Clinical outcomes of HIV-syphilis coinfection among patients with no neurological symptoms: a retrospective cohort study.

OBJECTIVE

Our objective was to describe and compare the occurrence of neurological outcomes and neurosyphilis in people living with HIV with incident syphilis and no neurological symptoms who underwent early screening for asymptomatic neurosyphilis (ANS) or regular clinical management without a lumbar puncture.

METHODS

This was a retrospective cohort study in a single referral centre of Sao Paulo, Brazil. Patients with incident syphilis diagnosed between January 2000 and August 2016 and meeting the adapted criteria for ANS investigation suggested by Marra et al. (CD4+ T-cell counts ≤350 cells/mm³ and/or venereal disease research laboratory test results ≥1:16) were identified. Those with no neurological symptoms and immediately referred for lumbar puncture were categorized as group 1, and those not referred for cerebrospinal fluid collection were categorized as group 2. We compared the occurrence of neurological symptoms and neurosyphilis diagnoses between the groups using incidence rates and Kaplan-Meier curves.

RESULTS

We included 425 participants with a median follow-up of 6 years. The incidence rate of neurological symptoms was 36.5/1000 person-years in group 1 and 40.6/1000 person-years in group 2 (incidence rate ratio [IRR] 0.90; 95% confidence interval [CI] 0.57-1.39; p = 0.62). The incidence rate of neurosyphilis was 15.0 cases/1000 person-years in group 1 and 6.7 cases/1000 person-years in group 2 (IRR 2.26; 95% CI 0.93-5.68; p = 0.05).

CONCLUSIONS

We found no statistically significant differences between groups in the incidence rates of neurological symptoms and neurosyphilis. Our findings support the current guidelines, which suggest a less invasive approach regarding ANS investigation among people living with HIV with incident syphilis.