SEROLOGIC RESPONSE TO TREATMENT OF SYPHILIS IN PATIENTS WITH HIV-INFECTION

Background: Much controversy exists concerning the manifestations, the rapy, and response to treatment of syphilis in patients coinfected wit h the human immunodeficiency virus (HIV). Objective: To assess the eff ect of HIV infection on the serologic response to treatment of patient s with syphilis. Methods: Sixty-four HIV-seropositive patients with sy philis were matched with 64 patients with syphilis who were HIV negati ve. Matching criteria included age (+/-5 years), sex, race, initial ra pid plasma reagin (RPR) titer (ii dilution), and stage of syphilis at entry. There were 26 matched patients with early syphilis, 26 matched patients with late syphilis, and 12 matched patients with biological f alse-positive RPR. The HIV-positive patients with early syphilis recei ved three doses of penicillin G benzathine. All other patients receive d treatment as recommended by the Centers for Disease Control and Prev ention, Atlanta, Ga. Our study's major end points were clinical and se rologic response to treatment. Results: All 16 patients with symptomat ic syphilis were cured. No patient developed clinical signs of neurosy philis during the 12-month follow-up period. Twenty-nine (56%) of 52 H IV-positive patients with early or late syphilis did not have a fourfo ld decrease in RPR titer 6 months after treatment compared with 20 (38 %) of 52 matched controls (P=.06). No unique characteristics identifyi ng patients who did not respond serologically could be established. Th e HIV-positive patients with initial RPR less than 1:32 experienced a significantly slower decrease in RPR at 12 months than did the control s (P<.001). Conclusions: Patients with syphilis who are HIV positive a re less likely to experience serologic improvement after recommended t herapy than are patients with syphilis who are HIV negative. Patients with-HIV infection who contract syphilis should receive intensive and prolonged follow-up, and consideration should be given to designing al ternative regimens.