Systemic Diseases Affecting the Kidneys

Question 1

Give examples of systemic diseases which can affect the kidneys

Answer 1

Diabetes mellitus
Atheromatous vascular disease
Amyloidosis
Systemic lupus erythematosus

Question 2

How can systemic diseases manifest in the kidneys?

Answer 2

Acute kidney injury
Chronic kidney disease
Nephritic syndrome
Proteinuria
Nephrotic syndrome

Question 3

What investigations are involved in diagnosing systemic diseases affecting the kidneys?

Answer 3

U&Es, 
Urinalysis 
Quantitative proteinuria
Special antibodies
Complement
Eosinophils
Imaging
Renal biopsy

Question 4

How can diabetes mellitus cause nephropathy?

Answer 4

Hyperglycaemia leads to volume expansion, intra-glomerular hypertension, hyperinflation, proteinuria, hypertension and renal failure

Question 5

What is a hallmark sign of diabetic nephropathy?

Answer 5

Proteinuria

Question 6

How can the risk of diabetic nephropathy be reduced?

Answer 6

Tight glycemic control
Good BP control
ACE inhibitors/ARB
SCLT2 inhibitors

Question 7

Renal artery stenosis requires angioplasty/stenting. T/F?

Answer 7

False - there is no evidence that this is effective in renal vessels

Question 8

Describe the pathogenesis fo how atheromatous vascular disease can damage the kidneys

Answer 8

Progressive narrowing od the renal arteries with atheroma causes a decrease in perfusion and a full in GFR. However, tissue oxygenation of the cortex and medulla can be maintained up to a point. As renal artery stenosis progresses hypoxia occurs which causes microvascular damage and activation of inflammatory and oxidative pathways. Parenchymal inflammation can result in irreversible firbosis

Question 9

How can renal artery stenosis be managed?

Answer 9

Blood pressure control (not with ACE inhibitors)
Statins
Good glycemic control (of diabetic)
Smoking cessation
Exercuse
Low sodium diet
Angioplasty in some cases

Question 10

What is amyloidosis?

Answer 10

The deposition of highly stable insoluble proteineous material in the extracellular space which can typically affect the kidney, heart, liver and gut

Question 11

What are the ultrastructural features of amyloidosis?

Answer 11

8-10nm fibrils which can cause mesnagial expansion

Question 12

What stain is used to see evidence amyloidosis on kidney biopsy?

Answer 12

Congo red

Question 13

What is AA amyloidosis?

Answer 13

Systemic amyloidosis associated with inflammation and infection

Question 14

What is AL amyloidosis?

Answer 14

Due to immunoglobulin fragments from a haematological condition e.g. myeloma

Question 15

There are multiple autoantibodies present in systemic lupus erythematosis. What are these autoantibodies directed against?

Answer 15

DNA
Histones
snRNPSs
Transcriptional/translational machinery

Question 16

In which sex is systemic lupus erythematosis more common?

Answer 16

Women

Question 17

Describe how systemic lupus erythematosis can cause kidney disease?

Answer 17

Autoantibodies are produced against dsDNA or nucleosomes and form intravascular immune complexes or attach to the glomerular basement membrane
This activates the complement system and causes renal damage

Question 18

How is kidney disease due to systemic lupus erythematosis treated?

Answer 18

Immunosuppression with steroids, mycophenolate mofetil, cyclophosphamide, rituximab