Immune Complex Membranoproliferative Glomerulonephritis (IC-MPGN)

Many diseases can affect your kidney function by attacking and damaging the glomeruli, the tiny filtering units inside your kidney where blood is cleaned. The conditions that affect your glomeruli are called glomerular diseases, which includes many conditions with many different causes. One of these conditions is immune complex membranoproliferative glomerulonephritis (IC-MPGN). 

IC-MPGN is a rare kidney disease caused by the immune system damaging the kidneys.

IC-MPGN is related to another disease, known as complement 3 glomerulopathy (C3G). They have similar symptoms and are treated in similar ways, but they are considered distinct diseases.

Signs and symptoms of IC-MPGN can include the following:

Not all people will experience  these symptoms in the same way. It is important to be aware of the above symptoms. Contact a healthcare professional if you or a family member has these symptoms or notices a sudden change in symptoms.

IC-MPGN is caused when parts of the immune system damage glomeruli, tiny filtering units within the kidneys.

Usually, the immune system protects the body from invaders, like viruses, bacteria, and other germs. 

In IC-MPGN, your immune system starts to attack the healthy cells in your kidneys which damage the glomeruli. Your immune system makes proteins called antibodies that attack substances in your body that they see as harmful. The harmful substances are called antigens. Antigens combine with antibodies to make immune complexes. These immune complexes get stuck in your kidneys and cause damage. 

Overactivity of the complement system can play a role in IC-MPGN. The complement system is a part of the immune system.

The disease process that leads to IC-MPGN may be caused or triggered by certain long-term infections (such as hepatitis C ), autoimmune diseases (such as lupus), or some types of cancer.

In some cases, the cause of MPGN cannot be found. This is known as primary or idiopathic MPGN.

Complications of IC-MPGN can include:

• High blood pressure (hypertension)
• High cholesterol
• Kidney failure

High blood pressure and kidney disease can also lead to heart problems in IC-MPGN.

A diagnosis can include an observation of any symptoms, blood and urine tests, and a kidney biopsy.

A urinalysis is a test that checks your urine for signs of health issues.

An eGFR, or estimated glomerular filtration rate, is a blood test that shows how well your kidneys are filtering, or removing, wastes form your blood.

A urinary albumin-to-creatinine ratio (UACR) is a urine test that checks for high amount of a protein (albumin) in the urine, which is a sign of kidney damage.

A urine protein-to-creatinine ratio (UPCR) may also be used. This test is similar to the UACR test, which measures albumin. But instead of measuring only the amount of albumin in your urine, it measures all the different proteins that may be present. A UPCR level of 150 mg/g or more can be a sign of proteinuria.

A genetic test may be done to see if the cause of your IC-MPGN comes from genes you inherited from your family.

A kidney biopsy is required to definitively confirm an IC-MPGN diagnosis. A kidney biopsy is a procedure where a tiny piece of your kidney is surgically removed with a special needle, and looked at under special microscopes. The image from the microscope reveals the pattern of damage linked with IC-MPGN. Because IC-MPGN is so rare, a person looking at your biopsy should be an expert in glomerular diseases. For this reason, your healthcare team may need to contact a large research center to find such an expert.

Treatment for IC-MPGN includes managing blood pressure, proteinuria, and cholesterol with medications, lifestyle changes, and complement-targeting therapies.

You should talk with a healthcare professional about your condition, because, like many kidney diseases, the progression of IC-MPGN is variable and depends on many factors. Some people may live with the disease for years without complications while being monitored. IC-MPGN can also lead to kidney failure, which requires a kidney transplant or dialysis. 

Currently, it is difficult to predict which people will progress to kidney failure and which will not. However, the ability for clinicians and researchers to predict what may happen is improving, but it's not a guarantee. Remember, IC-MPGN has a lifelong impact, so it is important to keep up with medical appointments, take your medicines, and stay with the treatment plan as recommended by your healthcare team.

Medications

Medications used to slow the process of kidney damage from IC-MPGN may include the following:

ACE inhibitors and ARBs are blood pressure medications used to reduce protein loss and control blood pressure.

Diuretics, or water pills, help rid your body of extra fluid if you have swelling (edema). They work by making your kidney create more urine.

Corticosteroids and immunosuppressive drugs are medications used to calm (or suppress) your immune system (to which the complement system belongs) and stop it from attacking the filtering units in the kidney (glomeruli). Immunosuppressive drugs are also used by people who received a kidney transplant. They help lower the body’s natural response to fight the new kidney.

A cholesterol medicine, such as a statin, can be prescribed to help protect your heart.

Complement inhibitors (or complement-targeting therapies) are medicines that can target the complement system. The complement system is part of the immune system. In certain diseases, the complement system can become overactive and damage glomeruli, tiny filtering units within the kidneys. 

• Eculizumab is a drug known as a monoclonal antibody. This drug can target the immune system and has been used to treat IC-MPGN. Rituximab is another monoclonal antibody that has been used to treat IC-MPGN. These drugs can slow down the complement system and may help people with IC-MPGN. However, they do not always work with IC-MPGN. They can also have major side effects.
• In July 2025, The FDA approved pegcetacoplan for the treatment of IC-MPGN. Pegcetacoplan is a complement C3 inhibitor. This drug works by binding to and inhibiting C3. C3, or complement 3, is a blood protein with a role in immunity and the disease. This approval also included pegcetacoplan for the treatment of complement 3 glomerulopathy (C3G). C3G is a similar to IC-MPGN, but it is a distinct disease. The drug previously received an approval to treat paroxysmal nocturnal hemoglobinuria (PNH).
• Other complement inhibitors are in clinical trials. You can discuss available treatments or clinical trials for complement inhibitors with a healthcare professional to find out which may be best for you.

Nutrition

Practicing a healthy lifestyle and getting regular exercise should also be part of the treatment plan. You may need to limit your sodium, or salt intake, especially if you have high blood pressure. You may also be asked to change your diet in other ways. A dietitian can help with a meal plan that’s right for you.

Questions to ask

• What was my most recent uPCR or uACR result? If my last result was not at goal, what can I do to make it lower?
• What is my risk of developing kidney failure because of my IC-MPGN?
• What lifestyle changes do you suggest I make to help prevent complications?
• Are there any changes I need to make with my diet? Can a dietitian help me with my diet?
• Do I have to make any changes with my medications?
• What symptoms should I watch for that might indicate my condition is worsening?

• If you need to limit sodium (English)
• If you need to limit sodium (Spanish)
• Choosing a treatment for kidney failure (English)
• Choosing a treatment for kidney failure (Spanish)