Poststreptococcal Acute Glomerulonephritis

PSAGN is the tmost common form of immune mediated inflamation of glomerules in childhood. It is caused by Streptococcus pyogenes infection.

Epidemiology and Ethiology
Typical age is 2-12 years. Patients usually have straptococcal pharyngitis or impetigo 5-21 days before PSAGN manifestation. Incidence is 6–20:100 000 in western countries (usually sporadic occurrence), in developing countries even higher because of lower hygienic standard and malnutrition (epidemic occurrence). Other risk factors are:
 * gender (more frequent in boys);
 * even genetic predisposition for PSAGN.

Nephritogenic beta-heamolytic streptococcus, group A, type M 12 and 49 ist the most often originator.

Pathophysiology
there are some antigenes produced by Streptococcus pyogenes the most important is NSAP-streptokinase (nephritogen strains associated protein), M-protein and endostreptosin. These antigenes are binded by specific antibodies. So creaed immunocomplexes are taken up in capillaries of glomerules as deposites. It is mediated by activation of complement too. Finally, it leads to proligerative glomerulonephritis with decreased glomelural filtration, higher natrium resorption in tubules (→ edema), increased renin secretion (→ hypertension).

Symptomes

 * edema (75% of patients);
 * gross hematuria (65%) - tea colored or cola colered urine;
 * hypertension (50%);
 * acute renal insufficiency with oliguria.

consequences of hypertension, oliguria and renal insufficiency can be"
 * heart failure;
 * encephalopathy.

Diagnostic Methods

 * urine examination → hematuria, mild to moderate proteinuria, concentrated urine (there is oliguria!), and the presence of casts.
 * blood examination → elevated creatinin (decreased glomerular filtration), ASLO,