White Blood Cells in the Urine. White blood cells (or leukocytes) in the urine may be detected in the microscopic analysis of urine. In general, the presence of these cells in the urine is suspicious for a urinary tract infection (UTI).hite Blood Cells in the Urine. White blood cells (or leukocytes) in the urine may be detected in the microscopic analysis of urine. In general, the presence of these cells in the urine is suspicious for a urinary tract infection (UTI).