Nephritic Syndrome

Question 1

Define glomerulonephritis.

Answer 1

Glomerulonephritis is a broad term that refers to a group of parenchymal kidney diseases that all result in the inflammation of the glomeruli and nephrons.

These are a common cause of end stage renal failure (ESRF).

Question 2

Explain the pathophysiology of glomerulonephritis briefly.

Answer 2

1. Damage to the filtration mechanism resulting in HAEMATURIA and PROTEINURIA.
2. Damage to the glomerulus restricts blood flow, leading to compensatory HYPERTENSION.
3. Loss of the usual filtration capacity leads to ACUTE KIDNEY INJURY.

Question 3

What is acute nephritic syndrome?

Answer 3

Refers to a group of symptoms, not a diagnosis.

When we say a patient has “nephritic syndrome”, it simply means they fit a clinical picture of having inflammation of their kidney.

It does not represent a specific diagnosis or give the underlying cause.

Question 4

Give 5 causes of acute nephritic syndrome.

Answer 4

1. ANCA associated vasculitis + Wegener’s granulomatosis
2. Goodpasture’s syndrome (anti-GBM ABs)
3. SLE nephropathy.
4. Post streptococcal infection (immune complex deposition in the kidney).
5. IgA nephropathy (AKA Berger’s disease).
6. Henoch-Schonlein purpura (AKA IgA vasculitis).
7. Infective endocarditis (IE).
8. Alport syndrome - inherited X-linked condition. Anti-GBM ABs to type IV collagen. Hearing loss

Question 5

Describe the pathophysiology behind nephritic syndrome.

Answer 5

Immune complex deposition in glomerular capillary -> neutrophil recruitment -> inflammation and damage to glomerular capillary membrane -> RBC, WBC, protein etc leaks into bowman’s capsule and is excreted in the urine.

Glomerulonephritic pathologies that cause both haematuria and proteinuria. Increased permeability of glomeruli allows movement of RBCs in to filtrate.

Question 6

Give 5 features of acute nephritic syndrome.

Answer 6

1. Inflammation of glomeruli.
2. HAEMATURIA and PROTEINURIA.
3. Hypertension.
4. Fluid overload.
5. Oliguria.
6. Polyuria - Red cell casts.

Question 7

What are the 4 characteristics of acute nephritic syndrome?

Answer 7

Characterised by:
1. Haematuria - visible or non-visible - usually microscopic (red cell casts seen on microscopy - 5 RBCs/uL)
- Dysmorphic RBCs if from glomerulus, with RBC casts

2. Proteinuria (usually < 2 g in 24 hrs; 1-3.5g/day)
3. Hypertension
4. Oedema (periorbital, leg, or sacral)

Question 8

What are the signs + symptoms for nephritic syndromes?

Answer 8

Fatigue, SOB, cough, haemoptysis - RPGN
Prior URTI - IgA neph / Strep GN
Purpuric rash - HSP
Uraemia
Anorexia
Nausea + lethargy

Question 9

What is the commonest primary cause of acute nephritic syndrome?

Answer 9

IgA nephropathy

Question 10

What is ANCA-associated vasculitis?

Answer 10

Multi-system small vessel vasculitis attack small vessels in the kidney and eye

Question 11

Investigations for ANCA-associated vasculitis.

Answer 11

Segmental glomerulosis with crescent formation
Fibrosis + tubular atrophy

• Happens really quickly - quick progression

Question 12

What is the management for ANCA-associated vasculitis?

Answer 12

Immunosuppression, steroids, cyclophosphamide, rituximab,
plasma exchange

Question 13

What is Goodpasture’s syndrome?

Answer 13

1. Co-existence of acute glomerulonephritis + pulmonary alveolar haemorrhage
2. Presence of circulating antibodies directed against an intrinsic antigen to the basement membrane of both kidney + lung.

!!* Antibodies against glomerular basement membrane (Anti-GBM)!!

3. Rapidly progressive kidney failure

Question 14

What 2 features would suggest Goodpature’s syndrome?

