Fig. 2.

Visits with enzyme-linked immunosorbent assay (ELISA) and tests for chlamydial infection in Group II subjects. Endocervical interleukin (IL)-2 (a) and IL-12 (b) concentrations in response to acquisition of Chlamydia trachomatis (CT) infection, with patients (Group II, n = 96) converting from chlamydia negative (CT⁻) to chlamydia positive (CT⁺) within two consecutive visits. Vertical lines correspond to the range of interleukin level (pg/ml) and the interquartile ranges are boxed. Horizontal lines within the boxes represent the median observed values (see text). P-values are based on nonparametric Wilcoxon signed-rank test on changes in cytokine concentration within these two visits.