Urine Sediments: Cells and Crystals II

Question 1

Composition of casts

Answer 1

fibrous protein network of uromodulin (any cells can get caught)

Question 2

Formation of casts

Answer 2

Cells of the ascending loop of hence continuously secrete uromodulin and as the urine becomes increasingly concentrated in the distal convoluted tubules and collecting ducts, uromodulin forms fibrils that attach it to the lumen cells.

Question 3

Another name for Tamm-Horsfall glycoprotein

Answer 3

Uromodulin

Question 4

Factors that promote formation of casts

Answer 4

Urinary stasis
Acidic pH
High specific gravity
Increased plasma proteins (such as albumin) in the ultrafiltrat

Question 5

Kidney Pathology and casts formation

Answer 5

Distal tubules and collection ducts are the sites of most formation because the SG is highest and the pH is lowest

Question 6

Factors that increase the rate of cast degradation

Answer 6

alkaline urine

low SG<1.003

Question 7

Stages of cellular degeneration in a cast

Answer 7

1. Hyaline Casts
2. Cellular Cast
3. Mixed Granular Cast
4. Coarsely Granular Cast
5. Finely Granular Casts
6. Waxy Cast

Question 8

significance of mucous

Answer 8

No significance, may be increased in inflammation irritation

Question 9

significance of bacteria with particular attention paid clue cells

Answer 9

frequently contaminant of skin or vagina, in combo with excess WBCs source is likely bacterial vaginosis

Question 10

significance of yeast/fungi

Answer 10

may be vaginal contaminant, candida albicans and candida glabrata are the most common species found, more common in immunocomp patients and diabetes mellitus patients