Glomerulonephritis Flashcards
What is GN?
immune mediated disease of the kidneys affecting the glomeruli
What are the two possible pathophysiologies of GN?
humoral antibody mediated - antigen recognises the kidney to be forgien in so there are immune complexes deposited and block the sieve
cell mediated - T cells are upregulated causing toxic damage
What is the underlying pathophysiology of GN?
distruption to the barrier of the glomerular capillary wall which leads to haematuria and/or proteinuria
What are the 3 cel types that can be damaged in GN?
endothelial cells
mesangial cells
podocytes
What is the most common cell to be damaged in GN?
mesangial cells
What are the characteristics of endothelial and mesangial cell GN?
proliferative lesion
aggressive disease
blood in urine
What are the characteristics of podocyte cell GN?
no inflammatory response
non proliferative lesion
protein leak
What do mesangium cells release when they are damaged?
Ang 2
chemokine release
What disease does mesangial cell damage commonly present with?
HSP
How is GN diagnosed?
painless haematuria microalbuminuria asymptomatic proteinuria nephrotic/nephritic syndrome impaired renal function
What do red cell casts in the urine show?
endothelial injury
What does nephritic syndrome indicate?
endothelial injury
What is nephritic syndrome?
acute renal failure oliguria and haematuria oedema/fluid retention hypertension active urinary sediment - granular casts, RBCs
What does nephrOtic syndrome indicate?
podocyte injury
What is nephrOtic syndrome?
proteinuria >3g/day hypoalbuminuria - causes low oncotic pressure so water is driven out of cells and into tissues oedema hypercholesterolaemia NORMAL RENAL FUNCTION
What are the complications of nephrotic syndrome?
infections
renal vein thrombosis
pulmonary emboli in lungs and legs
volume depletion - may lead to AKI
What are the blood pressure targets for someone with GN?
<130/80
OR <120/75 if proteinuria
What are the treatments for GN?
Antihypertensives - ACEis/ARBs (reduce proteinuria) diuretics statins Immunosuppresives Plasma pheresis IV immunoglobulins monoclonal T and B cell antibodies
What can cause GN?
idiopathic - mainly
infections - HIV, hepatitis, bacteria
drugs - gold, penicilamine
malignancies - immune response against abnormal cells
part of systemic disease - GPA, good pastures, HSP
How is GM diagnosed and classified?
light microscopy
electron microscopy
immunoflurensence
What is seen on light microscopy of GN?
sclerosis
crescents - BAD
if vasculitis - sarcoid
inflammatory cells and reactive proliferations
What is seen on electron microscopy of GN?
can look at the basement membrane and see what layers are damaged
What is seen on immunofluresence of GN?
in good pastures - linear IgG againsts the collagen in the basement membrane
What is goodpastures syndrome?
IgG antibodies attack the subunit of collagen in the basement membrane in the lungs and kidney
How does goodpastures present?
haemoptysis
kidney failure
How does vasculitis affect the glomerular sieve?
distrupts the membrane charges and blocks the membrane and allows things like RBCs and albumin and protien through
What are the different types of idiopathic GN?
IgA nephropathy Focal segmental Membranous Minimal change Membranoproliferative
Describe IgA nephropathy?
commonest GN in the world mesangial cell proliferation IgA depostis in mesangium on immunofloresence BP control/ACEi/ARBS/fish oil neprhitic syndrome and smokey urine
Describe focal segmental GN?
adults
- HIV, sickle cell, IV drug users, obesity
nephritic syndrome
remission with prolonged steroids
IgG/complement depositon on immunofluresence
Describe Membranous?
often caused by lupus
infections, drugs, malignancy, autoimmune
nephrotic syndrome
SPIKEY thick membranes - white spaces are the immune complexes in the basement membranes, antigens stick to and damage podocytes
treament - steroids, ankylating agents, B cell monoclonal antibodies
Describe Minimal change?
kids get it! presents with nephrotic syndrome good prognosis with steroid treatment antibody against Podocytes normal renal biopsy
Describe membranoproliferative?
adults and children are affected
can be nephrotic or nephritic
big lobulated hypercellular glomeruli with thick membranes - tram tracks
