2. General evaluation of health
Diagnosis of disease or disorders of the kidneys or
urinary tract
Diagnosis of other systemic disease that affect kidney
function
Monitoring of patients with diabetes
Screening for drug abuse (eg. Sulfonamide or
aminoglycosides)
3. 1.Randomly Collected Specimens,
A random urine specimen is urine voided without regard to
the time of day or fasting state.
Not specimens of choice because of the potential for dilution
of the specimen when collection occurs soon after the patient
has consumed fluids.
4. • 2. First Morning Specimen is the specimen
• should be delivered to the laboratory as quickly as possible.
• It is used to evaluate orthostatic proteinuria and
• to detect low levels of substances that are difficult to observe in a random
sample, such as hormones.
• are more concentrated (the urine is retained in the bladder overnight).
3. Midstream Clean Catch Specimens
recommended for microbiological culture and antibiotic susceptibility
testing
5. 4. Timed Collection Specimens 24 hour urine
●Urinate (empty the bladder) for the first time and flush it down the toilet.
Note the exact time.
●Collect every drop of urine during the day and night in an empty
collection bottle.
●Finish by collecting the first urine passed the next morning, adding it to
the collection bottle
required for quantitative measurement of certain analytes, including those
subject to diurnal variation.
Analytes commonly tested using timed collection include creatinine, urea,
potassium, sodium, uric acid etc.
usually 2, 12, or 24 hours
6. 5. Collection from Catheters
a sterile catheter is inserted by a physician through the urethra into the
bladder,
urine to flow down the catheter into a collection bag. can be random or
timed. They are used for routine testing and microbial cultures.
Urethral catheterization is also used to examine the efficacy of a single
kidney; dual-lumen urethral catheters retrieve a specimen from each
kidney.
A catheter is inserted through the urethra and into the ureter to obtain this
type of specimen
(e.g. Foley’s catheter) using a syringe, followed by transfer to a
specimen tube or cup.
Alternatively, urine can be drawn directly from the catheter to an
evacuated tube using an appropriate adaptor.
7. 6. Supra-pubic Aspiration
involves collecting urine directly from the bladder by puncturing the
abdominal wall and entering the bladder with a sterile needle and syringe.
to diagnose bacterial infections of the bladder, especially anaerobes, as
well as for cytology studies and routine testing.
may be used with infants to avoid fecal contamination of the specimen.
necessary when a non-ambulatory patient cannot be catheterized
7. Pediatric Specimens
for infants and small children, a special urine collection bag can be
adhered to the skin surrounding the urethral area.
8. 8. Drug-testing
• programs require particularly exacting methods of urine collection that follow a standard
“chain-of-custody” process..
• Signatures of all who come in direct contact with the specimen must be placed on the
chain-of-custody form.
• Typically, the urine specimen for drug testing is a random sample. Specimen collection may
be observed to guarantee that the sample is not being tampered with.
• To assess possible tampering, urine temperature can be measured within a period of 4
minutes following collection and must fall between 32.5◦C and 37.7◦C
9. 9. A“three glass ”specimen
• involves collection of three separate urine samples from a male.
• Urine is examined for presence of white blood cells and bacteria in each of the
three samples.
• The first sample is a control, the second midstream sample is used as a control for
kidney and bladder infection, and the third component of the sample follows
prostatic massage.
• The third “glass” will contain prostatic fluid, and in prostatic infection, will contain
a white blood cell and bacterial count at least ten times that of the first control
specimen.
• If the second sample contains bacteria from a kidney or bladder infection, the
results of the third sample are invalid.
12. Appearance (Color & Turbidity).
Observations of urine color and clarity formed on a well-mixed, uncentrifuged
specimen.
Urine color can vary from colorless to black.
Urine color is produced by the presence of three pigments:
(1) Urochrome, which is a yellow pigment that is present in the highest
concentration and is secreted by tubule cells;
(1) Uroerythrin, which is a red pigment
(2) Urobilin, which is an orange-red pigment from the oxidation of urobilinogen
13.
14.
