URINALYSIS (MLT 305) LECTURE TWO

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URINALYSIS (MLT 305)LECTURE TWO

• Dr. Essam H. Jiffri

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BLOOD

• - Blood may be present in the urine either in the
  form of intact red blood cells (hematuria) or as
  the red blood cell destruction product hemoglobin
  (hemoglobinuria).
• - Blood present in large quantities can be
  detected visually hematuria produces a cloudy
  red urine and hemoglobinuria appears as a clear
  red specimen.

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BLOOD

• Any amount of blood greater than 5 cells per
  microliter of urine is considered clinically
  significant, it is not possible to rely on visual
  examination to detect the presence of blood.
• - The microscopic examination can be used to
  differentiate between hematuria and
  hemoglobinuria.

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BLOOD

• REAGENT STRIP REACTIONS
• - Chemical tests for blood utilize the
  pseudoperoxidase activity of hemoglobin to
  catalyze a reaction between
• - hydrogen peroxide and the chromogen
  tetramethylbenzidine
• to produce an oxidized chromogen,
  which has a green-blue color.
• hemoglobin
• H2O2 Chromogen
  Oxidized Chromogen H2O
• peroxidase

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BLOOD

• REAGENT STRIP REACTIONS
• - Two color charts are provided that correspond
  to the reactions that occur with hemoglobinuria
  and hematuria.
• - In the presence of free hemoglobin
• - A strongly positive blue will appear on the
  pad.
• - In contrast, intact red blood cells
• - A speckled pattern will appear on the pad.

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BLOOD

• CLINICAL SIGNIFICANCE OF URINE BLOOD
• Hematuria
• 1. Renal calculi
• 2. Glomerulonephritis
• 3. Pyelonephritis
• 4. Tumors
• 5. Trauma
• 6. Exposure to toxic chemicals or drugs
• 7. Strenuous exercise

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BLOOD

• CLINICAL SIGNIFICANCE OF URINE BLOOD
• Hemoglobinuria
• 1. Transfusion reactions
• 2. Hemolytic anemia
• 3. Severe burns
• 4. Infections
• 5. Strenuous exercise

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BLOOD

• CLINICAL SIGNIFICANCE OF URINE BLOOD
• Myoglobinuria
• 1. Muscular trauma
• 2. Prolonged coma
• 3. Convulsions
• 4. Muscle-wasting diseases
• 5. Extensive exertion

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BILIRUBIN

• - The appearance of bilirubin in the urine is the
  first indication of liver disease and is often
  detected long before the development of jaundice.
  
• - Bilirubin provides early detection of
  hepatitis, cirrhosis, gallbladder disease, and
  cancer, and should be included in every routine
  urinalysis.

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BilirubinBilirubin,
a highly pigmented yellow compound, is a
degradation product of haemoglobin
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Bilirubin

• OXIDATION TESTS (FOUCHETS TEST)
• - Urine containing bilirubin usually appears dark
  yellow or amber and produces a yellow foam when
  shaken, this foam test was actually the first
  test for bilirubin.
• - Oxidation tests utilize the ability of feric
  chloride dissolved in trichloracetic acid
  (Fouchet's reagent) to oxidize bilirubin to
  biliverdin, producing a green color.

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Bilirubin

• REAGENT STRIP (DIAZO) REACTIONS
• Routine testing for urinary bilirubin by reagent
  strip utilizes the diazo reaction, in an acid
  medium to produce colors ranging from increasing
  degrees of tan or pink to violet, respectively.
• Questionable results should be retested using the
  Ictotest which produces a more sharply colored
  diazo reaction.
• - Colors other than blue or purple appearing on
  the mat are considered negative.

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Bilirubin

• CLINICAL SIGNIFICANCE OF URINE BILIRUBIN
• 1. Hepatitis
• 2. Cirrhosis
• Biliary obstruction

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Bilirubin

• - The presence or absence of bilirubin can be
  used in determining the cause of clinical
  jaundice.
• ( Urine Bilirubin and
  Urobilinogen in Jaundice )

Urine Urobilinogen Urine Bilirubin
Negative Bile duct obstruction
or - Liver damage
Negative Haemolytic disease
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UROBILINOGEN

• Like bilirubin, urobilinogen is a bile pigment
  that results from the degradation of hemoglobin.
• It is produced in the intestine by the oxidation
  of bilirubin by the intestinal bacteria.
• - Approximately half of the urobilinogen is
  reabsorbed from the intestine into the blood,
  recirculates to the liver, and is secreted back
  into the intestine through the bile duct.

