HOST IMMUNE-RESPONSE IN CHLAMYDIAL CERVICITIS

In order to study host immune responses to Chlamydia trachomatis infec tion in patients with chlamydial cervicitis, lymphoproliferative respo nses to purified protein derivative (PPD) and Chlamydia trachomatis an tigen (elementary bodies) were studied in 15 patients and 10 normal co ntrol subjects. A significant lymphoproliferation of peripheral blood mononuclear cells (PBMC) was obtained with PPD and C. trachomatis anti gen (P<0.001) as compared to unstimulated PBMC showing that antigen-re active T-cells are present in patients. There was no significant diffe rence in the lymphoproliferation response to C. trachomatis in patient s as compared to control subjects suggesting that the cell-mediated im mune (CMI) response in peripheral blood is not altered in chlamydial c ervicitis. Inhibition of IL-2 production in cervical secretions ranged from 44 to 84% in patients with chlamydial cervicitis while supernata nts derived from PBMC stimulated with PPD failed to show inhibition. H owever, there was no inhibition of IL-2 production in secretion or sup ernatants stimulated with PPD in control subjects, thereby showing tha t local cell-mediated immunity is impaired in patients. Significant C. trachomatis specific IgA antibodies, in cervical secretions, were pre sent in only three of 15 patients. C. trachomatis specific IgG, IgM an d IgA were detected in the serum of most patients, suggesting that ser um antibodies do not confer immunity at the local site. We conclude th at although circulating antigen-reactive T-cells are present in chlamy dial cervicitis patients, absence of protective antibody as well as im pairment of local cell-mediated immunity may be responsible for altera tion of the mucosal defence mechanism against chlamydial infection.