What causes C3G and primary IC-MPGN?
The complement system is a critical part of the immune system
Your complement system helps to:
- Fight infections
- Rid your body of infectious germs or damaged cells
Image is an actor portrayal.
How the complement system works
The complement system is made up of a network of proteins called complement proteins
Signals activate the system by causing a chain reaction
One complement protein activates the next complement protein and continues down the network to protect the body from infections, clear out damaged cells, and promote inflammation to heal injuries
The complement system is always active to protect your body, but it’s the overactivity that leads to kidney damage
Coming soon–a video that shows how the complement system works and how it can be affected by overactivation
C3: a central part of the complement system
C3 is a protein that plays a key role in the complement system. When the complement system becomes overactive, excessive breakdown of C3 results in inflammation and a buildup of C3 breakdown fragments in the kidneys
Some fragments cause reactions that damage the kidney, including fragment buildup that can lead to injury. Other fragments trigger inflammation. Both types of fragments result in the symptoms of C3G and primary IC-MPGN
Some C3 and other protein fragments trigger inflammation, while other fragments build up in the kidneys, causing damage
Up to 50% of adults with C3G will progress to kidney failure within 10 years of diagnosis
Confirming a C3G or primary IC-MPGN diagnosis
To understand how your kidneys are functioning and if they are impacted by C3G or primary IC-MPGN, your doctor will order tests for:
ProteinuriaHigh levels of protein in urine that is detected through a urine test (dipstick test and/or urinalysis).Proteinuria
High levels of protein in the urine
Urine testing
eGFRA measurement of how well your kidneys are filtering waste from your blood. It calculates this based on your blood creatinine levels, age, and gender.eGFR
How well your kidneys are functioning
Blood testing
Others
Tests for levels of C3 in the blood
Genetic testingA test that involves analyzing a person’s DNA to identify changes or mutations in genes, chromosomes, or proteins. Genetic testing and Immunological testingA test that evaluates the functioning of the immune system by measuring the levels and activity of immune components, such as antibodies, complement proteins, or immune cells. immunological testing
Getting a definitive diagnosis
To confirm a diagnosis of C3G or primary IC-MPGN, your doctor will perform a Kidney biopsyA medical procedure in which a small sample of kidney tissue is removed and examined under a microscope or other imaging tools to diagnose or monitor kidney diseases. kidney biopsy to check for a buildup of C3 fragments and immunoglobulin deposits in kidney tissue as shown through imaging (known as staining)
