Urine Sediments Flashcards
1
Q
Microscopic UA
- Recommended volume
A
10-15 mL (12mL is preferred)
2
Q
Microscopic UA
- Centrifugation time
A
5 minutes
3
Q
Microscopic UA
- Centrifugation speed
A
400-450g (1800 rpm)
4
Q
Procedure for preparing a specimen for sediment examination
A
- Mix specimen and pour aliquot of 10-12 mL into urine urine centrifuge tube
- Centrifuge for 5 minutes at 400-450g
- After coming to a complete stop, decant the tube
- Mix remaining sediment well
- Deliver well mixed sediment to the slide using disposable pipet
5
Q
Proper magnification for enumerating casts
A
Low (10x) but identify at High (40x)
6
Q
Proper magnification for enumerating mucus
A
Low (10x)
7
Q
Proper magnification for identifying and enumerating epithelials, WBCs, RBCs, crystals
A
High (40x)
8
Q
Proper magnification for evaluating the presence of bacteria, sperm, yeast, trichomonas, or other
A
High (40x)
9
Q
How do RBCs act in hyper/hypotonic urine?
A
- Hypertonic: crenate
- Hypotonic: swelled, lysed, or ghost cells (includes alkaline urine)
10
Q
RBCs will lyse in ____ ____
A
Acetic acid
11
Q
____ indicates damage to the kidney or urinary tract
A
Hematuria
12
Q
RBCs/RBC casts/protein indicate what?
A
Renal origin, either glomerular or tubular
- Glomerulonephritis
- Pyelonephritis
- Tumors
- Calculi
- Trauma
13
Q
RBCs/no RBC casts/no protein indicate what?
A
Bleeding “below” the kidney (cystitis) or contamination (menstrual or hemorrhoidal)
14
Q
T/R, hemoglobin levels < 250 RBCs/uL are likely to cause a positive protein
A
False
15
Q
If RBCs are seen microscopically but not on the strip, what does that mean?
A
- Expect interference w/ ascorbic acid
- Possible misidentification of RBCs
16
Q
How do WBCs act in hyper/hypotonic urine?
A
- Hypertonic: will shrink but won’t crenate
- Hypotonic: will enlarge and may lyse
17
Q
What do degenerated WBCs look like?
A
- Lyse
- Bleb formation
18
Q
If pyuria is seen w/ WBC casts, cellular casts, or granular casts, this indicates what?
A
Upper UTI is suspected; positive protein
19
Q
If pyuria is seen w/o casts, this indicates what?
A
Lower UTI is suspected; low protein
20
Q
What does the predominance of eosinophils indicate?
A
- Drug induced acute interstitial nephritis
- Renal transplant rejection
21
Q
What does the predominance of lymphs indicate?
A
Early renal transplant rejection
22
Q
Leukocyte esterase strip detects ____ and ____ WBCs
A
Intact; lysed
23
Q
What is a glitter cell?
A
Swollen neutrophils in a hypotonic solution
24
Q
What makes a swollen neutrophil a glitter cell?
A
Their refractile cytoplasmic granules move by Brownian movement and “glitter”
25
How do you differentiate RBCs from yeast?
Yeast varies in size, is not biconcave, and buds
26
How do you differentiate RBCs from air bubbles/oil droplets?
Air bubbles/oil droplets are refractile, vary in size, and have a uniform appearance
27
How do you differentiate RBCs from calcium oxalate crystals?
Calcium oxalate crystals have an envelope shape
28
How do you differentiate RBCs from starch?
Starch is not perfectly round, highly refractile, has a central dimple, maltese cross under polarized light
29
Squamous epithelial cells
| - Appearance
- Flat w/ irregular shapes
| - Central round nucleus
30
Squamous epithelial cells
| - Origin
Vaginal contamination
31
Squamous epithelial cells
| - Clinical significance
Rare diagnostic significance
32
Transitional epithelial cells
| - Appearance
- Round
- Pear-shaped or tail-like projection
- Central round nucleus
33
Transitional epithelial cells
| - Origin
Originates in renal pelvis, calyces, ureter, urinary bladder, and upper part of urethra in males
34
Transitional epithelial cells
| - Clinical significance
Increased numbers: UTI, viral illness, catheterization, malignancy (transitional cell carcinoma)
35
Sheets of transitional epithelial cells
Synctia
36
Presence of synctia w/o recent catheteriztion indicates what?
