Do patients who complain of lower urinary tract symptoms frequently have clinically significant pyuria?

There is still controversy about whether post-void residual (PVR) urine volume affects the onset of urinary tract infection (UTI). In addition, although male patients with lower urinary tract symptoms (LUTS) might potentially have PVR, the association between LUTS and UTI or asymptomatic pyuria with or without bacteriuria remains unclear. We studied the frequency of asymptomatic pyuria, with and without bacteriuria, in patients with LUTS without a previous history of urinary tract manipulation at the first visit and their sequential courses. This retrospective study was done by reviewing medical charts. A total of 453 male patients who complained of LUTS and visited our outpatient clinic in 2008 were included in this study. The frequency of pyuria, with or without bacteriuria, in this study at the first visit was 4.9%. The median PVR volumes at the initial examination were 79 ml in the 22 patients with pyuria and 22 ml in the 431 patients without pyuria. The difference of the PVR volume between the patients with pyuria and those without pyuria was statistically significant (p = 0.0095). Twelve patients were treated with alpha-blockers without antimicrobial chemotherapy and pyuria disappeared in 5 (41.7%) of them. However, the decrease in the rate of PVR was not significantly different between the patients with persisting pyuria and those without pyuria. A not negligible number of patients with LUTS had pyuria at the first visit; however, there was no febrile UTI in their clinical course even if they received no urological manipulation.