UA

Question 1

What are these?

Answer 1

Calcium oxlate crystals

Question 2

How long after urine collection should UA be run to be considered fresh?

Why do you centrifuge the sample?

Answer 2

60 min

Produce supernatant for dipstick and sediment for light microscopy

Question 3

Specific gravity vs. urine osmolarity

Answer 3

SG = weight and number of solutes in urine

Osm = number of solutes in urine

Question 4

What is the max dilution possible for urine in SG and osm?

Answer 4

1.002

~50

Question 5

What is the max concentration of urine in SG and osm?

Answer 5

1.030

1200

(urine can’t be more concentrated than medullary interstitium tonicity)

Question 6

What is the normal pH range of urine?

Under what condition would be it be >7.5?

Answer 6

5.0-6.5

UTI with urea-splitting bacteria (Klebsiella, proteus)

Question 7

What is the most common type of nephrolithiasis?

Answer 7

Calcium oxlate

Question 8

What happens to urine pH in a pt with metabolic acidosis?

Answer 8

<5.3

Question 9

Diagnosis for each pt?

Pt 1: UA shows glucose+ and BS is 190

Pt 2: UA shows glucose + and BS is 90

Answer 9

Pt 1 = DM

(Tm of glucose transporters exceeded when BS>185)

Pt 2 = Proximal tubular dysfunction

(normal BS with glucosuria = problem with PT)

Question 10

Fanconi’s syndrome (multiple myeloma, heavy metal poisoning) is associated with which UA finding?

Answer 10

Glucosuria

Question 11

What this is?

What causes this appearance?

Answer 11

Crenated RBCs

RBCs in concentrated supernatant = loss of cell volume

Question 12

Three conditions causing ketonuria

Answer 12

Fasting

DKA

Alcoholic ketoacidosis (AKA)

Question 13

What ketoacids are picked up by dipstick?

What would be the tonicity of urine of such a pt?

Answer 13

Acetate, acetoacetate

Hypotonic (ketoacids cause osmotic diuresis)

Question 14

What would you see in the urine of pt with liver dz?

Answer 14

Unconjugated bilirubin, urobilinogen,

(conjugated bilirubin is water insoluble so not in urine)

Question 15

What disease may cause this?

Answer 15

Homocystinuria

(flat, 6-sided crystals)

Question 16

What would cause + nitrite on UA?

What other finding might you expect?

Answer 16

UTI by nitrate-reducing bacteria (Gram -)

pH 7.5-8

Question 17

What organism is the most likely cause of a + urine nitrite?

Answer 17

E coli

Question 18

What would you expect to see on a UA of a pt with SLE?

Can a UTI cause the same finding?

Answer 18

Leukocyte esterase

(+ when increased # of PMNs in urine)

Yes

Question 19

What is this?

Answer 19

Fatty casts

Question 20

The most excreted protein under normal conditions also make up what type of cast?

Answer 20

Hyaline cast

(Tamm-Horsfall protein)

Question 21

Normal protein excretion is <___ mg/d of what types of protein?

Answer 21

< 150mg/day of Tamm-Horsfall protein, LMW protein, and micro-albumin

Question 22

What would you order to get a qualitative measure of urine protein? Quantitative?

Answer 22

UA

24 hr urine collection

Question 23

What can we use to estimate quantitative proteinuria since 24 hour collection is difficult?

What value suggests nephrotic syndrome?

Answer 23

Spot urine sample (urine protein:creatinine)

5g/24hr = nephrotic range

Question 24

What disease can cause this?

Answer 24

ATN, nephrotic syndrome, chronic renal failure

(granular cast)

Question 25

What protein is measured by dipstick? How can you measure all protein?

Answer 25

Albumin Sulfosalicyclic acid

Question 26

+ sulfosalicyclic acid test means what? Give an example of disease that could cause this.

Answer 26

Tubular proteinuria (LMW proteins exceed reabsorptive capacity of PT) Light chain proteinuria (Bence-Jones proteins) in multiple myelome

Question 27

3+ dipstick proteinuria suggests what?

Answer 27

Glomerular proteinuria (increased permeability of glomerulus so albumin can get through)

Question 28

What is overflow proteinuria? What would you see on UA?

Answer 28

Excess production of LMW proteins exceeds resorptive capacity of PT - dipstick (albumin can't get through intact glomeruli), + sulfosalicyclic acid

Question 29

How to tell glomerular vs tubular proteinuria

Answer 29

Glomerular = + dipstick, + sulf acid, albumin Tubular = - dipstick, + sulf acid, LMW protein

Question 30

What is this composed of?

Answer 30

Tamm-Horsfall protein | (Hyaline cast)

Question 31

What would you measure on UA to assess kidney stones?

Answer 31

Calcium, phosphorus, uric acid

Question 32

- urinary anion gap = + urinary anion gap =

Answer 32

- = high urinary NH4+ = GI loss of bicarb + = low urinary NH4+ = RTA = unable to excrete acids (NH3 binds H+ in lumen when acid is secreted)

Question 33

How do you calculate urinary anion gap and under what condition do you? How does this compare to the calculation for plasma anion gap?

