Urinalysis a comprehensive review

Outline:
• Collection and Handling of urine sample
• Types of urine specimen
• Physical & chemical examination of urinalysis
• Discrepancies in urinalysis
• Microscopic examination of urine sediment
• Quiz…
Alyazeed hussein, BSc-SUST
A Comprehensive Review of Urinalysis
Medical Laboratory
Science

Urinalysis
 A complete urinalysis is composed of multiple tests, including macroscopic, physical, chemical, and microscopic
examination.
 Specimen Collection and Handling: Use clean, dry container, receive and analyze the sample within 2 hours!!?
 Types of urine specimen:
1. Random urine: Most common type, for routine tests.
2. First morning: Concentrated specimen used for routine screening, pregnancy test.
3. Fasting & 2-Hour postprandial: for DM(insulin monitoring), 2 hours after eating.
4. 24-Hour: Collected over a period of 24 hours for creatinine clearance, Glomerular Filtration Rate (GFR).
5. Midstream clean-catch (MSU): urine collected in the middle of urination; used for bacterial culture.
6. Catheterized: Collected from a tube placed through the urethra into the bladder; used for bacterial culture and
routine screening.
7. Suprapubic aspiration: Needle inserted into the bladder through the abdominal wall; used for bacterial culture and
cytologic testing.
8. Pediatric collection: Use small, clear plastic bags with adhesive to adhere to the genital area.

URINE SPECIMEN STORAGE AND HANDLING
• Most common form of preservation, refrigeration at 2°C to 8°C, is suitable for the majority of specimens. Any
urine specimen for microbiological studies should be refrigerated immediately if it cannot be transported directly
to the laboratory, the specimen remains suitable for culture for up to 24 hours.
• Before testing, urine must be brought to room temperature.
• Other preservatives are: Boric acid (acceptable for culture), Thymol (cells & casts), formalin (cellular preservative)

Physical examination of urine
(Color, Appearance and Specific gravity)
A. color:
1. Pale yellow & yellow: normal color of urine(urochrome: urobilin).
2. Colorless: may due to dilution, or Diabetes Meletus.
3. Dark yellow: may due to dehydration, or First morning( concentrated), usually with high specific
gravity.
4. Orange or dark yellow-amber: Bilirubinemia occurs from liver problems, such as hepatitis >
bilirubinuria, yellow foam forms when urine is shaken due to the presence of conjugated
bilirubin. Smith iodine test positive (green ring), hay's test (sulfur powder) positive.
5. Red/pink: (RBCs, (hemoglobin-brown and myoglobin-muscle) or menstrual contamination.
6. Green/blue: medication or pseudomonas.
Note that! Uroerythrin adds a slight pink pigment, mostly apparent following refrigeration, when
the pigment attaches to precipitated amorphous urates.

B. Appearance and clarity:
1. Clear: normal.
2. Slightly cloudy: May be due to the presence of low numbers of formed
elements.
3. Cloudy or milky: presence of amorphous, crystals, pus cells, epithelial cells, also
due to Chyluria (W. bancrofti, lymphatic filariasis). Bence jones protein: light
chain of immunoglobulins in urine(multiple myeloma) = (heat test).
C. Specific Gravity: determines the kidney's reabsorption ability.
• Normal range: 1.015 to 1.030
• Low specific gravity: loss of the kidney's ability to concentrate urine or presence
of disease, It can also be found normally with large fluid intake.
• High specific gravity may result from adrenal insufficiency, diabetes
mellitus(glycosuria). Note that! If urine pH >8.0, add 0.005 to the reading.

Chemical examination of urine
multi-parameter reagent strip (Multistix)
Procedure: MUST BE FOLLOWED EXACTLY TO ACHIEVE RELIABLE TEST RESULTS
1. Collect FRESH urine specimen in a clean, dry container. Mix well immediately before testing.
2. Remove one strip from bottle and replace cap. Completely immerse reagent areas of the
strip in FRESH urine and remove immediately to avoid dissolving out reagents
3. While removing, run the edge of the strip against the rim of the urine container to remove
excess urine. Hold the strip in a horizontal position to prevent possible mixing of chemicals
from adjacent reagent areas/or contaminating the hands with urine.
4. Compare reagent areas to corresponding Color chart on the bottle label at the time
specified. Hold strip close to color blocks and match carefully. Avoid laying the strip directly on
the Color chart as this will result in the urine soiling the chart. For optimal results, read the
ketone test at 15 seconds after dipping; read the bilirubin test at 20 seconds; glucose at 30
seconds; blood at 40 seconds; urobilinogen at 45 seconds; and specific gravity from 45 to 60
seconds after dipping.

