Lesson 4.1: Urinary Sediments - Cells/Casts/Parasites Flashcards
3 primary Formed Elements
RBCs
WBCs
Hyaline casts
Formed elements disintegrate rapidly in dilute _________ urine
alkaline
What may cause precipitation of amorphous urates and phosphates?
Refrigeration
What specimen collection procedure for urine minimizes external contamination of sediment?
Clean-catch midstream
False positive or False Negative
Dilute random specimens
False-negative
Technical Tip: Warm refrigerated urine specimens to 37C before centrifuging to dissolve amorphous urate crystals
Okay! Thanks gid!
For specimen volume, what is the standard amount of urine
10-15mL
In a urine specimen volume, how much is usually used?
12-mL
Centrifugation for __ minutes at a relative centrifugal force (RCF) of ____ produces an optimum amount of sediment with the least chance of damaging the elements
5 minutes
400 RCF
A uniform amount of urine and sediment should remain in the tube after decantation, a volume of ___ and ___ are frequently used
0.5 mL and 1.0 mL
Technical Tip: Commercial Systems are available that have tubes designed for decanting and provide a constant volume for suspension
Yehey! Esnupi!
Technical Tip: Recheck urine specimens for both technical and clerical errors in which the physical, chemical, and microscopic results do not correlate
WOW!
These sediment is usually present to provide a “Point-of-Reference”
Epithelial Cells
Volume of Sediment Examined
When using the conventional glass-slide method, the recommended volume is ___ covered by a 22 x 22 mm glass cover slip
20uL (0.02mL)
Microscopic examination should be performed in a consistent manner and include observation of a minimum of ___ fields under both low (10x) and high (40x) power
10 fields
Technical Tip: Use reduced light when bright-field and phase-contrast microscopy at both LPF (10x) and HPF (40x) magnifications are used for sediment examination
Thank you for the information, Strasinger!
Normal values for Addis Count
0 to 500,000 RBCs
0 to 1,800,000 WBCs and Epithelial Cells
0 to 5000 Hyaline casts
An example of a sediment element that has a refractive index very similar to urine
Hyaline casts
It is the first procedure to standardize the quantitation of formed elements in urine microscopic analysis
Addis Count
Urine Sediment Stain Characteristics
Action: Delineates structure and contrasting
colors of the nucleus and cytoplasm
Function: Identifies WBCs, epithelial cells, and casts
Sternheimer-Malbin Stain
Urine Sediment Stain Characteristics
Action: Enhances nuclear detail
Function: Differentiates WBCs from RTE cells
Toluidine blue
Urine Sediment Stain Characteristics
Action: Lyses RBCs and enhances nuclei of
WBCs
Function: Distinguishes RBCs from WBCs, yeast, oil droplets, and crystals
2% acetic acid
Urine Sediment Stain Characteristics
Action: Stain triglycerides and neutral fats orange-red; do not stain cholesterol
Function: Identify free fat droplets and lipid containing cells and casts
Lipid stains: Oil Red O and Sudan III
Urine Sediment Stain Characteristics
Action: Stains structures containing iron
Function: Identifies yellow-brown granules of hemosiderin in cells and casts
Prussian blue stain
Urine Sediment Stain Characteristics
Action: Methylene blue and eosin Y stains eosinophilic granules
Function: Identifies urinary eosinophils
Hansel stain
Sternheimer-Malbin stain consists of?
Crystal violet and Safranin O
This stain lyses RBCs but also enhances nuclear detail of WBCs and Epithelial cells
2% acetic acid (1 or 2 drops)
Urine Sediment Stain Characteristics
Action: Differentiates gram-positive and gram-negative bacteria
Function: Identifies bacterial casts
Gram stain
This is a Supravital Stain that is the most frequently used stain in urinalysis
Sternheimer-Malbin stain
Bacterial casts are easily confused with what cast?
Granular casts
Commercial names of Sternheimer-Malbin stain (2)
Sedi-Stain
KOVA
It is a metachromatic stain that provides enhancement of nuclear detail and can be useful in the differentiation between WBCs and RTE cells
0.5% solution of Toluidine blue
Hansel stain consists of?
Methylene blue
Eosin Y in methanol
What microscope is used to check for Cholesterol?
Polarizing microscopy
When using a stain for Triglycerides and Neutral Fats, it results in what color?
