meaningful share of patients experience slow progression, and over the course of 20 to 30 years some develop advanced chronic kidney disease or kidney failure requiring dialysis or a transplant.

Doctors use several markers to estimate an individual’s risk, including the amount of protein in the urine over time, blood pressure control, kidney function at diagnosis, and the degree of scarring seen on biopsy. Persistent heavy protein loss and uncontrolled high blood pressure are among the strongest signs of higher risk, which is why treatment focuses so heavily on these two factors.

Living well with IgA nephropathy usually means building routines around long-term kidney protection: attending regular follow-up visits, taking prescribed medications consistently, monitoring blood pressure at home if advised, following dietary guidance on salt and protein, staying up to date with recommended vaccinations to reduce infection-triggered flares, and telling every healthcare provider you see, including dentists and pharmacists, that you have a kidney condition before starting any new medication or supplement. Most people can work, exercise, travel, and, with appropriate specialist care, have healthy pregnancies, although pregnancy with kidney disease requires closer monitoring and should be planned with your medical team.

Frequently asked questions

What is IgA nephropathy in simple terms?

IgA nephropathy is a kidney disease in which an antibody called immunoglobulin A builds up in the kidney’s tiny filters and causes inflammation. This can make blood and protein leak into the urine and, over many years, may reduce how well the kidneys work. It is one of the most common causes of kidney inflammation worldwide and is usually a long-term condition managed by a kidney specialist.

Can IgA nephropathy be cured or heal on its own?

There is currently no cure that removes the IgA deposits from the kidneys. In some people with very mild disease, urine abnormalities can improve or even disappear over time, but in most cases the condition is lifelong and requires monitoring. Treatment can often slow or stabilize the disease, protect kidney function, and reduce symptoms, which is why regular follow-up matters even when you feel well.

How serious is IgA nephropathy?

The seriousness varies greatly. Many people live for decades with stable kidney function and few or no symptoms, while others progress slowly toward chronic kidney disease, and a portion eventually need dialysis or a kidney transplant. Factors such as the amount of protein in the urine, blood pressure control, and the degree of scarring on biopsy help doctors estimate individual risk. Early diagnosis and consistent treatment generally improve the long-term outlook.

What are the first symptoms of IgA nephropathy?

Often there are no early symptoms at all, and the disease is found on a routine urine test. When symptoms do occur, the most recognizable early sign is urine that turns pink, red, or cola-colored during or shortly after a cold or sore throat. Other possible early signs include foamy urine, swelling in the ankles or around the eyes, and newly diagnosed high blood pressure.

Is IgA nephropathy hereditary or contagious?

IgA nephropathy is not contagious; you cannot catch it from or pass it to another person. Genetics do appear to play some role, and the condition occasionally runs in families, but most people who are diagnosed have no affected relatives. Routine screening of family members is not standard in most situations, though a doctor may suggest urine testing for close relatives in certain cases.

What foods should I avoid with IgA nephropathy?

There is no specific diet proven to treat IgA nephropathy itself, but dietary habits can protect the kidneys. Most patients are advised to limit salt to help control blood pressure and swelling, and some with reduced kidney function may need to moderate protein, potassium, or phosphorus intake under professional guidance. Because needs differ depending on your kidney function, it is best to follow individualized advice from your doctor or a kidney dietitian rather than general restrictions.

Will I eventually need dialysis or a transplant?

Not necessarily. Many people with IgA nephropathy never reach kidney failure, particularly those with low protein loss and well-controlled blood pressure. However, over 20 to 30 years, a significant minority of patients do progress to advanced kidney disease. Modern treatment aims to reduce that risk, and your nephrologist can give you a more personal estimate based on your test results and biopsy findings.

When to see a doctor

See a doctor promptly if you notice possible signs of kidney disease, such as blood in the urine, persistently foamy urine, unexplained swelling, or newly elevated blood pressure. If you have already been diagnosed with IgA nephropathy, keep your scheduled follow-up appointments even when you feel well, because the disease can progress silently.

Seek urgent medical care if you experience any of the following red-flag warning signs:

• Visible blood in the urine that does not clear within a day or two, or that occurs with fever or severe pain.
• A sudden, marked drop in urine output or inability to pass urine.
• Rapidly worsening swelling of the legs, face, or abdomen, or sudden unexplained weight gain from fluid.
• Shortness of breath or difficulty breathing when lying flat, which can signal fluid building up in the lungs.
• Severe headache, vision changes, chest pain, or confusion, which may indicate dangerously high blood pressure.
• Persistent nausea, vomiting, extreme fatigue, or muscle weakness, which can be signs of rapidly declining kidney function or dangerous shifts in blood chemistry.

These symptoms can have many causes, but in someone with known or suspected IgA nephropathy they should be evaluated without delay, as early treatment of a flare or complication can help protect the kidneys.