Microscopic exam Crystals

Iatrogenic

Iatrogenic

pertaining to a condition caused by treatment, meds, or diagnostic procedures

What "environmental" factors allow for crystals to form/dissolve?

- temp (more at low temp)
- solute conc.
- pH

uric acid crystals

Found in acid urine
Pleomorphic; red-brown
May find with gout or chemotherapy

In what pH would you see uric acid crystals?

< 5.5

What is the significance of uric acid crystals?

- chemo
- Gout
- Lesch-Nyhan syndrome

Calcium oxalate crystals

Found in acid urine
Colorless, refractile 'envelopes'

pH for calcium oxalate crystals

acidic to neutral

Monohydrate calcium oxalate crystals cause:

anti-freeze poisoning

Calcium oxalate crystals are a major component of what?

renal calculi

amorphous urate crystals

Found in acid urine that's been in the fridge
Pink macroscopic precipitate
Can be dissolved by warming

In wat specimens would you expect to fine amorphous urate crystals?

refrigerated urines

pH for amorphous urate crystals

acidic pH down to 5.5

What, macroscopically, can be seen with amorphous urate crystals?

pink sediment (uroerythrin)

Amorphous Phosphate Crystals

Where would you find amorphous phosphate crystals?

- refrigerated urine (doesn't dissolve after warming)
- alkaline urine

Triple Phosphate Crystals

Found in alkaline urine
'Coffin lids' or feathery, fern-leaf

Calcium Phosphate Crystals

Found in alkaline urine
Prisms, tapered at one end

Calcium Carbonate Crystals

dumbell shaped, alkaline urine

Ammonium Biurate Crystals

-Yellow brown "thorny apples"
-will convert to uric acid when acetic acid is added
-Alkaline pH
-Old specimen

Cystine Crystals

Abnormal, found in rare amino acid disorder (Cystinuria)
Colorless hexagonal plates

How can you confirm cystine crystals?

cyanide nitroprusside

Cholesterol Crystals

Abnormal, found in nephrotic syndrome, lipiduria
Flat plates with notched corners

What are the crystals of liver disease?

Leucine, Tyrosine, and Bilirubin

Leucine Crystal

- yellow/brown spheres w. radial striations
- seen with tyrosine crystals
- acidic

Tyrosine crystals

- needles in clumps/rosettes
- seen w/ pos. bilirubin
- acidic

Bilirubin Crystals

- made of conjugated bilirubin
- liver disease, tubular damage, viral hep

Sulfonamide Crystals

What is the clinical significance of Sulfonamide crystals?

- UTI treatment
- if in fresh, tubular damage

Radiographic Dye Crystals

- similar to cholesterol crystals, polarize
- patient history
- very high SG with refractometer

Ampicillin Crystals

Ampicillin crystals appear as colorless needles that tend to form bundles following refrigeration (massive dose check history)