NEPHRITIS AND NEPHROTIC SYNDROME Flashcards by Alex Kinsky

What are the characteristic features of acute nephritis?

Fluid retention (oedema, facial puffiness)

Hypertension

Haematuria

Proteinuria

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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)

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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

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What is the typical history of a child with acute nephritis?

Discoloured smoky urine

Facial swelling

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What will be seen typically on examination of a child with acute nephritis?

High blood pressure

Oedema

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What is the other name for IgA nephropathy?

Berger’s disease

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What would typically be elicited in the history of someone with acute nephritis caused by IgA nephropathy?

Preceding respiratory tract infection

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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.

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Which group of patients is Henoch-Schonlein purpura (HSP) most likely to affect?

Boys

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How does Henoch-Schonlein purpura (HSP) differ histologically from IgA nephropathy (Berger’s disease)?

It doesn’t

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What are the skin changes associated with Henoch-Schonlein purpura (HSP)?

Purpuric rash seen over the extensor surfaces of the legs, arms and buttocks

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What are the intestinal changes associated with Henoch-Schonlein purpura (HSP)?

Abdominal pain, vomiting and bleeding

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What is the treatment for Henoch-Schonlein purpura (HSP)?

Children usually recover without need for treatment

Parents will need reassurance

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What is the most common cause of acute renal failure in children?

Haemolytic uraemic syndrome

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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.

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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