8.13 Glomerular And Tubular Disease Flashcards
When doing renal biopsies; at what part do you look?
Renal cortex (glomeruli)
Macroscopy vs. Microscopy
- macro - can see with eyes
- micro - look through microscope
What does the filtration barrier consist of?
Filtration barrier = endothelial cells + basement membrane + epithelial cells (podocytes with foot processes)
Functions of kidneys:
- eliminate metabolic waste products
- regulate fluid and electrolyte homeostasis
- influence acid- base balance
- hormone production
What hormones are produced by the kidneys?
- prostaglandins - affect salt & water regulation
- erythropoietin - stim RC production
- 1,25-dihydroxycholecalcififerol - enhances calcium absorption from gut-phosphate reabsorption by renal tubules
- renin - acts on angiotention pathway to ⬆️ vascular tone
Classify Glomerular disease:
Primary - kidney is prime target (disease is in the kidney)
Secondary - glomerular injury sec to events elsewhere in the body (eg DM)
Immunological - nephrotoxic antibody; immune complex deposition
Non-immunological
What is a Diffuse glomerular injury?
A lesion involving the majority, or all, of the glomeruli (>50%) - kidney/biopsy
What is a focal glomerular injury?
A lesion involving some glomeruli (<50%)
What is a global glomerular injury?
The whole glomerulus is affected
What is a segmental glomerular injury?
A part of glomerulus is affected
Crescentric
- Proliferation of cells in Bowman’s space
- compresses the glomerulus
KNOW PICTURE ON SLIDE 25
Clinical presentation of Nephrotic syndrome
- severe proteinuria (>3,5 gm per 24hrs)
- resultant hypoalbuminaemia
- leading to oedema
- also hypercholestrolaemia
Goodpasture’s syndrome
Anti-GBM disease
- in men
- immunological: nephrotoxic antibody
- IgG antibodies formed against glycoprotein in own glomerular basement membrane (GBM)
- antibody bind with antigen in collagen IV
- binding of IgG activates complement cascade, neutrophils attracted -> proliferative (hypercellular) glomerulonephritis results
- uncommon form of glomerulonephritis <1%
- part where kidney disease occurs together with pulmonary haemorrhage
Presentation:
- presents with rapidly progressive renal failure, sometimes haematuria, proteinuria or nephrititc syn
- hemoptysis
Histologically:
- segmental necrosis with crescent formation can occur
Membranous glomerulonephritis
Antiphopholipase A2 receptor = primary
Crescentic glomerulonephritis
Clinical features
Three groups
- rapidly progressive glomerulonephritis
Clinical features:
- rapid deterioration. - loss of renal function within few weeks
- within immediate treatment with immunosuppression / Plasmapheresis pt can recover
- chance of permanent damage remains ⬆️
Three groups
1. Anti-GBM disease - goodpasture’s syn
2. Severe forms of IC disease - postinfec GN (complications of other forms of GN)
3. Pauci-immune - no or minimal immune complex material present. Most of these patients (pauci- immune group) have anti-neutrophil cytoplasmic antibodies (ANCA) in the serum, which play a role in some vascular diseases
Minimal change disease
- Also known as lipoid nephrosis - lipid in tubular epithelium most obvious LM abnormality
- Pathogenesis - not clear - loss of negative charge of the basement membrane
- Occurs at all ages-in particular in children 2–4
- Usually responds to steroids without permanent damage
Systemic lupus erythematosus
- Systemic condition affecting multiple organs - skin, joints, serosal membranes, heart and lungs
- Kidneys involved in about 70% - important cause of morbidity and mortality
- Occurs particularly in women 15 - 40
Diabetes mellitus
- Damage involving blood vessels large + small throughout body
- Medium and large arteries: Atherosclerosis
- Small: Arteriosclerosis
- Involvement of the microcirculation, in addition to causing lesions in the retina, nerves and skin, significantly affects the kidneys – diabetic nephropathy
- Diabetic glomerulopathy can cause proteinuria and renal failure
- Basement membrane thickening – yet more permeable to protein
- Nodular expansion of mesangium – nodular glomerulosclerosis
- necrotising papillitis
- Renal papillary necrosis also occurs more frequently in diabetics, with acute pyelonephritis
Amyloidosis
Abnormal folded proteins deposited as extracellular material in many organs (kidneys)
Can glomerular disease cause vascular damage?
Yes
