Pathology of renal disease Flashcards
We filter (fluid)
180 litres per day
We resorb (fluid)
178 litres per day
Urine amount
2 litres per day
How does the kidney work?
Glomerular capillary -blood comes in Interstitium -bigger molecules like red blood cells and albumin too big to pass into interstitium -smaller molecules like urea and creatinine passed through into tubules Tubules (site of most work) -site of resorption -eventually urine comes out
What can go wrong?
Not enough filtration -not enough blood flow -blocked filter -lack of glomeruli Too much filtration -leaky membranes Too little reabsorption -faulty tubules Blocked/ inflamed tubules Tubules die off in chunks Tumours can develop
Blood pressure vs urine output
Blood pressure drops –> urine output drops
Blood pressure increases
–> urine output increases
Low BP for long time –> renal failure
Renal disease - causes of acute renal failure
Lack of blood flow due to haemodynamic shock (bleeding, trauma)
Blocked filter
Leaky filter
Non-functioning tubules
What substances increase in concentration in renal failure?
Urea and creatinine levels in blood
Filter blockage and creatinine
Filter blockage leads to rise in creatitine levels
Causes of a blocked filter
Nothing to see (minimal change) -minimal change glomerulonephritis Proteins (membranous) -deposited in 'filter' -membranous glomerulonephritis Cells (proliferative) -proliferative glomerulonephritis
membranous glomerulonephritis
Membranes are thickened
Deposits of proteins in the glomerulus
Granular kidney post-mortem
Should be smooth
Groups of glomeruli have died off
Down to 30-40% leads to renal failure
Renal disease –> causes of chronic renal failure
Lack of glomeruli -chronic hypertension Blocked filter -chronic glomerulonephritis Non-functioning tubules -tubulointerstitial disease --> crystals or casts
Acute renal failure caused by too much filtreation - leaky membranes/ filters leads to
Proteinuria
-caused by bigger molecules than can usually pass through e.g. albumin
-frothy urine in morning
Test by dipstick in (blood and protein tested)
Too little resorption - Faulty tubules leads to
< reabsorption
> urine
Can lead to acute renal failure
Back to normal in couple of weeks with tubular dialysis
Blocked/ inflamed tubules causes
Casts Crystals Blood clot Bowel prep (cleans out colon) -calcium phosphate crystals can build up Inflammatory cell buildup (e.g. UTI for a long time) -bacteria -neutrophils -macrophages
Renal disease –> tubules die off in chunks due to
Infection e.g.
- pyelonephritis
- papillary necrosis
Renal cell carcinoma incidence
3% of all new cancers
8,000 cases per year in UK
Rates going up since 1975
Renal cell carcinoma risk factors
Obesity Cigarette smoking -stuff you smoke gets excreted in urine von Hippel Lindau syndrome Acquired renal cycstic disease (dialysis)
Renal cell carcinoma spread
Direct
Lymphatic
Peritoneum
Blood –> bone
Renal cell carcinoma treatment
Radiotherapy
Surgical resection
Renal cell carcinoma prognosis
Dependent on stage
Average 40% 5 year survival
Transitional cell carcinoma of the renal pelvis
-signs and symptoms
Haematuria
Loin pain
Transitional cell carcinoma of the renal pelvis
-risk factors
Cigarette smoking
Industrial dyes e.g. aniline
Long term painkillers
Transitional cell carcinoma of the renal pelvis
-incidence
<1% of all cancers
Transitional cell carcinoma of the renal pelvis
-treatment
Surgical resection
Transitional cell carcinoma of the renal pelvis
-spread
Direct
Lymphatic
Peritoneum
Blood
Renal disease –> types of tumours
Renal cell carcinoma
Transitional cell carcinoma
Not enough filtration - not enough blood flow
Sluggish flow means that small molecules needing to be filtered out don’t have enough chance to
-waste products like urea and creatinine accumulate
Low blood pressure –> considerably lower urine output
-will increase after fluids
-can lead to acute renal failure
Causes of blocked filter (leading to acute renal failure)
Acute glomerulonephritis
- nothing to see: minimal change glomerulonephritis
- proteins: membranous glomerulonephritis
- ->proteins are blocking the filter
- ->histology: membranes are thickened and proteins deposited in glomerulus
- cells: proliferative glomerulonephritis
- ->inflammatory cells are blocking the filter
- ->histology: inflammatory cells stacking up
Causes of ‘leaky’ filter (leading to acute renal failure)
Acute glomerulonephritis
- minimal change
- membranous
Causes of non-functioning tubules (leading to acute renal failure)
Acute tubulular necrosis
- ischaemia
- toxins (myoglobin or ethylene glycol)
Types of renal disease
Acute renal failure
Chonic renal failure
Tumours
Infection
Not enough filtration - blocked filter
If filter is blocked, nothing can come out
-kidneys have a lot of capacity so can be quite blocked before we notice change
Toxins will accumulate in blood
-urea and creatinine (these are easy to measure)
Not enough filtration - lack of glomeruli (including causes)
Ones there are working but not enough
Causes
-age: lose some as go through life
-chronic hypertension: high BP thickens BVs supplying glomerulus, knocks off glomeruli
Raised creatinine and urea
Often leads to stage 1 chronic kidney disease in 70s
-30-40% glomeruli working will lead to chronic renal failure
Granular appearance of kidney post mortem
Tubule dysfunction causes
Lack of blood supply can lead to acute tubular necrosis
Susceptible to toxins e.g. myoglobin, ethylene glycol
Blocked/ inflamed tubules leads to
Waste products can’t get out to urine
Can lead to chronic renal failure