15. Normal = 600-1550ml
Polyuria- >2000ml
Oliguria-<400ml
Anuria-complete cessation of urine(<200ml)
Nocturia-excretion of urine by a adult of >500ml
with a specific gravity of <1.018 at night
(characteristic of chronic glomerulonephritis)
Urinary volume:
19. Urine dipsticks provide a quick and inexpensive
method for detecting abnormal substances within the
urine
20. Reaction reflects ability of kidney to maintain normal
hydrogen ion concentration in plasma
21. Normal PH
The average is about 6
Range from 5~9 (depends on diet)
Higher PH---alkaline urine
drugs: sodium bicarbonate
alkalosis (metabolic or respiratory)
UTI- Proteus
Lower PH---acid urine
acidosis (metabolic or respiratory)
UTI- E.coli
Diet – high protein diet
Uric acid calculi
22. Reflect the density of the urine
Range of 1.003 to 1.035
23. Increase: can be caused by the presence of glucose or protein
in the urine.
Dehydration、Fever, Vomiting, Diarrhea
Diabetes Mellitus
Glycosuria, Congestive Heart Failure
(urine volume↓ and SG↑)
Decrease:
diabetes insipidus
renal failure
pyelonephritis
(urine volume↑ and SG ↓)
Specific gravity (SG)
A fixed specific gravity of 1.010 (isosthenuria) indicates a loss of the
concentrating ability of the glomerulus.
24. Glycosuria
Glucose is not typically detectable in urine.
It is excreted into the urine when the plasma level exceeds the kidney threshold
of 150 to 180 mg/dL or when there is a defect in the reabsorption mechanism of
glucose
A serum glucose of about 180 mg/dL; above this level, glucose will be detected
in the urine
(1) The test strip is specific for glucose. The sensitivity is 100 mg/dL.
25. Protein
Proteinuria
is normally excreted into the urine at a concentration of 150 mg/24 h.
Approximately one third is albumin, with the remainder being small globulins
with molecular weights <50,000.
27. Precipitation tests for protein
more sensitive than are the reagent strip methods and
detect other proteins besides albumin.
An aliquot (usually 1 mL) of 3% sulfosalicylic acid or trichloroacetic acid
is added to an equal amount of urine in a test tube and mixed by inversion.
The tube is allowed to stand for 10 minutes and then is inverted twice.
The degree of precipitation is graded
The test sensitivity is 5 to 10 mg/dL and detects albumin, globulins,
glycoproteins, and Bence Jones protein.
28. Ketones
products of incomplete fat metabolism,
and their presence in urine indicates acidosis.
The three ketone bodies present in urine are acetoacetic (diacetic) acid, acetone,
and 3-hydroxybutyrate
The test method is based on the reaction of sodium nitroprusside with
acetoacetic acid.
The test does not detect acetone or 3-hydroxybutyrate, but if one ketone is
excreted, all are excreted. Positive reactions produce a maroon color.
The test sensitivity is 5 to 10 mg/dL of acetoacetic acid.
29. Diabetic ketoacidosis
Non-diabetic causes-:
• Prolonged fasting
• high fever, starvation, severe vomiting/diarrhoea
30. Normal urine contains no bilirubin and only very small amounts of
urobilinogen
Conjugated bilirubin has a low molecular weight, is water soluble, and
normally passes from the liver into the small intestine through the bile
ducts, where it is converted to urobilinogen.
Therefore, conjugated bilirubin does not appear in the urine except in
pathologic conditions in which there is intrinsic hepatic disease or
obstruction of the bile ducts.
Indirect bilirubin is of high molecular weight and bound in the serum to
albumin. It is water insoluble and, therefore, does not appear in the urine
even in pathologic conditions.
32. Urobilinogen
Urobilinogen is the end product of conjugated bilirubin metabolism
is normally present in urine in small amounts up to 4 mg/24 h.
Fresh specimens should be used for testing because urobilinogen is
unstable in urine.
33. Normal urine should contain less than three red blood cells per HPF.
A positive dipstick for blood in the urine indicates either hematuria,
hemoglobinuria, or myoglobinuria.
The chemical detection of blood in the urine is based on the peroxidase-like
activity of hemoglobin
Hematuria can be distinguished from hemoglobinuria and myoglobinuria by
microscopic examination of the centrifuged urine;
The presence of a large number of erythrocytes establishes the diagnosis of
hematuria.
If erythrocytes are absent, examination of the serum will distinguish
hemoglobinuria and myoglobinuria
34. Pre renal- bleeding, hemoglobinopathies,
malignant hypertension.