Answer 14

1. Acute kidney failure
2. Haemoptysis (coughing up blood)

Question 15

Investigations for Goodpasture’s syndrome.

Answer 15

Histology:
- IgG deposits

Biopsy:
- Anti-GBM

Question 16

What is the treatment for Goodpasture’s syndrome?

Answer 16

1. Immunosuppression
2. Steroids/cyclophosphamide
3. Remove antibody via plasma exchange (plasmapheresis)

Question 17

Post streptococcal glomerulonephritis develops in who and following what kind of conditions?

Answer 17

1. Tonsilitis
2. Impetigo
3. Under 30’s
4. Immune complexes are deposited in glomerulus, causing inflammatory damage to podocytes

Question 18

When does the typical case of post strep glomerulonephritis occur?

Answer 18

Typical case of post-streptococcal glomerulonephritis occurs in a child 1-3 weeks after streptococcal infection (pharyngitis or cellulitis) with a Lancefield group A beta-haemolytic streptococcus e.g. streptococcus pyogenes

Question 19

3 investigations for post streptococcal glomerulonephritis?

Answer 19

1. U&E
2. Urinalysis
3. Biopsy - dead bacterial cells and antibodies causing inflammation

Question 20

What is the treatment of post strep glomerulonephritis?

Answer 20

Treatment:
- Antibiotics - penicillins
- Supportive

Usually a full recovery.

Question 21

IgA nephropathy outline:
Epidemiology
Aetiology
Pathophysiology
Clinical presentation
Investigations
Treatment

Answer 21

Epidemiology:
* COMMONEST CAUSE of nephritic syndrome in the developed world
* In the 20s

Aetiology:
* Following GI or URT (upper respiratory tract) infection
* Associated with tonsilitis

Pathophysiology:
* IgA deposition in mesangium (provided structural support
to glomerulus) of kidney and kidney gets attacked

Clinical presentation:
* Asymptomatic at first
* Haematuria
* Albuminuria
* End-stage renal failure S+S later on

Investigation:
* 1st line = Urine dipstick
* Gold standard = Kidney biopsy - shows IgA deposits and glomerular mesangial proliferation

• NOTE: C3 can be HIGH (due to activation of the complement system agaisnt the deposits), BUT can also be LOW or NORMAL (NOT DIAGNOSTIC!)
• Immunoflorescence = positive

Treatment:
1. BP control - ACEi / ARBs
2. Remove extra fluid - diuretics
3. Control the immune system - corticosteroids (e.g. prednisone) / cyclophosphamide
4. Lower blood cholesterol levels - maybe give statins

Question 22

SLE outline:
Pathophysiology
Clinical presentation
Investigations
Treatment

Answer 22

Pathophysiology:
* Anti-nuclear antibody (ANA) positive and Double stranded DNA
positive
* Low complement C3 & C4

Clinical presentation:
* Rash, arthralgia, kidney failure, neurological symptoms, pericarditis and pneumonitis

Treatment:
* Immunosuppression; steroids, cyclophosphamide, rituximab (monoclonal antibodies - mABs)

Question 23

IgA nephropathy and post strep glomerulonephritis are both nephritic conditions that develop after tonsilitis etc but what is the difference?

Answer 23

IgA - within a few days
Post strep - within a few weeks

Question 24

Gold standard investigation for nephritic syndromes?

Answer 24

Nephritic = biopsy - crescent shaped glomeruli

Question 25

General management of nephritic syndrome.

Answer 25

General:
1. Hypertension control

Proteinuria:
2. ACEi / ARB
3. Loop diuretic (furosemide)
4. Steroids - Prednisolone

Question 26

A patient presents complaining that they are hardly passing any urine and in the small amount of urine they do pass there is blood in it. On further questioning they tell you they have recently finished a course of antibiotics (amoxicillin) for a chest infection they had 2 weeks ago. Their BP is high. What is the likely cause?

Answer 26

Nephritic syndrome.

Question 27

What type of hypersensitivity syndromes are these?

Answer 27

Type III hypersensitivities