bodies are those cells containing fat globules, the nucleus, then, are not visible. FIGS 5.17A AND B: (A) White Blood Cells in urine;

 

look for casts, RBCs, pus cells and epithelial cells.

In most instances, an unstained sediment is sufficient.

However, should a difficulty arise or the examiner is

inexperienced, staining can be done with Sternheimer and

Malbin stain.

A drop of methylene blue solution can be added to the

sediment and would help in identifying cellular structure

and bacteria. A crystal violet safranin stain is used to

identify cellular elements; a peroxidase stain will diffeContd...

Blood SI units

Thallium <0.5 µg/dL <24.5 nmol/L

 Toxic concentration 10–800 µg/dL 0.5–39.1 µmol/L

Zinc 70–150 µg/dL 10.7–23 µmol/L

Antimony <10 µg/L <82.1 µmol/L

 Toxic concentration >10 µg/L >82.1 µmol/L

Arsenic 5-50 µg/L 0.067–0.665 µmol/L

Chronic poison 50–5000 µg/L 0.67–66.5 µmol/L

Acute poison 1000–20,000 µg/L 13.3–266 µmol/L

Bismuth 0.3–4.6 µg/L 1.4–22 nmol/L

Cadmium 0.5–4.7 µg/L 4.4–41.8 nmol/L

Industrial exposure 10–580 µg/L 0.09–5.16 µmol/L

Cobalt 1–2 µg/L 17–34 nmol/L

Copper 2–80 µg/L 0.03–1.26 µmol/L

Lead <80 µg/L <0.39 µmol/L

Industrial exposure <120 µg/L <0.58 µmol/L

Mercury

Adult <20 µg/L <0.10 µmol/L

Toxic concentration >150 µg/L >0.75 µmol/L

Lethal concentration >800 µg/L >4 µmol/L

Selenium 7–160 µg/L 0.09–2.03 µmol/L

Toxic concentration >400 µg/L 5.08 µmol/L

Thallium <2 µg/L <9.8 nmol/L

Toxic concentration 1–20 µg/L 4.9–97.8 µmol/L

Zinc 150–1200 µg/L 2.3–18.4 µmol/L

Toxic concentration >1200 µg/L 18.4 µmol/L

Urine Analysis 93

rentiate renal tubular cells that are peroxidase negative

and neutrophils (pus cells) that are peroxidase positive. In

most cases, qualitative or semiquantitative examination

of the urine is enough. For following the progress of active

renal disease, Addis’ count may be used. Cell counts can

be expressed as occasional, 1+, 2+, 3+ or full field. Count

in at least 10 high power fields for cells and express the

average as the number of cells per high power field.

Addis count: A method of quantitative enumeration of

red blood cells, white cells, and casts in a 12-hour urine

specimen is known as the Addis count (Addis, 1948). The

chief value of the Addis count is in following the progress

of known renal disease, e.g. acute glomerulonephritis. (For

diagnostic purposes, careful examination of the sediment

from a random fresh urine sample is usually sufficient).

An accurately time 12 hour urine specimen should be

collected, with attention to the factors which contribute

toward preservation of the formed elements, which are to

be counted A 6 to 9 hour specimen may be used. A concentrated specimen of low pH is desirable; this is most easily

obtained by collection of the specimen overnight while the

patient is not normally eating or drinking. Intake of fluids

should be restricted during the collection period as the

patient’s condition permits. Particular attention should

be paid to avoiding contamination of the specimen with

vaginal discharge or feces.

Formalin is the preservative of choice for preservation

of cells and casts; it also inhibits bacterial growth.

Sufficient formalin is introduced by rinsing the collection

bottle with a solution of 10% formaldehyde in water and

discarding the excess solution. It is advisable to keep the

specimen at room temperature during and after collection

in order to prevent precipitation of dissolved materials, for

precipitation obscures the cells, casts, and makes counting

difficult. The specimen should be examined as soon as

possible after collection.

Procedure

1. Mix the specimen well and measure the volume

carefully.

