Glomerular Disease Flashcards
How does blood enter to the glomerulus?
Via the afferent arteriole
What will NOT be filtered by the glomerulus and will stay in the plasma?
All proteins equal to or larger than albumin (including immunoglobulins)
Layers of the filter barrier
- Endothelial cell cytoplasm
- Basal lamina
- Podocytes
How many layers does the glomerular membrane / filter have?
3
What are mesangial cells?
Tree like group of cells (pericytes) which support capillaries
Where does filtrate go?
Into bowmans space then into the proximal tubule
What does the efferent arteriole contain?
Plasma
Unfiltered proteins e.g. albumin and antibodies
Classification of glomerulonephritis
Primary
Secondary
What is primary glomerulonephritis?
Only affects the glomerulus
What is secondary glomerulonephritis?
Other parts of the body are affected also e.g. Wegeners, SLE
What is glomerulonephritis a disease of?
The glomerulus
What are the 4 presentations of glomerulonephritis?
Haematuria
Heavy proteinuria (causing nephrotic syndrome). Very suddenly comes on
Slowly increasing proteinuria
Acute renal failure
Definition of haematuria
Blood in urine
4 most common causes of haematuria (in order of most to least common)
- UTI
- Urinary tract stone +/- infection
- Urinary tract tumour
- Glomerulonephritis
What must always be checked before a renal biopsy?
Clotting
Types of glomerulonephritis
IgA Glomerulonephritis
Membranous Glomerulonephritis
Diabetic Nephropathy
Crescentic Glomerulonephritis
Presentation of IgA Glomerulonephritis
Discoloured urine - dipstick +ve for blood
What would be seen in IgA Glomerulonephritis on kidney biopsy?
IgA immunoglobulins and complement C3 in mesangial area of all glomeruli
What would be seen in IgA glomerulonephritis on electron microscopy?
Deposits of IgA with prominent mesangial cells
Is there excess antibody produced in IgA glomerulonephritis?
Sometimes present in the serum however this is also sometimes true for people without the IgA glomerulonephritis - so no
Pathology of IgA glomerulonephritis
IgA gets stuck within the mesangium
IgA irritates the mesangial cells and causes them to proliferate and produce more matrix
Prognosis of IgA nephropathy
Usually self limiting i.e. return to normal
Small % go onto chronic renal failure due to continued deposition of the matrix
Presentation of membranous glomerulonephritis
Feeling generally unwell Swollen legs Low albumin Dipstick proteinuria Haematuria
Pathology of membranous glomerulonephritis
Thickened glomerular basement membrane
Spikes of new basement membrane matrix material underneath podocytes (matrix tries to surround and remove the deposit)
Deposit of IgG. IgG is too big to be filtered into the urine but activates complement (C3) which punches holes in the filter.
Damage to basal lamina
End up with leaky basal lamina - leaking albumin into the urine (nephrotic syndrome)
Is albumin filtered out of the plasma?
No
What is stuck in the membrane in membranous glomerulonephritis?
IgG
Prognosis of membranous glomerulonephritis
1/4 chronic renal failure within 10 years
What would be seen on a renal biopsy in diabetic nephropathy?
Glycated molecules -> matrix deposition in basal lamina underlying endothelium and in mesangial matrix -> thickened but leaky basement membranes and mesangial matrix compresses capillaries (no immune complexes)
Pathology of diabetic nephropathy
Thickened capillary wall which is leaking albumin
Increased mesangial matrix (which compresses capillaries)
Thickened, narrowed arterioles reduce blood flow to the glomerulus
Adhesions to Bowmans capsule are glomerulus attempt to stop massive leakage of albumin into the urine
Gross excess of mesangial matrix forming nodules
What are the nodules of the mesangial matrix in diabetic nephropathy called?
Kimmel-steil Wilson Lesion
When is there inevitable decline of diabetic nephropathy?
Established diabetic nephropathy
AND
Continued poor glycaemic control
What does rapidly rising creatinine indicate?
Acute renal failure
Pathology of crescentic glomerulonephritis
Cellular proliferation and influx of macrophages (=crescent) around glomerular tuft, within bowmans space
Endothelial damage with fibrin deposition
Crescent often ends up with a C shape
Causes of the pattern of injury seen in crescentic glomerulonephritis
Wegeners granulomatosis
Microscopic polyarteriits
Antiglomerular basement membrane disease
Other forms of glomerulonephritis
What is another name for wegeners granulomatosis?
Granulomatosis with polyangitis
What is wegeners granulomatosis?
A form of vasculitis which affects the vessels in kidneys, nose and lungs
Definition of vasculitis
Primary inflammation of the vessels
Investigation for wegeners
Serum ANCA
What does ANCA stand for?
Anti-neutrophil cytoplasmic antibodies
Is ANCA deposited in the kidney?
No
How does ANCA cause damage?
Antibodies directed against proteinase 3 and myeloperoxidase, 2 enzymes in primary granules of neutrophils
Antibodies product tissue damage via interactions with primed neutrophils and endothelial cells
Prognosis of wegeners
Fatal (mean survival 6 months) if untreated
Treatment of wegeners
Cyclophosphamde (chemotherapy) - 75% complete remission
Types of haematuria
Macroscopic
Microscopic
What is macroscopic haematuria?
Tea or cold coloured or frank blood in the urine
What is microscopic haematuria?
> 5 RBCs per high power field
What can be the source of haematuria?
Kidney Ureter Bladder Prostate Urethra
What type of haematuria is seen in glomerulonephritis?
Persistent microscopic haematuria
Microscopy shows dysmorphic RBCs (mickey-mouse like)
Types of proteinuria
Glomerular or tubular
Albumineria or proteinuria
Which of nephritis and nephrotic syndrome presents with haematuria more?
Nephritis > nephrotic
Which one of nephritis or nephrotic syndrome presents with haematuria more?
Nephritis = Nephrosis
What type of proteinuria is present in glomerulonephritis?
Persistent
Proteinuria of more than 1 gram/mmol creatinine