Renal- trauma, calculi, acute & chronic
glomerulonephritis, renal TB, renal tumors
Post renal – severe UTI, calculi, trauma,
tumors of urinary tract
35. Leukocytes- Leukocyte Esterase
Can be detected in urine with the leukocyte esterase
The test strip can detect 5 to 15 leukocytes per high-power field and is
even sensitive to lysed granulocytes.
Vaginal cellular contamination or trichomonads can cause a false-
positive result.
36. Nitrite test
provides a rapid screen for the detection of Gram Negative bacteria that are capable
of reducing nitrates to nitrite. The test results should be negative.
False-negative reactions may occur if:
(a) The bacteria in the specimen do not have the enzymes necessary to reduce
nitrates.
(b) The diet of the individual is deficient in nitrates.
(c) The bacteria reduce the nitrate beyond the nitrate state to nitrogen or ammonia.
(d) The urine has not been in the bladder at least 4 hours, so the bacteria did not yet
reduce the nitrates.
40. 1. pouring the urine sample(11ml) into a test tube
2. centrifuging it (5 min)
3. the supernatant is discarded
4. (the urine sediment) is mixed with the remaining
drop of urine in the test tube or distilled water
5. one drop is analyzed under a microscope
41. Examination
The sediment is first examined under low power field (LPF) to
identify
,the various types of cells are usually described as the number of each
type found per average high power field (HPF).
Observations :Cells ,Casts ,Crystals and miscellaneous
42. Normal and abnormal cells in urine
1. RBCs
are small biconcave disks without a nucleus.
They are 7–10 μm in diameter.
In a hypertonic urine they become crenated, appearing to have a crinkled
border.
In a hypotonic, alkaline urine, the RBCs swell and may lyse.
These lysed cell membranes are called “ghost” or “shadow cells” and
appear as faint, colorless circles.
Normally, a urine specimen can contain 0 to 3 RBCs per high-power field;
increased numbers may indicate renal bleeding or glomerulonephritis .
43. 2. WBCs,
usually neutrophils,
are larger than RBCs (10–15 μm diameter and contain a distinct
nucleus.
A normal urine sample contains 0 to 5 WBCs per high-power field.
An increase is called pyuria and indicates the presence of an infection
or inflammation in the genitourinary tract.
Frequent causes of pyuria include bacterial infections (e.g., cystitis,
pyelonephritis, prostatitis, urethritis)
or nonbacterial disor ders (e.g., glomerulonephritis, lupus
erythematosus, tumors).
44. In dilute alkaline urines, WBCs can lyse or swell and become glitter cells,
in which Brownian movement of their internal granules produces a
sparkling appearance .
Eosinophils in a urine specimen are identified with the stain and indicate
acute interstitial nephritis caused by hypersensitivity reactions to
medications such as penicillin derivatives.
Mononuclear cells (histiocytes, lymphocytes, or plasma cells) indicate an
inflammatory process or possible renal transplant rejection.
45. 3. There are three types of epithelial cells found in urine: squamous, transitional, and
renal tubular.
They are derived from the linings of the urogenital tract. A few of each type can
normally be found in urine because of normal sloughing of old cells.
a. Squamous cells are derived from the lining of the vaginal tract and lower
portions of the female and male urethras. They are the most frequently seen but
least significant epithelial cell..
Their cytoplasmic borders are irregular,
46. b. Transitional or caudate epithelial cells
• line the urinary tract from the renal pelvis to the proximal two thirds of the
urethra.
• round or pear-shaped with a centrally located nucleus.
• Unless present in large numbers (>10 per high-power field) with unusual
morphology, transitional cells are seldom pathologic.
• Catheterization often causes these cells to appear in urine.
• When unusual in morphology or in large numbers, samples of these cells should
be referred for cytologic examination
• may indicate renal transplant rejection, acute tubular necrosis, ischemic
injury to the kidney, or renal carcinoma
47. c. Renal tubular epithelial cells
• line each portion of the renal tubules and are considered the most clinically
important.
• They are oblong or round to oval and contain an eccentric nucleus. Renal
tubular cells from the collecting ducts are cuboidal, polygonal, or columnar.
They have a single, large,dense nucleus that takes up approximately two thirds
of its interior.