False-negativeFalse-positiveTest
Not mixed will, high
proteinuria, glucosuria,
Boric acid
Expired strip, formalinLeukocyte esterase
Formalin, lack of nitrateImproper storage
(bacterial proliferation)
Nitrite
Formalin, high vitamin CPeroxidasesBlood
High ketones, high
ascorbic acid
Alkaline urine, oxidizing
agent : bleach,
Glucose
Ascorbic acid, boric acid,
sample exposed to light
Colored substancesBilirubin
Boric acid, formalin,
hypochlorite, delay in
examination, volatilization
Highly pigmented urine,
drugs
Ketones
Bence-jones protein,
sperms
Alkaline urine, drugsProtein
Formalin, hypochlorite,
antibiotics
Sulfonamide, drugs, beetUrobilinogen
Discrepancies

Discrepancies
• Renal glycosuria: presence of glucose in urine with normal blood glucose level! Due to defect in renal
tubular dysfunction or by glucagon hormone. (>180mg/dl)
• Strip positive for blood with absence of RBCs microscopically: hemoglobinuria(Hb from lysed RBCs) or
diluted urine (Ghost RBCs) pH > 7, SG < 1.010, handling, old sample, high temperature, peroxidase
positive bacteria (E. coli), myoglobin, too fast centrifugation,
• Sterile pyuria, presence of pus in urine with no bacteria: using of antibiotics.
• RBCs can be confused with yeast cells or oil droplets. Diluted acetic acid can be used to lyse RBCs,
leaving only yeast, oil droplets, and WBCs.
• Positive leukocyte esterase with Glitter cells or absence of WBCs microscopically: dilute alkaline urine.
• Excessive shaking or taping of sediment against edges of table to mix it up> cause the casts to dissolve.
• Note that!! Native urine: urine not centrifuged > counting chamber method > small volume of urine
only.

• 10 to 15 mL (12ml) Centrifuged at 400 – 450 g (RCF), 1500 – 2000
(1600) (RPM) for 5 mins hold the test tube upside down and count to
3, then turn the test tube again and stand it upright mix drop (20
μL) in a slide + glass cover slip (carefully to avoid air bubbles) examine.
• Report RBCs/WBCs using high-power magnification (i.e., high-power field [hpf]),
report casts and crystals using low-power magnification (i.e., low-power field [lpf]).
• Normal Urines: Contain 0-4 RBCs (hpf), 0-3 WBCs (hpf), 0-2 hyaline casts (lpf), several
epithelial cells (hpf), some types of crystals, and mucus.
• Casts have a tendency to locate near the edges of the cover slip (LPF scanning around
the cover slip).
Microscopic examination

Sediment constituents such as bacteria, yeast cells, crystals,
and spermatozoa are not counted, but instead given as
crosses

Urine cells

Isomorphic RBCs
Dysmorphic RBCs, Have cellular blebs (mickey mouse ear), associated with glomerular bleeding
(glomerulonephritis).
Ghost RBC
In dilute urine, absorb
water, swell, and lyse
rapidly, releasing
hemoglobin. Examined
under reduced light.
RBCs, Seen in
kidney or urinary
tract diseases or
menstrual blood
contamination,
<3 /HPF is
normal

Pus cells, neutrophils in acute infections, eosinophils in interstitial nephritis, lymphocytes in renal transplantation
Elongated WBCs

Macrophages, Contain digested material, lipids, seen in chronic inflammation and radiation therapy

Renal tubular cells (RTEs) line the nephron, seen in renal tubular damage (acute tubular necrosis, viral infection, or renal
transplant rejection)

Sperms, found in men with retrograde ejaculation, post-prostatectomy, or in sample collected soon after ejaculation

Squamous epithelial cells, from urethra, skin and vaginal mucosa

Clue cell: Gardnerella vaginalis

Tadpole cells or caudate cells
Transitional epithelial cells (Urothelial cells), from renal pelvis, ureter and bladder, increased in infections, renal stones,
bladder cancer, and post-catheterization.
Chronic urinary tract infection