Transitional cell carcinoma
37
Renal tubular epithelial cells
| - Appearance
- Polyhedral (flat, cuboidal, columnar)
- Eccentric nucleus
- BIG nucleus
38
Renal tubular epithelial cells
| - Origin
Originate in lining of the renal tubules and collecting ducts
39
Renal tubular epithelial cells
| - Clinical significance
MOST SIGNIFICANT EPI
- Pathologic → pyelonephritis, kidney damage from meds or toxins, tubular necrosis, renal transplant rejection, viral infections (Hep B)
40
Origin of an oval fat body
Renal tubular epi cell w/ absorbed lipids
41
Cholesterol
| - Not/birefringent
Birefringent
42
```
Neutral fats (triglycerides, fatty acids)
- Not/birefringent
```
Not birefringent
43
Cholesterol
| - Stains
Does not stain
44
```
Neutral fats (triglycerides, fatty acids)
- Stains
```
Sudan Red or Oil Red O (identification)
45
What is the difference b/w oval fat bodies, air bubbles/oil droplets, and starch granules?
- Starch: maltese cross pattern under polarized light; under normal light, not spherical, highly refractive, dimple in center
- Oils: refractive, vary in size, uniform appearance
46
Clinical significance of sperm found in urine
- Males: recent ejaculation or nocturnal emission
| - Females: vaginal contamination
47
Normal acidic crystals
- Uric acid
- Amorphous urates
- Calcium oxalate
- Hippuric acid
- Monosodium urate
48
Abnormal acidic crystals (PATHOLOGIC)
- Tyrosine
- Leucine
- Bilirubin
- Cystine
- Cholesterol
- Sulfonamide
- Radiographic dye
49
Alkaline crystals (no abnormal crystals in alkaline urine)
- Amorphous phosphates
- Triple phosphate
- Calcium carbonate
- Calcium phosphates
- Ammonium biurates
50
Pathologic crystals appear in ____ and ____ pH
Acidic; neutral
51
Usually presented as rhomboid plates but can also be seen as six-sided plates or barrels; when multiple crystals laminate together, they form rosettes or stars; yellow-brownish in color
Uric acid crystals
52
Uric acid crystals
| - Clinical significance
- Normal, product from digestion of RNA and DNA
- Chemotherapy
- Gout
- Acute febrile conditions
- Chronic renal disease
- Lesch-Nyhan Syndrome
53
Yellow-brown, pink sediment; precipitation is enhanced on refrigerated specimens
Amorphous urates
54
Amorphous urate
| - Clinical significance
No clinical significance
55
Pencile/needle-like prisms; colorless to light yellow
Monosodium urate crystals
56
Monosodium urate crystals
| - Clinical significance
No clinical significance
57
Enveloped shape, colorless
Dihydrate calcium oxalate
58
Ovoid or dumbbell shape (may resemble RBCs), colorless
Monohydrate calcium oxalate
59
Nonpathologic calcium oxalate crystals are seen when?
After the ingestion of excess oxalate as seen in ascorbic acid, citrus fruits, and certain vegetables (tomatoes, asparagus, spinach, rhubarb)
60
Pathologic calcium oxalate crystals are seen when?
Following the ingestion of ethylene glycol (antifreeze) (usually monohydrate form), severe chronic renal disease, kidney stones
61
Six-sided prisms, needles, diamonds
Hippuric acid
62
Hippuric acid crystals are seen when?
After the ingestion of vegetables that have been preserved in benzoic acid
63
Hippuric acid
| - Clinical significance
- Usually not significant
| - May indicate hepatic disease or acute febrile conditions
64
Thin, needle-like, usually in clusters; coloreless to yellow in color; often seen w/ leucine crystals; reagent strip indicates presence of bilirubin as well
Tyrosine (pathologic)
65
Tyrosine crystals
| - Clinical significance
- Severe liver disorder (viral hepatitis, hepatocellular poisons)
- Inherited disorder in amino acid metabolism (tyrosinemia)
66
Sphere w/ concentric striations; yellow-brown in color
Leucine crystals (pathologic)
67
Leucine crystals
| - Clinical significance
- Severe liver disorder
- Liver disease (viral hepatitis, hepatocellular poisons)
- Maple Syrup Urine disorder (MSUD)
68
Small clusters of fine needles; yellow-brown
Bilirubin crystals (pathologic)
69
Bilirubin crystals
| - Clinical significance
Correlate w/ reagent strip
| Liver disease that leads to jaundice
70
Colorless, thin hexagonal plates; sometimes w/ two sides shorter or longer than the other four sides; may fuse/laminate to form rosettes
Cystine crystals (pathologic)
71
Cystine crystals
| - Clinical significance
Metabolic disorders (cystinosis, cystinuria)
72
Flat plate w/ notched corner (looks like Utah); may form in clusters
Cholesterol (pathologic)
73
Cholesterol crystals
| - Clinical significance
- Nephrotic syndromes
- Renal disease
- Deposition of lipids in the kidneys (chyluria)
74
Brown rosettes or spheres w/ irregular radial striations
Sulfamethoxazole (pathologic)
75
Shocks of wheat, needles, fans
Sulfadiazine (pathologic)
76
Sulfanomide crystals
| - Clinical significance
- Medication
| - Crystals may cause renal tubular damage
77
Pleomorphic needles (single or in sheaths) or in long flat rectangular plates; SG is > 1.040 (often > 1.050)
Radiographic dye crytals (pathologic)
78
Radiographic dyes
| - Clinical significance
Patient hx indicates recent administration of radiographic dye
79
Fine, colorless to slightly brown granules; white precipitate when centrifuged
Amorphous phosphates
80
Amorphous phosphates
- Soluble in...
