From the Guidelines
Epithelial cells in male urine are a normal finding, but their presence in large numbers may indicate inflammation, infection, or trauma to the urinary tract. These cells originate from the lining of the urinary tract, including the urethra, bladder, ureters, and renal pelvis. In healthy males, squamous epithelial cells from the distal urethra are most commonly observed, while transitional epithelial cells from the bladder and upper urinary tract may occasionally be present 1.
Significance of Epithelial Cells
The presence of epithelial cells in urine can be an indicator of various conditions. For example, large quantities of transitional epithelial cells could suggest bladder inflammation (cystitis) or urinary tract infection, while renal tubular epithelial cells might indicate kidney damage. During urinalysis, laboratory technicians typically report epithelial cells as "few," "moderate," or "many" to help clinicians determine if the levels are within normal range or potentially pathological.
Clinical Implications
A urine sample with more than 10 WBCs and a significant number of epithelial cells must be considered contaminated, and either an improved clean-catch method or catheterization must be tried 1. The presence of extracellular vesicles (EVs) in urine, which are derived from epithelial cells, can also provide valuable information about kidney function and disease 1.
Diagnostic Considerations
Normal male urine samples generally contain fewer epithelial cells than female samples due to anatomical differences in the urinary tract. However, the presence of epithelial cells in male urine should be evaluated in the context of other clinical findings and laboratory results to determine their significance. The recent study on extracellular vesicles in nephrology highlights the potential of EVs as biomarkers and therapeutic agents, and their characterization can provide a deeper understanding of kidney diseases 1.
Key Points
- Epithelial cells in male urine can be a normal finding, but their presence in large numbers may indicate inflammation, infection, or trauma to the urinary tract.
- The type and number of epithelial cells can provide valuable information about the source and potential cause of the condition.
- Urine samples should be evaluated in the context of other clinical findings and laboratory results to determine the significance of epithelial cells.
- Extracellular vesicles derived from epithelial cells can provide valuable information about kidney function and disease.
From the Research
Significance of Epithelial Cells in Male Urine
- Epithelial cells in male urine can originate from various parts of the urinary tract and kidneys, with podocytes and proximal tubular epithelial cells (PTECs) being the most relevant for studying genetic kidney diseases 2
- These cells can be used as models for discovering disease mechanisms and developing new therapies, and can also represent individual patients and their specific variants for personalized medicine studies 2
- Renal epithelial cells play a key role in coordinating the innate immune response to infection, producing inflammatory mediators and antimicrobial proteins to aid bacterial clearance 3
- Epithelial cells in male urine can also be used to study epithelial-pathogen interactions in vivo, with transitional and squamous cell populations being broadly categorized using morphological characteristics and immunostaining 4
- The detection of podocytes in the urine could be a valuable noninvasive method to get information about disease activity or disease type, and could be used as a follow-up after a biopsy in an outpatient setting 5
- However, the clinical relevance of renal epithelial cells in the urine is not yet fully understood, and further studies are needed to explore the complexity of epithelial cell populations in urine and to develop a more specific diagnostic approach 6, 4, 5
Types of Epithelial Cells
- Podocytes: specialized cells that play a crucial role in glomerular function and can be detected in the urine as a potential diagnostic marker for kidney disease 2, 5
- Proximal tubular epithelial cells (PTECs): cells that line the proximal tubules of the kidneys and can be used as models for studying genetic kidney diseases 2
- Transitional cells: cells that line the urinary tract and can be detected in the urine, with numbers correlating with squamous cell numbers 4
- Squamous cells: cells that can be detected in the urine, with numbers correlating with leukocyte numbers 4
Applications of Epithelial Cells in Male Urine
- Studying genetic kidney diseases: epithelial cells in male urine can be used as models for discovering disease mechanisms and developing new therapies 2
- Diagnosing kidney disease: the detection of podocytes in the urine could be a valuable noninvasive method to get information about disease activity or disease type 5
- Studying epithelial-pathogen interactions: epithelial cells in male urine can be used to study interactions between epithelial cells and pathogens in vivo 4