Glomerular disease (pathology) Flashcards
What are the 3 layers of the glomerular membrane that form the filter barrier?
fenestrated endothelial cells membrane
basal lamina
podocytes
What are Mesangial cells?
Mesangial cells - ‘tree-like’ group of pericyte cells which support capillaries within the glomerulus
What is Glomerulonephritis?
Glomerulonephritis (GN) is a term used to refer to several kidney diseases (usually affecting both kidneys). Many of the diseases are characterised by inflammation either of the glomeruli or of the small blood vessels in the kidneys, hence the name, but not all diseases necessarily have an inflammatory component.
Primary (only affects glomerulus) or Secondary (other parts of body affected, e.g. SLE or Wegener’s)
What are 4 common presentations in glomerulonephritis?
Haematuria (blood in urine)
Heavy proteinuria (nephrotic syndrome) - acute
Slowly increasing proteinuria over many years - chronic
Acute renal failure – shown by rising creatinine
What are the 4 most common causes of haematuria in order of likelihood?
- Urinary tract infection
- Urinary tract stone
- Urinary tract tumour
- Glomerulonephritis
What type of glomerulonephritis is associated with IgA and complement component C3 deposits in the mesangial area of all glomeruli?
IgA glomerulonephritis
Describe the features of IgA glomerulonephritis?
IgA and component C3 deposits in mensangial area
IgA irritates these cells, causing them to proliferate and produce more matrix
This can compress the capillaries
Describe the prognosis for those with IgA glomerulonephritis
Usually self limiting
Can progress to chronic renal failure in small % of cases
To which type of glomerulonephritis is IgA glomerulonephritis one of?
Proliferative glomerulonephritis
What is Nephrotic syndrome?
Nephrotic syndrome is a collection of symptoms due to kidney damage. This includes protein in the urine, low blood albumin levels, high blood lipids, and significant swelling. Other symptoms may include weight gain, feeling tired, and foamy urine. Complications may include blood clots, infections, and high blood pressure
Causes include a number of kidney diseases such as focal segmental glomerulosclerosis, membranous nephropathy, and minimal change disease. It may also occur as a complication of diabetes or lupus. The underlying mechanism typically involves damage to the glomeruli of the kidney. Diagnosis is typically based on urine testing and sometimes a kidney biopsy. It differs from nephritic syndrome in that there are no red blood cells in the urine
List some potential causes of nephrotic syndrome
Causes include a number of kidney diseases such as focal segmental glomerulosclerosis, membranous nephropathy, and minimal change disease. It may also occur as a complication of diabetes or lupus. The underlying mechanism typically involves damage to the glomeruli of the kidney. Diagnosis is typically based on urine testing and sometimes a kidney biopsy. It differs from nephritic syndrome in that there are no red blood cells in the urine
Describe membranous glomerulonephritis
- In membranous glomerulonephritis, IgG is stuck in membrane
- IgG deposits itself between basal lamina and podocyte but cannot go further and is not filtered into urine
- IgG is too big to be filtered into urine, but IgG activates complement protein C3 within the membrane, which punches holes in filter
- Leaky filter now allows albumin to be filtered into urine à nephrotic syndrome
Describe the prognosis of membraneous glomerulonephritis
1/4 of patients have chronic renal failure within 10 years
What causes IgG production and accumulation in membranous glomerulonephrits?
o Unknown but can sometimes have underlying malignancy
o In many patients antigen is phospholipase A2 receptor – why this protein? – as yet unknown.
Describe the features of diabetic nephropathy
- Diabetic nephropathy – Nodules of mesangial matrix known as Kimmelsteil-Wilson lesion found, which are made from gross excess of mesangial matrix forming nodules
- Glycated molecules are deposited in the matrix within the basal lamina underlying the endothelium and in the mesangial matrix. These then become thickened and the basement membrane becomes leaky. The mesingeal matrix can also compress he capillaries. This condition is not caused by immune complexes.
