Complement 3 (C3) glomerulopathy is a rare disease that affects kidney function and can lead to long-term health problems. Some people with C3 glomerulopathy develop severe complications that affect life expectancy. In this article, we’ll cover how C3 glomerulopathy may affect length of life and ways people living with the condition may be able to improve their outcome.

Each person with C3 glomerulopathy is different. Talk to your nephrologist about a personalized treatment plan to control your kidney disease and other steps you can take to live a longer life.

How Does C3 Glomerulopathy Affect Your Body?

Researchers estimate that in the United States, C3 glomerulopathy occurs in just 2 or 3 in 1 million people. With C3 glomerulopathy, a part of the immune system called the alternative complement pathway doesn’t function normally. The complement system involves different types of proteins called complement proteins. These proteins, including C3, help — or complement — the immune system to get rid of infections or toxic substances that may harm the body. The main function of your kidneys is to filter your blood so these substances are removed from your body when you urinate.

Normally, harmful substances get filtered out through areas of the kidney called the glomeruli. In people with C3 glomerulopathy, however, the glomeruli become damaged because the alternative complement pathway is too active. As a result, the C3 proteins break in pieces that get stuck in the glomeruli and cause inflammation. The damaged glomeruli can’t filter blood properly, so foreign substances start to build up and lead to poor kidney function and other problems.

Prognosis for C3 Glomerulopathy

The prognosis (outlook) for C3 glomerulopathy can be different for each person. For some people, the condition will continue to get worse over time and might cause long-term kidney disease. If the disease gets too severe, your kidneys may stop working completely. This is known as kidney failure, or end-stage renal disease (ESRD).

Unfortunately, kidney failure is a common complication of C3 glomerulopathy — it occurs in 30 percent to 50 percent of adults within 10 years of their diagnosis, according to the journal Advances in Kidney Disease and Health. Kidney failure is diagnosed when you have 10 percent to 15 percent of your kidney function left. If it’s not addressed in time, kidney failure can be fatal.

Although C3 glomerulopathy can decrease life expectancy because of kidney failure, not everyone develops long-term complications. Many people can be successfully treated and live for a long time after diagnosis. Your doctor will discuss your options based on your particular case and overall health condition.

Factors That Affect Prognosis for C3 Glomerulopathy

To better understand your prognosis, your doctor will consider many different factors. Here are some details that may give them more information about your possible disease course.

Type of Disease

There are two types of C3 glomerulopathy — dense deposit disease (DDD) and C3 glomerulonephritis (C3GN). These types are based on the pattern of kidney inflammation and damage. However, if you’ve had the disease for a long time, you may have been given a different diagnosis. Until 2013, C3 glomerulopathy was diagnosed as either mesangioproliferative glomerulonephritis or membranoproliferative glomerulonephritis.

Although prognosis may partly depend on the type of C3 glomerulopathy, the results from clinical trials — research studies that test drugs’ safety and effectiveness — have been mixed. In one study, the rate of kidney failure was about twice as high in people with DDD compared to those with C3GN. However, two other large studies found that people with these diseases had a similar chance of kidney failure.

It’s also important to note that people with either type of C3 glomerulopathy might not have kidney problems at all. So, while it’s important to know what type of disease you have, the diagnosis alone can’t predict your prognosis.

Age and Sex

C3 glomerulopathy can affect both children and adults, and research has suggested that the age at diagnosis can help predict prognosis. Some findings have shown that people diagnosed with C3 glomerulopathy as adults have a higher risk of kidney failure — and, therefore, an overall worse prognosis — compared with children. However, a 2012 study of 98 children and adults with DDD found no differences in kidney failure risk in these two groups.

The authors of the 2012 study also reported that in the younger population, females were at more risk of kidney failure. The results were published in the journal Pediatric Nephrology.

Laboratory Test Results

Your doctor may run laboratory tests to check for abnormalities and monitor the health of your kidneys.The results can give information about your risk of kidney failure. Lab tests look for signs of C3G, including:

• Proteinuria (too much protein in the urine)
• Hematuria (blood in the urine)
• High blood levels of creatinine (a waste product)
• Low estimated glomerular filtration rate (eGFR), a measure of kidney function

Research findings have shown that higher levels of proteinuria and kidney damage are linked to a greater risk of kidney failure. Rates of kidney failure are also higher in people with blood creatinine levels that rise quickly over time. By monitoring your lab results, your doctor can better understand your risk of severe health problems. A faster decline in eGFR also means a higher chance of kidney failure.

Your doctor may do a kidney biopsy to confirm the diagnosis and study the type of disease. They’ll take a tissue sample, process it, and look at it under a microscope to see how and where the kidneys have been damaged.

Treatment Options That May Improve Your Prognosis

There are different types of treatments for C3 glomerulopathy that may improve the outcome of people with the condition. These treatments may aim to improve kidney health, modify problems in the immune system, or extend life in the event of kidney failure.

Medication To Control Blood Pressure and Cholesterol

To improve kidney health, most people with C3 glomerulopathy are treated with a drug that can decrease both proteinuria levels and hypertension (high blood pressure). This may be either an angiotensin converting enzyme (ACE) inhibitor or an angiotensin-receptor blocker (ARB). If you have high levels of cholesterol in your blood, your doctor may also prescribe medication to lower your cholesterol and decrease your risk of heart disease.

Kidney Transplantation or Dialysis

Even with treatment, many people will progress to more severe kidney disease. If kidney failure does occur, you may require dialysis. This is a medical procedure repeated long term to filter the blood when the kidneys can’t. Once people begin dialysis, they live five to 10 years more, on average, although some live for as long as 30 years on dialysis. For those with kidney failure who choose not to get dialysis, research shows the median survival ranges from one month to 3.4 years.

Alternatively, if you’re eligible, you may be able to join the waiting list for a kidney transplant to replace damaged kidneys with healthy ones from an organ donor. While a transplant may help you live a longer life, there’s a chance that C3 glomerulopathy may eventually come back. If this happens, you’ll need additional treatment.

Drugs That Modify the Immune System

Fortunately, recent research has paved the way for more effective treatment options for C3 glomerulopathy. This includes immunosuppressive medications, which lower the activity of the immune system. Clinical trials have shown that immunosuppressive therapy using steroids with the drug mycophenolate mofetil may prevent kidney disease from getting worse.

Other medications are being studied for their safety and potential to treat people with C3 glomerulopathy by affecting the complement system directly. Eculizumab, a type of drug called a monoclonal antibody, modifies complement protein C5 and may improve outcomes. The C5a receptor inhibitor avacopan is also being looked at for people with C3 glomerulopathy.

A drug called iptacopan, which also modifies complement proteins, is currently being studied in a clinical trial as a potential treatment for C3 glomerulopathy. Research is ongoing, but there’s hope that these newer therapies may lead to better outcomes for people with C3 glomerulopathy.

Changes That May Improve Your Outcome

Although more treatments are now available for people with C3 glomerulopathy, the outcomes vary. However, not everything is out of your control — you can make lifestyle changes to improve your health and lower your chance of kidney failure. Your doctor may recommend exercise to maintain a healthy weight and help manage your C3 glomerulopathy. A kidney-friendly diet may also help prevent kidney failure.

Smoking and heavy drinking can make kidney disease worse, so if you smoke cigarettes or drink alcohol, quitting may improve your outcome. Read more about ways to improve life expectancy with kidney disease.

While the future may be uncertain, you can work with your doctor to plan your path forward. With healthy habits and more effective treatments, you can better manage your C3 glomerulopathy and live a longer, healthier life.

Talk With Others Who Understand

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