GN with pictures

Question 1

how does the basement membrane manage to control what is filtered?

Answer 1

see image

recall that flow is from the endothelium TOWARDS the podocytes

Question 2

what is the role of the mesangium?

Answer 2

see pic

Question 3

What do we look at in a renal biopsy?

Answer 3

see image

Question 4

what is the pathogenesis of membranous nephropathy?

Answer 4

There is some sort of anti-podocyte antibody that leads to clustering of complement on the podocyte. This leads to C5b-C9 on the podocyte surface.

This leads to change in the podocyte behaviour

There is also detection of an antibody against “PHOSPHOLIPID A2 RECEPTOR”

Question 5

What does the histopath slide look like in membranous nephropathy?

Answer 5

When you look at the histo slide you can see that the basement membrane is much thicker than adjacent tubular membrane. There is not increased cellularity. It is all about the membrane

Question 6

How do we treat membranous nephropathy?

Answer 6

We first have to stratify the patients.

Low risk: normal renal function and < 4gm proteinuria/day

Medium risk: normal RF and 4 – 8 gm/day

High risk: abnormal RF and >8gm/day

Low risk is treated with ACEi and bring down BP to <125/75

Medium risk: trial ACEi (many will spontaneously resolve) – if no response after 6 months of therapy, probably steroids and cytotoxics

If high risk – 3 month trial with ACEi, then steroids + cytotoxics or calcineurin inhibitor

ALSO MUST PAY ATTENTION TO ADJUVANT THERAPY

That is,

Control lipids

Manage fluid balance

No smoking or NSAID

Control BP (<125/75)

ACEi

Diet

ANTICOAGULATION IF SERUM ALBUMIN < 20g/dL

Question 7

What is the pathology of mesangiocapillary GN/membranoproliferative GN (MPGN)?

Answer 7

There are discrete deposits in the subendothelial space and in the mesangial space

There are several subtypes:

Type 1: subendothelial deposits

Type 2: dense desposits in GBM

Type 3: subepithelial and subendothelial deposits

HOWEVER, we no longer use this classification

Currently we use:

• Imune complex mediates – increased levels of immune complexes
• immunoglobulin negative, complement positive GN (this occurs through dysregulation of the alternative pathway of complement) – this can then be differentiated into dense deposit disease and C3GN

Question 8

What is the pathology of rapidly progressive glomerulonephritis (RPGN)?

Answer 8

This condition is also called crescentic nephritis.

This can be broken up into:

type I – anti-GBM

type 2 – pauci-immune

type 3 – immune complex

Type 3 RPGN can present as:

IgA immune complex:

• IgAN
• HSP

the full house of immune complexes:

• SLE

IgG and complement associated:

• postinfectious
• cryoglobulinaemia
• endocarditis

Question 9

What are some of the antibodies we use in post-infective GN?

Answer 9

Post streptococcal antibodies include:

• ASOT
• anti-DNAase B
• anti-hyaluronidase Ab

these can be present, but it does not predict the severity of disease

Question 10

What do we use for management of post-infective GN?

Answer 10

There is no role for immunosuppression. It is all supportive.

Question 11

What is the meaning of ANCAs?

How do they cause their pathology?

Answer 11

The attached slide gives the associations between these diseases and the ANCAs.

They are pauci-immune conditions

Question 12

How do we manage ANCA vasculitis?

Answer 12

It is similar to oncology - we need to complete remission, consolidation and then remission.

Question 13

What is the staging of lupus nephritis?

Answer 13

See the attached image. Class I and II are early days. III and IV are active mesangial disease

V is membranous

VI is burnt out

Question 15

What are some features you would use to differentiate IgAN and HSP?

Answer 15

.

Question 16

PAN v polyarteritis nodosa in renal disease?

Answer 16

.

Question 17

What are the things you might see on a renal biopsy of someone with diabetic nephropathy?

Answer 17

.

Question 18

What is the stain that we use in amyloid nephropathy?

Answer 18

In this condition we use the Congo red stain and we can see apple-green birefringence

This is amyloid deposition. An important tid-bit of info

Question 19

What is Alport syndrome?

What is thin basement membrane disease?

Answer 19

Alport is a genetic problem with collage and we get “splitting” of the basement membrane

in thin basement membrane disease, we often get isolated haematuria. Renal biopsy demonstrates a basement membrane that is about half the thickness of normal.

Question 20

What GNs are associated with which malignancy?

Answer 20

probably low yield for the amount of work needed to get this info in.

MCN with Hodgkin’s

bowel/GI malig more assoc with membranous

CLL (often Hep C assoc) can cause cryoglob GN

MM and waldenstrom’s can cause systemic amyloidosis

Question 21

Which of the nephrotic syndromes have the best evidence for anticoagulation when hypoalbuminaemic?

Answer 21

Membranous nephropathy seems to be the strongest (according to QLD lecture)

Question 22

Which of the following is most strongly associated with a PERSISTENT reduction of C3?

a. mesangiocapillary (mesangioproliferative GN)
b. diffuse SLE
c. idiopathic membranous
d. post-streptococcal
e. mesangial IgA disease

Answer 22

The answer is A. This is associated with persistent decrease

Both diffuse SLE and post-strept will have low C3, but only when disease is active.

Question 23

How does IgA nephropathy usually present?

Answer 23

It usually presents with recurrent episodes of isolated haematuria.

Question 24

On a renal biopsy from patient with SLE, what feature would suggest poor response to therapy?

a. wire loops
b. crescents
c. advanced glomerulosclerosis
d. immunoglobulin deposits in the tubules
e. diffuse glomerular involvement

Answer 24

The finding of advanced glomerulosclerosis in SLE suggests burnt out lupus. That’s bad news bears for treatment.

Question 25

Please tell me about the different types of amyloidoses that impact the kidney

Answer 25

see picture