Aims: A pilot feasibility study to investigate the local immune response in patients with non-gonococcal urethritis (NGU).
Methods: Urethral lymphocytes were extracted from first void urine (FVU) of patients with non-gonococcal urethritis and gonorrhoea using magnetic beads coated with antibody against either the pan-T cell marker CD2 or to CD4. The CD2+ and CD4+ lymphocyte content of FVU were compared between chlamydia-positive and chlamydia-negative and between first and subsequent attacks of NGU.
Results: Median CD2+ lymphocyte content of FVU was significantly higher in cases of gonorrhoea and chlamydia-positive urethritis than in chlamydia-negative NGU. Median CD2+ lymphocyte content of FVU in chlamydia-negative NGU was 15.6 x 10(4), (n = 14 range 3.2-111) which was significantly lower than in chlamydia positive NGU (35.2 x 10(4), n = 18, range 7.4-390 p = 0.037) and gonorrhoea (67.7 x 10(4), n = 8 range 13-501, p = 0.019). Comparing the first with subsequent attacks of NGU, CD2+ cell numbers were greater in those presenting with their first episode of chlamydia-negative NGU (21.8 x 10(4), range 5.6-111) compared with those who had experienced NGU before (12.3 x 10(4), range 3.2-20.4, p = 0.033), but not in those presenting with chlamydia-positive NGU. There was no difference in CD4+ cells between any of the groups.
Conclusion: The lower total lymphocyte content of subsequent attacks of chlamydia-negative NGU compared with the first attack chlamydia-positive and negative NGU suggests that a different aetiology may be operating in some of these patients. Sufficient lymphocytes can be isolated from the urethra in patients with NGU for studies of lymphocyte subsets to be carried out.