Nepthritic syndrome Flashcards
Nephritis syndrome : Causes
- Children and Adolescents
- IgA nephropathy
- Post streptococcal glomerulonephrotos
- Haemolytic uraemia syndrome - Adults
- Systemic lupus erythematosis
- Goodpasture’s syndrome
- Rapidly progressive glomerulonephritis
Nephritic syndrome : definition
- Diseased caused by inflammation and damage to glomeruli of kidney
- Glomeruli become more permeable -> Allow RBCs into the urine -> Haematuria
3 . Clincial features :
* Haemturia
* Oliguria
* Oedema
* Hypertension
Nephritis syndrome : Clinical signs and symptom
- Haematuria / Proteinuria : Damaged, Permeable glomeruli
- Odaema, Hypertension : Decreased glomerular filtration rate
- Uraemia : less waste product excreted
Post streptococcal glomerularnephritis : definition
- Inflammation of glomeruli, complication of bacterial infection
- Arises several weeks after : Group A beta haemolytic streptococcus infection
Post streptococcal glomerularnephritis : Pathophysiology
- Type III hypersensitivity reaction
- IgG/IgM antibodies bind to bacterial antigens } form immune complex in the blood stream.
- Complex deposits in the glomerular basement membrane
- Immune complex deposits trigger immune reaction -> inflammatory cells /Complement system recruited -> Basement membrane damage
Post streptococcal glomerularnephritis : Cause
Group A beta haemolytic streptococcus infection
Post streptococcal glomerularnephritis : Risk factors
Children - 6 weeks following Impetigo, 1-2 weeks after a throat infection
Post streptococcal glomerularnephritis : Complication
- Post-streptococcal glomerulonephritis causes progress to acute, diffuse proliferative glomerulonephritis
- Renal failure
Post streptococcal glomerularnephritis : Investigation
1 .Bloods
Antibodies against group A strep : Anti streptolysin O antibodies
2 . Renal biopsy
* Light microscopy - mesangial proliferation
* Electron microscopy : Subepithelial deposits of immune complexes ‘Humps’
* Immunofluorescence : ‘Starry sky’ granular deposits of IgG complement in the basement membrane of the mesangium
Good pasture’s syndrome : Definition
Goodpasture syndrome is an autoimmune disease in which the immune system attacks the A3 chain of Type IV collagen present in the basement membrane
Good pasture’s syndrome : Pathophysiology
- Auto-antibody igG bind to A3 chain of type IV collagen and activate the complement system
- Inflammation and damage to the basement membrane of the kidney and the lungs.
Good pasture’s syndrome : Risk factor
- Environmental
Damage to collagen molecules - exposing antigenic regions of A3 chain - Infection, smoking, occupational risk - Genetic - HLA-DR15 strong genetic susceptibility
Good pasture’s syndrome : Incidence
20-30 years
Good pasture’s syndrome : Clinical features
Pulmonary manifestations occur before renal ones
1. Damaged alveolar basement membrane : Cough, haemoptysis and dyspnea
2. Damaged GBM of the kidneys : Nephritic syndrome
Good pasture’s syndrome : Investigations
Renal biopsy
1. Light microscopy : Crescentric glomerularnephritis
2. Electron microscopy : Diffuse thickening of the glomerular basement membrane
3. Immunofluorescence : Linear deposition along basement membrane
Good pasture’s syndrome : Management
- Immunosuppressant : Corticosteroid, Cyclophosphamide
- Plasmapheresis
Rapidly progressive glomerulonephritis : definition
Inflammation of the nephrons - crescent shaped proliferation of cells in the Bowman’s capsule
* This leads to renal failure within weeks - months
Rapidly progressive glomerulonephritis : Pathophysiology
- Inflammation damages the GBM
- Inflammatory mediators enter the Bowman’s space
- Trigger expansion of thin epithelial layer of cells into thick, crescent moon shape
Rapidly progressive glomerulonephritis : Causes
1 .Primary : Idiopathic
2 .Secondary
* Type 1 : anti GBM antibodies
-Goodpasture syndrome
-
Type II : Immune complexes deposition
-Poststreptococcal glomerulonephritis
-Lupus
-IgA nephropathy -
Type III : ANCA antibodies in the blood
-Vasculitis : Wegener’s granulomatosis etc
Rapidly progressive glomerulonephritis : Complication
If untreated - Rapid progression to acute renal failure
Rapidly progressive glomerulonephritis : Diagnosis
- Light microscopy : crescent shaped glomeruli dueto proliferation of epithelial cells in bowmans capsule
-
Immunofluorescence - differentiate types of RPG
* Type 1 : Linear pattern
Anti GBM Antibodies bind to collagen of the glomerular basement membrane
* Type II : Granular pattern
Result of immune complex deposition int he sub endothelium
* Type III : negative
No antibodies or immune complex deposition } only associated with ANCA in the blood
Rapidly progressive glomerulonephritis : Incidence
Affects adults in their 50s and their 60s
Typically has a poor prognosis if not treated early.
Which is the most common nephropathy worldwide?
IgA nephropathy / Berger disease
IgA nephropathy : Definition
Abnormal IgA forms and deposits in the kidneys resulting in kidney damage
Where are igA antibodies found in the body?
IgA is the main antibody found in breast, tears, saliva and respiratory and gentiourinary tract
IgA nephropathy : Pathophysiology
-
Abnormal IgA form
* Abnormal IgA forms due to glycosylation
* Glycosylated IgA antibodies cannot be identified by the immune system - leading them to accumulate and not degraded. -
Immune system responds
* Immune system generates IgG antibodies which targets the abnormal IgA
* IgG antibodies bind to abnormal IgA and forms immune complexes, this travels through the blood stream and deposits in the kidneys. -
Kidney injury and inflammation
* Type 3 Hypersensitivity
* Immune complexes deposits in the mesangium
* Activates the complement pathway and inflammatory response resulting in glomerular injury.
IgA nephropathy : Clinical features
- Presents in childhood, normally young males with recurrent haematuria (v. Rarely proteinuria)
* develops during an infection involving mucosal lining of the GI or respiratory tract, these infections ramp up IgG anti-glycan formation. - Nephritic syndrome - Proteinuria, haematuria, Hypertension
IgA nephropathy : Investigations
-
Light microscopy
Mesangial proliferation and immune complexes in the mesangium -
Electron microscopy
-Immune complexes deposited in the mesangium -
Immunofluorescence
-Mesangial IgA deposits
IgA nephropathy : Management
- Isolate haematuria or minimal proteinuria and normal eGFR : no tx needed
- Persistent proteinuria + reduced eGFR : Ace inhibitors, also helps to manage hypertension and proteinuria
- Active disease : Immunosupression with corticosteroids
