I n t e r n a L medicine questions Bank

Platelets	65 * 109/l
WCC	11.1 * 109/l
Urea	23.1 mmol/l
Creatinin	366 µmol/l

What is the most likely diagnosis?

		A.	Wegener's granulomatosis
		B.	Thrombotic thrombocytopenic purpura
		C.	Haemolytic uraemic syndrome
		D.	Idiopathic thrombocytopenic purpura
		E.	Rapidly progressive glomerulonephritis

- HUS or TTP? Neuro signs and purpura point towards TTP

The combination of neurological features, renal failure, pyrexia and thrombocytopaenia point towards a diagnosis of thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura

Pathogenesis of thrombotic thrombocytopenic purpura (TTP)

• 
  abnormally large and sticky multimers of von Willebrand's factor cause platelets to clump within vessels
  
• 
  in TTP there is a deficiency of caspase which breakdowns large multimers of von Willebrand's factor
  
• 
  overlaps with haemolytic uraemic syndrome (HUS)
  

Features

• 
  rare, typically adult females
  
• 
  fever
  
• 
  fluctuating neuro signs (microemboli)
  
• 
  microangiopathic haemolytic anaemia
  
• 
  thrombocytopenia
  
• 
  renal failure
  

Causes

• 
  post-infection e.g. urinary, gastrointestinal
  
• 
  pregnancy
  
• 
  drugs: ciclosporin, oral contraceptive pill, penicillin, clopidogrel, aciclovir
  
• 
  tumours
  
• 
  SLE
  
• 
  HIV
  

1. 
   25-year-old man has a renal biopsy due to worsening renal function. This reveals linear IgG deposits along the basement membrane. What is the most likely diagnosis?
   

	A.	Systemic lupus erythematous
	B.	IgA nephropathy
	C.	Minimal change disease
	D.	Post-streptococcal glomerulonephritis
	E.	Goodpasture's syndrome

These changes are characteristic of Goodpasture's syndrome


Goodpasture's syndrome

Goodpasture's syndrome is rare condition associated with both pulmonary haemorrhage and rapidly progressive glomerulonephritis. It is caused by anti-glomerular basement membrane (anti-GBM) antibodies against type IV collagen. Goodpasture's syndrome is more common in men (sex ratio 2:1) and has a bimodal age distribution (peaks in 20-30 and 60-70 age bracket). It is associated with HLA DR2

Features

• 
  pulmonary haemorrhage
  
• 
  followed by rapidly progressive glomerulonephritis
  

Factors which increase likelihood of pulmonary haemorrhage

• 
  young males
  
• 
  smoking
  
• 
  lower respiratory tract infection
  
• 
  pulmonary oedema
  
• 
  inhalation of hydrocarbons
  

Investigations

• 
  renal biopsy: linear IgG deposits along basement membrane
  
• 
  raised transfer factor secondary to pulmonary haemorrhages
  

Management

• 
  plasma exchange
  
• 
  steroids
  
• 
  cyclophosphamide
  

3. 
   Which one of the following is the most common cause of nephrotic syndrome in children?
   

	A.	Minimal change disease
	B.	IgA nephropathy
	C.	Focal segmental glomerulosclerosis
	D.	Chronic pyelonephritis
	E.	Infantile microcystic disease

Minimal change glomerulonephritis nearly always presents as nephrotic syndrome, accounting for 75% of cases in children and 25% in adults. The main causes are drugs (NSAIDs, gold), Hodgkin's lymphoma and thymoma. The majority of cases respond well to steroids


Glomerulonephritides

Knowing a few key facts is the best way to approach the difficult subject of glomerulonephritis:

Membranous glomerulonephritis

• 
  presentation: proteinuria / nephrotic syndrome / CRF
  
• 
  cause: infections, rheumatoid drugs, malignancy
  
• 
  1/3 resolve, 1/3 respond to cytotoxics, 1/3 develop CRF
  

IgA nephropathy - aka Berger's disease, mesangioproliferative GN

• 
  typically young adult with haematuria following an URTI
  

Diffuse proliferative glomerulonephritis

• 
  classical post-streptococcal glomerulonephritis in child
  
• 
  presents as nephritic syndrome / ARF
  

Minimal change disease

• 
  typically a child with nephrotic syndrome (accounts for 80%)
  
• 
  causes: Hodgkin's, NSAIDs
  
• 
  good response to steroids
  

Focal segmental glomerulosclerosis

• 
  may be idiopathic or secondary to HIV, heroin
  
• 
  presentation: proteinuria / nephrotic syndrome / CRF
  

Rapidly progressive glomerulonephritis - aka crescentic glomerulonephritis

• 
  rapid onset, often presenting as ARF
  
• 
  causes include Goodpasture's, ANCA positive vasculitis, SLE
  

Mesangiocapillary glomerulonephritis (membranoproliferative)

• 
  type 1: cryoglobulinaemia, hepatitis C
  
• 
  type 2: partial lipodystrophy
  

1.