Focal Segmental Glomerulosclerosis

February 8, 2017

Focal Segmental Glomerulosclerosis (FSGS) is a kidney disease that involves the formation of scar tissue in the glomeruli. “Sclerosis” meaning scarring and “glomerulo-” which are tiny filters that filter circulating blood producing urine as an end-product. When these filters are damaged they become scarred and are no longer able to filter blood appropriately. “Focal” meaning that only some of the filters are damaged while some are normal and “segmental” is included because often only parts of the filters are scarred.

The urinary system consists of the kidneys, ureters, the bladder and urethra. The kidneys filter the blood to remove waste products and produce urine. The urine flows from the kidneys down through the ureters to the bladder, where it is stored until we go to the toilet. It passes through another tube called the urethra to the outside when urinating (peeing).

The kidneys contain millions of tiny filtering units called glomeruli. As blood passes through the tubes in the glomerulus, waste products pass through the walls of the tubes to form urine. Blood cells and other things such as protein cannot pass through the walls because they are too big. When someone has focal segmental glomerulosclerosis (FSGS), some of the glomeruli are damaged and become scarred. This stops them working properly, so that protein can pass through the walls of the glomerulus and into the urine. This means that the child develops nephrotic syndrome.

Types of FSGS

Primary FSGS – A significant number of people diagnosed with FSGS have no known cause for their condition. This is called primary (idiopathic) FSGS.
Secondary FSGS – This condition is brought on by any of several factors — for example, infection, drug toxicity, diseases such as diabetes or sickle cell disease, significant obesity, use of certain medications such as anabolic steroids, or other types of kidney diseases. Controlling or treating the underlying cause often improves kidney function.
Genetic (also called 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 on to the next generation. Therefore, even if the disease doesn’t show up in other family members, it’s possible that the disease may be inherited.

More than 5400 patients are diagnosed with FSGS every year, however, this is considered an underestimate because –

a limited number of biopsies are performed
the number of FSGS cases are rising more than any other cause of Nephrotic Syndrome

Glomerulosclerosis affects both children and adults. Males are affected slightly more often than females, and it occurs more frequently in African Americans.

Causes

FSGS most frequently occurs without a cause. In such cases it is called idiopathic or primary FSGS. Sometimes, though, FSGS does have a known cause, and these can include –

HIV infection
Obesity
Sickle cell disease
Birth defects of the kidneys
Heroin or other drug use
Genetic causes (in rare cases)

Besides FSGS, glomerulosclerosis can be caused by these diseases –

Diabetes
Lupus
HIV infection
Sickle cell disease
Hypertension

Conditions that damage the kidneys can also lead to glomerulosclerosis. These include –

Glomerulonephritis, which causes the glomeruli to become inflamed
Reflux nephropathy, in which urine flows back into the kidney

Chemicals and medicines that harm the kidneys can also cause glomerulosclerosis.

NSAIDs (non-steroidal anti-inflammatory drugs), such as ibuprofen and aspirin.
Gold injections, for the treatment of rheumatoid arthritis.
Lithium, for the treatment of depression.
Penicillamine, for the treatment of arthritis.

Symptoms

It is possible for there to be no signs or symptoms when in the early stages of FSGS. Typically the first sign that a patient commonly recognizes is edema, especially in the legs, and sudden weight gain.

Signs and Symptoms –

Massive proteinuria and foamy urine appearance
Edema, swelling and associated weight gain
Hypertension
Renal dysfunction with increased creatinine levels
Hypoalbuminemia
Hyperlipidemia
Microscopic hematuria is occasionally present
Fatigue
Poor appetite
Headache
Itchy skin
Shortness of air
Nausea

Complications

Chronic kidney failure
End-stage kidney disease
Infection
Malnutrition
Nephrotic syndrome

Treatment

FSGS is a severe form of nephrotic syndrome, and while no cure currently exists, medical care can improve the patient’s quality of life.

Immunosuppressants and steroids – These may be prescribed. However, FSGS is associated with a steroid-resistant gene, so most children with FSGS do not respond to any immunosuppressant therapy.

Medication – ACE-inhibitors (angiotensin converting enzyme inhibitors) and ARBs (angiotensin receptor blockers). Possible dialysis within a few years of diagnosis

Kidney failure – If the patient’s condition continues to worsen, kidney failure may occur and a kidney transplant would be needed. Receiving a kidney from a relative is ideal; because of the similarities between the donated kidney and the patient, the kidney may last longer. Learn more about kidney transplantation . In some patients with FSGS, the condition can recur after kidney transplantation, sometimes as quickly as a few days. Because of this, kidney transplantation from a live donor may not be recommended in this situation.

Plasmapheresis – This technique may allow for the removal of the FSGS factor and result in slow disappearance of proteinuria after transplantation.

Life Post-Transplant – Provided the transplant functions well, dialysis will no longer be required. In some patients, however, the kidney transplant may not function forever. Receiving a second kidney transplant may be an option. Transplant success rates are approximately 95% after one year, 80% after five years and 70% after 10 years.

Alternative Treatment

Reference –

http://jasn.asnjournals.org/content/10/9/1900.abstract

http://www.nejm.org/doi/pdf/10.1056/NEJMra1106556

http://www.nephropathology-esp.org/uploads/user-3/lectures/first-international-renal-pathology-conference-la-coruna-1/praga-m-primary-and-secondary-fsgs.pdf

http://www.nytimes.com/health/guides/disease/focal-segmental-glomerulosclerosis/overview.html

http://www.uncnephropathology.org/jennette/ch6.htm

http://www.fpnotebook.com/renal/Glomerulus/FclSgmntlGlmrlsclrs.htm

https://www.luriechildrens.org/en-us/care-services/conditions-treatments/focal-segmantal-glomerular-sclerosis/Pages/index.aspx

http://www.physio-pedia.com/Focal_Segmental_Glomerulosclerosis

http://unckidneycenter.org/kidneyhealthlibrary/glomerular-disease/focal-segmental-glomerulosclerosis-fsgs

http://dictionary.cambridge.org/pronunciation/english/focal-segmental-glomerulosclerosis