Patho Flashcards
What are 5 causes of Chronic renal failure?
1) Diabetic nephropathy
2) Glomerulonephritis
3) Hypertension
4) Interstitial nephritis
5) Chronic urinary outflow tract obstruction
6) Pyelonephritis
7) Polycystic kidney disease
8) Other congenital kidney diseases / malformations
9) Tumours
10) Unknown
What are 6 systemic manifestations/complicates of end stage renal disease?
1) Fluid and electrolytes
– Dehydration and fluid overload
– Anaemia
– Hyperkalaemia
– Metabolic acidosis
2) Calcium, phosphate and bone
– Hyperphosphataemia
– Hypocalcaemia (but later may have hypercalcaemia)
– Secondary hyperparathyroidism
– Renal osteodystrophy
3) Haematologic
– Anaemia
– Bleeding diathesis
4) Cardiopulmonary
– Hypertension
– Heart failure
– Cardiomyopathy
– Pulmonary oedema
– Uraemic pericarditis
5) Gastrointestinal
– Nausea and vomiting
– Bleeding
– Oesophagitis, gastritis, colitis
6) Neuromuscular
– Myopathy
– Peripheral neuropathy
– Encephalopathy
7) Skin
– Dermatitis
– Pruritus (itch)
– Sallow colour
What are 3 treatment options for chronic renal failure?
1) Haemodialysis
– Involves removal of solutes across a semi-permeable membrane within a dialysis
machine, from blood circulated through an extra-corporeal circuit
2) Peritoneal dialysis
– Involves removal of solutes across the peritoneal membrane into peritoneal dialysate
fluid.
3) Renal transplant
- need to be on immunosuppressive therapy for life
In chronic renal failure, both kidneys are (small, contracted/large and hypertrophic). The histological features include: (3).
Small and contracted kidneys (bilateral)
1) Widespread glomerulosclerosis
2) Tubular atrophy
3) Interstitial fibrosis
- Urine volume may be normal(ish) initially, or may even have polyuria as tubules cannot concentrate glomerular filtrate.
- Terminal oliguria when no functioning nephrons left.
In acute renal failure, there is:
i) Oliguria/anuria: ____________________
ii) Azotaemia: ________________________
Oligo/Anuria: marked ↓ in/absence of urine production
Azotaemia: Progressive/rapid ↑serum creatinine
What are 3 pre-renal causes of ARF?
- Hypotension
- Haemorrhage
- Severe dehydration
- Shock
- Heart disease
- Liver failure
What are 3 renal causes of ARF?
- Glomerulonephritis
- Acute tubular necrosis (due to drugs, toxins, pigment, etc)
- Acute interstitial nephritis
- Haemolytic uraemic syndrome
- Vasculitis
- Severe infections (eg. pyelonephritis, bilateral)
What are 2 post-renal causes of ARF?
1) Acute urinary tract outlet obstruction (eg. due to blood clots, stones, tumour, etc)
2) Acute atonia, hypotonia of the bladder to the nerve damage (neurogenic bladder)
What are 4 Ix for renal failure?
1) Blood tests:
- urea, creatinine, electrolytes
2) Urine tests:
- Protein, Hb, Myoglobin, RBC, WBC
3) Imaging:
- IVU, US KUB, CT urogram, CT/MRI, etc.
4) Kidney biopsy
What are 3 examples of renal disease?
1) Glomerular disease
2) Tubulo-interstitial disease
3) Vascular disease
What are 5 clinical presentations of glomerular disease?
1) Nephrotic syndrome
2) Nephritic syndrome
3) Microscopic hematuria
4) Proteinuria
5) ARF
6) CRF
What is nephrotic syndrome?
A leaky glomerular filter
What are 5 clinical manifestations of nephrotic syndrome?
1) Heavy proteinuria
2) Hypoalbuminemia
3) Anasarca
- generalised edema due to ↓serum oncotic P
4) Lipiduria
5) Hyperlipidemia (bi-product of hepatic albumin synthesis)
6) Polyuria with frothy urine (due to large amounts of protein in urine)
What are 2 complications of nephrotic syndrome?
1) Infection
2) Thromboembolism (loss of anticoagulants)
Why is the age of the px important in the differential diagnosis of nephrotic syndrome?
Causes of nephrotic syndrome in children and adults often differ
Px with nephrotic syndrome may be classified as steroid-sensitive or steroid-resistant. Childhood nephrotic syndrome is almost always _________________.
Childhood almost always steroid-sensitive
only if the child does not respond to treatment, will a renal biopsy be performed.
What is nephritic syndrome?
Glomeruli are damaged - some are unable to filter; others leaky
What are 5 clinical manifestations of nephritic syndrome?
1) Oliguria
2) Azotaemia
3) Oedema (usually not as prominent as in nephrotics)
4) Hypertension ← fluid retention
5) Gross hematuria
6) Proteinuria - mild to moderate, sometimes in nephrotic range
What are 3 complications of nephritic syndrome?
1) Hypertensive encephalopathy
- seizures
- strokes
2) Fluid overload
- CHF
- acute pulmonary edema
3) Acute kidney impairment
- uraemia
- HyperK+, HyperPO4
- HypoCa2+
What is glomerulonephritis?
“Inflammation of the glomeruli”
- diseases characterized by increased glomerular cellularity caused by proliferation of indigenous cells and/or leucocyte infiltration.
What are 3 antibody-mediated mechanisms for glomerular injury?