Orange-red
Preferred stain used for urinary “Eosinophils”
Hansel stain
Note: Wright’s stain and Giemsa stain can also be used
Eosinophiluria are usually found in cases of?
Renal transplant rejection
Pyelonephritis
Prostatitis
Cystitis
It is the most common type of microscopy performed in the urinalysis laboratory
Bright-Field microscopy
After episodes of hemoglobinuria, yellow-brown granules may be seen in RTE cells and casts or free-floating in the urine sediment
To confirm them as hemosiderin, what stain is used?
Prussian blue stain for iron
Note: It stains the hemosiderin granules a blue color
Light source, condenser, and field and iris diaphragms are part of what system?
Illumination system
Technical Tip: Use supravital stains to enhance the nuclei, cytoplasm, and cellular inclusions to aid in the identification of urine components
Sheesh!
Oculars, objectives, and coarse- and fine-adjustment knobs are part of the system?
Lens System
Enhances visualization of elements with “Low Refractive Indices”
Ex. hyaline casts, mixed cellular casts, mucous threads, and Trichomonas vaginalis
Phase-contrast microscopy
Aids in identification of cholesterol in oval fat bodies, fatty casts, and crystals
A microscopic technique
Polarizing microscopy
In what type of urine do RBCs shrink due to loss of water and may appear “crenated” or irregularly shaped
Hypersthenuria / concentrated
Produces a three-dimensional microscopy image and layer-by-layer imaging of a specimen
Interference-contrast
It is the ability of the lens to distinguish two small objects that are a specific distance apart
Resolution
Allows visualization of naturally fluorescent microorganisms or those stained by a fluorescent dye, including labeled antigens and antibodies
Fluorescence microscopy
Aids in identification of Treponema pallidum
Dark-field microscopy
In what type of urine do RBCs swell because they absorb water and lyse rapidly, releasing their hemoglobin and leaving only the cell membrane?
Hyposthenuria / diluted
When RBCs lyse, they are indicated as large empty cells and can be missed easily if specimens are not examined under reduced light, they are called as?
Ghost cells
What is the most difficult urine sediment to identify?
RBCs
Technical Tip: RBCs, particularly dysmorphic RBCs, are differentiated from yeast, which show budding, and from oil droplets and air bubbles, which are highly refractile, when the fine adjustment is focused up and down. They may appear in a different plane than other sediment constituents
Yessir!
Glomerular bleeding is usually associated with what type of RBCs?
Dysmorphic RBCs
What dysmorphic RBC is associated most closely with glomerular bleeding?
Acanthocytes
Microscopic vs Macroscopic Hematuria
Microscopic: >100 per hpf
Macroscopic: Urine is cloudy with a red to brown color
They are referred to as glitter cells because granules within these larger cells perform a Brownian movement that produces a sparkling appearance
Neutrophils
True or False
Glitter cells are of no pathologic significance
True
When WBCs are stained with Sternheimer-Malbin stain, they exhibit what color?
Light blue
Technical Tip: Use a supravital stain to differentiate mononuclear cells and disintegrating neutrophils from RTE cells, which are usually larger than WBCs and have an eccentrically located nucleus
LEZGO!
What percent of eosinophils found in urine is considered as significant?
more than 1%
Their presence is associated with drug-induced interstitial nephritis (acute interstitial nephritis = AIN)
Eosinophils
Primary concern in the identification of WBCs is the differentiation of mononuclear cells and disintegrating neutrophils from?
RTE Cells
Because they are the smallest WBCs, they may resemble RBCs
Lymphocytes
True or False
<5 WBCs per hpf are found in normal urine
True
Nucleus of RTE cells are located where?
eccentrically located
These are derived from the linings of the genitourinary system
Epithelial cells
An increase in urinary WBCs is called _______ and indicates the presence of an infection or inflammation in the genitourinary system
Pyuria
Differentiate the cause of Pyuria(increased urinary WBCs) if Bacterial or Non-Bacterial
Pyelonephritis
Prostatitis
Glomerulonephritis
Lupus erythematosus
Interstitial nephritis
Tumors
Cystitis
Urethritis
Bacterial:
- Pyelonephritis
- Prostatitis
- Cystitis
- Urethritis
Non-Bacteria
- Glomerulonephritis
- Lupus erythematosus
- Tumors
- Interstitial nephritis
They represent normal sloughing of old cells and are classified as squamous, transitional (urothelial), and renal tubular
Epithelial cells
They are the largest cells found in the urine sediment
Squamous Epithelial Cells
Identify the cell
Abundant, irregular cytoplasm
Prominent nucleus about the size of RBC
Squamous Epithelial Cells
These originate from the linings of the vagina and female urethra and the lower portion of the male urethra
Squamous Epithelial cells
Technical Tip: Epithelial cells can be misidentified when they are folded and look like a cast or when they begin to disintegrate in urine that is not fresh
Salamat po sa impormasyon!
