O06.2 Syphilis not associated with neurocognitive outcomes in people living with HIV in Ontario Canada

Background About 40–60% of people living with HIV (PLWH) experience neurocognitive impairments, irrespective of antiretroviral status. We hypothesized that a history of syphilis would be associated with worse neurocognitive outcomes in this population. Methods We conducted a retrospective study of PLWH enrolled between 2008–2017 in an Ontarian HIV cohort. Cognitive outcomes were the most recent measurements of: 1) self-reported MOS-HIV 4-item cognitive scale; 2) average T-score (ATS) based on formal neuropsychological testing of complex attention, speed of processing, and learning/memory; and 3) global deficit score (GDS) dichotomized into impaired/unimpaired. Syphilis history was based on chart review or lab data. We compared median MOS-HIV and ATS using Wilcoxon rank-sum tests, and proportion impaired on GDS using Chi-square/Fisher test. Multivariable models were fitted to estimate the association between syphilis and each outcome, adjusted for age, education, race, income, years of HIV, nadir and most recent CD4 count, most recent viral load, methamphetamine use, depression, and number of prior neurocognitive tests. Results Of 1434 participants, 76.4% were male at birth and 50.6% were white. At the time of the most recent MOS-HIV, median age was 47 (IQR: 37,54), median CD4 count was 517.5 (IQR: 360,678) cells/mm3 and 80.2% had HIV viral load Conclusion Among PLWH in care in Ontario, prior syphilis was not associated with worse neurocognitive outcomes according to self-reported scales or formal neuropsychological testing. Continued study into the etiology of neurocognitive impairments in PLWH is required.