What does trace leukocyte esterase in urine suggest?

The presence of trace leukocyte esterase in urine is indicative of a urinary tract infection (UTI). Leukocyte esterase is an enzyme produced by white blood cells (leukocytes), which are often present in increased numbers during inflammatory processes, such as infections. When a UTI occurs, leukocytes migrate to the site of infection in the urinary tract, leading to elevated levels of leukocyte esterase in the urine.

Detecting trace amounts of leukocyte esterase suggests that there is some inflammatory response occurring, which is commonly associated with a UTI. This finding is often used in conjunction with other urine tests, such as the presence of nitrites, to strengthen the diagnosis of a urinary tract infection. In contrast, normal urinary tract function would not typically present with increased leukocyte esterase levels, while dehydration generally reflects concentrated urine without specific markers of infection. Kidney stones can also cause irritation and blood in urine but do not typically correlate with leukocyte esterase levels associated with infection.