Nephrotic syndrome Flashcards
What at is the difference between nephrotic syndrome and nephritic syndrome?
Nephrotic syndrome triad: - break down of glomerular filtration barrier causing massive protein leak (injury to podocytes)
- Proteinuria >3.5g/day
- Low serum albumin <30g/L (hypoalbuminaemia)
- Oedema
Nephritic syndrome triad: - more severe glomerular damage causing loss of large proteins and red cell clasts.
- Haematuria
- Hypertension
- Oedema (+ oliguria <400ml/day)
What are the common primary causes of nephrotic and nephritic syndrome?
Nephrotic syndrome:
- Membranous glomerulonephritis (ICM)
- Minimal change disease (Non-ICM)
- Focal segmental glomerulosclerosis (Non-ICM)
- Mesangiocapillary glomerulonephritis (ICM/non-ICM)
Nephritic syndrome:
- IgA nephropathy
- Mesangiocapillary Glomerulonephritis
ICM = Immune Complex Mediated
What are the common secondary causes of nephortic and nephritic syndrome? (3)
Nephrotic syndrome:
- Diabetes
- SLE
- Amyloid
- HBV/HCV
Nephritic syndrome:
- Post streptococcal
- Vasculitis
- SLE
- Anti-GBM disease
- Cryoglobulinaemia
What causes hyperlipidaemia (>10mmol/L) in nephrotic syndrome?
Hypoalbuminaemia causes liver to try to compensate and increase albumin production but this also –> increased production of lipids (LDL and VLDL) –> hyperlipidaemia
Why can nephrotic syndrome cause a hypercoagulable state?
Hypercoagulable state due to loss of antithrombin III, hypogammaglobuliaemia
Damage to which cells in the glomerular capillaries is largely responsible for the proteinuria in nephrotic syndrome?
Podocytes - wrap around glomerular capillaries and maintain filtration barrier preventing LMW proteins from entering the urine
What is minimal change disease? Who is most affected?
Minimal change disease: glomeruli look normal under microscopy. (EM shows effacement of foot processes)
Common cause of nephrotic syndrome in children (905), more responsive to steroids
How common is nephrotic syndrome?
- Common in children 1-16/100,000 cases/yr worldwide
- DM is the most common secondary cause in adults and FSGF and memraneous nephropathy are the most common primary causes
- Higher incidence of MCD in white ethnic chldren compared to Arabic and Asian.
What are the signs and symptoms of nephrotic syndrome?
- Facial swelling/periorbital oedema - common in children
- Peripheral oedema of ankles and legs
- Frothy urine
- Hypercoagulability –> venous/arterial thrombosis (DVT/MI)
- Recurrent infections, general fatigue, lethargy, poor appetite, weakness or episodic abdominal pain
- Leukonychia
- SOB - pleural effusion, fluid overload (raised JVP), AKI
- Eruptive xanothomata, xanthelasmata
What investigations would you do for nephrotic syndrome?
Urinalysis -
- proteinuria - >3.5g/24hrs
- microscopic haematuria
- BUT few cells or casts
- MC&S
Serum albumin - low <30g/L
Serum lipids - hyperlipidaemia
FBC and coagulation screen - thrombotic disease
U&E and creatinine
LFTs - exclude liver pathology
CXR - check for pleural effusion or ascites
Renal USS - presence of 2 kidneys, size and shape
Suspect complications such as DVT, PE
What is the management of nephrotic syndrome?
MCD - steroid responsive in most, especially children
FSGS - usually steroid resistant; biopsy to confirm then immunosuppress with ciclosporin
Membranous nephropathy - measure anti-PLAR2 Ab titre to guide treatment; corticosteroids AND cytotoxic/ciclosporin
Diabetic nephropathy - control BM, ACEi or ARBs, lipid reduction, SGLT2 inhibitors
Amyloid - suppress plasma cell clone with Dara-CyBorD or other immunosuppressive regimens.
What are the complications of nephrotic syndrome?
Hypercholesterolaemia and hypertriglyceridaemia
DVT/PE - hypercoagulability from loss of anti-thrombin III, protein C and S in the urine and increased hepatic synthesis of pro-coagulant factors and platelet activation
Oedema
Infection - due to loss of Ig there is an increased risk of infection
How can you clinically distinguish between CCF and nephrotic syndrome?
CCF - cannot lie flat and do not develop facial oedema,
NS - can lie flat developing facial oedema
