Urine Abnormalities in Renal Disease

·         RBC: 1-2

·         WBC: 2-5

o        Up to 5 is normal for females, but would be considered high in males

·         Epithelial (Ep) Cells (squamous, transitional, renal tubular cells) 1-2

These are squamous epithelial cells. Note the centrally located nucleus. Sq cells are not pathologic, though may signify contamination. 

This pear shaped cell is transitional epithelium from the bladder. If we see lots of these cells it may signify cystitis. 

Casts:

·         Hyaline 1-2

o        Composed of Tamm Horsfall protein

o        Hyaline casts have the same light refractory index as glass, so to see must focus back and forth.

o        Totally normal, so regardless of the amount present is not pathologic.

·         Granular 1-2

·         composed of albumin & Tamm-Horsfall protein

·         seen in normal, and in pathology so Dr. Reddi says that granular casts are not pathgnomic

·         Vignette: if someone is dehydrated, they will have a lot of granular casts which signify decreased GFR. This patient will also probably have high serum creatinine

·         RBC: 1- many; the number will vary depending on the cause of the hematuria

·         WBC: 1-many

·         Renal Tubular Cells (RTC) : many

These are renal tubular cells. To distinguish from WBC note that RTCs are 2-3 times larger and have an eccentric nucleus. This are pathognomic for acute tubular necrosis.

Casts

·         Muddy Brown

o        Differential diagnosis of muddy brown casts is rhabdomyolysis (destruction of muscle cells leading to high levels of myoglobin) which can cause acute tubular necrosis

·         RTC cast (protein mixed w/ renal cells)

RTC casts are hard to distinguish from WBC casts. Are indicative of Acute tubular necrosis.

·         RBC: many

Here we see lots of RBC and a few WBC. The RBCs can have different shapes which can distinguish if they came from the kidney, urethra or bladder.

·         WBC: few

·         Ep. Cells: few

Casts

·         RBC

·         A RBC cast is pathognomic for GN & vasculitis. A RBC casts is BAD, red blood cells should not be found in the urine.

·         Often Hb (hemoglobin) casts may also be present, formed from Hb being released from a RBC cast.

·         RBC: many

·         WBC: many

·         Ep. Cells: 1-2

Casts

·         RBC

·         WBC

·         Broad

·         RBC: 1-10

·         WBC: many

·         Eosinophils (may have to use Hansen’s or Wright’s stain)

·         Ep Cells: 1-2

Casts

·         WBC

WBC casts are commonly seen in proximal tubulointerstitial disease, AIN, or pyelonephritis.

·         RBC: few

·         WBC: many

·         Ep cells: 1-2

Casts

WBC