• Increased numbers in urine are the result of acute tubular necrosis from heavy
metals or drug toxicity.
• Large numbers in urine are also caused by all types of renal diseases and are
often accompanied by granular, waxy, or renal tubular cell casts and an
increased number of blood cell
48. d. Renal tubular cells containing fat are called oval fat bodies.
They can be staine with SudanIII or oil redO.
fat bodies often indicate glomerular dysfunction with renal tubular cell death.
When present in a urine specimen, these cells are accompanied by increased
amounts of protein and cast formation ).
50. C. Urine casts
Urinary casts are formed in the distal and collecting tubules.
Except for a few hyaline or granular casts, which can accompany strenuous
exercise (athletic pseudonephritis) or severe stress, casts are not normally
present in the urine.
The presence of urinary casts is termed cylindroiduria and their appearance is
often accompanied by proteinuria.
Acid pH, urinary stasis, elevated protein, and concentrated solutes in urine
all favor the formation of casts.
Renal disease or damage along with these factors will produce different types
of urinary casts.
Casts are better identified with the use of a supravital stain and are typically
reported as number of casts per low power field through the microscope
51. 2. Tamm-Horsfall protein, which is a mucoprotein secreted only by renal tubular
cells, forms the matrix of casts
As the tubular lumen contents become concentrated (often due to stasis of urine
flow), Tamm-Horsfall protein forms fibrils that attach it to ductal cells and hold it
temporarily in place.
As it is held in the tubule, it enmeshes into its matrix any cellular or chemical
substance that is present in the filtrate at the time it is formed.
Eventually, the cast detaches from the tubular epithelial cells and is flushed into
the urine.
Because casts form in the tubules, they are cylindrical with parallel sides and
rounded ends.
Casts formed in the collecting ducts are broader than those formed in the proximal
and distal convoluted tubules.
52. The number and type of casts reflect the extent of renal tubule involvement
in disease processes.
They are classified by the composition of their matrix and the type of
substance enmeshed within them.
Hyaline casts consist primarily of a homogeneous Tamm-Horsfall protein
matrix with a low refractive index similar to urine.
Also, they are the hardest to view because they donot contain any inclusions;
These casts appear I n urine after strenuous exercise or stress,although in
small numbers they are considered as normal sediment.
53. 5. Cellular casts
consist of a matrix of protein covered with different cell types.
Red blood cell casts are reddish in color and signify glomerular disease or
physical damage to the glomerulus.
The outline of an erythrocyte must be observed in part of the cast to identify these
.
White blood cell (leukocyte) casts are associated with pyelonephritis and
infection.
The white blood cells are larger than red cells and have multilobed nuclei and
granules in the cytoplasm .
Renal tubular epithelial cell casts are noted in tubular diseases such as drug
toxicity and tubular necrosis;.
Casts containing a mixture of cells are referred to as “mixed cell casts.”
54. 6. Granular casts
may be degenerated cellular casts or they may represent protein aggregation on
the Tamm-Horsfall cast matrix.
They are classified as either finely granular or coarsely granular based on the
appearance of the inclusions.
Granular casts are always associated with renal disease, either glomerular or
tubulointerstitial.
Waxy casts
are the final degenerative stage of finely granular casts.
These casts are smooth with blunt ends and cracks along the lateral edges.
The appearance of waxy casts in urine is a sign of renal failure or severe nephron
damage.
7. Other casts include fatty casts, pigmented casts, bacterial, fibrin, and crystal
casts depending on the inclusions within the protein matrix.
55.
56. D. Crystals
are commonly found in urine sediment but are rarely clinically significant.
Crystal identification is based on microscopic appearance and urine pH.
Normal crystals can be found in acid, alkaline, or neutral urine and are
reported as few, moderate, many or too numerous to count (TNTC) under
microscopic high power.
57. 1. Normal crystals in acidic urine
a. Uric acid crystals
• yellow to red to orange in color and appear in many shapes,
• including four-sided and flat; rhombic plates or prisms; ovals with pointed
ends; rosettes; wedges; and needles.
a. Amorphous urates
• yellow-brown granules,often found in clumps that may obscure other elements
present in the urine sediment.
• When present in large amounts, they make the urine specimen appear pink-
orange or reddish-brown and turbid.
a. Calcium oxalate
• crystals can be seen in acidic or neutral urine.
