Thrombocytosis accompanying urinary tract infection suggests obstruction or abscess.

Objective: Reactive thrombocytosis can be found in patients with different types of infections, including upper urinary tract infection (UTI). In this study, we determined whether thrombocytosis in patients with upper UTI is a random phenomenon or is related to complications associated with the UTI.

Methods: We reviewed the charts of patients admitted to the urology department with a diagnosis of upper UTI and thrombocytosis (platelet count >500 x 10(9)/L) in the years 1991 to 2003 (study group).