M1: Urine Sediments (Part 3: Casts) Flashcards
Sole site of casts?
Kidney
They are formed within the** lumens of the distal convoluted tubules** and collecting ducts, providing a microscopic view of conditions within the nephron
Casts
Formed when proteins precipitate & gel in the lumen
Casts
Shape of of casts that is representatiave of tubular lumen?
cylindrical with parallel sides and somewhat rounded ends
they may contain additional elements present in the filtrate.
the cast matrix dissolves quickly in what concentration of urine?
dilute, alkaline urine
COMPOSITION AND FORMATION
major constituent of casts is?
uromodulin
COMPOSITION AND FORMATION
Other proteins present in the urinary filtrate, such as (blank) and (blank), are also incorporated into the cast matrix.
Albumin and Immunoglobulins
COMPOSITION AND FORMATION
1/3 of cast is made up of?
Tamm Horsfall protein/uromodulin
forms the matrix of all casts
COMPOSITION AND FORMATION
Forms a meshwork of fibrils that may trap cells and
granules
Tamm Horsfall protein/uromodulin
COMPOSITION AND FORMATION
2/3 of cast is made up of ?
Albumin and Globulin
5 factors involved in casts formation ?
- Lower pH
- Increased ionic concentration
- Stasis (decrease in flow)
- Obstruction of the nephron by cells or cell debris
- Proteinuria (increase in albumin and globulin)
factors involved in casts formation
this means there is decrease in flow
stasis
What equipment was used that have provided a step- by-step analysis of the formation of the uromodulin protein matrix?
Electron microscope
Familiarize the process of cast formation or memorize up to u
- Uromodulin protein aggregates into protein fibrils attached to RTEs
- The protein fibrils interweave until a solid structure is formed
- Urinary elements attach to the solid matrix
- Protein fibrils detach from the RTE
- Cast is excreted into the urine
Casts formation takes shape in what part of RTE?
Tubules
T or F
As the cast forms, urinary flow within the tubule increases as the lumen becomes blocked
F (As the cast forms, urinary flow within the tubule **decreases **as the lumen becomes blocked)
T or F
The accompanying dehydration of the protein fibrils and internal tension may account for the wrinkled and convoluted appearance of older hyaline casts
T
Formation of casts at the junction of the ascending loop of Henle and the** distal convoluted tubule **may produce structures with?
Tapered ends
referred to as cylindroids, same isgnificance as casts
The presence of urinary casts is termed?
Cylinduria
The appearance of a cast is also influenced by?
a. the materials present in the filtrate at the time of its formation
b. the length of time it remains in the tubule
c. both
d. NOTA
c. both
T or F
Any elements present in the tubular filtrate, including cells, bacteria, granules, pigments, and crystals, may become embedded in or attached to the cast matrix
T
Type of Casts
- Basis of all types of casts
- Most frequently seen cast which consists almost entirely of uromodulin.
Hyaline cast
Type of Casts: hyaline casts
appearance?
- colorless in unstained sediments
- Homogenous matrix
- low refractive index similar to that of urine
Type of Casts: hyaline casts
what stain is used in hyaline casts to produce a pink color
Sternheimer-Malbin stain (SM stain)
pink kasi logo ng sm enetrtainment basta yun
T or F
The morphology of hyaline casts is varied
T
Type of Casts: hyaline casts
morphology of hyaline casts is varied, consisting of what following shapes?
- normal parallel sides and rounded ends
- cylindroid forms
- wrinkled or convoluted shapes
Type of Casts: hyaline casts
Shape of hyaline casts
a. Normal parallel sides and rounded ends
b. Star shaped and Stick form
c. Cylindroid
e. Wrinkled or convoluted shape
f. a, b, c only
g. a, c, e only
h. ALL
i. NOTA
g. a, c, e only
Type of Casts: hyaline casts
normal value (reference range) of hyaline casts?
0-2/LPF
Type of Casts: hyaline casts
Pathological conditions where hyaline casts are increased?
- Acuteglomerulonephritis
- Pyelonephritis
- Chronic renal disease
- Congestive heart failure
PACCu pakyu
Type of Casts: hyaline casts
Non-pathological conditions where hyaline casts are increased?
- Strenuous exercise
- Dehydration
- Heat exposure
- Emotional stress (me rn)
hedds
Type of Casts: hyaline casts
Sources of error?
mucus, fibers, hair, increased lighting
Type of Casts
Composed of RBC and WBC casts
Cellular casts
Types of casts: Cellular casts
Protein matrix with RBCs
RBC Cast
Types of casts: Cellular casts
- Appears orange red under LPO
- Extremely fragile, degenerates to granular casts
RBC Cast
T or F
WBC may be seen in healthy individuals after strenuous exercise or activities
F (RBC)
Types of casts: Cellular casts (RBC)
Clinical significance
The presence of RBC casts is much more specific since it indicates ?
bleeding within the nephron
Types of casts: Cellular casts (RBC)
Clinical significance
RBC casts are primarily associated with damage to?
glomerulus
Types of casts: Cellular casts (RBC)
Damage to glomerulus is termed as?
