peripheral blood lymphocytes are able to maintain their viability and basic function in normal urine

background: similar to inflammatory cells, peripheral blood mononuclear cells (pbmcs) can also infiltrate in to kidney and urinary tracts and subsequently excreted by urine. in this study we determined the viability rate and response to phytohemagglutinin-a (pha) of human pbmcs in normal urine. methods: a number of 1×106 ficoll-hypaque isolated pbmcs were dispensed in 1 ml normal urine and 6 molar urea and rpmi-1640+fbs10 % were considered as negative and positive control, respectively. after 20, 60 and 120 minutes the viability of these cells was measured by trypan blue dye exclusion assay. 1×105 of pbmcs were isolated from urine and cultured as triplicate in rpmi-1640`supplemented with fbs 10% and  pha for 96hr. mtt assay was performed to determine the pbmcs response to pha. these experiments were repeated three times independently. results: there was no significant difference between the viability rates of the pbmcs incubated in urine and positive control after 20, 60 and 120 minutes while after 60 minutes they exhibited 75.6% of reactivity to pha versus positive control. overall, there was a significant difference in trends of viability rate across the three groups (p<0.05). conclusion: our results showed that not only pbmcs remained alive in urine after 120 minutes, but can also respond to pha up to 60 minutes at a remarkable level. these data open a new avenue in the designation for cell culture-based techniques in urine cell analysis.