White blood cells (WBC, pus cells, leucocytes, LEU)
The main function of white blood cells is fighting various pathogenic agents invading our body. White blood cells are better detected in the first morning urine as it is more concentrated and has more sediment. White blood cells in urine are detected by a microscopic examination and are measured in the amount of white blood cells seen in 1 field of view.
There are usually only a few white blood cells in urine of a healthy person. The presence of leukocytes in urine is referred to as leucocyturia or pyuria (pus in the urine). If urine contains large amounts of pus cells, it becomes muddy, with flakes and fibers.
The increase number of white blood cells in urine usually indicates inflammation in the kidneys (pyelonephritis), urinary tract (cystitis, urethritis, prostatitis) or genitals. In rare cases, an increased amount of white blood cells in the urine may be due to renal disease in tuberculosis, amyloidosis, acute and chronic glomerulonephritis.
High levels of leukocytes are found in the urine of women suffering from genital inflammatory diseases. Additional tests are needed for an accurate diagnosis.
White blood cells may enter the urine from the genital tract (the vagina in women and the urethra in men). Large amounts of leukocytes may be found in the genital tract of healthy individuals due to poor hygiene. Therefore, proper personal hygiene should be performed before collecting a urine sample.
In early childhood leukocyturia (white blood cells in the urine) may be caused by mild diseases due to the high sensitivity of the kidneys. In elderly patients, urinary tract infections (UTIs) may be caused by some functional inertness of the kidneys and intestinal atony.
White Blood Cells in the Urine During Pregnancy
Pregnancy causes hormonal and mechanical changes in the woman’s body. These changes increase the frequency of urinary tract infections (UTIs) during pregnancy. Pregnant women are more likely to develop a kidney infection if they have a urinary infection. The presence of significant numbers of white blood cells in the urine without any of the typical symptoms of UTI is called asymptomatic pyuria. Antibiotic treatment can reduce the risk of kidney infections in pregnant women who have a urine infection but show no symptoms of infection.