Nephritic & Nephrotic Syndrome (bj)

Question 1

What are the 3 layers of the Glomerular Filtration Barrier?

Answer 1

Endothelial Cell layer - fenestrated
GBM - Type 4 collagen & laminin with embedded mesangial cells (smooth muscle)
Podocytes (Podocin & nephrin proteins)

Question 2

Define Nephritic vs Nephrotic Syndrome?

Answer 2

Nephritic = High haematuria & intravascular overload

Nephrotic = High proteinuria & intravascular depletion

Question 3

Describe the typical presentation of nephrotic syndrome

Answer 3

Presentation:

• Oedema - face, legs, ascites, pleural effusions
• Frothy Urine
• Pale but mostly well
• +/- Raised BP

Question 4

What are the types/causes of Nephrotic Syndrome?

Answer 4

Minimal Change Disease (85%)

Steroid REsistant nephrotic syndrome (15%) - includes:

• Congenital - NPHS1 or 2 mutations
• Acquired FSGS (Focal segmental glomerular sclerosis)

Question 5

How do we diagnose nephrotic syndrome?

assume its minimal change disease

Answer 5

Triad of nephrotic syndrome = oedema, proteinuria & hypoalbuminaemia

Oedema - examination

Proteinuria:

• Dipstick - proteinuria & mild haematuria
• Protein:creatinine ratio! >250mg/mmol
• 24hr urine collection - gold standard but rarely done

Bloods:

• hypoalbuminaemia
• normal U&Es

Blood pressure - typically normal, can be raised
Trial Prednisolone

Question 6

Why don’t we biopsy in most nephrotic syndromes?

Answer 6

Most it’s almost always minimal change disease so we just trial treatment

Question 7

Nephrotic Syndrome is treated with 8wks of prednisolone. what are the major SEs?

Answer 7

Commonest:
GI due to high acid
Behaviour (irritable/moody/don't sleep)
HTN
Weight Gain

Uncommon:
Glucose intolerance
Adrenal crisis

Growth problems with recurrent courses

Question 8

Describe the outcome of MCD?

Answer 8

95% go into remission in 2-4wks

80% will relapse

Question 9

How do you treat Steroid Resistant Nephrotic Syndromes e.g. FSGS?

Answer 9

Second line immunosuppression - cyclophosphamide

Question 10

Try to list 8 major causes of childhood haematuria?

Answer 10

UTI
Trauma
Stones

Glomerulonephritis due to:

• Post-infective GN
• IgA nephropathy / HSP
• Membranoproliferative GN
• SLE
• ANCA +ve vasculitis e.g. GPA

Question 11

What’s the classic presentation of Nephritic Syndrome?

Answer 11

• Haematuria (frank or microscopic)
• Proteinuria
  Reduced GFR:
  –> Oligura
  –> Fluid overload (JVP/oedema)
  –> HTN
  –> High creatinine

Often comes post-infection, particularly throat

Question 12

What’s the most common nephritic syndrome in kids vs adults?

Answer 12

Kids - Post-infective Glomerulonephritsi

Adults – IgA Nephropathy

Question 13

What causes Post-infective Glomerulonephritis?

Answer 13

Group A strep
Throat infections 7-10days later
skin 2-4wks later

Nephrogenic strep antigens bind to sites in glomeruli & form immune complexes which are deposited there

This triggers Alternative Complement activation & Adaptive immune response leading to the nephritis

Question 14

How can you diagnose Post-infective Glomerulonephritis?

Answer 14

A bacterial culture & throat swab for Strep A

+ve ASO Titre

Low C3 (used up)

Normal Renal US

ANA (SLE) + ANCA (GPA) to rule out autoimmune

Question 15

So child with nephritic syndrome presents a week after having a throat infection.
Tests show Strep A culture, +ve ASO titre, low C3
Renal US, ANA & ANCA were all -ve
How would you treat the kid?

Answer 15

Diagnosis of Post-infective GN

Abx
Diuretic for fluid overload
Support renal function (e.g. restrict fluid, restrict Na, ACEI etc)

It will be self-limiting

Question 16

IgA nephropathy is a commoner cause of nephritic syndrome in older kids/adults. What causes it?

Answer 16

Often comes 1-2days post or during an URTI (So much quicker than post-infective GN)

Question 17

How do you diagnose and treat IgA nephropathy?

Answer 17

Clinical diagnosis with biopsy to confirm

ACEI
If severe give Immunosuppression

Question 18

What is IgA Vasculitis / HSP?

Answer 18

Henoch-Sholein Purpura

It’s very similar to IgA nephropathy but comes with more systemic problems. You need Palpable purpura + 1 of

• Renal involvement
• Abdo pain
• Arthritis
• Renal biopsy showing IgA deposits

Again it comes 1-3days post viral URTI

Question 19

How do you treat HSP/IgA vasculitits?

Answer 19

Symptomatic treatments for joint/gut symptoms e.g. analgesia & NSAIDs

CCS may help gut

Immunosuppression if severe

ACEI for kidneys

Long term monitor for HTN & Proteinuria

Question 20

Which Glomerulonephritidis affect which layer of the Glomerular Filtration BArrier?

Answer 20

Podocytes = MCD & SLE

GMB = Membranous & Post-infective (PIGN)

Endothelial cells = PIGN, HUS, Membranoproliferative glomerulonephritis or SLE

mesangial = HSP, IgA nephropathy or SLE