Disease of the urinary tract 1 Flashcards
What are the functions of the kidney?
eliminate metabolic waste products
regulate fluid, acid base balance and electrolytes
production of renin and erythropoietin
In the mechanism of glomerular damage, immunologically what part of the glomerular is affected?
Basement membrane
In the mechanism of glomerular damage, non- immunologically what part of the glomerular is affected?
vessels or basement membrane
In the mechanism of tubular damage, what is affected?
vessels
What 2 types of mechanisms of tubular damage occur?
ischemic
toxic
What marker gives a good guide to level of damage to the tubules?
creatinine - The degree of damage to renal tubules correlates well with renal function
In the mechanism of vascular damage, what is affected?
vessels
What is nephrotic syndrome?
ALWAYS due to damage to glomerulus Hypoalbuminaemia Oedema Proteinuria \+/- hypertension \+/- hyperlipidaemia
What are the complications of nephrotic syndrome?
infection
thrombosis
What are the 4 main causes of nephrotic syndrome in adults?
Membranous nephropathy - idiopathic. MAIN CAUSE
focal segmental glomerulosclerosis - various causes, mostly idiopathic
minimal change disease - biopsy normal
other: diabetes, lupus nephritis, amyloid
What are the 2 main causes of nephrotic syndrome in children?
minimal change disease - biopsy normal, majority have excellent prognosis
focal segmental glomerulosclerosis - various causes, mostly idiopathic
What is acute nephritis?
Hypertension
Oedema
Proteinuria
Acute renal failure
What are the 5 main causes of acute nephritis in adults?
Post infective glomerulonephritis - few weeks after streptococcal throat infection
IgA nephropathy - Most common primary glomerular disease worldwide, teenagers and young adults with haematuria
Vasculitis
Lupus - Autoimmune disease, typically young women
Other forms of primary glomerulonephritis
What are the symptoms of vasculitis?
fever malasia rash possible myalgia - muscle ache arthralgia - joint pain
What are the 4 main causes of acute nephritis in children?
post-infective glomeulonephritis
IgA nephropathy
Henoch-Schonlein purpura
Haemolytic-uraemic syndrome
What is Henoch-Schonlein purpura?
Specific type of IgA nephropathy Typically young boys/teenagers arthralgia abdo pain acute renal failure rash haematuria Most recover completely
What is Haemolytic-uraemic syndrome?
Typically children with E. Coli 0157 enteritis
Haemolysis
Acute nephritis
Thrombocytopaenia
What is the diagnosis and prognosis of acute renal failure?
Diagnosis: anuria/oliguria + raised creatinine and urea
Prognosis: Many will recover and have good renal function if they had healthy kidneys previously
What are the causes of acute renal failure?
Pre-renal: reduced blood flow to kidneys - most common
Renal: damage to the kidneys
Post-renal: obstructed urinary tract
What are the causes of acute renal failure in adults?
Vasculitis
Acute interstitial nephritis/tubulointerstitial nephritis - tubular damage with inflammation, most commonly caused by drug reactions
What are the causes of acute renal failure in children?
Henoch-Schonlein purpura
Haemolytic uraemic syndrome
Acute interstitial nephritis
What do all biopsies in acute renal failure show?
All biopsies will show “ATN” – acute tubular necrosis/ injury/damage/acute kidney injury (ATI/ATD/AKI)
What are the complications of acute renal failure?
Cardiac failure (fluid overload) Arrythmias (electrolyte imbalance) GI bleeding Jaundice (hepatic venous congestion) Infection, especially lung and urinary tract
What is chronic renal failure?
Permanently reduced GFR – reduced number of nephrons
What are the 3 most common causes of chronic renal failure in adults?
Diabetes (commonest)
Glomerulonephritis
Reflux nephropathy- chronic reflux of urine up the ureter
What are the 3 most common causes of chronic renal failure in children?
Developmental abnormalities/malformations
Reflux nephropathy
Glomerulonephritis
Why is renal biopsy often unhelpful in established chronic renal failure?
Kidney shows severe scarring with loss of glomeruli and tubules
Similar changes are seen in end-stage renal disease due to any cause
What are the effects of Chronic renal failure?
Reduced excretion of water and electrolytes = oedema, hypertension
Reduced excretion of toxic metabolites = generally unwell, reduced appetite
Reduced production of erythropoietin = anaemia
Renal bone disease
What would a Elderly patient with acute renal failure most likely present with?
Acute interstitial nephritis due to drug reactions
Myeloma
What would a Young male with haematuria and rash most likely present with?
Henoch-Schonlein purpura
What would a Teenager/young adult with haematuria most likely present with?
Post-infective glomerulonephritis
IgA nephropathy
What would a Adult with acute renal failure, fever and myalgia most likely present with?
Vasculitis
What would a Young woman with haematuria and facial rash most likely present with?
Lupus
What would a Adult with nephrotic syndrome most likely present with?
Membranous nephropathy
What would Child with nephrotic syndrome most likely present with?
Minimal change disease
What may cause isolated haematuria?
IgA nephropathy
Thin basement membrane disease
Alport type hereditary nephropathy
What may cause isolated proteinuria?
benign e.g. Postural, related to pyrexia or exercise
May be due to renal disease
What is renal artery stenosis?
Due to atheroma (most common) or arterial dysplasia
Leads to ischaemia of the affected kidney
Activation of renin-angiotensin-aldosterone = hypertension
Loss of renal tissue due to ischaemia = reduced renal function
How does vasculitis affect the kidney?
hypoxia of the tubules
How does diabetes affect the kidney?
Hyperglycaemia is the main cause of diabetic nephropathy by damaging the basement membrane
Basement membrane becomes thicker - glomerulus produces excess extracellular matrix which forms nodules
damages small vessels leading to ischaemia and damage to renal tubules
