Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 63

When observing RTE casts, the cells are primarily:

A. Embedded in a clear matrix

B. Embedded in a granular matrix

C. Attached to the surface of a matrix

D. Stained by components of the urine filtrate

Step 1 of 2

Renal Tubular Epithelial casts:

• The casts matrix made of uromodulin attaches to the renal tubular epithelial cells, which forms RTE casts

• Presence of RTE casts indicates advanced destruction of tubules with disruption in lining of the tubules

• Majority of the RTE cell casts are attached to the cast surface

• As the casts are formed in distal convoluted tubule, renal tubular epithelial cells on cast matrix appear round, oval, and smaller cells

Therefore, when observing RTE casts, the cells are primarily “attached to the matrix surface”. Hence, the correct answer is option.