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Flashcards in Renal diseases 1 Deck (94):

What are the 4 main functions of the kidney?

1) Eliminating metabolic waste products
2) Regulating fluid and electrolyte balance
3) Influencing acid-base balance
4) Production of hormones - renin, eryhtropoietin (stimulates red cell production)


What are the 6 main presentations of renal disease?

1) Acute renal failure
2) Nephrotic syndrome
3) Acute nephritis (nephritic syndrome)
4) Chronic renal failure
5) Haematuria
6) Proteinuria


Does the clinical presentation necessarily indicate the cause of renal disease?

No - each clinical presentation has a variety of causes


What are the clinical features of acute renal failure? 2

1) Rapid rise in creatinine and urea
2) Generally unwell


What 3 things make up nephrotic syndrome?

1) Oedema
2) Proteinuria
3) Hypoalbuminaemia


What is important about the proteinuria in nephrotic syndrome?

Must be greater than 3g per 24 hours
Mostly albumin


What are the 4 things that make up nephritic syndrome/acute nephritis?

1) Oedema
2) Proteinuria
3) Haematuria
4) Renal failure


How does chronic renal failure present?

Slowly declining renal function


What 5 disciplines are needed for diagnosis of renal disease?

1) Renal physician - clinical history and examination
2) Biochemists - blood tests and urinalysis
3) Pathologist - always light microscopy of renal biopsy, sometimes, electron microscopy and fluoroscopy in specific cases
4) Urologist
5) Radiologist- obstruction, kidney size, structural abnormalities


When may a urologist be needed in diagnosis of renal disease?

Cytoscopy may be needed in cases of obstruction and some cases of haematuria (could be a sign of malignancy)


What blood tests and urinalysis is performed in diagnosing renal disease?

Bloods - urea, creatinine
Urine - protein, electrolytes


What are the 3 things forming the filtration barrier in the kidneys?

1) Podocyte foot processes
2) Endothelial cells
3) Basement membrane
NB. damages to any of these can impair filtration and thus renal function


What is the course of blood/ filtrate through the nephron?

1) Branches of renal artery
2) Afferent arteriole
3) Filtrate filtered out into bowman's capsule
4) Filtrate through proximal convuluted tubule
5) Through descending limb of henle, loop of henle and ascending limb of henle
6) Through distal convuluted tubule
7) All excreted filtrate through the collecting duct leading to the pelvis of the kidney


Why can damage of the glomerulus lead to damage to the tubule?

Blood flowing through the glomerulus and the efferent arteriole is the blood supplying the tubules so any damage to glomerulus could alter the blood supply to the tubules which can become ischaemic and thus damaged


What are the 2 classes of mechanisms which can damage the glomerulus?

1) Immunological
2) Non immunological


Name 3 immunological mechanisms of damage to the glomerulus, which part specifically is damaged?

1) Circulating immune complexes deposited in the glomerulus
2) Circulating Ag deposit in the glomerulus
3) Ab to basement membrane or other components of the glomerulus produced
All of these lead to damage to the basement membrane through complement an neutrophil activation, production of reactive oxygen species and presence of clotting factors in glomerulus


Name a non immunological mechanism of damage to th glomerulus, which in particular damages the blood vessels of the glomerulus?

Injury to the endothelium of the vessels


Name 3 non immunological mechanisms of damage to the glomerulus which in particular damage the basement membrane?

1) Altered basement membrane due to hyperglycaemia in diabetes (abnormal sugars and glyocosylated proteins in blood)
2) Abnormal basement membrane or podocytes due to inherited disease
3) Deposition of abnormal proteins in the kidney eg. amyloid


What are the 2 classes of mechanisms damage to the tubules of the nephron?

1) Ischaemic
2) Toxic


What are the 3 ischaemic mechanisms of damage to the tubules of the nephron?

1) Hypotension
2) Damage to vessels within the kidney
3) Glomerular damage
All lead to reduced blood supply to the tubules and thus tubular damage


What is important about renal function in tubular damage?

The degree of tubular damage correlates well with renal function (this isnt however always the case with glomerular damage)


What are the 4 toxic mechanisms of damage to the tubules of the nephron?

1) Direct toxins
2) Hypersensitivity reactions eg. to drugs
3) Deposition of crystals in tubules (most common is gout)
4) Deposition of abnormal proteins in the tubules


Give the 5 mechanisms of vascular damage to the kidneys (blood supply to both glomerulus and tubules)?

1) Hypertension
2) Diabetes
3) Atheroma eg. renal artery stenosis
4) Thrombotic microangiopathy
5) Vasculitis


Give a common cause of thrombotic microangiopathy?

Haemolytic uraemic syndrome


What is thrombotic microangiopathy?

Thrombi in the capillaries and small arterioles due to damage to the endothelium
Causes of that endothelial damage include bacterial toxins (ie this can a complication of bacterial infection), some drugs and abnormalities in complement or clotting systems


What is vasculitis?

- Acute or chronic inflammation of blood vessel walls
- Can get obliteration of lumen by inflammation
- Various different types affecting different sizes of vessel
- Can affect adults and children


Give one common type of vasculitis?

