What time of day do you take the urine samples, this may make a difference.
You've sent me on a mission now
NHS website
What is normal range for leukocyte esterase?
A normal range in the bloodstream is between 4,500-11,000 WBCs per microliter. A normal range in the urine is lower than in the blood, and may be from 0-5 WBCs per high power field (wbc/hpf).
One can also have leukocytes in a urine sample but not have an infection.
What causes elevated leukocyte esterase?
Infection
A urinary tract infection (or UTI) is the most commonly occurring reason for increased levels of leukocytes in the urine. High levels indicate that the immune system is trying to fight off a fungal, bacterial or parasitic infection by fungus.