Primary Immune Complex Membranoproliferative Glomerulonephritis (IC-MPGN): Rare Disease Health Guide

IC-MPGN is a chronic condition, which means it can last for years. But some symptoms may come and go. Blood in your pee is more likely after an infection such as a cold or sore throat. Typically, it gets better after a few days. 

Swelling around your eyes may be worse in the morning and get better as the day goes on. But you may notice other swelling gets worse during the day, such as ankle swelling. 

Symptoms should get better as you treat the condition. There's no cure, but you can slow the progression and treat any symptoms.

What Causes IC-MPGN?

When you have IC-MPGN, your immune system attacks healthy cells in your kidneys by making proteins called antibodies. Antibodies go after substances your immune system identifies as harmful (antigens). Antigens and antibodies combine to make immune complexes. These immune complexes get stuck in your kidneys, and this causes damage. 

Doctors aren't sure why this happens. But they do know IC-MPGN is often linked to other diseases. People who get IC-MPGN usually have other health conditions, such as:

• Autoimmune diseases (most often systemic lupus erythematosus)
• Hepatitis B 
• Hepatitis C 
• Cryoglobulinemia, a rare condition that causes abnormal proteins in the blood
• Monoclonal immunoglobulin deposition diseases such as AL amyloidosis and light and heavy chain deposition diseases
• Subacute bacterial endocarditis, an infection of your heart lining
• Infection of a ventriculoatrial shunt
• Chronic lymphocytic leukemia (CLL)

Some of these health issues are hereditary, which means you get them through genes your parents pass down to you. 

IC-MPGN Risk Factors

You can get IC-MPGN at any age. But if you have it in relation to another disease, it's common to be diagnosed after age 30. If you don't have a related disease, you're more likely to get a diagnosis between ages 8 and 30. 

Getting IC-MPGN without a related disease is called primary or idiopathic MPGN. This type of IC-MPGN is very rare. 

You're at the highest risk of IC-MPGN if you have one of the related diseases listed above. But other diseases may cause it, too. They include:

• Sjögren syndrome
• Rheumatoid arthritis
• Scleroderma
• Celiac disease
• Systemic sclerosis
• Malaria
• Schistosomiasis
• Sickle cell anemia

Getting an IC-MPGN Diagnosis

Your doctor will start by getting your detailed medical history. They'll ask about any symptoms you have and how long you've had them. You'll need certain tests to confirm certain symptoms and the disease. 

Tests for IC-MPGN

Testing is the first step to see if you have IC-MPGN. Your doctor may give you a:

• Urine test. You'll pee in a cup and the clinic or lab will test it for protein and blood. 
• Blood test. A technician will collect blood from a vein in your arm and send the blood for testing in a lab. They'll look for levels of protein, cholesterol, and certain wastes in your blood. Using your blood, a doctor can find out more about:
  • Glomerular filtration rate (GFR). GFR measures the amount of fluid your kidneys filter each minute. When GFR is low, that means your kidneys aren't filtering as quickly as they should. 
  • Antibodies. Your doctor can look to see if there are any antibodies in your blood. This can tell them whether you've had an infection, and possibly what caused that infection. 
  • Protein levels. If you're losing protein in your pee, it usually means there's less of it in your blood. Your doctor can check this with a blood test. 
  • Cholesterol levels. High cholesterol levels can be a sign of nephrotic syndrome.
• Kidney biopsy. If some of your test results suggest you may have IC-MPGN, your doctor will order a kidney biopsy. A doctor will use a special needle to remove a small piece of tissue from your kidney and send it to a lab. The lab will look at it under a microscope to see how much damage there is. 
• Genetic test. Your doctor may suggest this if they want to find out whether your IC-MPGN came from genes you got from your parents.

Your IC-MPGN Care Team

Different types of doctors may help with the diagnosis, treatment, and management of your disease. 