Glomerulonephritis
Types of casts: Cellular casts (RBC)
RBC casts associated with glomerular damage are usually associated with (2) conditions
proteinuria and dysmorphic erythrocytes
Types of casts: Cellular casts (RBC)
Appearance?
- Granular, dirty, brown casts representing hemoglobin degradation
- products such as methemoglobin may also be present
Types of casts: Cellular casts (RBC)
Granular, dirty, brown casts is associated with what condition?
acute tubular necrosis
Types of casts: Cellular casts (RBC)
Condition often caused by the toxic effects of massive hemoglobinuria that can lead to renal failure
acute tubular necrosis
Types of casts: Cellular casts (RBC)
Granular, dirty, brown casts in microscopic view should be in conjunction with other (2) pathologic findings such as?
RTE cells, Positive reagent strip test for blood
Types of casts: Cellular casts
Cast matrix with WBCs
WBC Cast
Types of casts: Cellular casts
The appearance of WBC casts in the urine signifies infection or inflammation within the nephron
WBC cast
Types of casts: Cellular casts (WBC)
Clinical significance
WBC is frequently assocaited with what (2) conditions?
pyelonephritis (kidney infection), non-bacterial inflammations such as acute interstitial nephritis
Types of casts: Cellular casts (WBC)
WBC most frequently seen in WBC casts?
Neutrophils
Types of casts: Cellular casts (WBC)
may appear granular, and, unless disintegration has occurred, multilobed nuclei will be present
Neutrophils
It is particularly helpful for differentiating WBC casts from RTE casts
Types of casts: Cellular casts (WBC)
are present in cases of pyelonephritis, but are not present with acute interstitial nephritis
Bacteria
T or F
eosinophil casts are not present in appropriately stained specimens for WBC casts
F (may be present in appropriately stained specimens; Hansel and Wright’s stains_
Types of casts: Cellular casts (WBC)
Eosinophils may be present in WBC using what 2 stains?
Hansel and Wright’s stain
Types of casts: Cellular casts (WBC)
Casts tightly packed with WBCs may have what border?
Irregular borders
These structures should be carefully examined to determine that a cast matrix is present
T or F
WBCs frequently form clumps, and these do not have the same significance as casts
T
Types of casts
RTE cast: Cast matrix containing RTE cells
Epithelial cell casts
Types of casts: Epithelial cell cast
Clinical significance
Casts with RTE cells represent the presence of what conditions?
Advanced tubular destruction
Types of casts: Epithelial cell cast
produces urinary stasis along with disruption of the tubular linings
advanced tubular destruction
Types of casts: Epithelial cell cast
Epithelial cells are also associated with
a. heavy metal
b. allograft rejection
c. parasitic infection
d. a and c only
e. a and b
f. ALL
g. NOTA
e. a and b
also seen with WBC casts in cases of pyelonephritis
- heavy metal
- chemical or drug-induced toxicity
- viral infections
- allograft rejection
Types of casts: Epithelial cell cast
Source of error?
WBC clumps
Types of casts: Epithelial cell cast
are seen in cases of
hepatitis
Bilirubin-stained RTE cells
Types of casts
- Cast matrix with multiple cell types
Mixed Cellular cast
Types of casts: Mixed Cellular cast
Familiarze the following mixed cellular casts most frequently encountered
- RBC and WBC casts in glomerulonephritis
- WBC and RTE cell casts in pyelonephritis
- WBC and bacterial casts in pyelonephritis.
Types of casts: Mixed Cellular cast
following mixed cellular casts most frequently encountered:
RBC + WBC casts = ?
RBC + WBC casts = glomerulonephritis
Types of casts: Mixed Cellular cast
following mixed cellular casts most frequently encountered:
WBC + RTE = ?
WBC + RTE = pyelonephritis (kidney infection)
Types of casts: Mixed Cellular cast
following mixed cellular casts most frequently encountered:
WBC + bacterial casts = ?
WBC + bacterial casts = pyelonephritis
T or F
When mixed casts are present, there should also be hetereogenous casts and all of the cell types will be the primary diagnostic marker.
F (OPPOSITE; When mixed casts are present, there should also be homogenous casts of at least one of the cell types, and * they will be the primary diagnostic marker.)
MEANING: dapat may isang casts ang lamang
ex.1 in glomerulonephritis, the predominant
casts will be RBC
ex.2 pyelonephritis, the predominant casts will be WBC
Types of casts: Mixed Cellular cast
predominant casts in glomerulonephritis
RBC casts
Types of casts: Mixed Cellular cast
predominant casts in pyelonephritis
WBC casts
T or f
bacteria are often incorporated into WBC casts and provide little additional diagnostic significance.
T
Types of casts
Cast matrix that contains fat droplets or oval fat bodies
Fatty cast
Types of casts
most frequently associated with the nephrotic syndrome, but are also seen in toxic tubular necrosis, diabetes mellitus, and crush injuries
Fatty cast
Types of casts: Fatty cast
Fatty casts’ appearance are
a. low refractile unde rbirght field microscope
b. highly refractile under phase constrast microscope
c. highly refractile under birght field microscope
d. A and B
e. ALL
f. NOTA
c. highly refractile under birght field microscope
Types of casts: Fatty cast
Confirmation of fatty casts is performed using what equipment and stain?
