Nephrotic syndromes Flashcards
features of adult minimal change dx
age>45 yrs
sudden onset of symptoms
hypertension (43%)
laboratory data that support nephrotic syndrome
nephrotic range proteinuria >3g/day
serum albumin <2.2 g/dl
serum cholesterol is >420 mg/dl
see AKI (18%)
when do we see adult minimal change dx
after upper resp infection and after some infections.
what is seen on urinalysis with minimal change dx?
nothing on light microscopy
seen in minimal change dx
no RBCs or casts on UA
maintained GFR and normal BP
electron microscopy of kidney with minimal change dx
see effacement of podocyte foot processes
renal biopsy of minimal change dx
normal appearing glomeruli and no immune deposits by immunofluorescence
does a pt who presents with nephrotic syndrome suggestive of minimal change dx need a renal biospy?
yes because clinical phenotype doesn’t accurately predict renal histopathology and so most adults with non diabetic nephrotic syndrome need renal biopsy to confirm diagnosis and guide therapy.
nephrotic syndrome diagnostic criteria
24 hr urinary protein >3.5 g/day edema hypoalbuminemia <3g/dl hyperlipidemia lipiduria
causes of nephrotic syndrome
minimal change dx focal segmental glomerulosclerosis membraneous nephropathy amyloidosis diabetic nephropathy
complications of nephrotic syndrome
protein malnutrition hypovolumia VTE- especially the renal vein) infection (pneumococcal) proximal tubular dysfunction causing vitamin D deficiency
Why are nephrotic syndrome pts at greater risk for VTE?
due to urinary loss of antithrombin 3 and plasminogen and increased levels of fibrinogen and platelet activation
most common cause of nephrotic syndrome?
membranous nephropathy (seen in Hep B)
carries highest risk of VTE with up to 60% of pts developing renal vein thrombosis
Who has highest risk for renal vein thrombosis?
pts who have >10 g/day of urinary protein and <2g/dl of serum albumin
seen in menbranous nephropathy pts
chronic renal vein thrombosis presentation
can be chronic, asymptomatic, often not associated with worsening renal function or proteinuria and thrombosis can propagate to inferior vena cava and embolize to the pulmonary vasculature and cause PE (which can be only manifestation of chronic renal vein thrombosis)
acute renal vein thrombosis presentation
pain hematuria and renal failure
Diagnosis of renal vein thrombosis
selective venography, doppler ultrasound, CT scan or MRI
should we routinely screen those with membranous nephropathy for renal vein thrombosis?
no.
treatment of renal vein thrombosis?
anticoagulation
what is Pickering syndrome?
flash pulmonary edema from bilateral renal ARTERY stenosis and this is associated with hypoxia, severe HTN and JVD.
focal segmental glomerular sclerosis + HTN and edema should be treated with
ACE i because they have >1g/day of daily protein excretion into the urine which causes a more rapid decline in GFR than kidney function regardless of initial GFR or primary cause of renal dysfunction
membranous nephropathy is
most common cause of nephrotic syndrome in NON diabetic pts
prognosis of idiopathic membranous nephropathy
1/3 has spontaneous partial remission,
1/3 has partial remission <2g protein per day and 1/3 progressing to ESRD in 5-10 years
risk factors for progressive idiopathic membraneous nephropathy is
male sex
age >50 yrs
nephrotic range proteinuria and increased GFR
patients with idiopathic membraneous nephropathy and risk for becoming progressive
treat with cytotoxic or calcineurin inhibitors
cyclophosphamide with prednisone
newly diagnosed pts with membraneous nephropathy are:
observed for 6 to 12 months while on conservative therapy to see if there’s spontaneous remission before initiating immunosuppression.
most cases of membraneous nephropathy are:
primary 75%
25% - secondary causes SLE, hep B or C infection and solid tumors.
Pre eclampsia and sickle cell dx can have it
Presentation of nephrotic syndrome on physical exam:
facial and lower extremity swelling anasarca ascites pleural effusions foamy urinalysis hematuria and may see HTN
when working someone up for nephrotic syndrome you should get:
UA
urine protein measurement
serum albumin
serological work up for infection and immune abnormalities
need renal u/s to eliminate the differential diagnosis
nephrotic syndrome is classified by steroid:
steroid sensitive
steroid resistant
steroid dependent
frequently relapsing
maintstay of treatment is corticosteroids, cyclophosphamide and cyclosporine
what medication can cause nephrotic syndrome?
NSAIDS over a long period of time.