• Primary care doctor. You'll likely start out with this doctor if you have symptoms. After your diagnosis, they'll also want to know about your disease progress and management. That's so they can treat any other conditions with that in mind.
• Nephrologist. This is an expert in kidney diseases. They have special training and will be your main doctor for treating your IC-MPGN.
• Dietitian. Having IC-MPGN often means making important shifts to your diet to support your kidneys. Regular visits with a dietitian can help ensure you're getting the nutrition you need while also caring for your kidney health.

 Since IC-MPGN is a rare condition, it's important to see a doctor with experience treating it. You may have to travel to a research center to find them.

Questions for your doctor

When you meet with your health care team, take an active role in your care by asking questions to better understand your disease and treatment. Some helpful questions are:

• What caused my IC-MPGN? 
• What kinds of symptoms should I report to you right away?
• What kinds of tests do I need and what will they tell you?
• What treatment options are available? 
• What are the benefits and risks of each treatment option?
• How long will treatment last?
• What are potential side effects of my treatment and how do I manage them?
• How will you know if my treatment is working?
• Will my IC-MPGN get worse?
• Will I need dialysis or a kidney transplant?
• What lifestyle changes should I make?

What Are Treatments for IC-MPGN?

There's no cure for IC-MPGN, but you can treat symptoms and slow the disease's progression. The treatment that's best for you depends on what caused your IC-MPGN and how severe it is. If it happened because of another disease, your doctor will want to make sure you're treating that disease.

While treatment plans vary, they often include supportive care, immunosuppressants, and medications to control blood pressure and protein loss.

Medications that treat IC-MPGN

To slow down the damage happening to your kidneys, and treat your symptoms, your doctor may prescribe immunosuppressants to calm down your immune system, making it less active so it doesn't do more damage to your glomeruli. They include:

• Corticosteroids. These medications help reduce inflammation and suppress your immune system.
• Mycophenolate mofetil (MMF). This is another immunosuppressant drug you may take along with corticosteroids.
• Rituximab. This monoclonal antibody targets specific immune cells and can help reduce inflammation.
• Complement inhibitors. These are a new treatment class. They block certain proteins in your body from being part of the process that creates inflammation. In July 2025, the FDA approved pegcetacoplan (Empaveli), a complement inhibitor, as a new treatment for IC-MPGN. In phase III clinical trials, researchers showed pegcetacoplan reduced proteinuria by 67%, improving kidney function.

Supportive care

These treatments help manage conditions caused by IC-MPGN such as high blood pressure and protein in the urine.

• Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs). These medications help widen your blood vessels and lessen the work your heart has to do to pump blood, which lowers blood pressure and reduces protein in the urine. This can help slow kidney damage.
• Statins. These medications help control high cholesterol, which can also add to kidney damage
• Diuretics. These medications help you get rid of excess fluid and salt so swelling in your body can go down.

Other therapies

Your doctor may also suggest:

Dialysis. If your kidneys begin to fail, dialysis can work as an "artificial kidney" to help filter waste products from your blood.

Plasma exchange. This procedure takes harmful substances out of your blood, including parts of your blood causing inflammation (dysfunctional complement factors) and antibodies.

Kidney transplant. In severe cases, you may need a new kidney. With a kidney transplant, surgeons remove your damaged kidney and graft on a donor kidney. This isn't a treatment for the disease. But if needed, it can help you have better kidney function. 

What to Expect

IC-MPGN can progress in different ways, depending on its cause and how early you get a diagnosis and treatment.

In the early stages, you may not notice symptoms, or your symptoms might be mild. Signs in your pee or swelling may not be noticeable. But over time, IC-MPGN can lead to more protein and blood loss in your pee, high blood pressure, and worse kidney function. 

The outcome of IC-MPGN is often worse if you have primary or idiopathic MPGN (no underlying disease linked to the condition). Without treatment, 50%-60% of people with this type of MPGN will go on to have end-stage kidney disease in 10-15 years. 

It's possible to have spontaneous remission – a sudden stop of your symptoms and damage to your kidneys. This happens in less than 10% of cases.

