Human stools consist of a mixture of undigested food residues, colonic microflora, and cellular components shed from the walls of the gastrointestinal tract. The cellular components are made up mostly of terminally differentiated colonic epithelial cells. Using a combination of Percoll density gradient centrifugation and countercurrent centrifugal elutriation, it is now possible to recover these cells as an enriched fraction from fresh human stools. Cells can be visualized on heat-fixed smears of the enriched fractions stained with modified Wright's stain. The enrichment process is optimized by following the segregation of eukaryotic cells as determined by an ELISA technique using monoclonal antibodies against human double-stranded DNA. This work, demonstrating the feasibility of isolating intact colonic cells from stools, has important applications as a noninvasive approach to the biology of exfoliated cells from the gastrointestinal tract.
What are epithelial cells?
Epithelial cells are cells that come from surfaces of your body, such as your skin, blood vessels, urinary tract, or organs. They serve as a barrier between the inside and outside of your body and protect it from viruses.
A small number of epithelial cells in your urine is normal. A large number may be a sign of infection, kidney disease, or another serious medical condition. For that reason, your doctor may order a urine test or urinalysis to view your urine under a microscope.
Types of epithelial cells
Epithelial cells differ by size, shape, and appearance. There are three types of epithelial cells that can be found in your urine, depending on their origin:
- Renal tubular. These are the most important of the epithelial cells. An increased number can mean a kidney disorder. They’re also called renal cells.
- Squamous. This is the largest type. They come from the vagina and urethra. This type is most often found in female urine.
- Transitional. They can come from anywhere between the male urethra and the renal pelvis. They’re sometimes called bladder cells, and are more common in older adults.
Understanding your test results
A urine test may show that you have “few,” “moderate,” or “many” epithelial cells in your urine.
Epithelial cells naturally slough off from your body. It’s normal to have one to five squamous epithelial cells per high power field (HPF) in your urine. Having a moderate number or many cells may indicate:
- a yeast or urinary tract infection (UTI)
- kidney or liver disease
- certain kinds of cancer
The type of epithelial cells in the urine may also signal certain conditions. For instance, epithelial cells that contain a large amount of hemoglobin, or blood particles, may mean that you recently had red blood cells or hemoglobin in the urine, even if they weren’t there during the urinalysis.
More than 15 renal tubular epithelial cells per HPF may mean your kidney isn’t working properly.
Squamous epithelial cells in your urine may just mean the sample is contaminated.
A urinalysis that finds squamous epithelial cells in the urine isn’t the norm, William Winter, MD, a clinical chemist for Shands Hospital and professor of pathology and pediatrics at the University of Florida, told Healthline.
That’s because the clean catch method of obtaining a urine sample usually prevents squamous epithelial cells from turning up in the urine. When using the clean-catch technique, you’ll be given a sterilizing cloth to wipe the area around the vagina or penis before giving your urine sample. This prevents contaminants from your skin, like epithelial cells, from showing up in your sample.
Your doctor can help you understand your test results and whether you have a medical condition requiring treatment. To find a cause, the doctor may also order further testing.