Post-streptococcal glomerulonephritis

In nephrology, post-streptococcal glomerulonephritis is a disorder of the glomeruli (glomerulonephritis), or small blood vessels in the kidneys, following an streptococci infection. This condition is essentially defined as an inflammation of the kidneys.

A closely related term is "post-infectious glomerulonephritis", which accounts for infections by other agents. However, this term is used much less frequently.

Pathophysiology
The exact pathology remains unclear, but it is believed to be Type III hypersensitivity reaction. Immune complexes (antigen-antibody complexes formed during an infection) become lodged in the glomerular basement membrane. Complement activation leads to destruction of the basement membrane. It has also been proposed that specific antigens from certain nephrotoxic streptococcal infections have a high affinity for basement membrane proteins, giving rise to particularly severe, long lasting antibody response.

Presentation
Patients will present with acute nephritic syndrome, with the pentad of hypertension, decrease in glomerular filtration rate, hematuria, proteinuria and fluid retention.

Causes
Post-infectious glomerulonephritis can be a complication of streptococcal pharyngitis (strep throat).

Diagnosis
Diagnosis rarely requires a renal biopsy since there is usually a classical clinical presentation. There will be elevated levels of ASOT Ab and low complement levels in the blood.