Clinical Syndromes Overview Flashcards
Pretty much everything in this lecture is going to come up again...
Is there much protein in normal urine? What’s the normal range?
No, not much.
Normal range: 60-100mg/d (which I think means per “day”)
What’s the most abundant protein in normal urine?
Tam-Horsfall protein.
Two types of benign proteinuria?
Orthostatic (only occurs when standing)
Intermittent (excercise, fever, acute illness)
What’s the difference between microalbuminemia and macroalbuminemia?
Simply the quantity of albumin in the urine (the terms are confusing).
“Nephrotic-range” proteinuria means there’s even more.
3 “anatomic”ish categories of proteinuria?
Glomerular proteinuria (too much gets filtered). Tubular proteinuria (not enough gets reabsorbed). Overproduction proteinuria.
Albuminuria and low GFR are both predictors of bad outcomes.
We’re not surprised.
5 tests for analyzing protein in the urine?
24 hour urine collection (best, but hardest).
Urine dipstick (easiest, but most limited).
Spot collection.
Precipitation of urine proteins
Electrophoresis.
2 major limitations of testing for proteinuria with a dipstick?
It really only sees albumin.
It only assesses concentration. (so albumin will look high if urine volume is low, and vice versa)
How is proteinuria assessed with a spot urine? Clinical utility of this?
Protein:creatinine ratio is measured.
This is good for following the same patient over time, but not good for an absolute measure of protein because creatinine excretion will vary between people.
In urine protein electrophoresis, what’s the biggest protein found, and what’s the smallest?
Biggest: Albumin.
Smallest: Gammaglobulin aka. immunoglobulin.
Quick way to check for high levels of proteins (including non-albumin) in the urine?
Sulfosalicylic acid (SSA) test -> precipitates proteins if present.
How can you tell if the redness or brownness of urine is due to RBCs vs. hemoglobin vs. myoglobin vs. drugs/AIP/beets
Spin the urine: if supernatant clear, it was RBCs.
If the supernatant still is red/brown, test for heme.
What are acanthocytes? If present in urine, what process do they strongly suggest?
Dysmorphic RBCs with blebbing (sometimes “mickey mouse ears”) - not to be confused with schistocytes.
These strongly suggest glomerular inflammation.
What would blood in urine from a kidney stone look like?
Normal RBCs, no casts.
When do you see epthelial / squamous cells in the urine?
Ischemic or nephrotoxic injury to tubules, bladder, or other parts of collecting system.
3 things typically present in acute glomerulonephritis?
4 other things that are often present?
Hematuria.
RBC casts.
Proteinuria.
(Edema, HTN, reduced GFR, and systemic symptoms are also often present)
RBC casts are “almost pathognomonic” of what?
Acute glomerulonephritis.
3 classifications of nephrITIC disorders?
Immune complex deposition.
Anti-glomerular basement membrane Abs.
Pauci-immune (vasculitis).
Best way to see immune complex deposition?
Immunofluorescence on biopsy sammple.
Can also use EM.
What does crescentic glomerulonephritis suggest?
Rapidly progressive glomerulonephritis (RPGN).
What forms the crescent in crescentic GN?
Proliferating epithelial cells
What do people with nephrotic syndrome always have?
Heavy proteinuria.
edema, hypoalbuminemia, and hyperlipidemia are often present
4 classifications of nephrotic lesions?
covered in more detail in the non-inflammatory kidney disease lecture
Normal - “minimal change disease”.
Membranous.
Focal segmental glomerulosclerosis.
Other - diabetes, amyloid, light chain deposition,etc.
What’s the current definition of acute kidney injury (AKI)?
An abrupt decline in GFR.
-with this, you see increases in plasma Cr and BUN.
3 location-based categories of AKI?
Pre-renal (reduced renal perfusion).
Renal (GN, vasculitis, interstitium, tubules)
Post-renal (obstruction)
What’s a typical urine finding in acute tubular necrosis (ATN)?
Muddy brown casts
What are stages of chronic kidney disease (CKD) based on?
GFR
What are 80% of cases of CKD caused by?
Diabetes mellitus.
HTN.
(most of the rest is from GN and polycystic kidney disease)
What do most people with CKD die of?
Cardiovascular disease.. most die before reaching ESRD and needing transplant/dialysis.
Best treatment for CKD?
Aggressive blood pressure control.
