Pathophys and Clinical Nephrotic Syndrome Flashcards
What is the upper limit of normal protein excretion per day?
100 mg per day, with an average concentration of 7 mg/dl
What is the breakdown of normal protein in urine?
plasma protein (50%) and tissue origin protein (50%)
plasma protein is mostly albumin
Define postural proteinuria
Postural proteinuria is observed only when the subject assumes an upright or lordotic position. It may be associated with mild glomerular histological abnormalities, but there is no evidence linking this finding with significant renal disease.
Define persistent proteinuria?
Persistent proteinuria is present when several urine collections obtained with the subject supine at rest contain detectable protein.
What shape is the permselectivity curve that defines fractional clearance of a solute?
sigmoidal - upper limit is 56 angstroms in size
What is steric hindrance?
size selective permeability
How does convection lead to macromolecule movement across a barrier?
dragged across by increased filtration
How does diffusion lead to macromolecule movement across a barrier?
down a concentration gradient
A patient who has strong perfusion of fluid through the glomerular filter may pass more protein by: convection or diffusion?
convection
a patient who is dehydrated may filter more protein by: diffusion or convection?
diffusion because dehydration concentrates the plasma proteins.
Where is urumucoid protein (tamm horsfall protein) added to the urine?
the distal tubule
Define primary nephrotic syndrome
persistent proteinuria caused by selective mechanisms that affect handling of protein
What are examples of nephrotic diseases caused by decreased tubular REABSORPTION of protein?
Fanconi syndrome Dent disease tubulointerstitial nephritis drugs toxins
What processes would cause overflow proteinuria in the setting of normal renal function?
repeated albumin infusions or blood transfusions; myeloma,leukemia
What are the four findings that define nephrotic syndrome?
- proteinuria
- hypoproteinemia/hypoalbuminemia
- edema
- hypercholesterolemia
What is the cut off for hypoalbuminemia?
serum albumin of less than 2 gm/dl