How is waxy cast formed?
Casts are clusters of urinary sediment elements (red blood cells, white blood cells, fat bodies, etc.) wrapped in a protein matrix. Cast formation necessarily occurs in the kidney tubules, and the contents of the casts indicate the nature of the abnormalities occurring in the kidney itself.
What causes waxy casts in urine?
Waxy casts can be found in people with advanced kidney disease and long-term (chronic) kidney failure . White blood cell (WBC) casts are common with acute kidney infections and interstitial nephritis.
How are casts formed in kidney?
Casts are the result of solidification of material (protein) in the lumen of the kidney tubules, more specifically in the nephron. Once formed, these molds (or casts) of the tubule are eliminated via the urine and may be seen in the urine sedi- ment.
How are urinary casts formed?
Casts: Urinary casts are cylindrical structures that are formed from coagulated protein (Tamm-Horsfall protein) secreted by tubular cells. As their name implies, they are usually formed in the long, thin, hollow renal tubules and take their shape. They develop in the distal convoluted tubule or the collecting duct.
Why do casts form?
They form via precipitation of Tamm–Horsfall mucoprotein which is secreted by renal tubule cells, and sometimes also by albumin in conditions of proteinuria. Cast formation is pronounced in environments favoring protein denaturation and precipitation (low flow, concentrated salts, low pH).
What are the different types of casts in urine?
Urinary Casts
| Type | Description |
|---|---|
| Plain casts | |
| Hyaline | Glycoprotein matrix consisting mainly of Tamm-Horsfall protein secreted by tubules |
| Waxy | Glycoprotein matrix with degraded protein Formed in atrophic tubules Highly refractile with waxy appearance |
| Casts with inclusions |
What are waxy casts?
Waxy casts are believed by some to be the final stage of degeneration of the fine granules of granular casts. Since the granules need time to degrade, this finding implies localized nephron obstruction. Waxy casts are seen in chronic renal failure, and acute and chronic renal allograft rejection.
What do urinary casts indicate?
Urinary casts are microscopic clusters of urinary particles, such as cells, fat bodies, or microorganisms, wrapped in a protein matrix and found in the urine. Urinary casts serve as clinical indicators of kidney condition and can be assessed to determine the functioning of the kidneys.
Where is cast formed?
Casts are cylindrical bodies formed either in the distal convoluted tubules or the collecting ducts of the kidney.
Why do granular casts form?
Urine sediment showing waxy and fine and coarse (arrow) granular casts. The broader casts are thought to form when there is stasis (due to advanced kidney failure) in the wider collecting tubules into which many nephrons drain.
What are casts made of?
Casts are partly made from fiberglass or plaster, which form the hard layer that protects the injured limb and keeps it immobilized. Fiberglass has several advantages compared to plaster. It weighs less, so the cast made from it will be lighter. More durable and porous, fiberglass allows air to flow in and out.
What type of cast is most commonly found in urine?
Hyaline casts are the simplest and most common type of urinary cast. Urinary casts are microscopic clusters of urinary particles, such as cells, fat bodies, or microorganisms, wrapped in a protein matrix and found in the urine.
What do waxy casts look like?
Waxy casts appear as cylinders of smooth, highly refractive material. They are yellow, homogeneous, and their ends may be square or broken off. Cracks may occur within the cast, giving it a segmented appearance.
What are casts in the urine?
What causes hyaline casts?
The presence of hyaline casts typically indicates a decreased or sluggish urine flow, which can be a result of strenuous exercise, diuretic medications, severe vomiting, or fever.
What is granular cast?
Granular casts are casts that contain either proteins, tubular cells or leukocytes that have broken down. The presence of granular casts in the urine does not indicate the type of kidney disease present.
What is casting and its process?
Casting processes involve the use of molten material, usually metal. This molten material is then poured into a mould cavity that takes the form of the finished part. The molten material then cools, with heat generally being extracted via the mould, until it solidifies into the desired shape.
What are urinary casts?
Urinary casts are tiny tube-shaped particles that can be found when urine is examined under the microscope during a test called urinalysis .
What is a waxy cast in the kidney?
Since the granules need time to degrade, this finding implies localized nephron obstruction. Waxy casts are seen in chronic renal failure, and acute and chronic renal allograft rejection. Unusually broad waxy casts are known as renal failure casts. These very broad casts are created in the dilated tubules seen in end-stage renal disease.
What is the difference between renal tubular and waxy casts?
Renal tubular epithelial cell casts are found in diseases such as hepatitis and cytomegalovirus infection associated with tubular epithelial destruction. Waxy casts are acellular casts formed by the breakdown of cellular casts. They are associated with chronic renal disease.
What is a broad waxy cast?
Waxy casts are seen in chronic renal failure, and acute and chronic renal allograft rejection. Unusually broad waxy casts are known as renal failure casts. These very broad casts are created in the dilated tubules seen in end-stage renal disease.
What are the types of casts in nephrotic syndrome?
In nephrotic syndrome many additional types of cast exist including broad and waxy casts if the condition is chronic (this is referred to as a telescopic urine with the presence of many casts). Formed by the breakdown of lipid-rich epithelial cells, these are hyaline casts with fat globule inclusions, yellowish-tan in color.