deck_1662724 Flashcards
What are the main foci of kidney disease?
• Glomerulus • PCT • Interstitium • Vascular supply
What is a primary glomerular injury?
• One which just effects the glomerulus
What is a secondary glomerula injury?
• A systemic illness which happens to effect the glomerulus
What are the four main sites of glomerular injury?
• Subepithelial ○ Anything that effects podocytes/podocyte side of glomerular basement membrane • Within glomerula basement membrane • Subendothelial ○ Inside the basement membrane • Mesangial/parameangial ○ Supporting capillary loop
Why can the nephron be termed a “functional unit”
• Same blood supply to glomerulus and nephron ○ Thus, ischaemic disease in glomerulus reduces blood supply to nephron, causing damage
What are the two main pathologies of the glomerulus?
• It can become blocked ○ “Renal Failure” ○ Decreased GFR ○ Haematuria • It can leak ○ Proteinuria ○ Haematuria ○ One, other or both
What is proteinuria?
• Presence of excess serum proteins in the urine (
What does proteinuria indicate?
• Podocyte damage, causing fenestration to widen and causing protein to be leaked when it would normally be filteredLess severe nephrotic syndrome
What is nephrotic syndrome?
• More than 3.5g of protein lost in urine per daySoon becomes hypoalbuminaemia
How does the body respond to hypoalbuminaemia as a result of nephrotic syndrome?
• Oedematous • Liver starts to pump out more albumin, along with more cholesterol!
What is nephritic syndrome?
• Glomerulus is blocked • GFR drops • Creatinine increases • Haematuria (glomerulus blood vessels ruptured) • Hypertensive
What are the four main areas in the glomerula capillary loop where damage can occur?
• Subepithelial • With GBM • Subendothelial • Mesangial
What is the difference between primary and secondary kidney disease?
• Primary kidney disease - Pathology soley affecting kidney • Secondary kidney disease - Systemic disease which affects kidney
What is the likely site of injury in proteinuria/nephrotic syndrome?
• Podocyte/subepithelial damage
Give three primary causes of proteinuria/nephrotic syndrome
• Minimal change glomerulonephritis • Focal segmental glomerulosclerosis • Membranous glomerulonephritis
Give two common secondary cuases of proteinuria/nephrotic syndrome
• Diabetes mellitus • Amyloidosis
When does minimal change glomerulnephritis occur?
• Occurs in childhood/adolescence • Incidence reduces with increasing age
What are the symptoms of glomerulonephritis?
• Heavy proteinuria or nephrotic syndrome • Responds to steroids • Usually no progression to renal failure
Why does minimal change glomerulonephritis occur?
• Podocytes destroyed, loss of filtration slits
What is the pathogenesis of minimal change glomerulonephritis?
• Unknown circulating factor damaging podocytes • No immune complex deposition
Why is minimal change glomerulonephritis called thus?
• Normal golmeurli under a light microscope
How can you detect minimal change glomerulonephritis?
• Electron microscope, damage to podocytes evident
What is Focal segmental glomerulosclerosis
• Nephrotic syndrome which effects adults • Steroids minimally effective
What does a patient with focal segmental glomerulosclerosis normal present with?
• Massive proteinuria • Haematuria • Hypertension • Renal failure
Why is it called focal segmental glomerula sclerosis?
• Focal - Involving less than 50% of glomeruli on light microscopy • Segmental - Involving part of the glomerular tuft • Glomerular • Sclerosis - Scarring
What is the main pathology of Focal segmental glomerulosclerosis?
• Damage to glomerulus causing scarring • Circulating factor damages podocytes • Progressive renal failure
What causes Focal segmental glomerular nephritis?
• A circulating factor
What is membranous glomerulonephritis?
Commonest cause of nephrotic syndrome in adultsImmune complex depositsCapillary loop thickBasement membrane specley
What causes membranous glomerulonephritis?
• Autoimmune response to podocytes • Immune complex deposits (IgG) ○ May also be secondary, as often associated with diseases such as lymphoma
What is an immune complex?
• Äntigen complexed with multiple antibodies • IgG destroy antigen found on podocytes, destroying podocytes in process
What is a distinguishing feature of kidney disease as a result of diabetes mellitus?
• Progressive proteinuriaProgressive renal failure
How does the rule of thirds apply to membranous glomerulonephritis?
• 1/3 just get better • 1/3 grumble along, proteinuria but are fine • 1/3 progress to renal failure
What is the pathology of kidney disease as a result of diabetes mellitus?
o Progressive proteinuriao Progressive renal failureo Microvascular (Damages glomerulus directly)o Mesangial sclerosis noduleso Basement membrane thickening to 4-5x normal
What is nephritic syndrome?
• Renal failure due to blocking of filter
Give five causes of nephritic syndrome
• Good pasture syndrome • Vasculitis • IgA nephropathy • Thin GBM Nephropathy • Alport syndrome
What is IgA nephropathy?
• Commonest glomerular nephropathy • Characterised by deposition of IgA antibody in the glomerulus
How does IgA present?
• Will present with haematuria when get cold, due to relationship with mucosal infections • Significant proportion progress to renal failure • Some, not all, patients have proteinuria
What is haematuria as a result of IgA nephropathy a result of?
• Mesangial damage and scarring - Significant proportion of patients progress to renal failure
What happens to the mesangium in IgA nephropathy?
Mesangial proliferation and scarring
Give two types of hereditatary nephropathy
• Thin GBM Nephropathy • Alport syndrome
Outline thin GBM nephropathy
Isolated HaematuriaThin GBMBenign Course
What is alport?
• X linked • Abnormal collagen IV • Associated with deafness • Abnormal appearing GBM • Progresses to renal failure
What is Goodpasture Syndrome?
• Rapidly progressive glomerular nephritis • Acute onset of severe nephritic syndrome • Classically associated with pulmonary haemorrhage
What is the pathology behind goodpasture syndrome?
• Autoantibody to collagen IV in basement membranes Characterised by IgG deposition but no extracellular matrix deposit
How is goodpasture syndrome treated?
• Treatable by immunosupression • PlasmaphoresisTake patients blood out, remove plasma with IgG in and then exchange plasma
What is vasculitis?
• Inflammation of blood vessels which attacks highly vascularised kidney • No immune complex/antibody deposition • Blood vessels directly attacked by anti neutrophil cytoplasmic antibody • Nephritic presentation • Urgent biopsy required
What is a subepithelial deposit?
• Antigen abnormally recognised on podocytes, circulating IgG binds to it, forming immune complexes in the glomerulus ○ Membranous glomerulonephritis
What is a mesangial deposit?
• Immune complexes can be deposited directly in the mesangium as there is no podocytes or basement membrane to act as a barrier
