Postinfectious Glomerulonephropathy

GENERAL PRINCIPLES

• Postinfectious glomerulonephropathy classically presents as nephritic syndrome, with hematuria, hypertension, edema, and renal insufficiency. Proteinuria may be present and is usually in the subnephrotic range.

• This entity is classically associated with streptococcal infection, which typically affects children under the age of 10, after a latent period of 2-4 weeks from onset of pharyngitis or skin infection. However, bacterial endocarditis, visceral abscesses, and ventriculoperitoneal shunt infections can also lead to this immune complex-mediated disease.

• Low complement levels are usually seen. ASO titers may be elevated serially, as may anti-DNase B antibodies in streptococcal-associated disease.

DIAGNOSIS

Kidney biopsy reveals hump-shaped subepithelial deposits on electron microscopy corresponding to the deposits on immunofluorescence (C3 dominant, or C3 and IgG co-dominant staining). There is widespread mesangial proliferation and infiltration of polymorphonuclear neutrophils.

TREATMENT

Treatment is primarily supportive. Resolution of the underlying infection typically leads to renal recovery in 2-4 weeks, even in cases requiring dialysis. A brisk diuresis should be anticipated in the recovery period and electrolytes should be carefully monitored.