IgA nephropathy

IgA nephropathy (also known as Berger's disease - mesangioproliferative GN) is the commonest cause of glomerulonephritis worldwide. It classically presents as macroscopic haematuria in young people following an upper respiratory tract infection. ~0-3 days following an URTI (synpharyngitic)

N.B.. post-Strep GN takes about 1- 2 weeks

increased incidence in the Far East, Asian descendants(asso: with HLA DQW7)

Associated conditions

• alcoholic cirrhosis
• coeliac disease/dermatitis herpetiformis
• Henoch-Schonlein purpura
• rarely: mycosis fungoides; also Wiskott-Aldrich $

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