Systemic and Genetic Disease of the Kidneys Flashcards
What is the pathophysiology and presentation of diabetic nephropathy?
Pathophysiology - hyperglycaemia causes rise in oncotic pressure and volume expansion. This causes intra-glomerular hypertension which leads to proteinuria
Presentation - always presents with proteinuria and will always present with other diabetic vascular problems. On US it will present with normal sized kidneys
What is the management of diabetic nephropathy?
Blood glucose control,
Restrict dietary protein,
Aim for BP <130/80.
Start ACEi/ARB if uACR is >3mg/mmol.
Consider statin
What is the pathogenesis of renal artery stenosis?
It is progressive narrowing of the renal artery with an atheroma. With stenosis reaches 70% there is cortical hypoxia
What are the clinical features of renal artery stenosis?
Presentation: refractory hypertension, CKD, Flash pulmonary oedema, worsening renal function once started on ACE inhibitor.
Investigate via renal ultrasound and renal angiograophy
WHat is the management of renal artery stenosis?
Medical management - Control BP (not with ACEi/ARBs as they increaase BP in glomerulus) and give statin.
Lifestyle advice - Smoking cessation, exercise and low salt diet.
Angioplasty - Done when there is uncontrolled BP on multiple agents, rapidly deteriorating renal function or flash pulmonary oedema
Explain the pathophysiology of lupus nephritis
Autoantibodies produced against dsDNA or nucleosomes.
Formation of intravascular immune complexes which can attach to the GBM
Activation of complement (C4) occurs which causes damage to kidneys
Explain the diagnosis and management of lupus nephritis
Renal biopsy - Confirm and stage diagnosis
Management: Treat hypertension. Steroids and mycophenolate for stage III and IV. Followed by mycophenolate maintenance therapy.
Explain the pathogenesis of myloma renal disease
Cast nephropathy (renal damage due to excess amount of light chains which causes damage to tubules)
Hypercalcaemia which leads to dehydration
Light chain deposition disease
May have amyloid associated with myeloma
May develop fanconi syndrome (antibody fragments are toxic to proximal tubule)
What are renal casts and what are the different types?
Casts are clumped cells forming tubule shaped particles, they are seen microscopically.
Black/brown casts suggest acute tubular necrosis.
RBC casts suggest glomerulonephritis.
WBC casts may indicate acute interstitial nephritis
What is Alport’s syndrome?
X linked defect in type IV collage which causes an abnormal glomerular basement membrane.
Think deafness and renal failure
What is the presentation of Alport’s syndrome
Microscopic haematuria
Progressive renal failure,
Bilateral sensorineural deafness,
Lenticonus,
Retinitis pigmentosa
What are the investigations for Alports syndrome?
Molecular genetic tests
Renal biopsy - spliting of lamina densa
What is the management of Alport’s syndrome?
BP control
What is Fabry disease?
X linked lysosomal storage disorder caused by alpha galactosidase A deficiency resulting in accumulation of Gb3. Gb3 accumulated in glomeruli causing proteinuria.
It can also cause neuropathy, cardiac and skin features
When should you suspect Fabry Disease?
Intermittent episodes of burning in extremities,
Angiokeratomas,
Diminished perspiration,
Corneal and lenticular opacities,
Abdo pain, nausea and/or diarrhoea of unknown cause.
LVH of unknown aetiology
Arrhythmias of unknown aetiology
Stroke of unknown aetiology at any age,
CKD and proteinuria of unknown aetiology
What is the diagnosis and management of Fabry disease
Diagnosis - Measure alpha-Gal A activity in leukocytes (although unreliable in females) or renal biopsy with inclusion bodies of G3b.
Management - Enzyme replacement therapy
What are the different types of diabetes insipidus?
Cranial DI - Decreased secretion of ADH from pituitary
Nephrogenic DI - failure of the kidneys to respond
What are the causes of cranial diabetes insipidus?
Idiopathy,
Post head injury,
Pituitary surgery,
Haemochromatosis
Craniopharyngiomas,
Infiltrative (sarcoidosis),
Wolfram’s syndrome (DIDMOAD)
What are the causes of nephrogenic diabetes insipidus?
Genetics,
Hypercalcaemia,
Hypokalaemia,
Lithium,
Demeclocycline,
Tubulo-interstital disease (sarcoidosis, pyelonephritis)
What are the clinical features and investigations for diabetes insipidus?
Presents with polyuria and polydipsia.
Investigations - Water deprivation test (if responds then cranial, if doesn’t respond then nephrogenic) High plasma osmolality and low urine osmolality.
What is the management of diabetes insipidus?
Nephrogenic - Thiazides and low salt/protein diet.
Cranial - desmopressin
What are some of the causes of rhabdomyolysis?
Seizures,
Collapse/coma (long lie),
Ecstasy,
Crash syndrome,
McArdle’s syndrome,
Drugs (statin espcially if co-prescribed with clarithromycin)
What is the presentation of rhabdomyolysis?
AKI (with really high creatinine)
Raised creatine kinase (at least x5 upper limit of normal)
Myoglobinuria (dark red/brown urine)
Hypocalcaemia (free myoglobin binds to calcium)
Hyperkalaemia,
Metabolic acidosis