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UROBILINOGEN

• The urobilinogen remaining in the intestine is
  excreted in the feces, where it is oxidized to
  urobilin, the pigment responsible for the
  characteristic brown color of the feces.
• Urobilinogen appears in the urine because, as it
  circulates in the blood en route to the liver, it
  passes through the kidney and is filtered by the
  glomerulus.
• - A small amount of urobilinogen less than 1
  mg/dl or 1 Ehrlich unit is normally found in the
  urine.

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UROBILINOGEN

• EHRLICH'S TUBE TEST
• The reagent used in all tests was
• p-dimethylaminobenzaldehyde (Ehrlich's
  reagent), addition of Ehrlich's reagent to urine
  containing urobilinogen produces a cherry red
  color.
• - Positive results in dilutions greater than 1
  to 20 were considered significant.

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UROBILINOGEN

• EHRLICH'S TUBE TEST
• An Ehrlich unit is essentially equal to 1 mg of
  urobilinogen.
• - Normal values for females are 0.1 to 1.1
  Ehrlich units and for males, 0.3 to 2.1 Ehrlich
  units, these values are based on the recommended
  2-hour specimen collected after the noon meal
  between 2 and 4 PM, which is the time of greatest
  urobilinogen excretion.

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UROBILINOGEN

• CLINICAL SIGNIFICANCE OF URINE UROBILINOGEN
• 1. Early detection of liver disease
• 2. Hemolytic disorders

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NITRITE

• - The reagent strip test for nitrite provides a
  rapid screening test for the presence of urinary
  tract infection.

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NITRITE

• REAGENT STRIP REACTIONS
• Nitrite is detected by the Greiss reaction
• - nitrite at an acidic pH reacts with an
  aromatic amine to form a diazonium compound that
  react with quinolin compound to produce a pink
  color.

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NITRITE

• CLINICAL SIGNIFICANCE OF URNE NITRITE
• 1. Cystitis (initial bladder infection)
• 2. Pyelonephritis (an inflammatory process of the
  kidney and adjacent renal pelvis)
• 3. Evaluation of antibiotic therapy
• 4. Monitoring of patients at high risk for
  urinary tract infection
• 5. Screening of urine culture specimens
  (detection of bacteruria)

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SPICIFIC GRAVIIY

• The addition of a specific gravity testing area
  to Multistix has eliminated
• time-consuming step in routine urinalysis
• provided a convenient method for routine
  screening.
• - It is not recommended to replace osmometry or
  refractometry for critical fluid monitoring.

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SPICIFIC GRAVIIY

• REAGENT STRIP REACTION
• - The test is based on the change in pK-
  (dissociation constant) of poly methyl vinyl-
  ethermaleic anhydride.

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SPICIFIC GRAVIIY

• CLINICAL SIGNIFICANCE OF URINE SPECIFIC CRAVITY
• 1. Patient hydration and dehydration
• 2. Loss of renal tubular concentrating ability
• 3. Diabetes insipidus
• 4. Determination of unsatisfactory specimens due
  to low concentration

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LUKOCYTES

• - One of the most frequent findings in the
  routine urinalysis is the presence of leukocytes,
  indicating a possible infection of the urinary
  tract.
• - Detection of leukocytes was previously made
  only by microscopic examination of the urinary
  sediment.

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LUKOCYTES

• REAGENT STRIP REACTION
• The chemical reaction is enzymatic, utilizing
  esterases present in granulocytic white blood
  cells to hydrolyze indoxylcarbonic acid ester to
  produce indoxyl, which reacts with a diazonium
  salt to create a purple color.
• 
  leukocyte
• indoxylcarbonic acid ester
  indoxyl diazonium salt (purple
  color)
• 
  esterases
• - It is recommended that trace reactions be
  repeated on a fresh specimen and that microscopic
  examinations be performed on all positive
  specimens.

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LUKOCYTES

• CLINICAL SIGNIFICANCE OF URINE LEUKOCYTES
• 1. Urinary tract infection
• 2. Screening of urine culture specimens