FSGS and Nephrotic Syndrome
What is Focal Segmental Glomerulosclerosis (FSGS)?
Today, approximately 20,000 people in the US live with end stage kidney disease (ESKD) due to FSGS.1
FSGS is a rare, scarring disease of the kidney that generally causes excess protein in the urine, nephrotic syndrome, and progressive kidney failure.
There are four types of FSGS:2
- Primary FSGS: This type of FSGS means that the disease happened on its own without a known or obvious cause.
- Secondary FSGS: This type is caused by another source, such as aninfection, drug toxicity, diabetes, sickle cell disease, obesity, or even other kidney diseases.
- Genetic (familial) FSGS: This rare form of FSGS is caused by genetic mutations. It’s suspected when several members of a family show signs of FSGS. Familial FSGS can also occur when neither parent has the disease, but each carries one copy of an abnormal gene that can be passed onto the next generation.
- Unknown FSGS: The underlying cause of FSGS cannot be determined despite the evaluation of clinical symptoms and extensive testing.
What is Nephrotic Syndrome?
Nephrotic syndrome is a group of symptoms that indicate your kidneys are not working properly. These symptoms include:
Too much protein in the urine (proteinuria)
Low levels of albumin (protein) in the blood
(hypoalbuminemia)
Swelling in parts of the body (edema)
Your kidneys are made up of about a million filtering units called nephrons. Each nephron includes a filter-like part called glomerulus, and a tube-like part called a tubule. The glomerulus filters your blood, and the tubule returns needed
substances to your blood while also removing wastes, extra fluid, and toxins, which become urine.
Nephrotic Syndrome usually happens when the glomeruli are inflamed, allowing too much protein that is normally retained in the body to leak from your blood into your urine.
FSGS Signs and Symptoms
- Swelling in body parts like your legs, ankles and aroundyour eyes or edema.
- Weight gain due to extra fluid building in your body.
- Foamy urine caused by high protein levels in the urine or proteinuria.
- High fat levels in the blood (high cholesterol).
- Low levels of protein in the blood.
Prevalence of FSGS
The incidence of FSGS is
around 4 times higher in
black patients compared
to white patients.5
Both adults and children are affected by FSGS, but it is most common in people over 45 years old. It occurs more often in men than in women and in African Americans than other ethnicities.
FSGS is estimated to be responsible for 40% of adult nephrotic syndromes and 20% of pediatric nephrotic syndromes.3
Diagnosis of FSGS
- Blood test: Taking a sample of blood to measure levels of protein and fat.
- Glomerular filtration rate (GFR): Checking a blood sample to measure how well your kidneys work.
- Urine test: Measuring the levels of blood and protein in your urine. However, a definitive diagnosis of FSGS can only be made with a kidney biopsy.
- Kidney biopsy: Using a needle to take a small sample of tissue from the kidney for a lab to study for signs of FSGS under a microscope.
Management and Treatment of FSGS
Treatment for FSGS depends on the type and cause, your age, and whether you have other health conditions. Doctors aim to control symptoms to help you maintain a good quality of life and slow or prevent progressive scarring so that it does not lead to kidney failure.
In some people with secondary FSGS, treating the underlying condition may stop kidney damage from progressing. Doctors cannot repair glomeruli, but over time, kidney function may improve in these people.
Treatments for FSGS may include:1,6
- Angiotensin-converting enzyme (ACE) inhibitors: Drugs that treat high blood pressure.
- Antibiotics
- Diuretics: Medications that lower blood pressure and ridding the body of excess fluids.
- Immunosuppressive drugs: Drugs that manage the immune system response, such as cyclosporine and tacrolimus.
- Corticosteroids (e.g. Prednisone): Drugs that lowers levels of protein in the urine.
- Plasma Apheresis
- Lipoprotein Apheresis
References:
- “Focal Segmental Glomerulosclerosis (FSGS).” NephCure Kidney International®, 9 Feb. 2023, https://nephcure.org/livingwithkidneydisease/ns-and-other-glomerular-diseases/understanding-fsgs/
- “Focal Segmental Glomerulosclerosis (FSGS).” Mayo Clinic, Mayo Foundation for Medical Education and Research, 8 Mar. 2023, https://www.mayoclinic.org/diseases-conditions/fsgs/symptoms-causes/syc-20354693.
- Sprangers B, Meijers B, Appel G. FSGS: Diagnosis and Diagnostic Work-Up. Biomed Res Int. 2016;2016:4632768. doi: 10.1155/2016/4632768. Epub 2016 May 24. PMID: 27314022; PMCID: PMC4894996.
- Rosenberg, Avi Z, and Jeffrey B Kopp. “Focal Segmental Glomerulosclerosis.” Clinical journal of the American Society of Nephrology : CJASN vol. 12,3 (2017): 502-517. doi:10.2215/CJN.05960616.
- “NephCure Participates in Black Health Matters Summit and Health Fair: Rare Kidney Disease Across Generations Panel” NephCure Kidney International®, 4 Aug. 2022, https://nephcure.org/2022/08nephcure-participates-in-black-health-matters-summit-and-health-fair-rare-kidneydisease-across-generations-panel