- Insoluble in...
- Soluble in...acetic acid (good for clearing; but sure to check for RBCs before adding
- Refrigeration enhances precipitation but heating doesn't get rid of them
81
Amorphous phosphates
| - Clinical significance
Alkaline tide after eating
82
Coffin lids, prisms w/ 3-6 sides w/ oblique angles; colorless
Triple phosphate
83
Triple phosphate
| - Clinical significance
- Normal
- May cause stone formation
- Infection w/ urea-splitting bacteria`
84
Colorless granules; often form in pairs to give appearance of dumbbells; may aggregate to look like amorphous material
Calcium carbonate
85
Calcium carbonate
| - Clinical significance
- None
| - May be seen after ingesting a large amount of vegetables
86
Granular, amorphous, or crystalline prisms w/ one end (looks like a finger pointing)
Calcium phosphate
87
Calcium carbonate
| - Clinical significance
- Normal
- Cystitis w/ urinary retention
- May form stones
88
Yellow-brown spheres w/ radiating spicules (thorny apples)
Ammonium biurates
89
Ammonium biurates
| - Clinical significance
- None
| - May be seen w/ ammonia-producing bacteria
90
Presence of WBCs in urine
Pyuria
91
Presence of RBCs in urine
Hematuria
92
Fat in the urine
Lipiduria
93
Cells of ____ Loop of Henle continuously secrete ____
Ascending; uromodulin
94
Composition of casts
Fibrous protein network of uromodulin (as urine is concentrated)
95
Formation of casts
Cells of the ascending loop of hence continuously secrete uromodulin and as the urine becomes increasingly concentrated, in the DCTs and CDs, uromodulin forms fibrils that attach it to the lumen cells.
96
Another name for Tamm-Horsfall glycoprotein
Uromodulin
97
Factors that promote formation of casts
- Urinary stasis
- Acidic pH
- High SG
- Increased plasma proteins (such as albumin) in the ultrafiltrate
98
Two locations w/in the nephron are the sites of the most cast formation b/c the SG is the highest and the pH is lowest
Distal tubules; collection ducts
99
Two factors that increase the rate of cast degradation
- Alkaline urine
| - SG < 1.003
100
Stages of cellular degeneration in a cast
1. Hyaline casts
2. Cellular cast
3. Mixed granular cast
4. Coarsely granular cast
5. Finely granular casts
6. Waxy cast
101
Significance of mucus
- No significance
| - May be increased in inflammation or irritation
102
Significance of bacteria w/ particular attention paid to clue cells
Frequent contaminant of skin or vagina; in combination w/ excess WBCs source is likely bacterial vaginosis
103
Significance of yeast/fungi
- May be a vaginal contaminant (Candida albicans and Candida glabrata are the most common species found)
- More commonly found in immunocompromised and diabetes mellitus patients
104
Significance of Trichomonas vaginalis
- Protozoan flagellate (only one found in urine)
- STD
- Primarily a female infection (males asympatomatic carriers)
105
Significance of helminth Schistosoma hematobium
- Aka blood fluke
| - Introduced into urine through the bladder wall
106
Significance of helminth Enterobius vermicularisi
- Aka pin worm
| - Fecal contaminant
107
Significance of arthropod Scarcoptes scabei
- Aka mites (cause of scabies)
| - Found in the urine as a result of falling into urine from skin of the pubic or perianal area
108
Significance of arthropod Phthirus pubis
- Aka "crabs"
- Spread sexually
- Lives on pubic hair and falls into urine
109
Acellular casts
- Hyaline
- Granular
- Waxy
- Fatty
110
Cellular casts
- WBC
- RBC
- Bacterial
- Epithelial cells
- Mixed
111
Most common urinary cast composed almost entirely of uromodulin; low refractive index makes it difficult to visualize; may have a few inclusions
Hyaline cast
112
Hyaline cast
| - Significance
- A few are normal (0-2/lpf), esp after exercise and stress (athlete pseudonephritis)
- Physiologic dehydration
- Mild renal disease
