Glomerular Disease Flashcards
What proteins will not be filtered across the glomerular membrane?
All proteins equal to or larger than albumin (including immunoglobulins)
What are podocytes?
Cells in the Bowman’s capsule in the kidneys that wrap around capillaries of the glomerulus.
The long processes, or foot projections (pedicels) of the podocytes wrap around the capillaries, and leave slits between them. Blood is filtered through these slits, each known as a filtration slit or slit diaphragm. Several proteins are required for the foot projections to wrap around the capillaries and function.
What is nephrin?
Nephrin is a zipper-like protein that forms the slit diaphragm, with spaces between the teeth of the zipper, big enough to allow sugar and water through, but too small to allow proteins through.
What 3 things make up the Glomerular membrane/ filter barrier?
Endothelial cell cytoplasm,
Basal lamina,
Podocyte
Sort of 3 layer sandwich of endothelium then basal lamina (connective tissue) and then projecting podocytes
What are mesangial cells?
“Tree like” group of cells which support capillaries
Specialized cells around blood vessels in the kidneys, at the mesangium. Primary function of mesangial cells is to remove trapped residues and aggregated protein from the basement membrane thus keeping the filter free of debris.
The contractile properties of mesangial cells have been shown to be insignificant in changing the filtration pressure of the glomerulus.
What is glomerular nephritis?
Disease of glomerulus
-May be inflammatory or non-inflammatory
What is the difference between primary and secondary glomerular nephritis?
Primary (only affects glomerulus)
Secondary (other parts of body affected e.g. SLE or Wegener’s)
What is the aetiology of glomerulonephritis?
Some are due to immunoglobulin deposition
Some are diseases woth NO immunoglobulin deposition (e.g. diabetic glomerular disease)
What does glomerulonephritis cover?
Large range of conditions
Difficult to cover all variants
What are the 4 common presentations of glomerulonephritis?
- Haematuria (blood in urine)
- Heavy proteinuria (nephrotic syndrome)
- Slowly increasing proteinuria
- Acute renal failure
What are the main causes of haematuria?
Urinary tract infection
Urinary tract stone
Urinary tract tumour
Glomerulonephritis
What tests could you carry out in haematuria?
Send of urine culture
Abdomen USS
If both negative -> Check clotting then proceed to renal biopsy
What is IgA glomerulonephritis?
IgA deposits in mesangium
- Get stuck are not cleared
- No presence of IgA in urine
Increased proliferation of mesangial cells -> to try clear
-Mesangial cells try to produce more matrix
Aetiology unknown
Unknown how haematuria is caused
What is the prognosis of IgA nephropathy?
Usually self-limiting
-i.e. return to normal
Small % go onto chronic renal failure (via continued deposition of matrix)
What may be a renal cause of hypoalbuminaemia?
Nephrotic syndrome
-Abnormality of glomerular filter
Lots of albumin lost to urine