Glomerulonephritis

Question 1

What is GN

Answer 1

Group of diseases which are characterised by inflammatory changes in the glomerular capillaries and the glomerular basement membrane (GBM).

Usually immune mediated

Question 2

What are different types of GN?

Answer 2

Primary:
• Minimal change nephropathy
• Membranous GN
• Focal and segmental glomerulosclerosis
• IgA nephropathy
Rapidly progressive GN (anti-GBM disease)

Secondary to systemic disease:

	• Lupus
	• Amyloid
	• Vasculitis e.g. IgA in HSP
	• RPGN (as a result of vasculitis - small vessel ANCA or HSP - and lupus)
HIV, Hep B/C

Question 3

What are Sx of GN?

Answer 3

Often none

Haematuria
Proteinuria
Nephrotic or nephritic syndrome
acute renal failure

Question 4

What is nephrotic syndrome?

Answer 4

Non-proliferative injury to structure of glomerulus resulting in excessive leakage of key plasma molecules such as albumin.
This can lead to GBM thickening and sclerosis.

Question 5

What is criteria for nephrotic syndrome?

Answer 5

• Proteinuria >3.5g/24 hours, urine PCR >300mg/mmol
• Hypoalbuminaemia <30g/L
• Oedema
Also: hyperlipidaemia, giving risk of VTE and infection

Question 6

What types of GN result in nephrotic syndrome?

Answer 6

Minimal change
Membranous
FSGS
Membranoproliferative

Question 7

What is membranous nephropathy?

Answer 7

Most common GN in adults, common cause of ESRF.

Renal biopsy w EM: thickened BM with spikes

Ass. with anti-phospholipase A2 antibodies

Question 8

What are causes of membranous nephropathy?

Answer 8

idiopathic
infections e.g. hep B, malaria 
malignancy 
drugs: gold, NSAIDs
SLE, thyroiditis, RA

Question 9

How is membranous nephropathy treated?

Answer 9

ACEi/ARB

immunosuppression (if severe)

Question 10

What is nephritic syndrome

Answer 10

Usually proliferative changes within glomerulus resulting in increased cell numbers and inflammatory cell infiltration

Microscopy shows red cell casts, some proteinuria

Question 11

What are causes of nephritic syndrome?

Answer 11

IgA nephropathy
Small vessel vasculitis
Lupus nephritis
Post-strep GN

Question 12

What is IgA nephropathy?

Answer 12

Classically presents as macroscopic haematuria in young people 24-28 hours following an upper respiratory tract infection.

Overlap with HSP

Question 13

What Ix in IgA nephropathy?

Answer 13

histology: mesangial hypercellularity, positive immunofluorescence for IgA & C3

Question 14

What is anti-GBM disease

Answer 14

rare type of small-vessel vasculitis associated with pulmonary haemorrhage and rapidly progressive glomerulonephritis. It is caused by anti-glomerular basement membrane (anti-GBM) antibodies against type IV collagen.

Question 15

What does renal biopsy show in anti GBM disease

Answer 15

linear IgG deposits along the basement membrane

Question 16

What is post-streptococcal glomerulonephritis?

Answer 16

Develops 1-2 weeks following URTI, proteinuria and haematuria with low copmlement

Question 17

What is RPGN

Answer 17

Acute nephritic syndrome PLUS formation of crescents - necrotising histological response following thrombosis/rupture of glomerular capillaries

Question 18

What are causes of RPGN

Answer 18

ANCA vasculitis

Question 19

What Ix in suspected GN?

Answer 19

Urinalysis and microscopy: nephritic or nephrotic?

Urine ACR: > 220 indicates nephrotic

U+Es, metaoblic profile, eGFR

Serology: ANCA, anti-dsDNA, complement…

Renal US and biopsy

Question 20

How is nephrotic syndrome treated

Answer 20

• Diuretics (loop) with fluid and salt restriction
• Treatment of underlying cause
• Steroids to induce remission
• Renal biopsy should be done in adults
Reduce proteinuria with RAAS blockade