Transitional cells are identified and enumerated using what magnification?
Hpf
A variation of the squamous epithelial cell which DOES have a pathological significance
Clue cells
Clue cells are indicative of vaginal infection by the bacterium __________.
They appear as squamous epithelial cells covered with __________
Gardnerella vaginalis
Gardnerella coccobacillus
They are smaller than squamous epithelial cells and appear as:
spherical
polyhedral
caudate
Transitional Epithelial (Urothelial) Cells
To be considered a clue cell, the bacteria should cover most of the cell surface by how many percent?
70%
They originate from the lining of the renal pelvis, calyces, ureters, and bladder and from the UPPER PORTION of the male urethra
Transitional epithelial cells
Why are spherical transitional cells much larger than polyhedral and caudate cells?
Because spherical cells have direct contact with the urine and absorb more water, thus making them larger.
Nucleus of transitional cells are located where?
Centrally located
Increased number of transitional cells seen in clumps are termed as?
Syncytia
True or False
RTE cells vary in size and shape depending on the area of the renal tubules from which they originate
True
Differentiate the 3 different RTE Cells
From PCT:
From DCT:
From collecting ducts:
PCT: Largest, rectangular shape, referred to as “columnar” or “convoluted cells”
DCT: Smaller than PCT cells, round or oval shape
Collecting Duct: cuboidal shape, never round
True or False
RTE cells from the PCT are larger than other RTE cells
True
RTE cells often are present as a result of _________
necrosis (tissue destruction)
RTE cells from the collecting duct that appear in groups of 3 or more are called as?
Renal fragments
How many RTE cells per hpf would indicate that there is Tubular injury?
more than 2 RTE cells
What viral infection and bacterial infection causes necrosis of the renal tubules?
Viral: Hepatitis B
Bacterial: Pyelonephritis
This is a parasite with:
pear-shaped flagellate
undulating membrane
rapid darting movement
Trichomonas trophozoite
What type of RTE cells are particularly noticeable in cases of salicylate poisoning?
Cuboidal cells (Collecting ducts)
What microscopic technique is used to aid in the visualization of bacteria?
Phase-contrast microscopy
True or False
Salicylate poisoning causes necrosis of the tubules
True
These are the most clinically significant of the epithelial cells
RTE cells
To be considered as significant for UTI, bacteria should be accompanied by?
WBCs
RTE cells appear “deep yellow” in cases of liver damage from viral hepatitis.
They absorb what substance in the filtrate that gives them a deep-yellow color?
Bilirubin
Why is it not unusual for RTE cells to contain substances from the filtrate?
Because one of the functions of RTE cells is the reabsorption of glomerular filtrate
These gram-positive bacteria are also capable of causing UTI
Staphylococcus
Enterococcus
What yeast cells are primarily seen in the urine of patients who are either diabetic or immunocompromised, as well as in women with vaginal moniliasis?
Candida albicans
Technical Tip: Check urine sediments that are negative for fat after staining using polarized light to observe the Maltese cross formation, which occurs when only cholesterol is present.
Hatdog!
It is associated most frequently with damage to the glomerulus caused by nephrotic syndrome
Lipiduria
True or False
Lipiduria is also seen with severe tubular necrosis, Diabete mellitus, and in trauma cases that cause release of bone marrow fat from the long bones
True
They appear to represent injured cells in which the endoplasmic reticulum has dilated before cell death in cases of Acute Tubular Necrosis
RTE cells containing large, nonlipid-filled vacuoles
Bubble cells
The most common parasite ova contaminant is from?
Enterobius vermicularis
The bacteria associated with UTI most frequently are the?
