Acute nephritic syndrome

Definition

Acute nephritic syndrome is a group of disorders that cause swelling or inflammation of the internal kidney structures (specifically, the glomeruli).

Nephritic syndrome is a type of glomerulonephritis.

Alternative Names

Glomerulonephritis - acute; Acute glomerulonephritis; Nephritis syndrome - acute

Causes, incidence, and risk factors

Acute nephritic syndrome is often caused by an immune response that is triggered by an infection or other disease.

Frequent causes in children and adolescents include the following:

• IgA nephropathy
• Henoch-Schonlein purpura
• Hemolytic uremic syndrome
• Post-streptococcal glomerulonephritis

Frequent causes in adults include:

• Abdominal abscesses
• Infective endocarditis
• Klebsiella pneumonia
• Goodpasture syndrome
• Hepatitis
• Membranoproliferative GN I
• Membranoproliferative GN II
• Rapidly progressive (crescentic) glomerulonephritis
• SLE or lupus nephritis
• Syphilis and other sexually transmitted diseases
• Typhoid fever
• Vasculitis
• Viral diseases such as mononucleosis, measles, mumps

The inflammation disrupts the functioning of the glomerulus, which is the part of the kidney that controls filtering and getting rid of wastes. This disruption results in blood and protein appearing in the urine, and the buildup of excess fluid in the body.

Swelling occurs when protein is lost from the bloodstream. (Protein maintains fluid within the blood vessels, and when it is lost the fluid collects in the tissues of the body). Blood loss from the damaged kidney structures leads to blood in the urine.

Acute nephritic syndrome may be associated with the development of:

• High blood pressure
• Swelling of the spaces between the cells of the kidney tissue
• Acute kidney failure

Symptoms

Common symptoms of nephritic syndrome are:

• Swelling of the face, eye socket, legs, arms, hands, feet, abdomen, or other areas
• Blood in the urine (urine appears dark, tea colored, or cloudy)
• Decreased urine volume (little or no urine may be produced)

Other symptoms that may occur include:

• Blurred vision
• General aches and pains (joint pain, muscle aches)
• General ill feeling (malaise)
• Headache
• Slow, sluggish, lethargic movement
• Cough containing mucus or pink, frothy material
• Decreased alertness, drowsiness, confusion

Patients may develop symptoms of acute kidney failure or end-stage kidney disease.

Signs and tests

During an examination, your health care provider may find the following signs:

• High blood pressure
• Signs of fluid overload (when examining the abdomen)
• Enlarged liver
• Abnormal heart and lung sounds
• Enlarged neck veins from increased pressure
• General swelling
• Signs of acute kidney failure

Tests that may be done include:

• BUN
• Creatinine
• Creatinine clearance
• Urinalysis
• Urine appearance and color
• Potassium test
• Protein in the urine

A kidney biopsy will reveal inflammation of the glomeruli, which may indicate the cause.

Tests to determine the cause of acute nephritic syndrome may include:

• ANA titer (lupus)
• ANCA (antineutrophil cytoplasmic antibody for vasculitis)
• Anti-glomerular basement membrane antibody
• Blood culture
• Culture of the throat or skin
• Serum complement (C3 and C4)

Treatment

The goal of treatment is to reduce the inflammation. You may need to stay in a hospital to have acute nephritic syndrome diagnosed and treated. The cause must be identified and treated. Treatment may include antibiotics or other medications or therapies.

Your doctor may recommend bedrest. You may need to limit salt, fluids, and potassium in your diet. Your health care provider may prescribe medications to control high blood pressure. Corticosteroids or other anti-inflammatory medications may be used to reduce inflammation.

Other treatment of acute kidney failure may be appropriate.

Support Groups

For information and support, see kidney disease support groups.

Expectations (prognosis)

The outlook depends on the disease causing the nephritis. When the condition improves, symptoms of fluid retention (such as swelling and cough) and high blood pressure may go away in 1 or 2 weeks. However, urine tests take months to return to normal.

Children tend to do better than adults and usually recover completely. Only rarely do they develop complications or progress to chronic glomerulonephritis.

Adults do not recover as well or as quickly as children. Although it is unusual for the disease to return, at least one-third of adults whose acute nephritic syndrome does return will eventually develop end-stage kidney disease.

Complications

• Congestive heart failure
• Pulmonary edema
• Chronic glomerulonephritis
• Nephrotic syndrome

Calling your health care provider

Call your health care provider if you have symptoms of acute nephritic syndrome.

Prevention

Many times the disorder cannot be prevented, although treatment of illness and infection may help to reduce the risk.

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References

Haymart MR, Atta MG. Glomerular disease. In: Nilsson KR Jr., Piccini JP, eds. The Osler Medical Handbook. 2nd ed. Philadelphia, Pa:Saunders Elsevier;2006:chap 65.

Nachman PH, Jennette JC, Falk RJ. Primary glomerular disease. In: Brenner BM, ed. Brenner & Rector's The Kidney. 8th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 30.