2. A preliminary microscopic examination of the

urinary sediment should be performed with a 10:1

concentration of the sediment (centrifuge 10 mL of

urine, resuspend the sediment in 1 mL of urine and

examine). From the results of this examination, the

volume in which to resuspend the sediment in step 5

can be determined.

3. Transfer 10 mL of urine to a special Addis graduated

centrifuge tube and centrifuge for 5 minutes at 2000 rpm.

4. Pour off the supernatant urine and save for protein

determination. Adjust the volume of the remainder

to 1 mL. When the amount of sediment is large,

adjust the volume to 2 to 5 mL after the calculations

appropriately.

5. Mix well to resuspend the sediment, and with a

capillary pipette, mount the resuspended sediment

on both sides of two Levy-Hausser counting chambers

with improved Neubauer rulings.

6. Under low power, count the number of casts in the

four rule areas (4 × 9 = 36 sq mm) on the two sides of

the two counting chambers. Using the high-power

objective, count the red blood cells and white blood

cells and epithelial cells in 4 sq mm (usually 1 sq mm

from each side of each chamber). Squamous epithelial

cells are not countered.

The number of cells and casts excreted in 12 hours or

24 hours may be reported. This number is determined as

follows:

Number counted per sq mm × 1/10 = number/sq mm

corrected for concentration of specimen.

Number/sq mm × 1 mm/0.1 mm = number/cu mm.

Number/cu mm × 1000 = number/mL

Number/mL × 12 h vol in mL = number/12 h.

Interpretation

Normal values (see the following Table). Red blood cells,

0 to 500,000 per 12 h. Non squamous white cells, 0 to

1,000,000 per 12 h. Casts, 0 to 5000 hyaline casts per 12 h.

In children, the number of erythrocytes and

leukocytes may be lower and the number of casts greater

(Lyttle, 1933).

Addis has given the following average counts per 12

hours in cases of glomerulonephritis.

Casts Erythrocytes White cells

Acute 690,000 405,000,000 48,000,000

Chronic active 1,850,000 34,000,000 14,000,000

Chronic latent 48,000 16,000,000 2,400,000

Chronic terminal 398,000 26,400,000 10,000,000

Red Blood Cells (Figs 5.16A and B)

Under high power, they appear as pale discs. If the

specimen is stale, because of dissolution of hemoglobin,

these cells will appear as ghost cells. These red cells may

show crenated margins.

RBCs may be confused with oil droplets or yeast cells.

Oil droplets are variable in size and are refractile. Yeast

cells usually show budding. Alkaline hematin stains dark

purple in alkaline urine.

94 Concise Book of Medical Laboratory Technology: Methods and Interpretations FIGS 5.16A AND B: Red blood cells in urine

A

B

Neutrophilic Leukocytes (Pus Cells)

(Figs 5.17A and B)

Unstained neutrophilic leukocytes appear as round granular 12 µ spheres, larger than RBC. These may look like

small epithelial cells—let a drop of glacial acetic acid flow

under the coverslip—the segmented nucleus of a leukocyte

becomes clearer.

Epithelial cells have a single, rounded nucleus. Glitter

cells are larger neutrophils, cytoplasmic granules may

show brownian movement.

Renal Tubular Epithelial Cells (Figs 5.18A and B)

Unstained cells are almost the same size as that of a

neutrophil but contain a large round nucleus. Oval fat

bodies are those cells containing fat globules, the nucleus,

then, are not visible.

FIGS 5.17A AND B: (A) White Blood Cells in urine;

(B) Pus cells in urine

A

B

Bladder Epithelial Cells (Figs 5.19A and B)

Unstained cells are larger than renal tubular cells, have

a round nucleus and vary in size depending on depth of

origin in transitional epithelium. Superficial cells are large

and flat with small nucleus.

Squamous Epithelial Cells (Fig 5.20)

Unstained, these are large, flattened cells with abundant

cytoplasm and a small round nucleus. The cell may be

folded or rolled.