Glomerular disease

Question 1

For which glomerular disease is a biopsy not necessarily required?

Answer 1

If definitive diagnoses can be made by serology e.g. membranous nephropathy associated with anti-phospholipase A1 receptor (anti-PL2R autoantibodies)

Question 2

Review the structure of a glomerulus

Answer 2

See google image

Question 3

Diffuse vs focal and global vs segmental

Answer 3

Diffuse - all glomeruli
Focal - < 50 % glomeruli

Global - whole glomerulus (shaped like a globe)
Segmental - segment of a glomerulus involved < 50%

Question 4

What are crescents?

Answer 4

Crescents = rupture of the glomerular membrane (severe injury to capillary wall). Crescents are collections of macrophages, fibroblasts, fibrin, epithelial cells, etc. within Bowman’s space. They accumulate and can compress/replace glomeruli with fibrous tissue.

*See studying with pictures - Nephrology - RPGN

Question 5

Alport syndrome mutations

Answer 5

Collagen IV mutations

Question 6

Pathophysiology of minimal changes disease and FSGS

Answer 6

“Circulating factors” directly affect podocyte function –> proteinuria

Question 7

Pathophysiology of glomerular damage in DM and amyloidosis

Answer 7

Mechanical disruption of the glomerulus due to accumulation of proteins in capillary loops and mesangium

Question 8

Pathophysiology of glomerular damage in membranous nephropathy

Answer 8

In situ formation of immune complexes

Question 9

Pathophysiology of glomerular damage in Goodpasture’s disease

Answer 9

Localised effects of anti-GBM antibodies

Question 10

Pathophysiology of glomerular damage in SLE

Answer 10

Deposition of circulating immune complexes

Question 11

Pathophysiology of glomerular damage in ANCA-associated vasculitis

Answer 11

Neutrophils and macrophages directly injure glomeruli

Question 12

AKI in GN

Answer 12

Nephrotic syndrome - don’t typically present with AKI. May be seen in podocytopathies (minimal change, FSGS)

Commonly seen in nephritic syndrome. Especially in crescentic.

Patients with chronic glomerular disease may develop CKD

Question 13

Crescentic GN is often due to…

Answer 13

ANCA-associated vasculitis or anti-GBM disease

Question 14

GN may be primary or linked to systemic conditions, such as…
Therefore, Hx/Ix should include…

Answer 14

Infections
Autoimmune disorders
Malignancy
Drug reactions

Constitutional - fevers/LOW/night sweats/fatigue

Eye - retinitis, uveitis
ENT - epistaxis, sinusitis, oral ulcers

CV - murmurs, pain (pericarditis), HF

Lungs - haemoptysis, infiltrates, nodules

Abdomen - enteritis, colitis, pancreatitis

Nervous system - seizures, PN

Extremities - digital ischaemia, infarction

Skin - purpura, rash

MSK - arthritis, arthralgias, myalgias

Infections- staph, strep, hepatitis, HIV, syphilis

Question 15

Define nephrotic syndrome

Answer 15

Constellation of:
- Urine protein >3.0-3.5 g/day
- Peripheral oedema 
- Hypoalbuminaemia (serum albumin < 30) 
Also typically have hyperlipidaemia and lipiduria

Question 16

The most incredible diagram for GN and ddx!!!!

Answer 16

See studying with pictures - nephrology - diagnostic pathway for glomerulonephritis

Question 17

What are the most common causes of primary nephrotic syndrome in adults?

Answer 17

Membranous nephropathy (whites), FSGS (blacks)

Question 18

Serum complement levels in GN?

Answer 18

Useful in differentiating aetiology…
Typically normal in anti-GBM disease and pauci-immune GN..

Low in immune complex mediated GN (except IgA neprhopathy).

Question 19

Causes of isolated glomerular haematuria ….ie. no systemic features, no proteinuria, normal renal fn, normal BP, lab Ix all normal…

Answer 19

Biopsy NOT usually performed

Likely to have mild IgA nephropathy, membranoproliferative GN, Alport syndrome or thin basement membrane nephropathy