Chronic Kidney Injury Flashcards
What time frame of deteriorating kidney function fits the definition of chronic kidney disease?
> 3 months
List 12 causes of CKD:
1) polycystic kidney disease
2) medullary cystic disease
3) tuberous sclerosis
4) oxalosis
5) cystinosis
6) congenital obstructive uropathy
7) glomerulonephritis
8) hypertensive nephrosclerosis
9) tubulointerstitial disease
10) urinary tract obstruction
11) diabetic nephropathy
12) chronic pyelonephritis
Which type of polycystic kidney disease is more common?
Autosomal dominant (adult)
What is medullary cystic disease?
An autosomal dominant disorder characterised by tubulointerstitial sclerosis, leading to end-stage renal disease
What is tuberous sclerosis?
a rare, multisystem autosomal dominant genetic disease that causes benign tumours to grow in the kidneys, brain, heart, liver and lungs
What is oxalosis?
a hereditary or secondary condition where there is supersaturation of calcium oxalate in urine which results in kidney stones and cortical nephrocalcinosis
What is cystinosis?
an autosomal recessive disorder and lysosome storage disease characterised by the abnormal accumulation of cystine leading to crystal formation in the kidneys
What is Fanconi syndrome?
A defect in proximal tubule reabsorption so almost all of the filtrate is excreted (large loss of fluid, potassium, phosphate, and abnormal levels of carbohydrates and amino acids in urine)
What is the most common cause of Fanconi syndrome?
Cystinosis
What is glomerulonephritis?
inflammation and damage to glomeruli, allowing protein and sometimes blood to leak into the urine
Give 8 types of glomerulonephritis:
1) minimal change disease
2) focal segmental glomerulosclerosis
3) membranous glomerulonephritis
4) IgA nephropathy/ Berger’s disease
5) Post-infectious glomerulonephritis
6) membranoproliferative glomerulonephritis
7) Granulomatosis with polyangiitis
8) Microscopic polyangiitis
Does minimal change disease cause nephrotic or nephritic syndrome?
nephrotic
What would you find on light microscopy of a glomerulus affected by minimal change disease?
nothing (hence minimal change)
Does focal segmental glomerulosclerosis cause nephrotic or nephritic syndrome?
nephrotic
What is focal segmental glomerulosclerosis?
sclerosis affecting some but not all glomeruli and involving only segments of each
What is membranous glomerulonephritis?
deposition of immune complexes resulting in complement activation against the glomerular basement proteins, causing thickening
Does membranous glomerulonephritis result in nephrotic or nephritic syndrome?
nephrotic
What is nephrotic syndrome?
A condition results from excreting too much protein in urine due to a kidney disorder. This causes swelling in ankles, feet and around eyes, foamy urine, obesity, and fatigue.
The definition of nephrotic syndrome includes both massive proteinuria (≥3.5 g/day) and hypoalbuminaemia (serum albumin ≤30 g/L). 1
What is nephritic syndrome?
Nephritic syndrome is a condition involving haematuria, mild to moderate proteinuria (typically less than 3.5g/L/day), hypertension, oliguria and red cell casts in the urine.
What are 3 conditions associated with membranous syndrome?
- Hepatitis B
- SLE
- Malaria
What is the most common form of glomerulonephritis in adults, worldwide?
IgA nephropathy/ Berger’s disease
does IgA nephropathy (Berger disease)present as nephritic or nephrotic syndrome?
Nephritic
What is IgA nephropathy?
IgA immune complex deposition in mesangium tissue of glomeruli, causing scarring and increased matrix production
What is post-infectious glomerulonephritis?
an immunologically mediated glomerular injury triggered by an infection
What group of bacteria typically causes post-infectious glomerulonephritis?
Streptococci
How long after a Streptococci infection does post-infectious glomerulonephritis present?
2 weeks
What is membranoproliferative glomerulonephritis?
a group of immune-mediated disorders characterised histologically by glomerular basement membrane thickening including the mesangium tissue
What two diseases are associated with membranoproliferative glomerulonephritis?
- Hep C
- SLE
What is mesangium?
interstitial tissue located between glomerular capillaries
What is the difference between membranous glomerulonephritis and membranoproliferative glomerulonephritis?
white both result in thickening of the basement membrane, only membranoproliferative glomerulonephritis results in thickening of the mesangium
Does membranoproliferative glomerulonephritis present with nephrotic or nephritic syndrome?
nephritic
What is granulomatosis with polyangiitis?
an extremely rare systemic disorder which involves the formation of granulomas and inflammation of blood vessels
What antibody test can be used for granulomatosis with polyangiitis and microscopic polyangiitis?
anti-neutrophil cytoplasmic antibodies (ANCA)
What is microscopic polyangiitis?
a systemic, small-vessel vasculitis with no evidence of granulomatous inflammation
Does microscopic polyangiitis present with nephrotic or nephritic syndrome?
nephritic
Describe how high blood pressure can result in hypertension nephrosclerosis:
high blood pressure causes thickening of small vessels causing inadequate blood flow leading to kidney damage, hardening and thickening
What is tubulointerstitial disease?
a group of diseases that cause inflammation and fibrosis of the interstitial tissue and atrophy and dysfunction of the tubules
Give 6 examples of tubulointerstitial disease:
1) nephrocalcinosis
2) reflux nephropathy
3) schistosomiasis
4) multiple myeloma
5) reflux nephropathy
6) drug-induced tubulointerstitial nephritis
What are 4 examples of urinary tract obstruction that cause CKD?