Equipment: polarized microscopy
Stain: Sudan III or Oil Red O fat stain (SO FAT STAIN)
Types of casts: Fatty cast
demonstrates characteristic Maltese cross formations under polarized light
Cholesterol
Types of casts: Fatty cast
stain orange with fat stains
triglycerides and neutral fats
T or F
Fats do not stain with Sternheimer-Malbin stains
T
Types of casts: Fatty cast
Sources of error?
Fecal debris
Familiarize the phases of dissolution
- Hyaline
- Cellular
- Granular
- Loosely
- Finely
- Waxy
Hyaline –> Cellular –> Granular –> Loosely –> Finely –> Waxy
Types of casts
Final phase of the dssolution of the fine granules of the granular casts
Waxy casts
Types of casts
brittle, highly refractive cast matrix
Waxy cast
Refractile with rigid texture, frequent cracks and convolution “brittle”
Types of casts: Waxy casts
Waxy casts are representative of extreme urine stasis, indicating what condition?
chronic renal failure
T or F
Waxy casts are more easily visualized than hyaline casts because of their higher refractive index
T
Types of casts: Waxy casts
Clinical significance
- Tubular inflammation & degeneration
- Nephroticsyndrome
- Extreme stasis of urine flow
- Chronic renal failure
Types of casts: Waxy casts
Sources of error?
Fibers and fecal material
Types of casts
- 2 to 6x diameter of a normal cast
- Renal failure casts, ______ casts like waxy casts represent extreme urine stasis or tubular atrophy/dilatation.
Broad cast
Types of casts: Broad cast
Broad casts are formed in?
Collecting ducts or distended distal tubules
Types of casts: Broad cast
T or F
When the flow of urine to the larger collecting ducts becomes severely compromised, casts form in this area and appear narrow
F (When the flow of urine to the larger collecting ducts becomes severely compromised, casts form in this area and appear broad)
Types of casts: Broad cast
2 most commonly senn broad casts
Granular and Waxy
Types of casts: Broad cast
Bile-stained broad, waxy casts are seen as the result of the tubular necrosis caused by?
Viral hepatitis
Type of casts
From disintegrated cellular cast
Granular cast
Type of casts
Cast matrix with small, fine granules or large, coarse granules
Granular Cast
Type of casts
Appearance of granular casts frequently seen in the urinary sediment and may be of pathologic or non- pathologic significance
Coarsely and finely granular casts
Type of casts: Granular cast
Identify if non-pathologic or pathologic condition
Lysosomes excreted by RTE cells during normal metabolism
non-pathologic
Type of casts: Granular cast
Identify if non-pathologic or pathologic condition:
Lysosomes excreted by RTE cells during normal metabolism
non-pathologic
Type of casts: Granular cast
Increased cellular metabolism occurring during periods of strenuous exercise accounts for the transient increase of granular casts that accompany the increased hyaline casts
non-pathologic
Type of casts: Granular cast
Identify if non-pathologic or pathologic condition:
Glomerulonephritis
pathologic condition
Type of casts: Granular cast
Identify if non-pathologic or pathologic condition:
Pyelonephritis
pathologic condition
Type of casts: Granular cast
Identify if non-pathologic or pathologic condition:
Tubule-interstitial disease
pathologic condition
Type of casts: Granular cast
Identify if non-pathologic or pathologic condition:
Renal allograft rejection
pathologic condition
Type of casts: Granular cast
Identify if non-pathologic or pathologic condition:
protein aggregates filtered by the glomerulus
pathologic condition
Type of casts: Granular cast
What phenomenon which allows the casts to remain in the tubules must be present for granules to result from disintegration of cellular casts.
Urinary stasis
Type of casts: Granular cast
Sources of error?
clumps of small crystals, fecal debris, columnar RTE cells
T or F
When granular casts remain in the tubules for extended
periods, the granules further develops, and the cast matrix develops a waxy appearance.
F (When granular casts remain in the tubules for extended
periods, the granules further disintegrate, and the cast matrix develops a waxy appearance)
structure becomes more rigid, the ends of the casts may appear jagged or broken, and the diameter becomes broader.
Familiarize other casts mentioned
- Hemosiderin casts
- Crystal casts
- Pigmented casts:
other casts
What casts to these belong: Urates, calcium oxalates & sulfonamides
Crystal casts
other casts
Cast matrix with coloration due to pigment incorporation
Pigmented casts
other casts
3 examples of pigmented casts?
bilirubin, hemoglobin, myoglobin
other casts: pigmented cast
Goldenbrown; Obstructive jaundice
bilirubin casts
other casts: pigmented cast
Yellow to red; Glomerular disease
hemoglobin
other casts: pigmented cast
red brown; acute renal failure
Myoglobin cast
What are the telescoped sediments?
- Elements of glomerulonephritis
- Elements of nephrotic syndrome
- RBCs, RBC casts, cellular casts, broad waxy casts, lipid droplets, oval fat bodies, fatty casts
- Collagen vascular disease (lupus nephritis)
- Subacute Bacterial Endocarditis