1) In situ formation of immune complexes
- against native antigen eg. Anti-GBM disease (Goodpasture’s Disease).
- against planted antigen that localises in glomerulus eg. HBV.
2) Circulating immune complexes
- antigen in excess of antibody leads to circulating immune complexes that get lodged in the glomeruli eg. Lupus nephritis.
3) Antineutrophil Cytoplasmic Antibodies (ANCA)
- antibodies bind to the neutrophils in glomeruli
→ release toxic granules and substances in the glomeruli
→ glomerular damage.
What are 2 Ix for mechanisms of glomerular injury?
1) IF
- Allows determination of what types of antibody and complement involved
2) EM
- Allows more precise localisation of immune complexes
– Allows identification of ultrastructural pathology eg. GBM abnormalities
What are 3 microscopy methods used in a renal biopsy?
1) LM: formalin
2) IF: Fresh
3) EM: Glutaraldehyde
What are 4 causes of nephrotic syndrome?
Common:
1. Minimal change disease
2. Idiopathic focal segmental glomerulosclerosis (FSGS)
3. Membranous glomerulonephritis.
Uncommon:
1. Membranoproliferative glomerulonephritis.
2. IgA nephropathy
True or false:
Minimal Change Disease is the most common cause of childhood nephrotic syndrome. It has a very good prognosis as it is curable with steroids.
True
What is the etiology and pathogenesis of Minimal Change Disease?
Unknown
In Minimal Change Disease:
Proteinuria: (±)
LM: __________
IF: ________________
EM:_______________
In Minimal Change Disease:
Proteinuria: Selective
LM: no abnormality
IF: no deposits
EM: fusion of foot processes and occasionally detachment from basement membrane
Focal Segmental Glomerulosclerosis causes (nephritic/nephrotic) syndrome and is steroid (sensistive/resistant).
FSG:
Nephrotic
Steroid Resistant
What is the etiology and pathogenesis of Focal Segmental Glomerulosclerosis?
Idiopathic and 2° causes
- podocyte injury w loss of podocytes
In Focal Segmental Glomerulosclerosis:
Proteinuria: (±)
LM: __________
IF: ________________
EM:_______________
In Focal Segmental Glomerulosclerosis:
Proteinuria: +
LM: segmental sclerosis of glomeruli
IF: sclerotic lesions stain w IgM and C3
EM: loss of podocytes
True or false: Focal segmental glomerulosclerosis, though steroid resistant, can be treated and often do not progress to chronic renal failure.
False, many progress to chronic renal failure
What is the most common cause of nephrotic syndrome in children?
MCD
What is the most common cause of nephrotic syndrome in adults?
Membranous Glomerulopathy
In Membranous glomerulopathy:
Proteinuria: (±)
LM: __________
IF: ________________
In Membranous glomerulopathy:
Proteinuria: +
LM: basement membrane thickening
IF: IgG and C3 on the epi-membranous side of basement membrane (“spikes” or “string of pearl appearance”).
What are 3 causes of nephritic syndrome?
Usually glomerulonephritis:
1. IgA nephropathy
2. Post-infectious glomerulonephritis
3. Lupus nephritis
4. Membranoproliferative glomerulonephritis
What is the most common cause of glomerulonephritis?
IgA nephropathy
What are 2 microscopic features of IgA nephropathy?
1) Microscopic proteinuria w hematuria
2) Mesangial proliferation with mesangial deposits of immune complexes containing IgA
What is post-infectious glomerulonephritis?
Glomerulonephritis follows infection by nephritogenic strains of streptococci, classically streptococcal pharyngitis.
In Post-infectious Glomerulonephritis:
(Nephrotic/Nephritic)
LM: __________
IF: ________________
EM: ________________
In Post-infectious Glomerulonephritis:
Nephritic
LM: diffuse proliferative changes
IF: Granular IgG and C3
EM: sub-epithelial humps of large electron-dense deposits
What is Lupus Nephritis?
2° SLE
- any clinical/histological pattern
- aggressive forms a/w proliferative changes, present w nephritic syndrome and may have crescents
- membranous variant present w nephrotic syndrome
What is seen on an IF of lupus nephritis?
“Full house” pattern
IgG, IgA, IgM, C1q, C3
In Membranoproliferative Glomerulonephritis:
(Nephrotic/nephritic)
LM: ______________
a/w: ________________
In Membranoproliferative Glomerulonephritis:
BOTH Nephrotic/nephritic
LM: proliferative changes involving mesangium + thickening of basement membrane
a/w: ↓serum C3
In which condition is Crescentic glomerulonephritis seen?
1) Post-infectious glomerulonephritis (most commonly rapidly progressive)
2) Goodpasture’s
3) Other RPGN (eg. ANCA related)
Rapidly Progressive Glomerulonephritis requires _________________, otherwise all progress to ______________.
Requires immunosuppressive treatment, otherwise all progress to renal failure
How is RPGN classified?
IF staining pattern:
1) IF+
- immune complex proliferative GN, but if linear pattern, due to anti-GBM disease.
2) IF- (pauci-immune)
- due to systemic vasculitis. (ANCA-related)
What is Goodpasture’s syndrome?
Anti-glomerular basement membrane disease
- antigen is part of D-chain of Type IV collagen
What organs are most commonly affected in Goodpasture’s syndrome?
Kidney and Lungs (both have basement membrane with similar type 4 collagen)