Why Are Black People More at Risk to Develop FSGS Kidney Disease?

FSGS, a rare kidney disease, occurs more commonly in Blacks than Whites, largely because of specific genetic variants prevalent among those of African ancestry.

Focal segmental glomerulosclerosis (FSGS) affects the filters in your kidneys. When these filters are scarred, they are unable to filter your blood, which can lead to kidney damage and failure. Treatment for FSGS focuses on treating the symptoms and preventing any additional scarring.

FSGS is not caused by a single disease. It can have many different causes. The scarring may happen because of an infection, or drug, or a disease that affects the entire body, like diabetes, HIV infection, sickle cell disease or lupus. FSGS can also be caused by another kidney-related disease that you had before you got FSGS.

FSGS has different types based on the cause. Primary FSGS is a type of FSGS that means the disease happened on its own without a known or obvious cause. Secondary FSGS is caused by another disease or drug, such as HIV or anabolic steroids that some people use to speed up their muscle growth.

Early stages of FSGS may not cause any symptoms. You may only see some signs on your own, while others may be found by your healthcare provider.

Signs and symptoms of FSGS include:

• Swelling in body parts like your legs, ankles and around your eyes (called edema)
• Weight gain due to extra fluid building in your body
• Foamy urine caused by high protein levels in the urine (called proteinuria)
• High fat levels in the blood (high cholesterol)
• Low levels of protein in the blood

FSGS has no cure. The prognosis varies depending on the person. For some people, FSGS goes away on its own without treatment. For others, the disease continues for many years but does not get worse.

In the U.S., approximately 40,000 patients are living with FSGS, and more than 60% of patients do not have a durable response to current FSGS treatments, which usually include steroids, immunosuppressive drugs, diuretics, and a diet change. Because of this, 50% of patients with FSGS will progress to kidney failure.

Blacks are at least four times more likely to get FSGS in comparison with Whites. Much of this disparity can be attributed to genetic variants of the APOL1 gene found only in individuals with recent African ancestry, according to this study. These variants greatly increase rates of FSGS, among other forms of kidney disease.

Here’s how APOL1 is a factor for Blacks with kidney disease: Forty-five percent of Black Americans under 60 years old on dialysis have the APOL1 genotype. The APOL1 genotype is also found in 75% of Black patients with FSGS.

Many people with the high-risk APOL1 genotype do not show any signs or symptoms of FSGS until kidney failure is approaching. Knowing if you have the APOL1 gene variants is the key to unlocking the mystery of kidney disease in people with African and Caribbean ancestry, medical professionals say.

This awareness is needed in the medical community as well, as providers might not know this link exists, and therefore do not test for it. NephCure is an organization that focuses on raising awareness of FSGS in the Black community. It conducts “culture conversations” with Black kidney doctors and has monthly health fairs where doctors and nurses offer support in some of its locations. NephCure also hosts webinars, educational articles, blog posts, support groups, and its Kidney Health Gateway, which connects people to top nephrologists and research.

“If FSGS is caught early, you can stop the damage and live a regular life,” Deja Ivy, NephCure’s associate director of community health. “Our work is important because of the low quality of life with dialysis, but we’re showing that you can be aware and active in your kidney health.”

Black participation in clinical trials could also improve outcomes, as research could determine whether or not drugs being tested for FSGS will work equally as well for Blacks with the APOL1 gene. Clinical trial participation is particularly important for those who are newly diagnosed because FSGS is a rapidly progressing form of disease.