5 Microscopy of urine (cells, etc)

RBC normal

• 7 micron

• 0-2/hpf

Crenated RBC

occurs in concentrated urine

Ghost cells

• in dilute urine

• Not included in microscopic count

Acetic acid

• used to distinguish RBC from oil, air bubbles, yeast, WBC

• Will lyse RBC only

Hematuria

RBC in urine

Strip Blood neg limit of RBC

>4 RBC/hpf (possible negative RBC on strip)

Dysmorphic RBC

• Cellular protrusions, vary in size, fragmented

• Associated with Glomerular bleeding (RBC squeezing through glomerulus)

  • Second tech/or specialist must review and confirm

  • Rarely seen due to strenuous exercise

WBC normal

• 12 micron

• 0-5/hpf

• usually PMN

WBC in hypertonic solution

• Shrunk cells

• False negative for leukocyte esterase on strip

WBC in hypotonic solution

Glitter cell (swollen WBC with granules)

Pyuria

increase in WBC’s in urine

WBC in urine cause

infection or inflammation

Lymphocytes

• Small, may resemble RBC - but has nucleus

• Seen in early stages of renal transplant rejection

Eosinophils

• Usually not in urine

• >1% of WBC is clinically significant

• Causes

  • Drug-induced acute interstitial nephritis (AIN) (primary reason)

  • UTI

  • Parasitic infection

  • renal transplant rejection.

Eosinophil stain

Wrights stain or Hansel stain

Squamous cell

Epithelial cell from urethra

• largest of epithelial cell

• no pathology if found in urine

Transitional cell

Epithelial cell from renal pelvis, calyces, ureters, bladder, and upper portion of the male urethra

• smaller than squamous, similar to RTE but usually with more defined cell edge and central nucleus

• Normal <0-2 /hpf

• Nonpathological increase: invasive procedures like catheter

• Pathological: cells w/ abnormal morphology from malignancy or viral infection

Renal tubular cell (RTE)

Epithelial cell from inside kidney (renal tubules)

• Usually smallest epithelial cell, but bigger than WBC

  • size and shape variation: cuboidal, columnar or round (usually not round and has flattened side)

  • eccentric nuclei

• Reabsorbs material from glomerular filtrate, can cause them to die and slough off

• 0-2/hpf = normal

• >2/hpf = damage or necrosis to renal tubules

  • Infection, drug toxicity, heavy metals, allergic reactions

Clue cells

Squamous epithelial cells covered in Gardnerella vaginalis

• from bacterial vaginosis

• usually not reported in Urine results

Yellow RTE

RTE reabsorbed bilirubin from glomerular filtrate and sloughed off into urine

Yellow brown RTE

RTE reabsorbed hemosiderin from glomerular filtrate and sloughed off into urine

Oval fat bodies

RTE reabsorbed lipids from glomerular filtrate and sloughed off into urine

• seen in lipiduria, free fat droplets and/or fatty casts also seen

Lipiduria

Lipid (cholesterol or triglyceride) in urine

Causes:

• Nephrotic syndrome: damage to glomerulus (most common)

• Tubular necrosis (most common)

• Diabetes melitus (rare)

• Trauma (bone marrow fat leak)

• Oval fat bodies from histocytes (instead of RTE) are seen in lipid storage diseases

Oil Red O or Sudan III

lipid stain that only stains triglycerides and not cholesterol

Maltese cross

Polarized cholesterol will show this pattern. Triglycerides will not.

Confirmation of oval fat bodies

Both Sudan stain and polarized light check must be done to check for triglyceride and/or cholesterol

Oval fat bodies can be confused with starch or crystals

Cause of bacteria in urine

• sample left in RT >2h

• Collection method bad

• UTI !!

tests that coincide with bacteria in urine

• Leukocyte esterase +

• Nitrite +/=

• follow up with urine culture

Yeast in urine

• can be confused with RBC —> use acetic acid

• If INFECTION. Leukocyte esterase should be + or WBC should be observed

  • more common in patients with diabetes mellitus, immunocompromised patiernt

• Usually contaminant from bad collection or vaginal yeast infection

Mucus in urine

• produced by glands and RTE cells

• major constituent: tamms-horsfall protein

• More in female sample > male sample

• NOT CLINICALLY SIGNIFICANT

Increased amounts of semen may produce a ____ protein on the reagent strip test

Positive