When treatment doesn't work

If treating your IC-MPGN doesn't change or slow down damage to your kidneys, your doctor may suggest dialysis (a procedure that filters your blood for you when your kidneys can't) or a kidney transplant. A transplant is usually a last resort, since MPGN usually comes back even after the transplant.

What Are Complications of IC-MPGN?

When IC-MPGN goes untreated or becomes severe, you may have complications, including:

Acute nephritic syndrome

Much like nephrotic syndrome, which can be a symptom of IC-MPGN, this affects your kidneys and can cause protein in your pee. But acute nephritic syndrome also causes swelling in your kidneys, specifically in your glomeruli. 

Acute renal failure

This is a sudden loss of kidney function. If IC-MPGN isn't treated, or treatment isn't working, your kidneys may stop working within hours or days. Warning signs of kidney failure include:

• Extreme tiredness
• Confusion or trouble concentrating
• Nausea and vomiting
• Sudden swelling in the hands or ankles
• Loss of appetite
• Metallic taste in your mouth
• Muscle spasms
• Peeing a lot
• Itchy skin

Chronic kidney disease

Loss of kidney function over months and years is called chronic kidney disease (CKD). The final stage of CKD is end-stage renal disease (ESRD). When you have ESRD, you need dialysis or a transplant to stay alive. 

Living With IC-MPGN

While MPGN is a serious and often progressive kidney disease, many people are able to maintain a good quality of life for years or even decades with a proactive approach. You can help protect your kidneys with healthy lifestyle choices, like not smoking, getting regular exercise, and eating a kidney-friendly diet.

Diet changes

Your doctor can recommend diet changes and refer you to a dietitian who'll guide you through kidney-friendly diet changes. Always talk to your doctor or dietitian before making big changes to your diet. 

A kidney-focused diet aims to lower certain nutrients like salt, protein, and potassium so you're not overtaxing your damaged kidneys. Tips may include:

• Limit your sodium (salt) – ask your doctor how much you can have a day.
• Eat enough protein for health but keep it moderate.
• Avoid too much potassium or phosphorus.
• Drink plenty of water while following any fluid restrictions from your doctor.
• Follow a heart-healthy diet with unsaturated fats, fruits, veggies, and whole grains.

How can you help manage IC-MPGN? 

What's the Prognosis for IC-MPGN?

If you know the cause of your IC-MPGN (like hepatitis C, lupus, or certain cancers), treating that cause can sometimes lead to a remission – which means the disease becomes inactive or goes away for a time. For some people, kidney function stays stable for years.

If you have idiopathic or primary IC-MPGN and there isn't a known disease behind it to treat, your treatment will focus on symptoms. The risk of kidney failure goes up with this type of IC-MPGN. Even with treatment, you may progress to chronic kidney disease or kidney failure over time. But this doesn't happen to everyone. 

Takeaways

IC-MPGN is a rare kidney disease that has no cure. It happens when immune system proteins build up in your kidneys. That causes inflammation and damage to the tiny filters (glomeruli) that clean your blood. This damage makes it harder for your kidneys to work. IC-MPGN can happen on its own or be caused by infections, autoimmune diseases, or some cancers.

Symptoms often start with blood or protein in your pee, swelling in your body, and high blood pressure. Many people with IC-MPGN live for years without serious problems. Treatment can slow the disease and help protect your kidney function.

IC-MPGN FAQs

How do you treat IC-MPGN?

Treatment focuses on slowing kidney damage, managing symptoms, and treating any cause, such as an infection or autoimmune disease. This may include blood pressure medications, immunosuppressants, diet changes, and regular monitoring by a kidney specialist. 

Is IC-MPGN curable?

No. But in many cases, you can manage symptoms to slow or stop damage to your kidneys.

What's the most common cause of MPGN?

Other diseases or disorders such as lupus, hepatitis C, cancers like leukemia and lymphoma, and monoclonal immunoglobulin deposition disease (MIDD)