Peripheral blood T cell proliferative response to chlamydial organisms in gonococcal and non-gonococcal urethritis and presumed pelvic inflammatory disease
M. Shahmanesh et al., Peripheral blood T cell proliferative response to chlamydial organisms in gonococcal and non-gonococcal urethritis and presumed pelvic inflammatory disease, SEX TRANS I, 75(5), 1999, pp. 327-331
Objective: To study peripheral blood mononuclear cell (PBMC) proliferative
response to Chlamydia trachomatis elementary bodies in (a) controls, (b) va
rious stages of gonococcal (c) and non-gonococcal urethritis, and (d) women
with a clinical diagnosis of pelvic inflammatory disease (PID).
Methods: We categorised 102 men presenting to a GUM clinic with urethritis
by organisms (C trachomatis (CT) or Neisseria gonorrhoeae (NG) (both by cul
ture), and whether it was their first (urethritis naive) or subsequent (ure
thritis experienced) attack. 23 women presenting to the clinic with a clini
cal diagnosis of PID were also investigated. We measured PBMC proliferative
responses to C trachomatis (DK20-an oculogenital strain, serovar E), lysat
e of McCoy cells (used to propagate chlamydiae), and the recall antigen PPD
. Controls were 37 men and women without present or past history of urethri
tis or chlamydial infection. Results were expressed as the ratio of the sti
mulation index (SI) obtained with DK20 compared with McCoy cells (DK index)
, and the ratio of the SI obtained with DK20 compared with PPD (PPD index).
Results: The median SI to DK20 in the urethritis was 12.7 which was signifi
cantly higher than the controls (7.6, p <0.003). The median SI to the recal
l antigen PPD was similar in the urethritis patients (17.4) and the control
s (22.4). All urethritis patient subgroups had a significantly higher DK in
dex and PPD index than the controls. There was no difference in the PPD and
DK index between urethritis naive and urethritis experienced patients and
between the culture positive and culture negative urethritis subgroups. In
PID patients only the PPD index was significantly higher than the controls.
Conclusion: Men presenting with urethritis and women presenting with PID bo
th have significantly greater peripheral blood mononuclear cell proliferati
ve responses to the DK20 strain of C trachomatis than controls. A similar T
cell proliferative response pattern in urethritis naive patients with eith
er gonococcal or non-gonococcal urethritis could be because low sensitivity
of CT culture failed to diagnose some cases of C trachomatis. However, it
may also signify earlier exposure of the patients to chlamydial antigens (f
or example, C pneumoniae), cross reacting antigens such as heat shock prote
ins from other microbial species, or a "bystander" activation of chlamydia
specific memory T cells trafficking through mucosal lymphoid tissue during
urethritis. These results suggest evidence of T cell mediated response to C
trachomatis cannot be used as a diagnostic tool.