• appear under the microscope as small, colorless octahedrals that resemble
envelopes or dumbbell shape
58. 2. Normal crystals found in alkaline urine ) are predominantly
a. Triple phosphate crystals ,coffin lids .
b. amorphous phosphates
c. Ammonium biurate
• yellow-brown spheres with irregular projections
or“thorns”andarereferredtoasthornyapples.Theyareoften seen in
oldspecimens .
59. d. Calcium phosphate
• appears as colorless,thin prisms, plates, or needles.
• when present can be confused with sulfonamide crystals , which are
abnormal.
• The two are distinguished by adding dilute acetic acid to the urine
sediment. Calcium phosphate is soluble; sulfonamides are insoluble.
e. Calcium carbonate
• small, colorless dumbbells or spheres.
• They often appear in clumps and can be confused with amorphous
phosphates.
• They are distinguished by the formation of carbon dioxide gas after the
addition of acetic acid
60. 3. Abnormal crystal
found in acidic or neutral urine and have characteristic shapes .
a. Cystine crystal
• colorless hexagonal plates that precipitate in acidic urine.
• They result from an inherited metabolic defect that prevents the
reabsorption of cystine by the proximal convoluted tubule
b. Cholesterol
• crystals in acidic urine resemble rectangular plates with a notch inone or more
corners.
• individuals with nephrotic syndrome or if the lymphatic system has been
damaged.
• They are seen when urine specimens have been refrigerated and in urine
specimens with elevated protein
61. c. Leucine
• appears as yellow-brown oily looking spheres that contain concentric
circles with radial striationse).
• individuals with liver failure.
d. Tyrosine
• look like sheaths of fine needles.
• in individuals who have severe liver disease.
e. Bilirubin
• can precipitate in acidic urine as yellowish spheres with spicules.
• from individuals with liver disease
.
62. f. Sulfonamides
• colorless or yellow-brown bundles
• rosettes, arrowheads, needles, petals, or round forms with striations.
• appear when individuals are not adequately hydrated
g. Ampicillin
crystals appear as long, fine colorless needles or form coarse sheaves after
refrigeration.
70. Microorganisms, artifacts, and miscellaneous
1. Bacteria may or may not be significant, depending on the method of specimen
collection and how soon after collection the specimen is examined. If WBCs are also
present in the sediment with bacteria, an infection may exist.
2. Yeasts are usually found in the urine of individuals who have diabetes, but may
also have gained access to the urine from places they usually reside (e.g., skin,
vaginal tract) as the urine is voided.
• yeasts can be confused with RBCs.
• To differentiate RBCs and yeast, it is best to add a drop of dilute acetic acid to the
urine sediment and re-examine it. RBCs lyse; yeast cells remain intact.
Occasionally, mycelial forms of Candida are seen
71. 3. The parasite Trichomonas vaginalis (8–20 μm) is seen in urine specimens as
the result of vaginal contamination.
Small species can be confused with WBCs, but the parasite has a characteristic
undulating flagella.
4. Ova of the parasite Schistosoma haematobium are shed directly into urine.
These are large (30×80 μm) ovals with a trminalal spine .
5. Occasionally, amoebae can find their way to the bladder through the
lymphatics. Entamoeba histolytica (cyst 10–20 μm) is usually accompanied by
erythrocytes and leukocytes
72. 6. Enterobius vermicularis (pinworm) eggs or ova (30 ×50 μm) can contaminate
urine when the female migrates to the perianal fold to lay its eggs.
7. Artifacts seen in urine include muscle fibers and vegetable cells seen with
fecal contamination, hair, cotton fibers from diapers or other cloth materials,
starch granules from surgical gloves , and oil droplets from lubricants used as
catheter lubricants or vaginalcreams.
73. • 8. Mucus, a protein material produced by glands and epithelial cells in the
urogenital tract, is commonly observed in urine specimens, but has no clinical
significanceMicroscopically, mucus appears as threadlike structures with low
refractive indexes, which requires subdued light for observation.
• Spermatozoa maybe found in a female urine specimen after sexual
intercourse and are considered vaginal contaminants.
• Spermatozoa may be found in the urine of men after recent sexual activity,
ejaculation or nocturnal emission.
• Disease of the genitourinary tract must also be considered if sperm are found
in a male’s specimen .
