Histopathology of Chlamydia trachomatis salpingitis after primary and repeated reinfections in the monkey subcutaneous pocket model

Monkeys with subcutaneously autotransplanted salpingeal fimbrial tissues were subjected to primary and repeated infections with Chlamydia trachomatis. The inflammatory response after primary inoculation was characterized by infiltration with polymorphonuclear leucocytes in the acute phase and mononuclear cells in the chronic phase. However, the inflammatory response after repeated infections was dominated by a mononuclear cell infiltration with a conspicuous absence of the initial phase of polymorphonuclear leucocyte infiltration. The remarkable findings of repeated infections were plasma cell infiltration, lymphoid follicle formation, and increased fibroblast activity resulting in extensive fibrosis. These findings are similar to those described for monkeys inoculated directly into the oviducts with C. trachomatis and support our original hypothesis that, after chlamydial infection, the tissue damage is provoked by immune-mediated mechanisms.