IgA nephropathy

IgA nephropathy (also known as Berger's disease) is the commonest cause of glomerulonephritis worldwide. It classically presents as macroscopic haematuria in young people following an upper respiratory tract infection.

Associated conditions

• alcoholic cirrhosis
• coeliac disease/dermatitis herpetiformis
• Henoch-Schonlein purpura

Pathophysiology

• thought to be caused by mesangial deposition of IgA immune complexes
• there is considerable pathological overlap with Henoch-Schonlein purpura (HSP)
• histology: mesangial hypercellularity, positive immunofluorescence for IgA & C3

Proliferation and hypercellularity of the mesangium is seen in the glomerulus

Immunostaining for IgA in a patient with HSP

Presentations

• young male, recurrent episodes of macroscopic haematuria
• typically associated with a recent respiratory tract infection
• nephrotic range proteinuria is rare
• renal failure is unusual and seen in a minority of patients

Differentiating between IgA nephropathy and post-streptococcal glomerulonephritis