AUBF- URINE CRYSTALS

to detect the presence of few abnormal types that may represent disorders caused by crystallization of medications compounds within the tubules.

The primary reason for the identification of urinary crystals is

Rare, few, moderate, or many per hpf

Urine crystals reported as

caused by medications or treatments

Iatrogenic

Crystal formation

Urinary solute increase + Ability to remain in solution decrease =

refrigerated acid urine

Amorphous urates form in

refrigerated alkaline urine

Amorphous phosphates form in

Heat

Amorphous urates dissolves with

Acetic acid

Amorphous phosphates dissolve with

Urine pH

The first consideration when identifying crystals

amorphous urates, uric acid and sodium urates

Most common crystals seen in acidic urine

Yellow to reddish brown

Color of crystals in acidic urine

a pH greater than 5.5

Amorphous urates found in urine pH with

Amorphous urates (Acidic)

-Yellow-brown granules microscopically
-Pink sediment due to pigment uroerythrin
-pH greater than 5.5

Uric Acid Crystals (Acidic)

-Shapes: rhombic, four-sided flat plates, wedges, and rosettes.
-Color: Yellow- brown, may be colorless
-Highly birefringent under polarized light.
-↑ purines, nucleic acids
-Can be seen with patients receiving chemotherapy for leukemia, gout.

Calcium Oxalate Crystals (Acidic)

-Acid/neutral (alkaline)
-Common form: dihydrate or colorless, pyramid like
-Monohydrate is oval or dumbbell shaped; ethylene glycol poisoning.
- can relate to renal calculi

Amorphous Phosphates (Alkaline)

- Similar to amorphous urates
- Alkaline pH and heavy white precipitate after refrigeratio

Triple Phosphate (Alkaline)

-prism shape "coffin lid"
-Highly alkaline urine and urinary tract infections (UTIs)
-colorless

Calcium Phosphate(Alkaline)

-may appear colorless

-rosette form

-Calcium phosphate crystals dissolve in dilute acetic acid and sulfonamides do not.

-common constituent of renal calculi.

Calcium Carbonate (Alkaline)

- Small, dumbbell, and spherical shapes , colorless
- Gas produced with addition of acetic acid
- No clinical significance

Ammonium biurate crystals (Alkaline)

-thorny apple appearance
- Yellow-brown, spicule-covered spheres
-old specimens
-may be associated with the presence of the ammonia produced by urea-splitting bacteria

Cystine Crystals

-found in persons who inherit metabolic disorder prevent reabsorption of cystine
-Hexagonal, thin and thick plates
-Seen in cystinuria: inability to reabsorb cystine
-Confirmation by: Cyanide nitroprusside

Cholesterol Crystals

-seen in refrigerated specimens
-Rectangular plates with characteristic notched corners
-associated with disorders producing lipiduria (Nephrotic S. ,fatty casts, & Oval fat bodies)

Radiographic Dye Crystals

Very high specific gravity

Similar to cholesterol crystals, polarize

Tyrosine crystals

Fine yellow needles in clumps or rosettes

Seen with leucine crystals

Seen w/ Inherited amino acid disorders

Leucine crystals

Yellow-brown spheroids with concentric rings and radial striations in the center

when present, should be accompanied by tyrosine crystals

Bilirubin crystals

present in hepatic disorders (Viral Hepatitis) producing large amounts of bilirubin in the urine

Color: Yellow

Clumped needles or granules

Sulfonamide Crystals

Seen in patient treated for UTI

Possibility of tubular damage if crystals are forming in the nephron

Shapes and Color: needles, rhombics, whetstones, sheaves of wheat, and rosettes with colors ranging from colorless to yellow-brown

Ampicillin Crystals

Colorless needles that tend to form bundles following refrigeration

Urinary Sediment Artifacts

Material fibers, meat
and vegetable fibers,
and hair

Starch, oil droplets, air
bubbles, pollen grains,
vegetable fiber, hair,
diaper fiber

SULFONAMIDE

AMPICILLIN

URIC ACID

CHOLESTEROL

SULFONAMIDE

CALCIUM OXALATE

TRIPLE PHOSPHATE

TYROSINE

CYSTINE

LEUCINE

AMMONIUM BIURATE

BILIRUBIN