- Pathologic causes (acute glomerulonephritis, pyelonephritis, chronic kidney disease)
113
Two types of granular casts
Fine and coarse
114
Formed by the lysosomal excretion of metabolism byproducts by the renal tubular epi cells; normal patients may have them after strenuous exercise
Fine granular casts
115
Formed by the death and degeneration of renal tubular cells or cellular casts; pathologic (renal disease)
Coarse granular casts
116
Parallel sides w/ notches or serrations; often broad; fragile, may be stubby casts, blunt or broken ends are highly likely; believed to be an advanced stage of degeneration for other casts such as hyaline, granular, or cellular; takes up to 48 hours to form (prolonged urinary stasis); more refractile than hyalline; often other types of casts are also present
Waxy casts
117
Waxy casts
| - Significance
- Severe renal disease
- ESRD (esp. broad and waxy)
- Chronic glomerulonephritis
- Diabetic nephrosclerosis
- Malignant hypertension
- Renal transplant rejection
118
Contains free fat or oval fat bodies
Fatty casts
119
Fatty casts
| - Significance
- Nephrotic syndrome
- Fatty degeneration of tubules (tubular necrosis)
- Diabetic glomerulsclerosis
- Chronic glomerulonephritis
120
Contains WBCs; 1/3 of the cast surface must be covered in order to be identified
WBC casts
121
Two different origins for WBC casts
- Glomerular
| - Tubular
122
WBC casts (glomerular origin)
RBC casts will also be seen (greater number than WBC)
123
WBC casts (tubular origin)
- Leukocytes migrate into tubular lumen
- Look for bacteria (often accompanied by protein and blood)
- If no bacteria, suspect viral (CMV)
124
WBC casts
| - Significance
- Renal infection (pyelonephritis) → look for bacteria and neutrophils
- Glomerular disease → Red, white, and/or mixed cell casts
- Acute interstitial nephritis → no bacteria, look for eosinophils, renal inflammation
125
Contains intact RBCs; enters through damaged glomerular basement (most common) or tubular damage; correlate b/w blood reagent strip
RBC cast
126
RBCs are not intact; usually red/brown; may have granular inclusions; correlate w/ blood reagent group
Hemoglobin casts (aka blood cast)
127
RBC casts
| - Significance
- Glomerulonephritis (Acute, rapidly progressive, Goodpasture's syndrome)
- Subacute bacterial endocarditis (SBE)
- Renal trauma (boxing, football, etc)
128
Often mixed w/ WBCs in the cast; easily confused w/ granular casts (correlate w/ free bacteria and WBCs)
Bacterial casts
129
Bacterial cast
| - Significance
Diagnostic of pyelonephritis
130
Aka epithelial cast; cells are sloughing from the renal tubular epithelium; arranged randomly or in parallel rows; often accompanied by proteinuria and granular casts
Renal tubular cell casts
131
Epi vs. WBC cast
Epithelial casts are larger and nucleus w/o lobes; sparse cytoplasm w/o granules
132
Renal tubular cell casts
| - Significance
- Tubular necrosis
- Nephrotoxins (mercury, diethylene glycol, chemotherapeutic agents)
- Viral disease (hepatitis → correlate w/ bilirubin; CMV)
133
RBC/WBC casts
Glomerulonephritis
134
WBC/RTE casts; WBC/bacterial cast
Pyelonephritis
135
2-6x larger than other casts; formed in pathologically dilated renal tubules or collecting ducts (destruction and widening of tubular walls); accompanied w/ urinary stasis; all types of casts occur in this form, waxy and granular are more common
Broad casts
136
Broad casts
| - Significance
- Severe renal disease
| - ESRD
137
Describe hemoglobin/myoglobin casts
- Yellow-brown
| - Hematuria
138
Describe bilirubin casts
- Yellow-brown
- Bilirubinuria
- All elements in entire sediment will be pigmented
139
Long thread or ribbon-like structures; produced by glands or lower urinary tract and by vaginal epi cells as well as RTE which secrete uromodulin
Mucus
140
Spherical/ovoid, budding, hyphal forms
Fungi/yeast
