Segmental glomerulosclerosis; Focal segmental glomerulosclerosis
Glomeruli are structures in the kidney that filter harmful or unnecessary substances out of the body. Each kidney has thousand of glomeruli. Focal segmental glomerulosclerosis is an illness that occurs when scar tissue forms in some of the glomeruli of the kidney.
The term “focal” means that some of the glomeruli become scarred, while others remain normal. The term “segmental” means that only part of an individual glomerulus is damaged.
Causes, incidence, and risk factors
The cause of focal segmental glomerulosclerosis is usually unknown. A small number of cases result from reflux nephropathy. The condition affects both children and adults. Males are affected slightly more often than females, and it also occurs more frequently in African-Americans.
Focal segmental glomerulosclerosis causes about 10 to 15% of all cases of nephrotic syndrome. In this condition, protein is persistently released in the urine, especially in the form of urine albumin. Most cases will progress to long term, chronic renal failure.
Although the disorder seems to be immune system related, response to corticosteroid or immunosuppressive medications, which modify our immune response, is inconsistent.
- Foamy urine
- Swelling of the body, called generalized edema, from retained fluids
- Weight gain
- Poor appetite
Signs and tests
There are no strong clues to the diagnosis on physical examination, other than evidence of edema and elevated blood pressure. Evidence of chronic renal failure and associated fluid overload may develop as the illness progresses.
Tests may include:
- A urinalysis, which shows protein, with or without small amounts of blood.
- A renal biopsy, which shows scarring of parts of some.
- An immunofluorescence microscopy test showing deposits of the antibody IgM.
The goal of treatment is to control the symptoms associated with nephrotic syndrome and chronic renal failure. Treatment may be chronic and lifelong.
Corticosteroids and immunosuppressive medications may be prescribed to reduce the immune response.
Medicines to treat high blood pressure, especially a group of drugs called angiotensin converting enzyme inhibitors, and diuretics may help control symptoms such as high blood pressure and edema. Antibiotics may be needed to control infections.
Your doctor may treat high blood cholesterol and triglyceride levels, which are also common with this disorder, to reduce the development of atherosclerosis. Reducing cholesterol and saturated fats in the diet may be of only limited benefit as the high levels seen in this condition seem to result from overproduction of cholesterol and triglycerides by the liver rather than the excessive intake of fats. Medicines to reduce cholesterol and triglycerides may be recommended.
In most cases, a moderate-protein diet (1 gram of protein per kilogram of body weight per day) is usually recommended. In cases where renal failure is present, a low-protein diet may be preferred.
Sodium (salt) in the diet and fluids may be restricted to help control swelling (see also renal disease - diet). Vitamin D may need to be supplemented if nephrotic syndrome is chronic and unresponsive to therapy.
Dialysis or kidney transplantation may be necessary to control renal failure.
Over 50% of people with focal or segmental glomerulosclerosis develop chronic renal failure within 10 years.
- Chronic renal failure
- End-stage renal disease
- Nephrotic syndrome
Calling your health care provider
Call your doctor if you or someone you know have the symptoms suggestive of focal segmental glomerulosclerosis.
You should also call your doctor if new symptoms develop, especially fever, pain with urination, or decreased urine output.
No prevention is known.
by Dave R. Roger, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.