AUBF - Microscopic Examination

Third part or routine urinalysis that is mainly for the microscopic examination of the urinary sediment

Microscopic examination

Specimen volume for routine testing

10 and 15 mL ( average of 12 mL )

Cetrifugation of Urine

400 rcf / 2000 rpm for 5 minutes

The volume of sediment after decantation

0.05 to 1.0 mL

Enhancing nuclear details

Tolouidine blue

Lyses RBC's and enhances nuclei of WBC's

2% acetic acid

Triglycerides and neutral fats

Lipid stains: Oil red O and Sudan III

Gram positive

Gram negative

Gram stain

Eosinophilic granules

Hansel stain

Stain structures containing iron

Prussian blue stain

2 types of desiments

Organized

Unorganized

Organized sediments / Urine Sediment Constituents

RBC's

WBC's

Epithelial cells

Casts

Miscellaneous Structures

Smooth, non-nucleated, biconcave disks

Red blood cells

Gram positive

Violet or purple

Gram negative

Pinkish or reddish

Hypersthenuric urine

Crenated / Shrink

Hyposthenuric urine

Swollen / Ghost cells r Shadow cells

glomerular membrane damage

Dysmorphic cells

Normal RBC in urine

0-2/hpf

It measure an average of about 12 micrometers in diameter

WBC

Predominant type of WBC

Neutrophils

Increased white blood cells in urine

Pyuria

Seen in dilute or hypotonic urine (sparkling appearance)

Glitter cells

Neutrophils using Sternheimer-Malbin stain

Violet

Leukocytes using Sternheimer-Malbin stain

Light blue

Normal range of WBC in urine

0-5/hpf

Types of Epithelial cells

Squamous epithelial cells

Renal Tubular epithelial cells

Transitional epithelial cells

Largest cell in the sediment with abundant, irregular, cytoplasm, and prominent nuclei

Squamous epithelial cells

Clue cells

Vaginal infection by Gardnerella vaginalis

Also covered with coccobacillus

Purple or violet

It is smaller than squamous and has a centrally located nucleus

Transitional Epithelial Cells

It is usually round and is slightly larger than WBC's, with a single round eccentrically located nucleus.

Renal Tubular Epithelial Cells

It is the most clinically significant type of epithelial cells

Renal tubular epithelial cells

Significant number of RTE cells

At least more than 2 RTE/hpf

2 types of renal tubular epithelial cells

Oval Fat Bodies

Bubble cells

RTE cells with non-lipid containing vacuoles

Bubble cells

Lipid-containing RTE cells

Nephrotic Syndrome

Oval fat bodies

These are the only elements found in the urinary sediment that are unique to the kidney.

They are formed (gels) during urine flow statis, acidity and the presence of sodium and calcium

Casts

It is a glycoprotein that is produced by the RTE cells and is excreted at a constant rate

TAMM-HORSFALL PROTEIN (UROMDULIN)

It is the presence of casts in the urine

CLYNDRURIA

Types of casts

Hyaline casts

RBC Cast

WBC Cast

EPITHELIAL CELL CAST

GRABNULAR CAST

Waxy Casts

Fatty cast

BROAD CAST

Most frequently seen casts

It is colorless, homogenous, and has the same refractive index as urine

Consists almost entirely of Tamm-Horsfall protein

Presence of 0-2 is normal

Hyaline Casts

Orange-red in color

Cast matrix containing rbc's

- Glomerulonephritis

RED BLOOD CELL CAST

Cast matrix containing wbc's

It signifies infection or inflammation within the nephron

- Pyelonephritis

WHITE BLOOD CELL CAST

Renal tubular attached to protein matrix

Renal tubular damage

EPITHELIAL CELL CAST

Coarse and fine granules in a cast matrix

Glomerulonephritis, Pyelonephritis

GRABNULAR CAST

Highly retractile cast with jogged ends notches

Chronic renal failure, statis of urine flow

WAXY CAST

Fat droplets and oval fat bodies attached to protein matrix

Nephrotic Syndrome

FATTY CAST

Most commonly seen broad casts are granular and waxy casts

BROAD CAST

Miscellaneous structures that are found in urine

Mucus Threads

Bacteria

Yeast cells

Parasites

Spermatozoa

Long, thin, wavy threads of ribbon like-structures produced by glands and epithelial cells in genitourinary tract and RTE cells

The major constituent of mucus threads in the Tamm-Horsfall protein

No clinical significance when present in either female or male urine

Mucus Threads

To be considered significant, for UTI, bacteria should be accompanied by WBC.

