Glomerulonephritis Flashcards
What is glomerulonephritis?
immune-mediated disease of the kidneys affecting the glomeruli with secondary tubulointerstital amage
What mediates GN?
humoral- antibody mediated- intrinsic or planted antigent or deposition of circulating immune complexes
What happens in GN to the glomerular membrane?
disruption of the barrier leads to haematuria and/or proteinuria
What happens if there is damage to enothelial or mesangial cells?
proliferative lesion and RBCs in the urin
What happens if there is damage to the podocytes?
non-proliferative lesion and protein in the urine
Why does damage to different cells at the glomerulus cause different responses?
cells of the nephron respond to injury in different ways
What happens to the podocytes when they are injured?
atrophy- loss of size/charge specific barrier
What happens if there is injury to the mesangium?
mesangial cells proliferate and release ATII and chemokines; attracts inflammatory cells
What happens if there is injury to the endothelial cells?
vasculitis
What is the difference between endothelial and mesnagial injury if they are both prolferative lesions?
endothelial injury is a much more aggressive process and has lots of inflammation
What is done if there is haematuria seen on urinalysis?
RBC (dysmrophic; granular casts and lipiduria
What is done is there is protein seen on UA?
PCR
What is the typical presentation of haematuria with GN?
asymptomatic microscopic or painless macroscopic
What is microalbuminuria?
30-300mg albuminuria/day
What is heavy proteinuria?
1-3g/day
What is nephrotic syndrome efined as in proteinuria?
> 3g/day
What is the appearance of RBCs on microscopy if they have come from the glomerulus? why?
dysmorphic- have been squeezed through the tubule
What are RBC casts?
protein that tubules produce gathers roudn the blood cells and they end up in a tubular shaped clump
What is nephritic syndrome?
ARF; oliguria; oedema/fluid retention; HT; active urinary sediment
What is active urinary sediment?
RBCs; RBC and granular casts
What is nephritic syndrome indicative of?
a proliferative process affeting endothelial cells
What is nephrotic syndrome?
proteinuria >3g/day; hypoalbuminaemia; oedema; hypercholeseterolaemia
What is nephrotic syndrome indicative of?
a non-proliferative process affecting podocytes
What are the complications of nephrotic syndrome?
infections; renal vein thrombosis; PE; volume depletion
Why do patients with nephrotic syndrome get infections?
loss of opsonising antibodies
What should be suspected with AKI in nephrotic syndrome?
renal vein thrombosis
What causes volume depletion with nephrotic syndrome?
overagressive use of diuretics
What may volume depletion lead to?
pre-renal ARF
What is the difference between interstital nephritis and GN on urinemicroscopy?
interstital nephritis doesn’t have dysmorphic RBCs
How are renal biopsies analysed?
light microscopy; immunofluorescence; EM
What does diffuse GN indicate?
> 50% glomeruli affeced