Urinary Week 9 - glomerular injury

Question 1

What renal compartments can be damaged in renal disease

Answer 1

Glomerular
Tubular
Interstitial
Vascular

Question 2

Sites of glomerular injury

Answer 2

Subepithelial
Glomerular basement membrane
Subendothelial
Mesangial

Question 3

Secondary causes of glomerular injury

Answer 3

Diabetes

Hypertension

Question 4

What occurs in blockage of the glomerulus

Answer 4

Renal failure (nephritic syndrome)
Low GFR
High stage AKI
Haematuria due to degradation of the glomerulus
Hypertension due to failure to control blood volume

Question 5

What occurs in leakage of the glomerulus

Answer 5

Proteinuria including nephrotic syndrome

Haematuria

Question 6

Criteria for nephrotic syndrome

Answer 6

> 3.5g filtered in 24 hours

Question 7

Isolated proteinuria suggests what site of glomerular injury

Answer 7

Sub epithelial

Question 8

Symptoms of nephrotic syndrome

Answer 8

Hypoalbuminaemia causes generalised oedema

Poor renal perfusion pressure leads to RAAS activation so more fluid retention

Question 9

Primary causes of nephrotic syndrome/proteinuria

Answer 9

Minimal change glomerulonephritis
Focal segmental glomerulosclerosis
Membranous glomerulonephritis

Question 10

Secondary causes of nephrotic syndrome/proteinuria

Answer 10

Diabetes mellitus (causes microvascular damage, BM thickening, mesangial sclerosis, progressive proteinuria and progressive renal failure)
Amyloidoses

Question 11

Describe minimal change glomerulonephritis - demographic, symptoms, treatment, outcome, histology

Answer 11

Presents in childhood/adolescence and incidence decreases with increasing age
Causes heavy proteinuria or nephrotic syndrome
Responds well to steroids
Usually doesn’t progress to renal failure
Under an EM, widened filtration slits are visible

Question 12

Pathogenesis of minimal change glomerulonephritis

Answer 12

Unknown

Damage caused by a circulating factor that is not an immune complex

Question 13

What does focal segmental glomerulosclerosis include

Answer 13

Focal - <50% glomerulus affected
Segmental - involves glomerular tuft
Glomerulosclerosis - patchy scarring of glomerulus

Question 14

Describe focal segmental glomerulosclerosis - demographics, symptoms, treatment, outcome

Answer 14

Presents in adults
Causes nephrotic syndrome and glomerulosclerosis
Not very responsive to steroids
Can progress to renal failure

Question 15

Pathogenesis of focal segmental glomerulosclerosis

Answer 15

Unknown

Damage is caused by a circuiting factor which is not an immune complex

Question 16

What is an immune complex

Answer 16

Antigen-antibody complex that circulates and activates complement

Question 17

Describe membranous glomerulonephritis - demographics, symptoms, outcome, histology

Answer 17

Commonest cause of nephrotic syndrome in adults
Complement activation causes cell damage
1/3 recover, 1/3 don’t improve and 1/3 progress to renal failure
Capillary loop is thickened and BM appears spiky due to immune complex deposition

Question 18

Pathogenesis of membranous glomerulonephritis

Answer 18

Antigen and IgG are filtered and react in the sub epithelial space to produce immune complexes I.e it has an autoimmune basis
May also be secondary to malignancies likely lymphoma which triggers the immune system

Question 19

Causes of haematuria

Answer 19

IgA nephropathy

Hereditary nephropathy

Question 20

Causes of nephritic syndrome

Answer 20

Good pasture syndrome

Vasculitis

Question 21

Demographics of IgA nephropathy

Answer 21

Any age

Question 22

Presentation of IgA nephropathy

Answer 22

Haematuria
Triggered by mucosal infections (IgA secreted onto mucosa and activated in infection)
May be proteinuria

Question 23

Treatment and outcome of IgA nephropathy

Answer 23

No treatment (can have transplant)
Significant number progress to renal failure

Question 24

Where is IgA usually deposited and why

Answer 24

Mesangium because there is no basement membrane between the mesangium and blood

Question 25

What are the types of hereditary neuropathies

Answer 25

Thin glomerular basement membrane neuropathy | Alport syndrome

Question 26

Describe thin glomerular basement membrane nephropathy

Answer 26

Isolated haematuria Thin glomerular basement membrane Benign

Question 27

Describe Alport syndrome

Answer 27

``` X linked condition Abnormal collagen IV production Deafness Abnormal glomerular basement membrane Progresses to renal failure ```

Question 28

Describe good pasture syndrome

Answer 28

Rapidly progressing glomerular nephritis

Question 29

What is common in smokers with good pastures syndrome

Answer 29

Haemoptysis

Question 30

Cause of good pasture syndrome

Answer 30

Autoantibody (IgG) against collagen IV glomerular basement membrane

Question 31

Outcome of untreated good pasture syndrome

Answer 31

Loss of kidney architecture (irreversible) so fibrosis occurs

Question 32

Treatment of good pasture syndrome

Answer 32

Immunosuppression | Plasmapheresis

Question 33

What is vasculitis

Answer 33

Group of systemic disorders causing inflammation of blood vessels

Question 34

Describe vasculitis

Answer 34

Blood vessels are attacked in the glomerulus by anti neutrophil cytoplasmic antibodies (ANCA) which damage endothelia by activating neutrophils

Question 35

What is required in suspected vasculitis

Answer 35

Urgent biopsy to confirm

Question 36

Histological appearance of vasculitis

Answer 36

Segmental necrosis and crescent formation on a light microscope