Characteristics of inflammatory cells in urethral smears from men with non-gonococcal urethritis.

Differential cell counts in inflammatory exudates were undertaken in urethral smears from men with non-gonococcal urethritis (NGU) for the first time, recurrent NGU (presumably reinfection) after a new sexual contact, or persistent NGU (in patients with no recent history of sexual exposure). Patients experiencing first episodes of NGU had significantly higher macrophage counts, both in relative and absolute terms, than the other two groups, regardless of the presence or absence of Chlamydia trachomatis in the urethral culture. The estimated total inflammatory cell count (ETICC) in the urethral exudate was assessed by counting the number of inflammatory cells in the first voided urine. The ETICC was significantly lower in patients with persistent NGU but no recent history of sexual exposure than in patients with NGU for the first time or with NGU presumably caused by a new infection. The ETICC in all three groups of patients was significantly higher than in controls. A more precise definition of NGU or more reproducible methods of diagnosis may possibly differentiate patients without an infective cause.