Answer 33

UAG = Na + K - Cl; to determine hyperchloremic MA PAG = Na - HCO3 - Cl

Question 34

What finding is pathognomonic for nephrotic syndrome?

Answer 34

Fatty casts Maltese crosses on bifringence

Question 35

How do you determine if + blood on UA is due to RBC or myoglobin/Hb?

Answer 35

Look for RBC in sediment, which will be absent if due to myoglobin/Hb

Question 36

UA + for blood most likely due to:

Answer 36

Presence of RBC in sediment

Question 37

Are RBC normally found in urine? What would cause myoglobin or Hb to show up in urine?

Answer 37

Yes, 0-2 RBC/hpf Rhabdo or hemolysis, respectively

Question 38

What is causing the + blood on dipstick? No RBC casts, normal RBCs in sediment, clots in urine, albumin -

Answer 38

Extra-renal cause (i.e. hemorrhagic cystitis, bladder CA, menstruation)

Question 39

UA findings of pt with glomerulonephritis: Blood? RBC casts in sediment? If so, shape? Protein? Clots?

Answer 39

+ +, dysmorphic + -

Question 40

Why is proteinuria associated with glomerular cause of hematuria but not extra-renal causes?

Answer 40

Duh! If glomerulus is messed up enough that blood gets through, protein will get through, too. If blood is extra-renal, the glomerulus is fine and won't filter blood or protein!

Question 41

What is pathognomonic for renal dysfunction?

Answer 41

RBC casts (if absent, look for extra-renal cause of hematuria)

Question 42

Name some causes of RBC casts.

Answer 42

Glomerulonephritis (IgA nephropathy, PSGN, Goodpasture) Malignant HTN Renal ischemia Vasculitis

Question 43

Why are RBCs dysmorphic in the sediment of pt with renal origin hematuria?

Answer 43

They get beat up as the pas through the glomerulus

Question 44

What is this?

Answer 44

WBC cast (Granular cytoplasm, irregular nuclei)

Question 46

What type of cell in urine is called "glitter cell"? Why? Causes of this finding?

Answer 46

WBC, intracellular components shine in fresh specimen Anything inflammatory = UTI, pyelonephritis, allergic interstitial nephritis, intense glomerulonephritis, Lupus

Question 47

What is the largest cell in the field?

Answer 47

Tubular epithelial cell (hard-boiled egg; not a great example)

Question 48

What does this finding tell you about renal function?

Answer 48

Nothing! This is a squamous epithelial cell (abundant cytoplasm) and is found lining the lower urinary tract = nothing to do with kidney

Question 49

What is hallmark finding of ATN?

Answer 49

Tubular epithelial cell (hard-boiled egg; think: if tubule is necrotizing, you should see the cells in the urine)

Question 50

A marathon runner is likely to have what cast after finishing a race?

Answer 50

Hyaline cast | (Volume depletion = hyaline cast)

Question 51

What is the matrix of all casts? Where is this produced?

Answer 51

Tamm-Horsfall protein in TALH

Question 52

Dx?

Answer 52

Chronic kidney disease (waxy cast = large, white outline, sometimes cracked, acellular, sharp broken ends)

Question 53

What are the arrows pointing to? What would cause this finding?

Answer 53

WBCs, inflammation

Question 54

Name two conditions that could cause this finding

Answer 54

Tumor lysis syndrome, gout | (uric acid cystals = rhomboid)

Question 55

What are "coffin-lid crystals"? Cause?

Answer 55

Triple phosphate Infection

Question 56

Dx?

Answer 56

ATN (ethylene glycol, acute transplant rejection, heavy-metal poisoning) (hard-bolied egg)

Question 57

Dx?

Answer 57

Nephrotic syndrome (fatty casts are pathognomonic for nephrotic synd)

Question 58

Why do these casts form?

Answer 58

Breakdown of cellular debris Very non-specific finding, can be ATN, nephrotic syndrome, chronic renal failure

Question 59

Answer 59

Ca ox crystals

Question 60

Casts associated with ATN?

Answer 60

Tubular epithelial (hard-bolied egg) Granular

Question 61

Name a condition in which you would see these in urine?

Answer 61

WBC

Question 62

Dx?

Answer 62

Chronic renal failure

Question 63

Dx: Urine with protein and lipid

Answer 63

Nephrotic syndrome

Question 64

Dx: Protein, hematuria, RBC casts

Answer 64

Nephritic syndrome

Question 65

Dx: Hematuria, heavy proteinuria, RBC casts, lipiduria

Answer 65

Mixed nephrotic/nephritic syndrome

Question 66

Dx: Granular casts, SG 1.010, hematuria

Answer 66

Tubular damage (can also have tubular epithelial cells)

Question 67

Why does tubular injury cause SG of 1.010?

Answer 67

Lose ability to concentrate urine so it matches osmolarity of plasma, 300 mOsm ~ 1.010

Question 68

What is pyuria?

Answer 68

Pus in urine

Question 69

Sterile pyuria

Answer 69

Inflammatory tubulitis

Question 70

Dx: Pyuria, bacturia, hematuria, SG 1.010

Answer 70

Pyelonephritis