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Flashcards in Pathology Deck (35):
0

What problems can occur with the glomerular filter and signs of this?

Get blocked -> renal failure
-hypertensive
-haematuria

Can leak
-proteinuria (albumin)
-haematuria

Can both occur together

1

Where are the four sites for glomerular injury?

Subepithelial affects podocytes/podocyte side of basement membrane

Within glomerular basement membrane

Sub endothelial - inside basement membrane

Mesangial/paramesagial - supporting the capillary loop

2

What is proteinuria

Presence of excess serum proteins in urine

3

What allows proteins to leak through the filtration barrier?

Podocyte damage
-widening of fenestration slits
-causes proteins to be leaked when they would normally not be filtered

4

Causes of nephrotic syndrome/proteinuria?

Minimal change glomerulonephritis
Minimal change focal glomerulosclerosis
Membranous glomerulonephritis

5

When is minimal change glomerulonephritis seen?

Childhood/adolescence
Decreasing incidence with age

6

What happens in minimal change glomerulonephritis?

Podocyte damage mediated by T cells
Under light microscope, appears normal, under electron microscope, can see podocyte damage

7

How is minimal change glomerulonephritis treated?

Steroids
Relapse common if stopped

9

What does each part of the name focal segmental glomerulosclerosis mean?

Focal - involves

10

What happens in focal segmental glomerulosclerosis?

Podocytes undergo damage and subsequent scarring
-> protein in urine

Caused by a circulating factor (because transplanted kidneys undergo the same damage)

10

What is the commonest cause of nephrotic syndrome in adults?

Membranous glomerulonephritis

11

What can focal segmental glomerulosclerosis lead to?

Renal failure

12

What happens in membranous glomerulonephritis?

Immune complex deposits in sub-epithelial space
Autoimmune basis caused by an auto-antibody to podocytes

Evidence that it may be secondary because it is associated with other conditions such as lymphoma

13

Prognosis of membranous glomerulonephritis?

Rule of thirds
-third will remit
-third will continue in nephrotic state
-third will show progressive loss of renal function

14

What is nephritic syndrome?

Renal failure due to blocking of the filter

15

What can cause nephritic syndrome?

IgA nephropathy

Hereditary nephropathies
-Thin GBM nephropathy
-Alport

Diabetes mellitus

Goodpasture's syndrome

Vasculitis

16

What is the most common glomerular nephropathy?

IgA nephropathy
Can happen at any age

17

What happens in IgA nephropathy?

Deposition of IgA antibodies in the glomerulus
Can lead to mesangial proliferation and scarring

18

Presentation of IgA nephropathy?

Visible/invisible haematuria
Some patients have proteinuria
Relationship with mucosal infections
Significant number progress to renal failure

19

Treatment of IgA nephropathy?

None

20

What is thin glomerular basement membrane nephropathy? Features?

A benign familial nephropathy
Isolated haematuria
Thin GBM
Benign course

21

What is Alport?

X linked causing abnormal collagen IV production
Get abnormal appearance of GBM a
Can progress to renal failure

22

What is Alport associated with?

Deafness

23

How can diabetes mellitus lead to nephritic syndrome?

Microvasculature is damaged which damages the glomerulus

Get expansion of mesangium with collagen deposition - mesangium sclerosis

Thickening of the basement membrane (4.5x of normal)

24

What causes diabetes mellitus to lead to nephritic syndrome?

infections
abnormality of blood supply from atheroma or microvascular disease

25

What is seen in nephritic syndrome caused by diabetes?

Progressive proteinuria
Progressive renal failure

26

What is Goodpasture's syndrome characterised by?

Acute onset of severe nephritic symptoms
Combination of glomerulonephritis with pulmonary (alveolar) haemorrhage -> haemoptysis
Deposition of IgG

27

Pathology of Goodpasture's syndrome?

Circulating anti-glomerular basement membrane antibodies bind to basement membranes (collagen IV) in lungs and kidney, fix complement and trigger a cell-mediated inflammatory response

This causes glomerulonephritis and pulmonary capillaries

28

Pre-disposing factors of Goodpasture's syndrome?

HLA-DR2 gene
Smoking
Influenza
Exposure to organic solvents or hydrocarbons
Codeine inhalation
Metal dusts

29

How do you treat Goodpasture's syndrome?

Immunosuppression
Plasmaphoresis if caught early

30

What is vasculitis?

Inflammation of blood vessels

31

How does vasculitis lead to nephritic syndrome?

Blood vessels in the glomerulus see attack end and become inflamed by neutrophil cytoplasmic antibody (ANCA)

32

What is the mechanism for getting sub-epithelial deposits?

Antigen on podocytes abnormally recognised
Circulating IgG binds to it, forming immune complexes in the glomerulus
Eg membranous glomerulonephritis

33

What is the mesangium?

Cells continuous with the smooth muscle of the arteriolar wall in the afferent arteriole in the glomerulus. Not blocked by podocytes.

34

Mechanism for mesangial deposits?

Immune complexes are deposited directly into the mesangium as there are no podocytes or basement membrane to act as a barrier