Segmental glomerulosclerosis

Alternative names

Focal segmental glomerulosclerosis; Focal sclerosis with hyalinosis

Definition

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.

Symptoms

• 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.
  

Treatment
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.