Proteinuria

Question 1

How is proteinuria defined microscopically?

Answer 1

• Early morning collection
○ P:Cr ratio > 20mg/mmol
○ Albumin:Cr ratio > 3.5mg/mmol

Question 2

How does proteinuria affect renal prognosis?

Answer 2

• Quantity of protein equates to renal prognosis, except for in the case of minimal-change disease.

Question 3

Compare features of nephrotic vs nephritic syndrome.

Answer 3

Nephrotic:

1. Proteinuria (>3.5g/24h)
2. Hypoalbuminaemia (30mg/L)
3. Oedema - everywhere, pitting, non-dependent oedema
4. Hyperlipidaemia
5. (Only a small increase in BP)
6. 🐝 Fatty casts in urine
7. Filtration normal

Nephritic:

1. High BP**
2. Macroscopic haematuria
3. Oliguria
4. Raised serum Cr
5. 🐝red cell casts
   - Filtration abnormal
   - Mild proteinuria and mild oedema only

Question 4

What is the most common cause of nephrotic syndrome in children? What is the buzz word for it?

Answer 4

Minimal change GN - swelling/puffy face: responsive to steroids

Question 5

Outline causes of nephrotic syndrome in children

Answer 5

• Idiopathic nephrotic syndrome
○ Minimal change disease (85%)
○ Focal segmental glomerulosclerosis (10-15%)

• Non-idiopathic(rare):
○ Secondary: SLE, HSP, MPGN
○ Membranous nephropathy
○ Congenital nephrotic syndrome

Question 6

What is the classic presentation for minimal change GN?

Answer 6

2-10 years, atopic, triggered by infection

Question 7

Outline where oedema can occur/what it can lead to, and thus outline mild-mod-severe oedema.

Answer 7

• Or associated weight gain/poor urine output/dizziness
• Mild (subtle peri-orbital region, scrotum or labia)
• Moderate with peripheral pitting oedema of the limbs and sacrum.
• Severe with gross limb oedema, ascites and pleural effusions.

Question 8

What are the possible complications of nephrotic syndrome?

Answer 8

• Infection (especially susceptible to encapsulated bacteria)

- Cellulitis from gross oedema with skin compromise
- Spontaneous bacterial peritonitis – abdominal pain, fever, nausea/vomiting, rebound tenderness

• Thrombosis: DVT, PE, renal vein thrombosis, cerebral vein thrombosis

• Dehydration
• Effusions

Question 9

What are some DDx for nephrotic syndrome?

Answer 9

• Cardiac failure
• Liver failure
• Protein losing enteropathy causing oedema

Question 10

What are some Rx used in managing nephrotic syndrome?

Answer 10

1. Steroids - underlying cause (course 6 weeks with weaning
2. Symptoms: albumin and frusemide IV
   • Albumin causes brief increased plasma oncotic pressure
   • Then quickly give frusemide to help the kidneys flush it out

3. Prevention of complications: 
	• Penicillin (prevents infection)
	• Aspirin (clotting)
	• Ranitidine (prevents gastritis)
	• (Na + fluid moderation)

Question 11

What percentage of INS will respond to steroids? What is important to remember about steroid-sensitive nephritic syndrome?

Answer 11

• 90% INS respond to steroids

- SSNS 80% chance of relapse

Question 12

What is important to educate a family about re: nephrotic syndrome management?

Answer 12

• Amount of water can drink and salt restriction
• How to do urine dipstick - daily (rec even for 1-2 years post-remission)
• Steroids during infection to prevent relapse
• Vaccinations usually wait until after steroid, except pneumococcal and flu

Question 13

What are some common causes of nephritic syndrome in children?

Answer 13

e.g. SLE, IgA, post-streptococcal glomerulonephritis

Question 14

Post-strep GN:

• how long following URTI
• Ix results
• Rx

Answer 14

• 2-4 weeks following strep skin/throat infection
• Positive streptococcal serology
• Low C3, possibly normal C4
• Rarely need biopsy
• Rx: frusemide

Question 15

List some investigation you might order to investigate nephritic syndrome.

Answer 15

Haematology
	• FBE, film
	• UEC (biochem)
	• ESR
	• PTT
	• Prothrombin / INR
	• Fibrinogen

Bacteriology
• MSU-MCS
• Pr:Cr
• Phase contrast micro for red cell casts

Virology (selected cases only)
• Hepatitis B Surface Antigen
• Hepatitis C and CMV antibodies
• HIV antibodies

Immunology
	• Serum Complement ( C3 and C4)Immunoglobulins
	• Anti- Double Stranded DNA
	• ANF
	• ASO Titre
	• Anti- streptococcal DNase B titre
	• Blood culture/throat swab

Procedure/imaging
• US
• Biopsy