Nephrotic Syndrome Flashcards
What constitutes as remission for nephrotic disease?
3 days dipstick -ve for proteins (?)
Make sure to cover hsp and it’s extrarenal manifestations
GI Bleed
Glomeurlonepgritis
Abdo sepsis
Intrsusseption
What are the causes of increased interstitial fluid?
Poor lymph drainage:
Lymphoedema - Congenital vs Physical/blockage
Poor venous drainage + pressure:
Venous obstruction
E.g. venous thrombosis
Low oncotic pressure - low albumin/protein:
Malnutrition
Decreased production - Liver disease
Increased loss:
Gut
Kidney - Nephrotic syndrome
Salt and water retention:
Kidney - impaired GFR
Heart failure
What symptoms characterise nephrotic syndrome?
Hypoalbuminaemia -> Proteinuria (heavy) -> Oedema \+ Hyperlipidaemia (from reactive hepatic protein synthesis, including of lipoproteins)
(depending on the cause/types of protein lost, may also be other complications e.g. infection, thrombosis)
How do you test for heavy proteinuria?
Semi-quantitative = Dipstick: Negative-trace = 0-30mg/dL 1+ = 30-100mg/dL 2+ = 100-300mg/dL 3+ = 300-1000mg/dL 4+ = >1000mg/dL 3-4 = increased likelihood of hypoalbuminaemia
Quantitative = First morning urine: Protein:creatinine
Normal = <20mg/mmol
No definite level that means its nephrotic but >600mg/mmol is likely to produce hypoalbuminaemia (although can occur at lower levels)
What is hypoalbuminaemia?
Normal albumin range = 35-45g/L
Hypo = <25-30g/L – this level usually associated with fluid retention and oedema
What characterises the oedema?
Pitting
Gravitational e.g. shifting dullness
What is hyperlipidaemia?
Normal lipid range = 100-129mg/dL
Hyper = 160-189mg/dL
Arises due to the low serum oncotic pressure which then leads to reactive hepatic protein synthesis including lipoproteins
What are the different types of nephrotic syndrome?
Congenital - <1yr
Steroid sensitive NS (SSNS)
Steroid resistant NS (SRNS)
What are the clinical features of steroid sensitive NS?
Normal BP
No macroscopic haematuria
Normal renal function
No features to suggest nephritis
Respond to steroids
Histology – “minimal change” usually
What are the clinical features of steroid resistant NS?
Elevated BP
Haematuria
May be impaired renal function
Features may suggest nephritis
Failure to respond to steroids
Histology – various: underlying glomerulopathy, basement membrane abnormality
What is the epidemiology of different nephrotic syndromes? (general)
Most common age 1-15yrs = minimal change disease – 85-40% (decreases with age)
Focal segmental glomerulosclerosis – makes up about 20% of the cases between ages 10-15rys
Other causes – mesangiocapillary glomerulonephritis etc make up about 30-40% total age 10-15yrs
What is the epidemiology of steroid sensitive nephrotic syndrome? (mostly minimal change)
Peak incidence age 2-5yrs M>F Greater incidence in Asian populations Recurrent relapse + 5% continue into adult life Potential immunological aetiology
Normal renal function if treated with steroids
How do you treat SSNS?
First episode:
Admission
If ?septic - treat as such
Address oedema - Na/water moderation, diuretics (furosemide), IV albumin
Steroid therapy - prednisolone 60mg/m2 OD for 4 weeks then 40mg/m2 alternate days for 4 weeks
Complication prophylaxis - phenoxymethylpenicillin (Pen v), measles + varicella + pneumococcal vaccination
Relapse = protienuria of 3+ on 3 consecutive days - prompts restarting of prednisolone
What is a common renal cause of AKI and how does it present?
Acute glomerulonephritis:
Haematuria – often macroscopic
Proteinuria – variable amounts
Impaired GFR – rising creatinine (variable)
Salt and water retention – hypertension and oedema
What is acute post-streptococcal glomerulonephritis?
Follows a nasopharyngeal or skin infection
Often group A beta-haemolytic strep infections – nephritogenic strains
Antigen-antibody complexes deposit in the glomeruli and result in complement system activation and subsequent inflammation
Presents c.10days+ post infection – initially with haematuria, swelling, decreased urine output then HTN and signs of CV overload
How do you investigate post-streptococcal glomerulonephritis?
Bloods:
FBC – mild, normochromic, normocytic anaemia
U+E – increased urea + creatinine; possible hyperkalaemia + metabolic acidosis
Immunology – raised antistreptolysin O (ASO) (raised - >200units/ml - after strep infections), antiDNAse B (antibodies to protein produced by group A strep), low complements – C3 + C4
Urinalysis:
Haematuria – often macroscopic
Proteinuria – dipstick elevation
Microscopy – RBC casts (WBC casts may indicate tubular disease including acute pyelonephritis)
Swabs:
Throat, nasal, skin etc - for the strep infection itself + MC+S
How is post-streptococcal glomerulonephritis managed?
Penicillin:
Treat the strep infection (if still ongoing)
Fluids:
Monitor input/output, ?catheter
Fluid + salt restriction
Diuretics:
For fluid balance and HTN
Correct any electrolyte imbalances – K, acidosis etc.
Possible dialysis if necessary (rare)
What is the prognosis of acute post-streptococcal glomerulonephritis?
95% full recovery + no long term impact on renal function
Non-recurrent
What is Henoch-Schonlein Purpura (HSP)?
Aka IgA vasculitis - involving skin, joints, gut and kidneys
IgA deposition in the glomerulus = IgA nephropathy (Berger’s disease)
More common in young adults - 16-35
Symptoms usually begin 1-2 days post URTI (unlike the post-strep = weeks)
Possible renal symptoms: Haem/proteinuria Nephrotic syndrome Acute nephritis Renal impairment HTN
Skin/MSK symptoms:
Petechial, mostly buttocks and extensor surfaces of arms and legs
Swollen, painful knees and ankles
Steroid resistant – may need immunosuppression
Variable prognosis – can end up with end stage renal disease (ESRD) + dialysis