Wegener's granulomatosis


Which 3 glomerular 'diseases' can be both descriptions of the microscopic appearance due to a known cause and also disease names when the cause is unknown ie. idiopathic diseases?

All can be secondary to known cause or idiopathic diseases:
1) Membranous nephropathy
2) Focal segmental glomeruloscelrosis (FSGS)
3) Mesangiocapillary glomerulonephritis


1) proliferative glomerulonephritis
2) Crescentic glomerulonephritis
3) Thrombotic microangiopathy
appearances or diseases of the glomeruli?

Appearances secondary to known causes


Name 6 glomerular diseases (which don't describe glomerular appearances but just diseases)?

1) Minimal change disease
2) Post infective glomerulonephritis
3) Anti-GBM disease
4) IgA nephropathy
5) Henoch-Schonlein purpura
6) Lupus nephritis (SLE)


What is always the cause of nephrotic syndrome?

Always due to damage to the glomerulus


Other than the 3 defining features of nephrotic syndrome, what 2 other clinical features can be present?

1) Hypertension
2) Hyperlipidaemia


What are the 2 main complications of nephrotic syndrome?

1) Infection
2) Thrombosis


What is the most common cause of nephrotic syndrome in adults seen on renal biopsy?

Idiopathic membranous nephropathy


Which age group and gender is idiopathic membranous nephropathy most common in?

More common in males than females
Common in adults 30-60


What percentage of people with idiopathic membranous nephropathy progress to end stage renal failure?



What are the second and third most common causes of nephrotic syndrome in adults seen on renal biopsy?

2nd = focal segmental glomerulosclerosis
3rd = minimal change disease


Give 3 other causes of nephrotic syndrome in adults?

1) Diabetes
2) Lupus nephritis
3) Amyloid


What are the biopsy findings in minimal change disease, is it more common in males or females?

Same frequency in both sexes
Biopsy is normal on light microscopy


What are the 4 common causes of focal segmental glomerulosclerosis?

1) idiopathic
2) genetic
3) Heroin use
4) HIV


What is the most common cause of nephrotic syndrome in children seen on renal biopsy?

Minimal change disease - no abnormality seen on light microscopy, majority of children have excellent prognosis


What is the second most common cause of nephrotic syndrome in children, are there any other causes?

focal segmental glomerulonephritis
Other causes are rare


What is the 5th possible clinical feature of acute nephritis in addition to the 4 defining features?



What is the most common cause of acute nephritis/nephritic syndrome in adults?

1) Post infective glomerulonephritis


What are the 2nd, 3rd and 4th most common causes of acute nephritis/ nephritic syndrome in adults?

2nd = IgA nephropathy
3rd = Vasculitis
4th = Lupus


Post infective glomerulonephritis typically occurs when, what is the recovery rate?

A few weeks after streptococcal throat infection (Abs cross react)
Most recover completely


What is the most common primary glomerular disease worldwide?

IgA nephropathy


Teenagers and young adults with haematuria are most likely to be suffering from which glomerular disease?

IgA nephropathy - 20-50% progress to renal failure over 20 years


What 5 other clinical features may a patient with acute nephritis due to vasculitis present with?

1) Fever
2) Generally unwell
3) May have rash
4) Myalgia
5) Arthralgia


Lupus nephritis typically occurs in which group of people?

Young women


What are the 4 most common causes of acute nephritis in children (in order)?

1st = post infective glomerulonephritis
2nd = IgA nephropathy
3rd = Henoch-Schonlein purpura
4th = Haemolytic-uraemic syndrome


What is Henoch-schonlein purpura, who is it most common in and what are the 5 clinical features?

A specific type of IgA nephropathy
Most common in you boys/ teenage males
Clinical features:
1) Arthralgia
2) Abdo pain
3) Rash
4) Haematuria
5) Acute renal failure


What is haemolytic uraemic syndrome, who does it typically occur in?

Acute nephritis + haemolysis + thrombocytopaenia
Typically occurs in children whit E coli enteritis


On what basis is a diagnosis of acute renal failure made?

Anuria/oliguria + raised creatinine and urea


What is the prognosis of acute renal failure?

Many patients will recover and have good renal function if they had healthy kidneys previously
Short term dialysis may be needed in some patients


What are the 3 classes of causes of acute renal failure, in which is a renal biopsy useful?

1) Pre renal: reduced blood flow to kidney
2) Intra-renal
3) Post renal: obstructed urinary tract
Biopsy only useful in renal causes


Give 5 pre renal causes of acute renal failure?

1) Severe dehydration
2) Hypotension eg.
3) Bleeding
4) septic shock
5) Left ventricular failure


What is the most common type of cause of acute renal failure?

Pre renal causes


Name 4 post renal causes of acute renal failure?

1) Tumours of the urinary tract
2) Tumours in the pelvis
3) Bladder stones
4) Prostatic enlargement


What is the treatment for acute renal failure?

1) Short term dialysis may be needed
2) Treat the underlying cause


What are the 5 possible complications of acute renal failure?

