Post-streptococcal GN

Alternative names:

glomerulonephritis - post-streptococcal; post-infectious glomerulonephritis

Definition:

A disorder of the kidneys involving inflammation of the glomeruli after infection with certain strains of the streptococcus bacterium.

Causes, incidence, and risk factors:

Post-streptococcal glomerulonephritis is now an uncommon form of glomerulonephritis. It is the result of an infection, not of the kidneys but of a remote site such as the skin or pharynx, with a specific type of Group A hemolytic streptococcus bacterium.

As a consequence of trapping immune complexes (formed from streptococcal antigen, antibodies, and complement) in the glomeruli of the kidneys, the glomeruli become inflamed, causing inefficient filtering and excreting function by the kidneys. Protein and blood may be present in the urine, and excess fluid commonly accumulates in the body. Hypertension characteristically is present.

The disorder is uncommon, affecting about 1 out of 10,000 people. The actual incidence may be higher, as asymptomatic cases are predicted to be as many as 4 to 5 times the number that are seen by health care providers. It may occur in people of any age, especially children 6 to 10 years old. The disorder develops 1 to 2 weeks after the skin or throat infection began, and often after the infection has subsided.

Risk factors include recent having a history of sore throat, strep throat, streptococcal skin infections such as impetigo, and other streptococcal infections.