Acute Nephritic Syndrome (Glomerulonephritis - acute; Acute glomerulonephritis; Nephritis syndrome - acute)

What is Acute Nephritic Syndrome?

Acute Nephritic Syndrome is a group of disorders that cause inflammation of the internal kidney structures (specifically, the glomeruli).

Statistics on Acute Nephritic Syndrome?

This is uncommon in developed countries due to improved hygiene and decreased post-streptococcal and other post-infection glomerulonephitis. However, it is still a common presentation in third world countries. Children between 2 and 12 are most commonly affected, but it may occur at any age. Males predominate, especially with the serious cases.

Risk Factors for Acute Nephritic Syndrome

1. Infections with Group A Streptococcal bacateria (APSGN): In warm climates, the disease most commonly follows infected skin lesions and occurs more often in the summer. In cold climates the disease occurs more frequently because of streptococcal throat infection during winter months. The risk of developing acute nephritic syndrome depends on the type of streptococcal bacteria. There are a variety of other causes of this syndrome. The following is a list of such conditions: 2. Primary renal diseases: immunoglobulin A nephropathy, membranoproliferative glomerulonephritis, Idiopathic rapidly progressive crescenteric glomerulonephritis. 3. Secondary renal diseases: subacute bacterial endocarditis, infected ventriculoperitoneal shunt. GN with visceral abscess, GN with bacterial, viral or parasitic infections. 4. Multi-system disease: systemic Lupus Erythematosus (SLE), Wegener's granulomatosis, Goodpasture's syndrome, Microscopic polyarteritis, Mixed cryoglobulinaemia, Henoch-Schonlein purpura, Haemolytic uraemic syndrome. 5. Allergy: acute allergic tubulointerstitial nephritis.

Progression of Acute Nephritic Syndrome

The prognosis of post-streptococcal GN is good. Outcome in SLE, systemic vasculitis and Goodpasture's syndrome is less favourable. The risk of progression to end stage renal failure with post-streptococcal GN is very small for children but becomes worse with increasing age. In adults 5% have persistent proteinuria, hypertension and reduced renal function. Some of these may progress to endstage renal failure.

How is Acute Nephritic Syndrome Diagnosed?

Blood tests and urine analysis will be required to obtain a diagnosis of acute nephritic syndrome. This may require the collection of urine over a 24 hour period to assess the amount of protein lost over this time period. The function of the kidneys will also be tested using a simple blood test to detect signs of renal failure and treat these accordingly.

Prognosis of Acute Nephritic Syndrome

The microscopic appearance of the kidney defines the prognosis of the condition. Clinical findings of no urine production, heavy amounts of protein in the urine and persistent elevated blood pressure are associated with poor prognosis. Recovery from other post-infectious cases is expected except when associated with the complication of abscess formation where only 50% recover renal function. Recovery from causes other than streptococcal infection is less predictable. Some forms of GN such as, rapidly progressive crescentic GN move to end stage renal failure if early treatment is not administered (especially when due to anti-glomerular basement membrane antibody disease and systemic vasculitis.)

How is Acute Nephritic Syndrome Treated?

The principles of managing this condition include: 1. Control and prevention of elevated blood pressure: The presence of hypertension can increase the rate of deterioration of renal function in this condition. This may involve the use of anti-hypertension medications, and restriction of fluid and salt from the diet. 2. Anti-inflammatory and immunosupressant therapy: To control the inflammatory process of some causes of nephritic syndrome including vasculitis causes. 3. Supportive therapy for renal failure: Blood tests will be required regularly to ensure that renal failure is diagnosed and controlled early. Dialysis may be required if the renal failure cannot be controlled by conservative means. 4. Antibiotic therapy: For those with proven post-streptococcal nephritic syndrome.

Acute Nephritic Syndrome References

[1] Braunwald, Fauci, Kasper, Hauser, Longo, Jameson. Harrison's Principles of Internal Medicine. 15th Edition. McGraw-Hill. 2001. [2] Cotran, Kumar, Collins 6th edition. Robbins Pathologic Basis of Disease. WB Saunders Company. 1999. [3] Hurst JW (Editor-in-chief). Medicine for the practicing physician. 4th edition Appleton and Lange 1996. [4] Kumar P, Clark M. CLINICAL MEDICINE. WB Saunders 2002 Pg 427-430. [5] Longmore M, Wilkinson I, Torok E. OXFORD HANDBOOK OF CLINICAL MEDICINE. Oxford Universtiy Press. 2001.