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Blood Test Tracker

Urine Renal Tubular Epithelial Cells

A count of kidney tubule cells in urine, where none seen is the usual result and more can mean the tubules are irritated or injured.

AI-verified against cited sources. Awaiting expert reviewAlso called RTE, RTEC, RTE cellsLOINC 26052-1

What it is

Renal tubular epithelial cells line the tiny tubes inside your kidneys. These cells can shed into urine, and the lab sees them when it looks at urine under a microscope. They are counted in a standard field of view called a high-power field (HPF). Some labs report a number per HPF, and others use words like none seen, few or many. They are different from the flat skin-type cells and the round bladder-lining cells, which are common and usually harmless.

Why it matters

Finding renal tubular cells can point to irritation or injury in the kidney tubules. That is why clinicians read this result with your kidney blood tests (creatinine and eGFR) and the rest of the urine microscopy, such as casts. How much it matters depends on how many cells are seen and on your other results. The count is also easy to get wrong, because other round cells look similar, so labs and clinicians often confirm it by looking at the slide.

If it’s high

Finding renal tubular cells suggests that cells are shedding from the kidney tubules. It is linked to conditions that irritate or injure the tubules, such as a sudden drop in blood flow to the kidneys, kidney inflammation, exposure to some toxins or metals, or rejection of a transplanted kidney. It can also be a mix-up with look-alike cells. One result is not a diagnosis, and your clinician will read it with your kidney tests and symptoms.

Common causes

  • Look-alike cells counted by mistake, such as bladder-lining (transitional) cells, small squamous cells or white blood cells
  • A sample that sat too long or was not kept cool, so cells broke down
  • Sudden injury to the kidney tubules (acute tubular necrosis)
  • Inflammation of the kidney tissue (interstitial nephritis)
  • Rejection of a transplanted kidney
  • Exposure to heavy metals
  • High blood pressure and seizures in pregnancy (eclampsia)
  • Other kidney disease

What can help

  • Ask whether the finding was confirmed by a person looking at the slide
  • Ask whether a repeat urine test with a fresh, clean sample would help
  • Tell your clinician about recent illness, dehydration, new medicines or supplements, and any contact with chemicals or metals

What can affect your result

  • How fresh the sample is: cells break down in dilute, alkaline or unrefrigerated urine
  • Who or what does the counting: a trained person at a microscope or an automated analyzer
  • Look-alike cells that are easy to confuse
  • Recent kidney injury or illness
  • How your lab reports it: per high-power field, per low-power field or in words
  • Cells break down in dilute, alkaline or unrefrigerated urine, as Labcorp notes for white blood cells, so a sample that sat too long can be miscounted.
  • Bladder-lining (transitional) cells, small squamous cells and white blood cells can look like renal tubular cells, so counts depend on who or what does the reading.
  • Automated analyzers often group cells as non-squamous or small round cells rather than separating renal cells.
  • Labs count differently: per high-power field, per low-power field, or in words.

A fresh midstream sample, often the first morning urine, delivered to the lab promptly. Reflects the moment of collection. Cells appear while the tubules are irritated and a repeat sample shows whether the finding persists.

When to talk to a clinician

A renal cell finding alone is not an emergency, but it is worth discussing with a clinician soon, especially if your kidney blood tests are changing. Contact a clinician promptly if you pass much less urine than usual, notice new swelling, or feel unusually tired. Call 911 or your local emergency number for chest pain, trouble breathing or confusion.

Questions you could ask

  • Do my other urine and blood kidney tests fit with this result?
  • Was this result confirmed under the microscope?
  • Should we repeat the urine test or check my kidney blood tests?
  • Could a medicine or recent illness explain this?

Questions people ask

Does a renal epithelial cell finding mean my kidneys are damaged?

Not by itself. Look-alike cells are sometimes counted by mistake, and one sample is only a snapshot. When renal cells are confirmed, clinicians look at your kidney blood tests and the rest of the urine microscopy to see whether the tubules are injured.

Why does my report say 'epithelial cells (non renal)' or 'non-squamous' instead?

Labs group cells differently. A 'non renal' count covers the flat skin-type cells and bladder-lining cells and leaves out renal cells. A 'non-squamous' count groups renal and bladder-lining cells together. Ask your lab which cells it counted.

Show the science and sources

For clinicians and researchers

Renal tubular epithelial (RTE) cells are shed in tubular injury and are recognized by morphology, which makes identification observer-dependent: transitional (urothelial) cells, small squamous cells and white blood cells are common look-alikes. AAFP (2005) states that transitional cells are normal while the presence of renal tubule cells indicates significant renal pathology, and lists epithelial casts containing renal tubule cells in acute tubular necrosis, interstitial nephritis, eclampsia, nephritic syndrome, allograft rejection, heavy metal ingestion and other renal disease. Perazella (2015) reviews the urine sediment as a biomarker and concludes that sediment examination remains valuable because it often identifies the compartment of kidney injury. Reporting varies: Labcorp's routine urinalysis sample report prints 'Epithelial Cells (non renal)' at 0–10 /hpf rather than a renal cell line, and automated analyzers often report non-squamous or small round cells, a combined count (LOINC 41284-1) that includes both renal and transitional cells and is not the same measurement. No laboratory-published numeric reference interval was found, so this marker is stored as an ordinal result with word grades and no numeric range; the usual expectation is none seen.

LOINC 26052-1 (primary), 12248-1, 45391-0, 105116-8. Specimen: urine.

Sources

  1. Urinalysis: A Comprehensive Review, American Family Physician (2005)
  2. The urine sediment as a biomarker of kidney disease, American Journal of Kidney Diseases (2015)
  3. Urinalysis, Routine With Microscopic Examination on Positives: sample report (test 003038), Labcorp (2026)
  4. Urinalysis, Routine With Microscopic Examination on Positives (test 003038), Labcorp

AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.

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