What does it mean to have granular casts in urine?
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 normal or abnormal occurrences found in the kidney itself.
What does a granular cast look like?
Granular casts Their appearance is generally more cigar-shaped and of a higher refractive index than hyaline casts. While most often indicative of chronic renal disease, these casts, as with hyaline casts, can also be seen for a short time following strenuous exercise.
Is it normal to see casts in urine?
Normally, the presence of casts in the urine is considered to be an unusual finding. However, small amounts of hyaline casts (between 0–2 casts per low power field of the microscope) may be detected in the urine of healthy individuals without necessarily indicating a serious condition like kidney disease.
How are 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.
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 does a granular cast in urine mean?
Granular casts are a sign of underlying kidney disease. However, they are nonspecific and may be found in people with many different kidney disorders. Hyaline casts are usually caused by dehydration, exercise, or diuretic medicines. Renal tubular epithelial cell casts reflect damage to the tubule cells.
Where does granularity come from in a cast?
In clinical grounds, granular casts are typically associated with acute tubular injury (ATI) and guide the differentiation between prerenal and overt tubular insult. The traditional view is that the granularity of granular casts comes from tubular epithelial cell debris that fill the cylindrical structure.
How are granular casts different from hyaline casts?
Granular Casts Granular casts result either from the degeneration of cellular casts, or direct aggregation of plasma proteins or immunoglobulin light chains. They have a textured appearance which ranges from fine to coarse in character. Their appearance is generally more cigar-shaped and of a higher refractive index than hyaline casts.
Which is better granular cast or muddy brown cast?
Finely granular cast B. slightly coarser granular cast C. “urine poker quads” showing a fine (f), coarse (c) and muddy brown (mb) granular cast accompanied by a waxy (wx) cast D. “Muddiness” of mb granular casts is better appreciated at low power field compared to high power field (inset).