1) Cardiac failure (fluid overload)
2) Arrhythmias (electrolyte imbalance)
3) GI bleeding
4) Jaundice (hepatic venous congestion)
5) Infection, especially lung and urinary tract


What define chronic renal failure?

Permanently reduced GFR - due to a reduced number of nephrons


What are the 5 stages of chronic renal failure?

1) Kidney damage with normal or increased GFR >90ml/min/1.73m^2
2) Mild reduction in GFR (60-89)
3) Moderate reduction in GFR (30-59)
4) Severe reduction in GFR (15-29)
5) Kidney failure GFR


Which 2 stages of chronic renal failure require treatment?

Stage 4 and 5


If a patient is on dialysis which stage of chronic renal failure are they automatically at?

Stage 5


What are the 3 most common causes of chronic renal failure in adults?

1) Diabetes
2) Glomerulonephritis
3) Reflux nephropathy


What is reflux nephropathy?

Chronic reflux of urine up the ureter leading to repeated infections and scarring of the kidney


What are the 3 common causes of chronic renal failure in children?

1) Developmental abnormalities/malformations
2) Reflux nephropathy
3) Glomerulonephritis


Why is a renal biopsy often unhelpful in established chronic renal failure?

Similar changes are seen in end stage renal disease due to any cause
Kidney shows severe scarring with loss of glomeruli and tubules


What are the 4 main effects of chronic renal failure?

1) Reduced excretion of water and electrolytes: oedema and hypertension
2) Reduced excretion of toxic metabolites
3) Reduced production or erythropoietin: anaemia
4) Renal bone disease


What are the 2 most likely diagnosed in an elderly patient with acute renal failure?

1) Acute interstitial nephritis due to drug reactions
2) Myeloma (tumour of plasma cells secreting proteins which block up the tubules)


What is the most likely diagnosis in a young male with haematuria and a rash?

Henoch-schonlein purpura


What are the 2 most likely diagnoses in a teenager/young adult with haematuria?

1) Post infective glomerulonephritis
2) IgA nephropathy


What is the most likely diagnosis in an adult with acute renal failure, fever and myalgia?



What is the most likely diagnosis in a young woman with haematuria and a facial rash?



What is the most likely diagnosis in an adult with nephrotic syndrome?

Membranous nephropathy


What is the most likely diagnosis in a child with nephrotic syndrome?

Minimal change disease


What investigations are needed in isolated haematuria?

Cystoscopy and other urological investigations as may be bleeding from a urinary tract tumour


What are the 3 likely renal causes of haematuria +/- proteinuria with normal renal function?

1) IgA nephropathy
2) Thin basement membrane disease
3) Alport type hereditary nephropathy


What is thin basement membrane disease?

Inherited condition causing abnormally thin basement membranes in the glomerulus - if no other renal disease present, kidney function will remain normal


What is alport type hereditary nephropathy?

Inherited abnormalities of collagen type 4 cause abnormal basement membrane in the glomerulus, sometimes with eye and ear problems
Renal failure +/- deafness/ocular problems


What is isolated proteinuria?

Proteinuria less than the nephrotic range, without haematuria, renal failure or oedema


What are the 3 likely causes of isolated proteinuria in adults?

2) Diabetes
3) Lupus


What are the 2 likely causes of isolated proteinuria in children?

1) Henoch-schonlein purpura


What is pyelonephritis?

Infection of the kidney


What is the most common cause of chronic pyelonephritis?

Obstruction of the urinary tract and reflex of urine up the ureter


What is the main complication of acute pyelonephritis?

Abscess formation


What are the 2 complications of chronic pyelonephritis?

1) Scarring of kidney
2) Chronic renal failure


What is the cause of renal artery stenosis?

Usually due to atheroma, can be due to arterial dysplasia


What are the 2 main complications of renal artery stenosis and why?

1) Hypertension - due to activation of RAAS
2) Reduced renal function - due to loss of renal tissue due to ischaemia


In what 2 ways does vasculitis mainly affect the kidney?

1) Inflammation can affect the glomerular vessels and lead to obliteration of capillary lumens and destruction of the glomerulus
2) Inflammation of larger arterioles within the kidney can lead to hypoxia of the tubules


How does hypertension lead to damage of the kidney?

1) Hypertension damages renal vessels leading to thickening of the vessel wall and reduction in size of lumen
2) This produces chronic hypoxia which leads to loss of renal tubules and reduced renal function
3) Reduced blood flow in the kidneys leads to activation of RAAS which exacerbates hypertension


How does diabetes damage the kidney?

1) Hyperglycaemia is the main cause of diabetic nephropathy by damaging the basement membrane
2) Basement membrane becomes thicker and the glomerulus produces excess extracellular matrix which forms nodules
3) Diabetes also damages small vessels leading to ischaemia and damage to renal tubules


How does a myeloma damage the kidney?

1) Tumour of plasma cells producing immunoglobulins
2) Excess immunoglobulins deposit in the kidney tubules
3) Tubules become damages
4) Get inflammation and fibrosis of the kidneys
5) Loss of renal tubules leads to declining kidney function
Renal impairment due to myeloma is usually irreversible

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