NEPHRITIS AND NEPHROTIC SYNDROME Flashcards
What are the characteristic features of acute nephritis?
Fluid retention (oedema, facial puffiness)
Hypertension
Haematuria
Proteinuria
What is the cause of the majority of acute nephritis in children?
Postinfectious - following a throat or skin infection with group A Beta haemolytic streptococci (eg strep pyogenes)
What are the non-streptococcal causes of acute nephritis in children?
HSP - Henoch-Schonlein purpura (see haematological cards)
IgA nephropathy
Systemic lupus erythematosus (SLE)
Mesangiocapillary glomerulonephritis
Haemolytic uraemic syndrome
What is the typical history of a child with acute nephritis?
Discoloured smoky urine
Facial swelling
What will be seen typically on examination of a child with acute nephritis?
High blood pressure
Oedema
What is the other name for IgA nephropathy?
Berger’s disease
What would typically be elicited in the history of someone with acute nephritis caused by IgA nephropathy?
Preceding respiratory tract infection
What is Henoch-Schonlein purpura (HSP)?
An immune mediated systemic vasculitis that affects many parts of the body including skin, joints, gut, and kidney. HSP can follow an upper respiratory tract infection.
Which group of patients is Henoch-Schonlein purpura (HSP) most likely to affect?
Boys
How does Henoch-Schonlein purpura (HSP) differ histologically from IgA nephropathy (Berger’s disease)?
It doesn’t
What are the skin changes associated with Henoch-Schonlein purpura (HSP)?
Purpuric rash seen over the extensor surfaces of the legs, arms and buttocks
What are the intestinal changes associated with Henoch-Schonlein purpura (HSP)?
Abdominal pain, vomiting and bleeding
What is the treatment for Henoch-Schonlein purpura (HSP)?
Children usually recover without need for treatment
Parents will need reassurance
What is the most common cause of acute renal failure in children?
Haemolytic uraemic syndrome
What normally causes haemolytic uraemic syndrome in children?
It is caused by Shiga-like toxin produced by E. coli O157:H7 which bind to GB3 receptors in the kidney. Children have more GB3 receptors than adults. The toxin results in red blood cell fragmentation (glomerular microangiopathic haemolytic anaemia) and thrombocytopenia.
Other than shiga-like toxin produced by E. coli, what are the causes of haemolytic uraemic syndrome (a lot of them not really seen in children)?
Tumours
Pregnancy
Ciclosporin
The Pill
Systemic lupus erythematosus
HIV
What are the classic triad of haemolytic uraemic syndrome?
Haemolytic anaemia
Uremia (acute kidney failure)
Thrombocytopenia
What are the clinical features of haemolytic uraemic syndrome?
History of diarrhoea
Abdominal pain
Confusion, fatigue, oedema
Nausea and vomiting
Haematuria
What investigations would you do in a child who presents with a history of bloody diarrhoea, abdominal pain and haematuria suggestive of haemolytic uraemic syndrome? What would you expect to find to confirm your diagnosis?
FBC: anaemia, thrombocytopaenia, fragmented blood film
U&E: acute renal failure
Stool culture: E. coli
How do we manage children with haemolytic uraemic syndrome?
Management is supportive (fluids, blood transfusion, dialysis) and 90% of children recover full renal function
Antibiotics are contraindicated as they induce expression and release of Shiga-like toxin.
The indications for plasma exchange in HUS are complicated. As a general rule plasma exchange is reserved for severe cases of HUS not associated with diarrhoea
What investigations would you do for a child that presents with clinical features of acute nephritis?
Urine dip - positive for blood and protein
Microscopy of urine - reveals red cells and casts
U&Es
Abdominal USS can exclude other causes of haematuria eg cysts
Throat swab - Group A strep
Anti-DNAase B - positive in Group A strep
Complement C3 levels - decreased in mesangiocapillary GN and post-strep GN
Biopsy if severe - histology
How do we manage children with acute nephritis?
Control of fluid and electrolyte balance
Diuretics and antihypertensives as required
Treat underlying cause
No evidence that treatment of the preceding infection prevents renal complications.
What is the prognosis for postinfectious acute nephritis in children?
Usually very good. Rarely, a rapidly progressive glomerulonephritis with renal failure occurs, especially with nephritis from other causes.
What is the classic triad of nephrotic syndrome in children?
Proteinuria - loss of more than 1 g per day in children
Oedema
Hypoalbuminaemia - serum albumin typically less than 25g/L
What are the other features of nephrotic syndrome in children (aside from proteinuria, hypoalbuminaemia and oedema)?
Hyperlipidaemia/Hypercholesteraemia - liver respond to loss of protein
Hypercoagulability - loss of antithrombin III
Predisposition to infection
What is the most common cause of nephrotic syndrome in children?
Minimal change disease (80%)
What are the two types of minimal change disease?
Steroid sensitive (90%)
Steroid resistant (10%)
What is the peak incidence of nephrotic syndrome in children?
2 to 5 years old
What are the clinical features of nephrotic syndrome in children?
Oedema:
- Facial puffiness
- Leg and foot swelling
- Gross scrotal oedema
- Ascites
- Pleural effusions
What baseline investigations should be carried out in a child that presents with signs and symptoms consistent with nephrotic syndrome?
U&Es
Urine microscopy - check for blood
C3 and C4 levels - usually normal
Anti-DNAase B - should be negative
Hepatitis serology - non-minimal change nephrotic syndrome is associated with hep B
What features from the history and baseline investigations in a child with nephrotic syndrome should prompt biopsy to rule out rarer causes?
Age: less than 1 or more than 12 years old
Macroscopic haematuria
Low C3
Failure to respond to steroid therapy
Hypertension
Renal failure
How do we manage a child with features of classic nephrotic syndrome?
4 weeks of oral prednisolone 60 mg/m^2/day with a gradually reducing regimen
Fluid balance must be closely monitored with daily weighing and salt restriction
Prophylactic penicillin is given in the acute phase to prevent secondary infection
Pneumococcal vaccination
What is the definition of steroid resistant minimal change disease?
No remission (ie continued proteinuria) within 4 weeks
What are the serious complications of nephrotic syndrome in children?
Hypovolaemia
Thrombosis
Secondary infection
Hyperlipidaemia
What is the relapse rate of nephrotic syndrome in children?
70%
What additional immunosuppressants might be given to a child with recurrent nephrotic syndrome?
Ciclosporin
Cyclophosphamide
Levamisole
What histological patterns are typically associated with a nephritic picture (haematuria/hypertension)?
Rapidly progressive glomerulonephritis (aka crescentic glomerulonephritis)
IgA nephropathy
What histological patterns are typically associated with a mixed nephritic/nephrotic presentation?
Diffuse proliferative glomerulonephritis
Membranoproliferative glomerulonephritis (mesangiocapillary)
What histological patterns are typically associated with a nephrotic picture?
Minimal change disease
Membranous glomerulonephritis
Focal segmental glomerulosclerosis