- kidney stones
- Prostatic disease
- pelvic tumours
- Retroperitoneal fibrosis
What two measurements are used to assess, diagnose and stage CKD?
1) eGFR
2) albumin-creatinine ratio
How many stages of CKD are there based upon GFR?
5
How many stages of CKD are there based upon albumin: creatinine ratio?
3
Describe the pathophysiology of chronic kidney progression: (4)
- in CKD, many nephrons have failed so that the burden of filtration falls to fewer functioning nephrons
- The remaining nephrons experience hyperfiltration
- they adapt with glomerular hypertrophy and reduced arteriolar resistance
- This increases flow, stress and shear, accelerating remnant nephron failure
Give 9 clinical features of CKD:
1) oedema (ankle swelling, weight gain)
2) polyuria
3) lethargy
4) pruritis (secondary to uraemia)
5) anorexia
6) insomnia
7) nausea and vomiting
8) hypertension
9) proteinuria
Give the three albumin: creatinine ratio thresholds for referral to nephrology:
1) ACR > 70mg/mmol
2) ACR >30mg/mmol with prolonged haematuria
3) ACR 3-29mg/mmol with persistent haematuria and other risk factors such as declining eGFR or CVD
How do you treat CDK associated acidosis?
Sodium bicarbonate
What is given to treat CKD-associated anaemia?
erythropoiesis stimulating agents - always correct any iron deficiency first
What drugs should be withheld in patients with CDK?
nephrotoxic drugs (NSAIDS, some antibiotics, tetracyclines, K+ sparing agents)
What drug is used to treat CKD-associated hyperkalaemia?
Patriomer
What two drugs are given to all CKD patients to protect against CVD?
- Statin
- ACEi
At which stage of CKD is renal replacement therapy considered?
stage 5 (GFR of <15 ml/min)
What are the three types of renal replacement therapy?
1) haemodialysis
2) hemofiltration
3) peritoneal dialysis
Describe how haemodialysis works:
anticoagulated blood is pumped around a circuit through a semipermeable membrane before being returned to the circulation
dialysate flows in the opposite direction so small solutes can pass the membrane and diffuse down a concentration gradient, maintaining electrolytes, prevents acidosis and maintains euvolaemia
What is the name given to dialysis fluid?
dialysate
What is haemofiltration?
similar to haemodialysis, however there is no dialysate - rather there is just plasma water with suspended solutes. The patient is infused with substitution fluid of a desired biochemical composition to replace losses
What is peritoneal dialysis?
uses the peritoneal membrane as a semi-permeable membrane, avoiding the need for extracorporeal circulation of blood. A catheter is placed in the peritoneal cavity, diastylate runs through the cavity and solutes pass in down their concentration gradients
What is the main risk associated with peritoneal dialysis?
bacteria peritonitis
Name 4 organisms associated with peritoneal dialysis-associated peritonitis?
1) Staphylococcus epidermidis
2) E. coli
3) Staphyloccocus aureus
4) Candida
True or false: renal transplantation offers potential for almost complete rehabilitation of end-stage renal disease
true
What % of kidney grafts survive 5-10 years?
80%
Give 4 classes of immunosuppressive drugs used in renal transplantation:
1) calcineurin inhibitors
2) inhibitors of purine synthesis
3) steroids
4) anti-CD25 antibodies
How do calcineurin inhibitors prevent organ rejection?
they disrupt T cell signalling
Give two examples of calcineurin inhibitors:
1) Tacrolimus
2) Ciclosporin
How do inhibitors of purine synthesis act as immunosuppressants?
they stop the proliferation of lymphocytes
Give 2 examples of inhibitors of purine synthesis that act as immunosuppressants:
1) Azathioprine
2) Mycophenolate mofetil
How do steroids act as immunosuppressants?
they inhibit cytokine regulated T cell signalling
How do anti-CD25 antibodies act as immunosuppressants?
they are monoclonal antibodies that block IL-2 receptors
Give two examples of anti-CD25 antibodies:
1) dacliziumab
2) basiliximab
Give 4 complications associated with renal transplantation?
1) acute tubular necrosis due to hypotension and prolonged ‘cold’ ischaemic tie
2) acute rejection
3) infection
4) post-transplant osteoporosis (due to steroid use)
What type of anaemia is seen in CKD?
normochromic and normocytic
Give 3 causes of anaemia in CKD:
1) reduced EPO
2) RBCs have a shortened lifespan in uraemia
3) bone marrow toxins cause anaemia
Give two ways in with CKD can cause bone disease:
1) reduced kidney function results in reduced vitamin D activation leading to reduced bone mineralisation and calcium absorption
2) reduced calcium absorption causes secondary hyperparathyroidism leading to osteosclerosis
Give 4 drugs used to keep calcium and phosphate in their normal ranges in CDK mineral and bone disorder:
1) gut phosphate binders (calcium carbonate used to reduce phosphate absorption)
2) tenapanor (inhibits phosphate transport)
3) calcitriol vitamin D analogues (suppress PTH)
4) calcimimetic agents
Give an example of a caclimimetic agent:
cinacalcet (reduces PTH)
What is calciphylaxis?
The process in which CaHPO4 gets precipitated and deposited in soft tissues, causing…
1) vascular calcification
2) small vessel thrombosis
3) painful skin patches, plaques, ulcers and dermal necrosis
How does CKD cause cardiovascular disease?
coronary artery calcification
What is the name of the skin fibrosis condition associated with CKD?
nephrogenic systemic fibrosis
Give 3 CKD complications associated with raised urate/urea?
1) pruritis
2) gout
3) nervous and muscle problems (e.g. seizure and tremor)
