What are the complications of IC-MPGN?

The kidneys are a pair of organs that act like filters for the body. Blood passes through the kidneys, and the kidneys filter out excess fluid, waste, and substances the body does not need, which are then expelled as urine. Immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) is a rare disorder that causes damage and a loss of function in the kidneys, reducing their ability to filter blood.

When the kidneys are damaged, proteins and blood cells can leak into the urine, and waste and excess fluid can remain in the blood. Over time, as waste and excess fluid buildup in the blood, serious complications can occur. IC-MPGN is a progressive condition, meaning kidney damage will get worse over time, especially when the condition is untreated or undertreated.

What happens when a person has IC-MPGN?

One of the key components of the immune system are antibodies, proteins that attach to harmful substances (like viruses and infection-causing bacteria), which are called antigens. When an antibody attaches to an antigen it creates an immune complex. Under normal circumstances, immune complexes are removed from the bloodstream by the immune system.

When a person has IC-MPGN, abnormal immune complexes become stuck in the delicate filtering units inside the kidneys (called glomeruli). As the immune system attempts to remove these immune complexes, inflammation and damage occur in the kidneys and the kidneys lose function.

IC-MPGN can occur for unknown reasons (primary IC-MPGN), or it can occur as a result of another condition (secondary IC-MPGN) such as an autoimmune disorder. Secondary IC-MPGN is more common.

What are the complications of IC-MPGN?

As the kidneys lose function, complications can occur. Some of the potential complications of IC-MPGN include:

High blood pressure (hypertension)

Blood pressure is the force that blood exerts on the walls of blood vessels as it travels through the body. When the kidneys do not function normally, excess fluid and other substances (like salts and hormones) cause blood pressure to increase. Kidney damage can cause hypertension, or blood pressure that is chronically elevated. Hypertension can accelerate kidney damage, and also damage the eyes, heart, and brain.

Nephritic syndrome

Hypertension can belong to a cluster of symptoms called nephritic syndrome. In addition to hypertension, symptoms of nephritic syndrome include blood in the urine, decreased urine output, and edema. Edema is swelling due to a buildup of fluid, and may affect the hands, feet, face, eye sockets, or other areas of the body. A person with nephritic syndrome may also experience blurred vision, fluid in the lungs, and feeling generally unwell (malaise, brain fog, headaches, other aches and pains).

Nephrotic syndrome

This is another cluster of symptoms that can occur with IC-MPGN, where the main features are large amounts of protein in the urine (proteinuria), low amounts of a protein called albumin in the blood (hypoalbuminemia), and high levels of blood cholesterol (hyperlipidemia). Though different from nephritic syndrome, the two syndromes overlap with a number of symptoms, including hypertension and edema.

Chronic kidney disease (CKD)

Chronic kidney disease, or CKD, is a loss of kidney function that gets progressively worse, meaning the kidneys will filter less and less blood over time. IC-MPGN can progress to CKD in a significant number of patients. There are different stages of CKD, which are calculated based on the amount of blood being filtered through the kidneys and the amount of protein that is present in the urine.

Kidney failure

When the kidneys are functioning at 15 percent or less of the rate of healthy kidneys, a person has kidney failure, or end-stage renal disease (ERSD). This will require treatment with dialysis or kidney transplant for a person to remain alive.

Treatment

There is no cure for IC-MPGN, but there are therapies that can manage the condition, slow the progression of damage to the kidneys, and prevent complications. Treatment will depend on the underlying cause, the severity of the disease, and other factors. Treatment can include:

• Medications to control blood pressure, reduce protein in the urine, and lower cholesterol.
• Corticosteroids to reduce immune system activity and inflammation.
• Treatment of any underlying conditions that may be contributing to IC-MPGN, such as infections or autoimmune diseases.
• Changes to diet and other lifestyle modifications, such as reducing sodium intake, which may help prevent further damage to the kidneys.

New and emerging therapies include complement inhibitors, medications that reduce activity in a part of the immune system called the complement system. Your best source of information about a diagnosis and recommended treatment options will be a healthcare provider.