Renal

Question 1

What is IgA nephropathy?

Answer 1

IgA nephropathy (also known as Berger’s disease) is the commonest cause of glomerulonephritis worldwide. It classically presents as macroscopic haematuria in young people following an upper respiratory tract infection.

Pathophysiology:
- thought to be caused by mesangial deposition of IgA immune complexes
- there is considerable pathological overlap with Henoch-Schonlein purpura (HSP)
- histology: mesangial hypercellularity, positive immunofluorescence for IgA & C3

Associated conditions
alcoholic cirrhosis
coeliac disease/dermatitis herpetiformis
Henoch-Schonlein purpura

Question 2

IgA nephropathy presentation?

Answer 2

• young male, recurrent episodes of macroscopic haematuria
• typically associated with a recent respiratory tract infection (typically develops 1-2 days after rather than 1-2 weeks seen in post-strep)
• nephrotic range proteinuria is rare
• renal failure is unusual and seen in a minority of patients

Question 3

Renal transplant hyper acute rejection?

Answer 3

Hyperacute rejection (minutes to hours):
- due to pre-existing antibodies against ABO or HLA antigens
- an example of a type II hypersensitivity reaction
- leads to widespread thrombosis of graft vessels → ischaemia and necrosis of the transplanted organ
- no treatment is possible and the graft must be removed

Question 4

Renal transplant rejection - Acute graft failure (< 6 months)?

Answer 4

Acute graft failure (< 6 months):
- usually due to mismatched HLA. Cell-mediated (cytotoxic T cells)
usually asymptomatic and is picked up - by a rising creatinine, pyuria and proteinuria
- other causes include cytomegalovirus infection
- may be reversible with steroids and immunosuppressants

Question 5

Renal transplant rejection - Causes of chronic graft failure (> 6 months)?

Answer 5

Causes of chronic graft failure (> 6 months):
- both antibody and cell-mediated mechanisms cause fibrosis to the transplanted kidney (chronic allograft nephropathy)
- recurrence of original renal disease (MCGN > IgA > FSGS)

Question 6

Post-strep glomerulonephritis features?

Answer 6

general
headache
malaise
visible haematuria
proteinuria
this may result in oedema
hypertension
oliguria
bloods:
raised anti-streptolysin O titre are used to confirm the diagnosis of a recent streptococcal infection
low C3