Cells & Microorganisms & Casts (Sediment Constituents)

Red Blood Cells

• Biconcave disks, ~7 um in diameter

• Normal: 0-2 / HPF

• Hematuria: ⬆RBCs seen in glomerulonephritis, renal calculi, malignancy, strenuous exercise

Ghost cells

Under RBCs:

• seen un diluted hypotonic urine

Crenated cells

Under RBCs:

• seen in concentrated urine

Dysmorphic RBCs (Pathologic)

Under RBCs:

• seen in Glomerulonephritis

• Few irregular prutusions

White Blood Cells

• Larger than RBCs, ~12 um in diameter

• Normal: 0-5 / HPF

• Pyuria: ⬆ WBCs seen in urinary tract infection or inflammation (acute interstitial nephritis)

Neutrophils

Under WBCs:

• most common WBC

Glitter cells

Under WBCs:

• sparkling appearance due to Brownian movement of granules

Eosinophils

Under WBCs:

• >1% - AIN

Mononuclears

Under WBCs:

• Seen in Graft rejection, Viral Infection

Renal Tubular ECs

• Rectangular or Columnar (PCT), round or oval (DCT), cuboidal (CD) with Large Eccentric Nucleus

• Most significant EC type

• >2/HPF = tubular injury

Oval Fat Bodies

Under RTECs:

• seen in Nephrotic Syndrome

Bubble Cells

Under RTECs:

• seen in Acute Tubular Necrosis

Bilirubin-laden

Under RTECs:

• seen in liver disorder

Hemosiderin - laden

Under RTECs:

• seen in hemolytic disorders

Transitional ECs

• Spherical, polyhedral or caudate with Central Nucleus

• Singly or in Syncytia after urologic procedures (catheterization)

• Abnormal Morphology indicates

  • Malignancy

  • Viral infection

Squamous ECs

• Largest cell in the urine Sediment

• With abundant, irregular cytoplasm and a prominent central nucleus about the size of an RBC

Clue cells

Under Squamous ECs:

• SECs covered with G. vaginalis cocobacilli

Bacteria

• Gram neg rods and cocci esp. Staphylococcus and Enterococcus spp; indicate UTI when seen in conjunction with pyuria and a positive culture

Yeast

• small, retractile oval structures associated with diabetes, immunocompromised state, vaginal moniliasis

• Most common agent: C. albicans

T. vaginalis trophozoite

Under Parasites:

• most commonly encountered

• May resemble a WBC or EC

• Causes urethritis

S. haematobium eggs

Under Parasites:

• With a terminal spine

E. vermicularis eggs

Under Parasites:

• contaminant from the perianal area

Casts

Sites of Formation:

• Lumen of DCT & Collecting Duct

Factors the Encourage formation:

• ⬆ Concentration of Solutes (Acid pH, Stasis, Tann-Horsefall protein)

Hyaline Casts

Major Component:

• Tamm Horsefall protein (uromodulin)

RI = ⬇ (same as urine)

Normal # : 0-2/LPF

Significance of ⬆ no:

• Pathologic: congestive heart failure, renal disease

• Non Pathologic: Strenuous Exercise, Fever, stress

Cellular Casts

Types and Significance

RBC (orange red color) cast:

• strenuous exercise

• Glomerulonephritis

WBC cast:

• Pyelonephritis

RTE cast:

• Advance Tubular damage or Acute Tubular Necrosis

Granular Casts

• Normal no: 0-1/LPF

Significance of ⬆ no:

• Strenuous exercise

• Glomerulonephritis

• Pyelonephritis

• “Athletic pseudo nephritis”

  • Common in athletes

  • May see hyaline, WBC, ?

Waxy Casts

• Appearance: with jagged ends and notches; easily fragmented

• RI = High

• Significance:

  • Severe stasis → Chronic GN, Chronic PN, Renal Failure

RBC Cast

• Acute Glumerulonephritis

WBC cast

• Acute Pyelonephritis

Lipids

• fatty casts associated with Nephrotic Syndrome

Broad waxy cast

• Renal Failure cast (extreme stasis)

• No net movement = anuria

Cylindroid

• with tapered end due to formation at the junction of ascending LOH & DCT

Fatty Cast

• Highly retractile and may produce Maltese cross pattern (when contained w/ cholesterol

• Seen in Nephrotic Syndrome

• most notable with lipiduria