Enterobacteriaceae (gram-negative rod)
Technical Tip: Phase Microscopy is used to differentiate Trichomonas from WBC, transitional, and RTE cells
Kendrick > Drake
The parasite encountered most frequently in the urine is?
Trichomonas vaginalis
They are easily identified in the urine sediment by their:
Oval
Slightly tapered heads
Long, flagella-like tails
Sperematozoa
A positive reagent strip test for _____ may be seen when increased amounts of semen are present
Protein
It is a protein material produced by the glands and epithelial cells of the lower genitourinary tract and the RTE cells
Mucus
Most frequently seen cast, which consists almost entirely of uromodulin
Hyaline Casts
Immunologic analysis has shown that _________ is a major constituent of mucus
uromodulin
Technical Tip: Mucous threads have irregular ends that help to distinguish clumps of mucus with hyaline casts
WRAHHHHHHHHH!
Major constituent of casts
Uromodulin
The presence of urinary casts is termed as?
Cylindruria
It is a glycoprotein excreted by the RTE cells of the thick ascending loop of henle and by DCT
uromodulin
It appears microscopically as “thread-like” structures with a low-refractive index that is why subdued light is required when using bright-field microscopy
Mucus
These are the only elements found in the urinary sediment that are unique to the kidney
Casts
Casts formed at the junction of the ALH and DCT produce structures with a “tapered end” called as?
cylindroids
These casts may result from tubular distension or in the case of extreme urine stasis, from formation in the collecting ducts
Broad casts
RBC casts are associated primarily with damage to the __________ that allows passage of the cells through the glomerular membrane
glomerulus (glomerulonephritis)
Sternheimer-Malbin stain produces what color in Hyaline casts?
Pink
Technical Tip: Use a lower light when using bright-field microscopy to identify hyaline casts because the matrix of the cast has a low refractive index, which can cause hyaline casts to be missed
WOWST!
True or False
Any damage to the nephron capillary structure can cause their formation
True
Technical Tip: RBCs in the urine sediment and a positive reagent strip test for blood, as well as intact RBCs in the cast matrix, must be present to identify a RBC cast
SHEEEEEESH
WBC casts are associated most frequently with what upper UTI?
Pyelonephritis
This is a primary marker for distinguishing pyelonephritis (upper UTI) from cystitis (lower UTI)
WBC casts
WBC casts are also present in nonbacterial inflammations such as ___________ and may accompany RBC casts in _________
acute interstitial nephritis
glomerulonephritis
Bacterial casts containing bacilli both within and bound to the protein matrix are seen in _________
pyelonephritis
Technical Tip: The presence of a WBC cast is diagnostic for pyelonephritis and would not be present in cystitis
They not like us!
Technical Tip: Free-floating WBCs must be in the urine sediment and well-defined WBCs present in the cast to classify a WBC cast
Grabeeeeee!
Bilirubin-stained RTE cells are seen in cases of?
Hepatitis or Liver damage
Fatty casts are associated most frequently with what disease?
Nephrotic syndrome
Mixed cellular cast mostly encountered in pyelonephritis
WBC and RTE casts
or
WBC and Bacterial casts
Fatty casts, aside from nephrotic syndrome, can also be seen in?
Toxic tubular necrosis
Diabetes mellitus
Crush injuries
True or False
Fats can be stained with Sternheimer-Malbin stains (Supravital stains)
False, it can only be stained with Oil Red O or Sudan III or by polarized microscopy
Technical Tip: A hyaline cast with a few granules within the matrix does not constitute a granular cast
STRASINGER WRAH!!!!!!
Mixed cellular casts encountered most frequently in glomerulonephritis are?
RBC and WBC casts
The origin of the granules in casts (granular casts) in nonpathological conditions appear to be from the ________ excreted by RTE cells during normal metabolism
lysosomes
These are representative of extreme urine stasis, indicating chronic renal failure usually seen in in conjunction with other types of casts associated with conditions caused by renal failure, such as hyaline, granular, and cellular
Waxy Casts
These casts are formed from the disintegration or degeneration of the hyaline cast matrix or granules from the matrix
Waxy casts
With supravital stain, like in the KOVA stain, the waxy cast shows what color?
Dark Pink
They are often referred to as “RENAL FAILURE CASTS”
Broad Casts
What are the 2 casts that represent extreme urine stasis?
Broad casts and Waxy casts
