The effect of treatment with doxycycline on serum IgG and IgA antichlamydial antibodies was evaluated in 33 women who had had acute salpingitis associated with high titers of serum IgG (> or = 1:128) and/or IgA (> or = 1:16) antichlamydial antibodies. Overall, 29 women (87.9%) remained with high titers of IgG and/or IgA antibodies. No change or insignificant change in IgG antibody titer was demonstrated in 21 women (63.6%) and in IgA antibody titer in 21 women (63.6%). Positive seroconversion or a significant increase (> or = 4-fold) in IgG antibody titer was demonstrated in eight women (24.2%) and in IgA antibody titer in six women (18.1%). Negative seroconversion or a significant decrease in IgG antibody titer was demonstrated in four women (12.1%) and in IgA antibody titer in six women (18.1%). It is concluded that in most patients who had acute salpingitis associated with pretreatment high titers of serum antichlamydial antibodies, posttreatment titers may remain high even if treatment with doxycycline results in complete resolution of clinical signs and symptoms of the disease.