It is confirmed with a positive urine culture.

Presence in indicative of lower or upper UTI

Bacteria

Small, refractive oval structures that may not contain a bud

Smooth, colorless, usually ovoid cells with double refractile walls

Insoluble in alkali and acid and will not stain with eosin

Yeast cells

Most frequent parasite encountered in the urine, associated with "PING-PONG DISEASE"

Trichomonas vaginalis

May cause hematuria because it lacerates the bladder

Schistosoma haematobium

Most common fecal contaminant

Enterobius vermicularis

Found in the urine after sexual intercourse, nocturnal emissions.

(+) Protein reagent strip in increase amount of semen

Spermatozoa

Urine Artifacts

Starch from gloves

Droplet

Air bubble

Pollen

Fiber

Hair & (granular cast)

Fecal contamination

Unorganized Sediments

crystals

These are formed by the precipitation or urine solutes: inorganic salts, organic compounds, medications

Crystals

It is the most valuable parameter in the identification of crystals

pH

Average and reported per LPF

Abnormal crystals

Rhombic, four-sided flat plates, wedges, rosettes and lemon-shaped.

Yellow brown, but may be colorless and have a six-sided shape.

Similar to cysteine crystals.

Uric acid

uric acid increased in

Lesch-Nyhan syndrome

Leukemia patiens

Gout

Octahedral square with diagonal lines

Colorless envelopes

Oxalate crystals

Octahedral or envelope shaped

DIHYDRATED/WEDDELIT

Dumbbell or ovoid

MONOHYDRTE

2 forms of Calcium Oxalate

Dihydrated

Monohydrate

Brick dust/yellowish-brown granules, often in clumps

in acidic urine

Amorphous urates

Alkaline urine crystals:

Amorphous phosphate

Ammonium biurate

Triple phosphate

Calcium phosphate

Calcium carbonate

Acidic urine crystals

Uric acid

Calcium oxalate

Amorphous urate

Found in alkaline urine

Looks the same as amorphous urates microscopically

Can't be dissolved by warming

Amorphous phosphate

Yellow brown "thorny apples"

Will convert to uric acid when acetic acid is added

Alkaline pH

Old specimen

Ammonium biurate

Found in alkaline urine

'Coffin lids' or feathery, fern-lea

Triple phosphate

Found in alkaline urine

Colorless, prisms, tapered at one end

Calcium phosphate

Colorless, dumbell shaped

May occur in clumps that resemble amorphous material but they can be distinguished by the formation of gas after that addition of acetic acid.

Calcium carbonate

Abnormal Crystals in Urine:

Cystine

Cholesterol

Leucine

Tyrosine

Bilirubin

Sulfonamides

Ampicilin

Six sided puffy crystals

Colorless hexagonal plates

Often mistaken with uric acid

Cystine

Abnormal, found in nephrotic syndrome, lipiduria

Staircase pattern or Broken Window Panes

Cholesterol

Abnormal, found in liver disease

Fine, delicate needles

Tyrosine

Abnormal, found in severe liver disease

Dark yellow/brown spheres with radial striations

Leucine

Abnormal, found in bilirubinuria (hepatic and posthepatic jaundice)

Delicate red-brown needles

Bilirubin crystals

Associated with sulfa meds and decreased hydration.

Yellow to brown.

Bundles of sheaves, whetstones and rosettes:

Confirm with diazo reaction

Sulfonamides

Appear as colorless needles that tend to form bundles following refrigeration

Ampicillin