Glomerulosclerosis

Glomerulosclerosis (glow-MARE-yoo-low-skleh-ROW-sis) is a general term to describe scarring of the kidneys' tiny blood vessels, the glomeruli, the functional units in the kidney that filter urine from the blood.

One sign of glomerulosclerosis is proteinuria (larger amounts of protein appearing in the urine) because the scarring disturbs the kidneys' filtering process and allows protein to leak from the blood into the urine.

But glomerulosclerosis is just one of many possible causes of proteinuria. To find out whether a patient has glomerulosclerosis or some other kidney problem, the doctor will often need to perform a kidney biopsy -- using a special needle to remove a tiny sample of the kidney to be examined under a microscope. About 15 percent of people with proteinuria turn out to have glomerulosclerosis.

Glomerulosclerosis can develop in children and adults and may result from different types of kidney conditions. One kind of glomerulosclerosis frequently encountered is caused by diabetes. (See Kidney Disease of Diabetes http://www.niddk.nih.gov/health/kidney/pubs/kdd/kdd.htm .) Focal segmental glomerulosclerosis (FSGS), another chronic kidney condition, may be caused by infection or drug use; it may occur in patients with AIDS. However, most cases of FSGS are of unknown cause.

The early stages of glomerular disease may not cause any symptoms. One of the most important warning signs of glomerular disease is proteinuria, usually discovered during a routine medical exam. The loss of large amounts of protein may cause swelling in the ankles or accumulation of fluid in the abdomen.

Scarred glomeruli cannot be repaired. Many patients with glomerulosclerosis gradually get worse until their kidneys fail completely. This condition is called end-stage renal disease or ESRD. Patients with ESRD must go on dialysis (hemodialysis or peritoneal dialysis) to clean their blood or get a new kidney through transplantation.

A patient who has just received a diagnosis of glomerulosclerosis may reach ESRD within a variable period of time; it can be a year, or it may take 10 years or more.

The best treatment for glomerulosclerosis depends upon what caused the scarring. This is determined by renal biopsy. Immunosuppressants -- drugs that block the body's immune system -- stop proteinuria in about half of the patients with glomerulosclerosis. But when the course of treatment is over, proteinuria returns for many patients. In some cases, the drugs actually may end up hurting the kidneys of certain patients.

Most doctors try to slow down the progression of kidney failure by controlling the patient's blood pressure. This is one of the most important tools available. A class of blood pressure medicines called ACE inhibitors appears to preserve kidney function in patients with diabetes. Further studies may show that ACE inhibitors slow down kidney failure even in patients who do not have diabetes. Some doctors advise their patients to go on a low-protein diet to lighten the load of wastes on the kidneys. Some kidney patients may need to control their cholesterol through diet or both diet and medicine.