Alternative names
Necrotizing glomerulonephritis; Rapidly progressive (crescentic) glomerulonephritis; Crescentic glomerulonephritis

Definition
Rapidly progressive glomerulonephritis is a form of kidney disease that causes damage to the internal structures of the kidneys and rapid loss of function, with crescent-shaped abnormalities showing on a biopsy of the kidney.

Causes, incidence, and risk factors
The glomeruli are the portions of the internal kidney structures where the blood flows through very small capillaries and is filtered through membranes to form urine.

Rapidly progressive glomerulonephritis includes any type of glomerulonephritis (inflammation of the glomerulus) in which progressive loss of kidney function occurs over weeks to months. Most pathologists define crescentic glomerulonephritis when 50% or more glomeruli reveal crescents on kidney biopsy. It may manifest itself as an acute nephritic syndrome or unexplained renal failure. It often progresses rapidly to renal failure and end-stage renal disease.

The disorder occurs with varying incidences in different geographic regions. Mini-epidemics of this disorder have also been described. It is most common in people 40 to 60 years old, and slightly more common in men but, depending on the cause, occurs in both sexes and at any age. It is unusual in preschool children, and slightly more common in later childhood.

Many conditions are known to cause or increase the risk for development of this syndrome. These include vascular (blood vessel) diseases such as vasculitis or polyarteritis, abscess of any internal organ, collagen vascular disease such as lupus nephritis and Henoch-Schonlein purpura, Goodpasture’s syndrome, IgA nephropathy, membranoproliferative GN, anti-glomerular basement membrane antibody disease, a history of malignant tumors or blood or lymphatic system disorders, and exposure to hydrocarbon solvents. The symptoms are similar regardless of the cause.

Symptoms
Common symptoms include the following:

 
• Edema (swelling)       o face       o eyes       o ankles, feet, extremities       o abdomen       o generalized  
• Dark or smoke-colored urine  
• Blood in the urine  
• Decreased urine volume

Symptoms that may also appear include the following:

 
• Fever  
• Myalgia (muscle aches)  
• Arthralgia (joint aches)  
• Shortness of breath  
• Cough  
• Malaise (general ill feeling)  
• Abdominal pain  
• Loss of appetite  
• Diarrhea

Signs and tests
An examination reveals edema (swelling). Circulatory overload, with associated abnormal heart and lung sounds, may be present. The blood pressure may be elevated. Rapid, progressive loss of kidney function may be present.

 
• Urinalysis may be abnormal, showing blood in the urine, urine protein, white blood cells, casts, or other abnormalities.  
• The BUN and creatinine may rise rapidly.  
• The creatinine clearance decreases.  
• Anti-glomerular basement membraneantibody tests may be positive in some cases.  
• Antineutrophil cytoplasmic antibodies (ANCAs) may be present.  
• Complement levels may be decreased in some cases.  
• Other tests for suspected causes may be performed.  
• A kidney biopsy confirms crescentic glomerulonephritis.

Treatment

The treatment varies with the suspected cause. The treatment goals may be a cure of the causative disorder, the control of symptoms, or the treatment of renal failure.

Corticosteroids may relieve symptoms in some cases. Other medications may include immunosuppressive agents including cyclophosphamide, azathioprine, and others depending on the cause of the disorder.

Plasmapheresis may relieve the symptoms in some cases. The blood plasma (the fluid portion of blood) containing antibodies is removed and replaced with intravenous fluids or donated plasma (without antibodies). The removal of antibodies may reduce inflammation in the kidney tissues.

Observation for a progression to renal failure, and the treatment of renal failure if it is present, should be ongoing. Dialysis or a kidney transplant may ultimately be necessary.

Expectations (prognosis)
Without treatment, crescentic glomerulonephritis often progresses to renal failure and end-stage renal disease in 6 months or less, although a few cases may resolve spontaneously.

Treated patients may recover some or rarely all of their baseline renal function. The extent of recovery is related to the degree of kidney function at diagnosis and degree of crescent formation. The disorder may recur. If the disease occurs in childhood, it is likely that renal failure will eventually develop.

Complications

 
• Congestive heart failure  
• Pulmonary edema  
• Hyperkalemia  
• Acute renal failure  
• Chronic renal failure  
• End-stage renal disease

Calling your health care provider
Call your health care provider if symptoms indicate rapidly progressive glomerulonephritis may be present.

If you have this disorder, call if new symptoms develop, especially irregular heartbeat, difficulty breathing, increased edema, or decreased urine production.

Prevention
The prompt treatment of causative disorders may prevent the development of rapidly progressive glomerulonephritis.

Medical Encyclopedia

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.