Glomerular Disease (Pathology)

Question 1

What is the molecule size above which substances will not be filtered in the glomerulus and remain in the plasma?

Answer 1

Equal or larger in size than albumin

Question 2

What is the filter barrier? What are the three parts?

Answer 2

The membrane of the glomerulus

Cell cytoplasm, basal lamina, podocyte

Question 3

What name is given to the tree-like group of cells which support the glomerular capillaries?

Answer 3

Mesangial cells

Question 4

What is glomerulonephritis?Is it inflammatory?

Answer 4

Disease of the glomerulus

It can be either

Question 5

Differentiate between primary and secondary glomerulonephritis

Answer 5

Primary disease affects only the glomerulus

Secondary disease also affects other parts of the body e.g. SLE or Wegner’s

Question 6

What is the aetiology of glomerulonephritis?

Answer 6

Some are due to immunoglobulin deposition

Some have no deposition foe example diabetic glomerular disease

Question 7

Give four common presentations of glomerulonephritis

Answer 7

Haematuria (blood in the urine)
Heavy proteinuria (nephrotic syndrome)
Slowly increasing proteinuria
Acute renal failure

Question 8

What are the main causes of haematuria?

Answer 8

Urinary tract infection
Urinary tract stone
Urinary tract tumour

Question 9

What should be done for a patient who has discoloured urine that provides a positive dipstick result for blood? If these Ix prove normal, what should be done?

Answer 9

A urine sample should be sent off and an ultrasound arranged

Renal biopsy

Question 10

What is the result of immunoglobulin deposition in the centre of the glomerulus?

Answer 10

It causes increased proliferation of mesangial cells and gets stuck within them and the mesangium becomes clogged, forming more matrix as it enlarges

Question 11

What is the prognosis of IgA nephropathy?

Answer 11

It is usually self-limiting and will return to normal, however a percentage continue to proliferate and go onto chronic renal failure as the matrix continues to be deposited

Question 12

What should be done in a patient whose serum albumin is low and a dipstick test is positive for proteinuria?

Answer 12

Should see a nephrologist and if albumin levels in the urine found to be very high then the clinical diagnosis of nephrotic syndrome can be made as there must be a problem with the glomerular filter
A clotting screen should be done and then a renal biopsy

Question 13

What occurs in membranous glomerulonephritis?

Answer 13

There is a thickening of the glomerular membrane due to IgG deposition between the basal lamina and podocyte. It remains there and activates a complement which punches holes in the filter, allowing the albumin which would normally stay in the plasma to leak through the filter into the urine = nephrotic syndrome

Question 14

What is the prognosis of mambranous glomerulonephritis?

Answer 14

A quarter reach chronic renal failure within 10 years

Question 15

What is the cause of the IgG deposition between the basal lamina and the podocytes in membranous glomerulonephritis?

Answer 15

The cause is unknown but there can sometimes be underlying malignancy

Question 16

Is mesangial thickening always due to immunoglobulin deposition?

Answer 16

No, in diabetic patients, there is matrix deposition in the basal lamina and the mesangial matrix which leads to thickened but leaky basement membranes (complex punching through) and the mesangial matrix compresses capillaries = nephrotic syndrome - diabetic nephropathy

Question 17

Describe the histopathological changes in diabetic nephropathy

Answer 17

Small compressed capillary lumens due to compression by the matrix
Thickened capillary walls which leak albumin
Increasing mesangial matrix
Adhesions to Bowmans capsule to try to prevent massive leakage of albumin into the urine

Question 18

What are Kimmelsteil-Wilson lesions?

Answer 18

Gross excess of nodules of the mesangial matrix seen in nephropathy

Question 19

What are the two factors which influence an inevitable decline in diabetic nephropathy?

Answer 19

If the nephropathy is established

f the diabetic control is poor

Question 20

What is thh diagnosis in a patient with rapidly increasing serum creatinine? What is the Ix?

Answer 20

Rapidly rising creatinine means acute renal failure
Ultrasound to check no renal tract lesion
Check clotting then renal biopsy

Question 21

What are the histolopathological changes in crescentic glomerulonephritis?

Answer 21

There is early endothelial damage with fibrin deposition, cellular proliferation and influx of macrophages forming a crescent around the glomerulus within Bowman’s space

Question 22

What are some causes of crescentic glomerulonephritis?

Answer 22

WEGNER’S GRANULOMATOSIS - form of vasculitis which affects the kidneys, nose and lungs
Microscopic polyarteritis (like Wegner’s)
Antiglomerular basement membrane disease

Question 23

WHat is a specific test for Wegner’s?

Answer 23

Serum Anti-Neutrophil Cytoplasmic Antibodies

Question 24

Outline anti-neutrophil cytoplasmic antibodies

Answer 24

They are not deposited in the kidney, and are directed against proteinase 3 and myeloperoxidase - 2 enzymes in the primary granules of neutrophils
The antibodies produce tissue damage via interactions with primed neutrophils and endothelial cells. The reason for their formation is unknown

Question 25

What is the prognosis of Wegner’s granulomatosis?

Answer 25

Fatal in 6 months if untreated

75% complete remission with Cyclophosphamide