Transitional cell
carcinoma

Decoy cells: viral infection (polyoma virus) or malignancy

Oval fat bodies: with marked proteinuria, acute tubular necrosis or nephrotic syndrome

Urine casts

Fatty casts, with marked proteinuria, acute tubular necrosis or nephrotic syndrome
Oval fat bodies

Renal tubular epithelial cells (RTEs) casts: Found in tubular damage, acute
tubular necrosis, or renal transplant rejection

White blood cells (WBCs) casts: in pyelonephritis, lupus or allergic nephritis

Granular casts: found in normal urine following stress, strenuous exercise, or in renal diseases

Hyaline casts: seen in normal urine following strenuous exercise also seen in renal diseases

Red blood cells (RBCs) casts: indicates serious renal disease, acute nephritis, glomerular injuries, or glomerulonephritis
and malignant hypertension Alyazeed hussein, BSc-SUST

Hemoglobin casts

Myoglobin cast

Bilirubin/bile cast

Waxy cast: found in sever renal disease or acute glomerulonephritis

Broad cast: poor prognosis, renal failure

Crystals cast: amorphus

Myeloma cast

Mixed cast (yeast, WBC, granular ,hyaline)
Bacterial cast

Urine crystals at acid pH

Cystine crystals: in patients with cystinosis, a congenital condition, most common aminoaciduria

Sulfonamide crystals: form renal calculi in dehydrated patients, infrequently seen today

Ampicillin crystals

Drug crystals

Uric acid crystals: associated with hyperuricemia, uric acid stone, tumor lysis syndrome, gouty nephropathy

Found in concentrated urine associated with fever and dehydration, may hide bacteria, casts and crystals
Amorphus urate
(acidic urine)
Amorphus phosphate
(alkaline urine)

Bilirubin crystals: in urine contain high amounts of bilirubin

Calcium oxalate crystals: patients consume tomatoes, apples, oranges (rich in oxalic acid) may have these crystals in
urine. Found in renal calculi.

Cholesterol crystals: associated with nephrotic syndrome

Hippuric acid: in person who eat a diet rich in benzoic acid, may also seen in liver diseases

Leucine crystals: in liver disease, appears in
association with tyrosine crystals

Tyrosine crystals: seen in hepatic failure

Acid urate: old sample not significant

Sodium urate: no clinical significance

Urine crystals at neutral
or alkaline pH

Calcium carbonate: no
clinical significance

Calcium phosphate: in normal urine may cause renal calculi

Ammonium biurate crystals (thorn apple): seen in old urine sample (teaching sample), have no clinical significance

Ammonium magnesium phosphate (triple phosphate, struvite crystals, coffin lid), appear fern-like feathery
(dissolved), normal in urine but may be associated with bacterial growth (Proteus). Calculi seen in chronic UTI

Organisms

Bacteria: in urinary tract infection, or may be a vaginal or fecal contaminant

Yeast/fungi: candida albicans, appears as budding yeast or pseudohyphae, may be from a vaginal contaminant, bladder or
kidney inaction Alyazeed hussein, BSc-SUST

Adult female of E. vermicularis
Eggs of E. vermicularis
Trophozoites of T. vaginalis
Egg of S. haematobium

Miscellaneous

Oil droplets
Corpora amylacea
Glass artifacts

fibers

Mucus threads: infections of lower urinary and vaginal tract.

Pollen grains: from contaminate urine and urine container

Air bubbles
Starch globules

Fecal contamination
Rotifer
Alternaria
Pubic lice
Dust mite

• This has been a presentation of Alyazeed Hussein.
• Thanks for your attention and kind patience.
• Any questions, additions, or comments?

References
• Urinalysis Benchtop Reference Guide, CAP.
• Kjeldsberg's Body Fluid Analysis, ASCP.
• A Handbook Of Routine Urinalysis, Sister Laurine Graff.
• Textbook of urinalysis and body fluids, Landy J. McBride-Lippincott.
• Graff's textbook of urinalysis and body fluids, Lillian A. Mundt, 3rd e
• Success in clinical laboratory science, ANNA P. CIULLA, 4th e
• www.researchgate.net
• www.sciencedirect.com
• www.diagnostics.roche.com

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