hello, Leukocytes are white blood cells, the body s defense mechanism against invaders such as infection and disease. When foreign materials enter the body, white blood cells attack it by destroying infectious agents or producing antibodies. When there is an infection in the body, these white cells appear in higher concentration in the urine.urinary tract infection (UTI) refers to a bacteria infection somewhere in the urinary tract. Individuals who have leukocytes in their urine typically are diagnosed with a urinary tract infection. Symptoms for a urinary tract infection include painful and frequent urination. Treatment for positive leukocytes includes treating the underlying infection with antibacterial medication such as Trimpex, Polycillin, Floxin, Noroxin, Cipro orTrovan. Typically the infection clears up in one to two days after starting the medicine regimen. Additional medication may be prescribed for pain associated with urinary tract infections.