L7: Pathology 4 Flashcards
Proteinuria is protein that is present in the urine. What specific protein is this normally in relation to?
albumin
What numerical value is considered proteinuria?
greater or equal to 3.5g/24 hours
What is nephrotic syndrome? (characteristics)
- loss of protein in urine
- no glomerular inflammation (affects visceral epithelial cells)
- no increase in BP
- no haematuria
- hypoalbuminaemia, oedema, hypercholesterolaemia, hypercoagulable state (thrombophilia)
What are the main effects of nephrotic syndrome? [5]
- proteinuria
- hypoalbuminaemia
- oedema
- hypercholesterolaemia
- thrombophilia (hypercoagulable state)
List the 5 main causes of Nephrotic Syndrome
- Minimal Change Disease
- Focal and Segmental Glomerulosclerosis
- Membranous Glomerulonephritis
- Amyloidosis
- Diabetes Mellitus
What is the most common cause of nephrotic syndrome in children?
Minimal Change Disease
What is minimal change disease? (characteristics) What can it cause?
- can cause nephrotic syndrome
- all ages (esp. children)
- self limiting // responds well to steroids
- results from direct injury to foot processes (flattening of foot processes)
What is the underlying pathology/mechanism of minimal change disease?
Nephrotic syndrome as a result of direct injury to foot processes (flattening of foot processes)
What can focal and segmental glomerulosclerosis cause? What are the 2 types?
can cause Nephrotic Syndrome
- Steroid Responsive
- Steroid Unresponsive
What is steroid RESPONSIVE FSGS? (characteristics)
- circulating factor thought to cause foot process injury
- if weaned off steroids, can get it again
- recurs in transplants
What is steroid UNRESPONSIVE FSGS? (characteristics)
- abnormality/absence of foot process protein (e.g. Nephrin)
- does not recur in transplants
In steroid-unresponsive FSGS, there is usually an abnormality in the foot processes - what abnormality is usually present?
abnormality in Nephrin (forming podocyte slit diaphragm)
What is membranous glomerulonephritis? (characteristics) What is targeted?
- causes nephrotic syndrome
- immune complex deposition disease
- antigen/target: Phospholipase A2 Receptor (in foot processes)
- sub-epithelial deposits (“spikes”)
What are some histological findings of membranous glomerulonephritis?
- sub-epithelial deposits
- spikes
- thickened basement membranes
Membranous glomerulonephritis is an immune complex deposition disease - what is the antigen targeted?
Phospholipase A2 Receptor (abundant in foot processes)
Amyloidoisis can lead to nephrotic syndrome. What are some characteristics of this type of amyloidosis?
- fibrils deposited in mesangium, capillary loops, arterioles + interstitium
- all types of amyloid may affect kidney (except alzheimer’s)
What is the most common type of amyloid seen in the kidney?
multiple myeloma/plasma cell dyscrasia
How does diabetic nephropathy cause nephrotic syndrome?
through glycosylation of lipo-proteins in the mesangium and basement membranes
– this has secondary effects on the epithelial cells
– effects due to mesangial expansion + BM thickening
What is a characteristic histological finding of diabetic nephropathy? (hint: micro-aneurysm)
Kimmelstein Wilson micro-aneurysm
- seen in nephrotic syndrome caused by diabetes
What is nephritic syndrome? (characteristics)
- affects endothelial cells
- glomerular inflammation
- haematuria
- proteinuria
- often hypertension
- acute renal failure
What is membranoproliferative glomerulonephritis (in relation to the acute nephritic syndrome)?
- immune complex deposition disease
- chronic disease (chronic endothelial cell injury)
- chronic inflammation of mesangium and basement membrane
What are 3 causes of membranoproliferative glomerulonephritis?
- C3 Glomerulonephritis
- Cryoglobulinaemia
- Severe SLE
What is cryoglobulinaemia? What kidney condition can it cause?
- in cold temps, immune complexes form that can cause inflammation and block blood vessels
- can cause membranoproliferative glomerulonephritis