Nephritic Syndrome Flashcards
Define glomerulonephritis.
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).
Explain the pathophysiology of glomerulonephritis briefly.
- Damage to the filtration mechanism resulting in HAEMATURIA and PROTEINURIA.
- Damage to the glomerulus restricts blood flow, leading to compensatory HYPERTENSION.
- Loss of the usual filtration capacity leads to ACUTE KIDNEY INJURY.
What is acute nephritic syndrome?
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.
Give 5 causes of acute nephritic syndrome.
- ANCA associated vasculitis + Wegener’s granulomatosis
- Goodpasture’s syndrome (anti-GBM ABs)
- SLE nephropathy.
- Post streptococcal infection (immune complex deposition in the kidney).
- IgA nephropathy (AKA Berger’s disease).
- Henoch-Schonlein purpura (AKA IgA vasculitis).
- Infective endocarditis (IE).
- Alport syndrome - inherited X-linked condition. Anti-GBM ABs to type IV collagen. Hearing loss
Describe the pathophysiology behind nephritic syndrome.
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.
Give 5 features of acute nephritic syndrome.
- Inflammation of glomeruli.
- HAEMATURIA and PROTEINURIA.
- Hypertension.
- Fluid overload.
- Oliguria.
- Polyuria - Red cell casts.
What are the 4 characteristics of acute nephritic syndrome?
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
- Proteinuria (usually < 2 g in 24 hrs; 1-3.5g/day)
- Hypertension
- Oedema (periorbital, leg, or sacral)
What are the signs + symptoms for nephritic syndromes?
Fatigue, SOB, cough, haemoptysis - RPGN
Prior URTI - IgA neph / Strep GN
Purpuric rash - HSP
Uraemia
Anorexia
Nausea + lethargy
What is the commonest primary cause of acute nephritic syndrome?
IgA nephropathy
What is ANCA-associated vasculitis?
Multi-system small vessel vasculitis attack small vessels in the kidney and eye
Investigations for ANCA-associated vasculitis.
Segmental glomerulosis with crescent formation
Fibrosis + tubular atrophy
- Happens really quickly - quick progression
What is the management for ANCA-associated vasculitis?
Immunosuppression, steroids, cyclophosphamide, rituximab,
plasma exchange
What is Goodpasture’s syndrome?
- Co-existence of acute glomerulonephritis + pulmonary alveolar haemorrhage
- Presence of circulating antibodies directed against an intrinsic antigen to the basement membrane of both kidney + lung.
!!* Antibodies against glomerular basement membrane (Anti-GBM)!!
- Rapidly progressive kidney failure
What 2 features would suggest Goodpature’s syndrome?
- Acute kidney failure
- Haemoptysis (coughing up blood)
Investigations for Goodpasture’s syndrome.
Histology:
- IgG deposits
Biopsy:
- Anti-GBM
What is the treatment for Goodpasture’s syndrome?
- Immunosuppression
- Steroids/cyclophosphamide
- Remove antibody via plasma exchange (plasmapheresis)
Post streptococcal glomerulonephritis develops in who and following what kind of conditions?
- Tonsilitis
- Impetigo
- Under 30’s
- Immune complexes are deposited in glomerulus, causing inflammatory damage to podocytes
When does the typical case of post strep glomerulonephritis occur?
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
3 investigations for post streptococcal glomerulonephritis?
- U&E
- Urinalysis
- Biopsy - dead bacterial cells and antibodies causing inflammation
What is the treatment of post strep glomerulonephritis?
Treatment:
- Antibiotics - penicillins
- Supportive
Usually a full recovery.
IgA nephropathy outline:
Epidemiology
Aetiology
Pathophysiology
Clinical presentation
Investigations
Treatment
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
SLE outline:
Pathophysiology
Clinical presentation
Investigations
Treatment
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)
IgA nephropathy and post strep glomerulonephritis are both nephritic conditions that develop after tonsilitis etc but what is the difference?
IgA - within a few days
Post strep - within a few weeks
Gold standard investigation for nephritic syndromes?
Nephritic = biopsy - crescent shaped glomeruli
General management of nephritic syndrome.
General:
1. Hypertension control
Proteinuria:
2. ACEi / ARB
3. Loop diuretic (furosemide)
4. Steroids - Prednisolone
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?
Nephritic syndrome.
What type of hypersensitivity syndromes are these?
Type III hypersensitivities
