Nephrotic and Nephritic kidney disease Flashcards
(41 cards)
What are the 5 main features of nephrotic syndrome?
- Proteinuria >3- 3.5g/day
- Hypoalbuminaemia <30g/dL
- Oedema
- Raised cholesterol
(hyperlipidaemia) - hypercoagulable state
What is the general cause of nephrotic syndrome?
structural changes in the glomeruli in response to glomerular injury causing excessive leakage of key plasma molecules including albumin.
This leads to the typical features of heavy proteinuria and hypoalbuminaemia.
Why are patients with nephrotic syndrome at increased risk of infections?
loss of immunoglobins from the glomerulus
Why does nephrotic syndrome present with Hyperlipidaemia?
due to a loss of oncotic pressure, which leads to elevated levels of cholesterol, low-density lipoprotein and triglycerides within the serum.
Increased hepatic lipogenesis due to low albumin and loss of oncoming pressure
a consequence of increased synthesis of lipoproteins (such as apolipoprotein B, C-III lipoprotein (a)), as a direct consequence of a low plasma albumin
Why do patients with nephrotic syndrome have a hypercoagulable state?
thought to be due to the loss of key anti-clotting factors such as anti-thrombin III, plasminogen, and protein C and S
Which conditions are known to cause nephrotic syndrome?
minimal change disease,
membranous glomerulopathy (nephropathy)
focal segmental glomerulosclerosis (FSGS)
Diabetic glomerulonephropathy
Amyloidosis
What is Minimal-change disease?
Immature differentiating CD34 stem cells appear to be responsible for the pathogenesis.
- most common in children, particularly boys
- Glomeruli appear normal on light microscopy
- Negative immunofluorescence
- On electron microscopy, fusion or effacement of the foot podocytes is seen, consistent with a disrupted podocyte actin cytoskeleton
In which population is Focal segmental glomerulosclerosis most common in?
African American
Hispanic
Which conditions is Focal segmental glomerulosclerosis commonly associated with? (2)
Sickle cell disease
HIV
In the histological images for Focal segmental glomerulosclerosis, what will you most likely see?
Effacement of food podocytes
Hyalinosis and segmental sclerosis
Non specific IgM, C1 or C3 deposition in the mesangial matrix
Describe what is primary and secondary membranous nephropathy
Primary - Autoimmune -
Antibodies to phospholipase A1 (anti-PLA2R)
Secondary
- Infection (Hep C, Hep B. HIV, Malaria, syphilis, sarcoidosis)
- Autoimmune (SLE / lupus nephritis)
- Medications (NSAIDS, Penicillamine, Gold, Anti- TNF)
- Malignancy
-
What would the histology of membranous nephropathy look like?
Spike and dome appearance of subendothelial deposits
Thickened basement membrane and capillaries
Describe the pathophysiology of Diabetic glomerulonephropathy?
Non enzymatic glycosylation of the vascular basement membrane leading to hyaline arteriosclerosis in kidneys.
This causes hyperfiltration at the efferent arterioles and microalbuminuria
What would the histology of Diabetic glomerulonephropathy look like?
Mesangial sclerosis
Kimmelstiel wilson nodules
which is —- Sclerotic eosinophilic nodules with a central acellular region
In the context of Systemic amyloidosis and its effect on the kidneys, which conditions is it associated with? (3)
Tb, Multiple myeloma, Rheumatoid arthritis
In amyloidosis there are 2 main proteins associated with 2 main pathologies, what are they and which pathologies are they associated with?
AA protein - Chronic inflammation
AL- multiple myeloma
What would the histology of amyloidosis look like?
Apple green birefringence under polarized light
Describe the 2 ways in which proteinuria is assessed?
Urine dip stick
25 hour urine collection (gold standard)
What are the 2 underlying mechanisms causing oedema in nephrotic syndrome?
Underfill hypothesis-
Decrease in intravascular colloid osmotic pressure due to low serum albumin
Intravascular volume depletion due to Movement of water from vascular space
into the interstitium
Activation of the renin angiotensin system and retention of salt and water
Overfill hypothesis
Primary sodium retention
Increased Na-K ATP pump in the collecting tubule
List the indications/ symptoms of nephritic syndrome
Early
- Urine Dip blood/ mild protein present
- Red cell cast on urine microscopy
Aggressive High Bp Mild oedema Urine Dip blood/ mild protein present Azotaemia (High BUN and creatinine) Oliguria - AKI
In the context of nephritic syndrome, when the urine dip comes back positive for blood and protein, which tests should be done next?
send for cytoloy( to look for
red cell casts) and culture (to rule out
infection)
Describe what post streptococcal glomerulonephritis is?
Usually occurs in childrne 2-4 weeks after group A beta haemolytic strep infection
List the causes of nephritic syndrome
Autoimmune/Immune mediated Small vessel vasculitis e.g ANCA associated vasculitis SLE Anti-GBM disease[Goodpastures] IgA nephropathy Cryoglobulinaemia
Infections
Viral- Hepatitis C, Hepatitis B, HIV
Post streptococcal
Subacute bacterial endocarditis
Malignancies
Lymphoma
Multiple Myeloma
Describe what post streptococcal glomerulonephritis is?
Usually occurs in childrne 2-4 weeks after group A beta haemolytic strep infection
Its a type 2 hypersensitivity reaction
Antistreptococcal antibodies are formed (ASO)
There will be low C3 levels
