Berger Disease (IgA Nephropathy)

Question 1

What is berger disease a type of?

Answer 1

Most common primary glomerulonephritis

Question 2

What is the pathophysiology of Berger disease?

Answer 2

Increased number of defective, circulating IgA antibodies (triggered by mucosal infections eg URTI, GI infections) -> IgA antibodies form immune complexes that deposit in the kidney -> glomerulonephritis

Question 3

What are the clinical features of Berger disease?

Answer 3

Highly variable

Can be asymptomatic

Recurring episodes of - gross or microscopic Hematuria, flank pain, low grade fever, and or nephritic syndrome (including hypertension), usually during or immediately following a respiratory or GI infection

Can progress to RPGN and or nephrotic syndrome (<10% of cases)

Up to 50% of cases progress to end stage renal disease within 20-25 years

Question 4

What is the diagnosis for Berger disease?

Answer 4

Based on clinical presentation and lab results

Urinalysis - signs of nephritic sediment including persistent microhematuria and possibly minor proteinuria
Episodic flare ups of gross Hematuria in 50% of patients

Lab tests - serum IgA level is elevated in 50% of cases, complement levels are generally normal

Renal biopsy - usually only indicated if there are signs of severe or progressive disease, including - urinary protein >.5-1g/24 hours, increased serum creatinine, hypertension.
Findings - light microscopy - mesangial proliferation. Immunofluorescent microscopy - mesangiasl IgA deposits, electron microscopy - mesangial immune complex deposits

Question 5

What is the DD for Berger disease?

Answer 5

PSGN - associated with low complement levels, typically occurs 10-20 days following infection

Lupus nephritis

Membranoproliferative GN

Question 6

What is the treatment for Berger disease?

Answer 6

Patients with isolated Hematuria - regularly monitor kidney function and initiated treatment if disease progresses (eg occurrence of proteinuria), symptoms resolve spontaneously in 30% of patients

Patients with proteinuria or hypertension - ACE inhibitors/ARB’s

For severe or rapidly progressing disease - glucocorticoids plus possibly cyclophosphamide/azathioprine