nephrotic syndrome is characterised by
proteinuria - typically >3g/24hr
hypoalbuminaemia - typically serum album <25g/L
oedema
hyperlipidaemia
what happens in the kidney in nephrotic syndrome
glomerular basement membrane damage and increased pore size leads to increased permeability of glomerular filter to albumin
capillary walls become permeable to proteins of higher molecular weights, as severity of injury continues
loss of albumin
what happens in hypoalbuminaemia
heavy proteinuria leads to low plasma albumin
colloid osmotic pressure is not maintained. so less fluid moves back into capillaries
stimulates RAAS- leads to further water and Na+ retention
complications from nephrotic syndrome
immunosuppression - immunoglobulins lost in urine
hypercoagulable - controlling proteins lost in urine – increases risk of DVT, PE, renal vein thrombosis
hyperlipidaemia - increases risk of vascular disease, IHD
management options in nephrotic syndrome
BP control ACE inhibitors to reduce proteinuria control hyperlipdaemia if hypercoagulable - anticoagulation treat underlying condition if possible
primary causes of nephrotic syndrome
minimal change disease
membranous glomerulonephropathy
membranoproliferative GN
focal segmental glomerulosclerosis
secondary causes of nephrotic syndrome
HSP (Henoch-Schlönlein purpura) SLE tumour amyloid diabetes mellitus drugs, e.g. penicillamine bacterial endocarditis congenital nephrotic syndrome
minimal change disease causes/associations
cause unknown associated with: - NSAIDs - lithium/gold - post allergy - Hodgkin's
minimal change disease histology
no significant change under light microscopy
under electron microscopy: podocyte fusion (foot process effacement)
minimal change disease presentation
frothy urine
low albumin
preserved renal function
= nephrotic syndrome
minimal change disease treatment
corticosteroids calcineurin inhibitors (tacrolimus)
membranous glomerulonephropathy histology
sub-epithelial deposition of immune complexes
basement membrane thickening, widespread (caused by immunoglobulin deposition)
abnormal mesangial matrix causes hyalinisation of glomerulus and death of individual nephrons
membranous glomerulonephropathy causes
- idiopathic (85%)
- autoimmune disease: SLE, RA, ankylosing spondylitis, post transplant
- infection: hep B, syphilis, hep C, malaria
- drugs: mercury, captopril, gold, heroin
membranous glomerulonephropathy presentation
nephrotic syndrome
AKI / CKD
membranous glomerulonephropathy treatment
underlying cause
steroids
calcineurin inhibitors
focal segmental glomerulosclerosis presentation
proteinuria or nephrotic syndrome
later develop: haematuria and hypertension
most develop CKD within 10 years
focal segmental glomerulosclerosis causes
primary
- idiopathic
secondary
- familial - reoccurs after transplantation
- virus - HIV
- drugs - heroin, pamidronate
- obesity, HTN, atheroemboli, sickle cell anaemia
focal segmental glomerulosclerosis treatment
primary and familial: immunosuppression and BP control
treat secondary underlying cause
symptoms and signs of nephritic syndrome
oliguria/anuria hypertension fludi retention - seen as facial oedema haematuria - microscopic or macroscopic uraemia proteinuria
patients may also complain of: loin pain, headache, general malaise
nephrotic vs nephritic syndrome
nephrotic: characterised by massive loss of protein causing various complications
nephritic: may be some proteinuria, more importantly there is haematuria, oliguria and hypertension
primary causes of nephritic syndrome
mesangial proliferative GN
diffuse proliferative GN
crescentic (rapidly progressive) GN
membranoproliferative / mesangial capillary GN
secondary causes fo nephritic syndrome
SLE
Wegner’s granulomatosis
microscopic polyangiitis
mesangial proliferative GN causes
can occur in several diseases: IgA nephropathy, IgM nephropathy, lupus
mesangial proliferative GN presentation
variable
haematuria
nephrotic syndrome?
AKI / CKD
mesangial proliferative GN treatment
depends on cause
steroids
mycophenolate mofetil
cyclophosphamide
diffuse proliferative GN
IgG, IgM, C3 deposition
presents with AKI, haematuria
diffuse proliferative GN causes + treatment
endocarditis
post-streptococcal GN
treat underlying infection
crescentic GN (rapidly progressive) histology
fibirin leaks, stimulating endothelial cells and macrophages in Bowman’s capsule to proliferate and create crescent shaped masses
reduces glomerular blood glow
seen as a part os systemic illness
crescentic GN causes
ANCA-associated - related to small vessel vasculitis
- granulomatosis with polyangiitis, Wegner/s granulomatosis
- GDM disease (Goodpasteurs)
aggressive IgA nephropathy
crescentic GN treatment
strict BP control ACE inhibitors for proteinuria >1g/day immunosuppression: - steroids - cyclophosphamide - mycophenolate mofetil - rituximab
membranoproliferative / mesangial capillary GN histology
diffuse global membrane thickening and mesangial proliferation
membranoproliferative GN presentation
asymptomatic haematuria or combined with nephrotic/nephritic syndrome
membranoproliferative GN causes
primary (mostly)
secondary: hep C, endocarditis, viral infections, malaria, sickle cell disease
membranoproliferative GN treatment
strict BP control ACE inhibitors for proteinuria >1g/day immunosuppression: - steroids - calcineurin inhibitors - mycophenolate mofetil - rituximab