What condition is associated with an increase in white blood cells (WBC) in urine?

An increase in white blood cells (WBC) in urine is typically indicative of an infection or inflammation within the urinary tract. Pyelonephritis, which is an infection of the kidney, leads to a significant immune response as the body attempts to fight off the infection. The presence of bacteria or other pathogens in the renal tissue triggers this immune response, resulting in the migration of white blood cells to the area. Consequently, these WBCs can be filtered into the urine, leading to pyuria, which is characterized by an elevated number of white blood cells in the urine.

This association with urinary tract infections and kidney infections emphasizes the importance of monitoring WBC levels in urine as a diagnostic tool. In contrast, conditions such as hematologic disorders may influence the body's overall immune status or blood cell counts but do not specifically lead to an increase of WBCs in the urine. Diabetes mellitus may affect kidney function over time, resulting in various complications, but it does not inherently cause white blood cell elevation in the urine unless there is a concurrent infection. Similarly, hypertension is a risk factor for kidney disease but does not directly cause changes in urine WBC counts. Thus, pyelonephritis stands out as the condition most closely linked to increased W