Quantitative analysis of epithelial cells in urine from men with and without urethritis: implications for studying epithelial: pathogen interactions in vivo

The majority (77/87 = 89%) of samples contained both transitional (76/87 = 87%; range 1 × 104 – 6 × 105, median 6 × 104) and squamous (57/87 = 66%; range 1 × 104 – 8 × 105, median 2 × 104) epithelial cells. The number of transitional cells correlated with the number of squamous cells (Spearman's rho = 0.697 p < 0.001). Squamous, but not transitional, cell numbers correlated with leukocyte numbers (Spearman's rho = 0.216 p = 0.045 and rho = 0.171 and p = 0.113, respectively). However there was no significant difference in epithelial cell numbers between men with and without urethritis. Nevertheless, some men with urethritis had relatively high numbers of transitional cells in their FCU. Transitional cells were morphologically heterogeneous and appeared to display complex cytokeratin phenotypes.Further studies are required to explore the complexity of epithelial cell populations in urine. These would provide novel opportunities for studying cellular interactions of C. trachomatis in male urethral infections, about which little is currently known.We have undertaken a preliminary quantitative analysis of epithelial cells in the urine of men with urethritis and compared the cellular profiles to those without urethritis. We wished to test whether the presence of epithelial cells has any significance in relation to urethritis and C. trachomatis and N. gonorrhoeae infection. Epithelial cells and leukocytes, identified using appropriately specific monoclonal antibodies, were quantified in first catch urine (FCU) specimens from men with and without acute urethritis.To our knowledge, there has been no systematic attempt to quantify epithelial cells in FCU specimens, or examine their identity. Similarly, the significance for disease of epithelial cells in FCU and, indeed, whether there is a "normal" and "abnormal" epithelial cell content or profile in urine, is currently unknown.Clinical guidelines for the diagnosis of urethritis rely solely on the presence of polymorphonuclear