Glomerular pathology Flashcards
What is meant by nephrotic syndrome?
Collection of symptoms due to glomerular damage
What part of the glomerulus is damaged in nephrotic syndrome?
Podocytes
Glomerular basement membrane
What are the symptoms of nephrotic syndrome?
Proteinuria
Low blood albumin levels
Oedema
High blood lipids
What are the groups of causes of nephrotic syndrome?
Primary causes
Secondary causes
What is meant by primary causes of nephrotic syndrome?
Damage is limited to the kidney glomerulus
What is meant by secondary causes of nephrotic syndrome?
Damage to multiple parts of body
including kidney glomerulus
What are some examples of primary causes of nephrotic syndrome?
Minimal change glomerulonephritis
Focal segmental glomerusclerosis
Membranous glomerulonephritis
What are some examples of secondary causes of nephrotic syndrome?
Diabetes mellitus
What is meant by minimal change glomerulonephritis?
Inflammation of the glomerulus
but changes to glomerulus cannot be seen on light microscope
What are the effects on the glomerulus of minimal change glomerulonephritis?
Loss of podocyte foot process, filtration slits
Loss of negative charges in glomerular basement membrane
How does minimal change glomerulonephritis give nephrotic syndrome?
Larger gaps in glomerular capillary membrane, loss of negative charges that repel
proteins are filtered out of glomerulus into Bowman’s capsule
this is mainly albumin
reduced oncotic pressure of blood
loss of albumin for lipids to bind to in the blood
Does minimal change glomerulonephritis usually give kidney failure? Why?
No
because glomerulus can still filter blood, normal GFR
How is minimal change glomerulonephritis treated?
Steroids to reduce inflammation of glomerulus
What age group is minimal change glomerulonephritis most common in?
Children
Adolescents
How does minimal change glomerulonephritis relate to focal segmental glomerulosclerosis?
Minimal change glomerulonephritis eventually develops into focal segmental glomerulosclerosis
What is meant by focal segmental glomerulosclerosis?
Focal meaning some glomeruli are affected
segmental meaning parts of glomeruli are affected
glomerulosclerosis meaning fibrous scarring of glomerulus
What are the effects on the glomerulus of focal segmental glomerulosclerosis?
Glomerulus is damaged beyond regeneration
fibrous scarring of glomerulus
blocks glomerulus
Does focal segmental glomerulosclerosis usually give kidney failure? Why?
Yes
because it blocks part of the glomerulus
reduced filtration of blood at glomerulus, reduced GFR
How does focal segmental glomerulosclerosis respond to steroids?
Less of a response to steroids
because fibrous scarring is irreversible unlike inflammation
What age group is focal segmental glomerulosclerosis most common in?
Adults
Which primary cause is the most common cause of nephrotic syndrome in adults?
Membranous glomerulonephritis
What is meant by membranous glomeronephritis?
Inflammation of the glomerular basement membrane
What are the causes of membranous glomerulonephritis?
Autoimmune conditions
Infection
What is the effect on the glomerulus of membranous glomerulonephritis?
Immune complexes deposit in glomerular basement membrane
it becomes inflamed
thickening of glomerular basement membrane
but with holes in it
What particular antibody is part of the immune complexes in membranous glomerulonephritis?
IgG
How do the immune complexes reach the glomerular basement membrane?
Antigen is on podocyte
or antigen is filtered out of the glomerulus into Bowman’s capsule, binds to podocyte
IgG is filtered from glomerulus into Bowman’s capsule
binds to antigen
What is the prognosis of membranous glomerulonephritis?
Third of patients recover
Third of patients stay the same
Third of patients develop acute kidney injury
What is nephritic syndrome?
Collection of symptoms due to glomerular inflammation
What are the signs and symptoms of nephritic syndrome?
Haematuria
Decreased GFR
Maybe proteinuria…
What are the some of the causes of nephritic syndrome?
IgA nepropathy
Goodpasture syndrome
Vasculitis
Hereditary nephropathies
What is the most common type of glomerulonephritis?
IgA nephropathy
What is the effect of IgA nephropathy on the glomerulus?
IgA deposits in the mesangium
gives mesangial hyperplasia and increased matrix
damage to glomerular capillaries
leak blood
How does IgA reach the mesangium?
In glomerular capillaries
diffuses out to adjacent mesangium
What is a non-renal symptom of IgA nephropathy? Why?
Mucosal infections
IgA deposition in mesangium reduces IgA in mucosa
less protection against bacterial invasions
What is meant by hereditary nephropathy?
Diseases of the nephrons that are inherited from parents to children
What are some examples of hereditary nephropathies?
Alport syndrome
Thin GBM disease/benign familial haematuria
What is meant by thin GBM disease/benign familial haematuria?
Abnormal thinning of glomerular basement membrane
gives haematuria
but have normal kidney function
What is the inheritance pattern of Alport syndrome?
X-linked recessive
What gene is affected by Alport syndrome?
Gene for type 4 collagen
What protein is affected by Alport syndrome?
Type 4 collagen
What is the effect on the nephron of Alport syndrome?
Abnormal glomerular basement membrane
gives glomerulonephritis, haematuria
What are the non-renal signs and symptoms of Alport syndrome?
Hearing loss
Eye problems
What is the cause of Goodpasture syndrome?
Autoantibodies against type 4 collagen on glomerular basement membrane of nephron
gives glomerulonephritis
What autoantibody is involved in Goodpasture syndrome?
IgG
What are the signs and symtpoms of Goodpasture syndrome?
Acute but severe nephritic syndrome
Pulmonary haemorrhage due to type 4 collagen also being present in alveoli
How is Goodpasture syndrome treated?
Immunosuppression
Plasmaphoresis
What is plasmaphoresis?
Process of removing the plasma which contains autoantibodies
replaced with IV fluid
What is meant by vasculitis?
Inflammation of blood vessels
What is the cause of vasculitis?
Anti neutrophil cytoplasmic antibody
activates neutrophils
which are active against blood vessels
What does a glomerulus affected by vasculitis look like under the microscope?
Segmental necrosis
inflammatory cells surrounding it
