Co-infection with human immunodeficiency virus (HIV) and syphilis creates a clinical and diagnostic challenge due to overlapping transmission routes and immunosuppression secondary to HIV. We describe a case concerning possible serological rebound in syphilis, which may be attributed to delayed initiation of antiretroviral therapy (ART), although this was not confirmed by a repeat non-treponemal test. A 40-year-old man with HIV and symptomatic secondary syphilis delayed ART initiation in the setting of poor treatment adherence for three months after syphilis diagnosis. During that three-month delay, his toluidine red unheated serum test (TRUST) titer was noted to rebound from 1:32 to 1:128. After ART initiation, he achieved sustained viral suppression (< 20 cp/mL) and immune recovery (CD4 + T cell count: 577/µL) within eight months of ART initiation; however, his syphilis titer did stabilize at 1:32. There is a need for caution in evaluating whenever possible when two diseases share a diagnosis. Our case highlights may highlight possible effects of deferral of ART initiation on immunologic recovery and the serological response for syphilis, and a need for ongoing comprehensive follow-up and circumspection in evaluation of serological change overall. Interpretation was limited by the absence of parallel repeat TRUST testing and being unable to entirely rule out possible reinfection.
Zhang et al. (Thu,) studied this question.