CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

1241 Unravelling the Pathogenesis and Outcome of Serofast Status in People Living With HIV Leticia Espinosa 1 , Ana Moreno 2 , María Ezquerra Marigómez 3 , Cristina Fernández Chica 4 , Javier Guzman 3 , Ana Abad 2 , Pedro Esteve 1 , Jose L. Casado 4 1 Hospital Universitario San Juan de Alicante, Alicante, Spain, 2 Hospital Juan Ramón Jiménez, Huelva, Spain, 3 Hospital Sierrallana, Torrelavega, Spain, 4 Hospital Universitario Ramon y Cajal, Madrid, Spain Background: The pathogenesis of the syphilis serofast status has not well established in people living with HIV (PLH). We conducted a study to evaluate possible predictors and outcome of serofast status. Methods: Prospective cohort study of 348 episodes of syphilis in 175 PLH. Serofast status was defined as persistence of positive non-treponemal RPR titer after serological response to therapy (at least a 4-fold decline in the titer of RPR 12 months after treatment). Demographic and HIV-related data, RPR titer at diagnosis, time of response and outcome of serofast-diagnosed PLH were analyzed. Results: At the first episode of syphilis, median age was 47 years, 99 were males and 95% had MSM as risk practice. Median time of HIV infection was 101 months and nadir CD4+ count of 303 cells/mcL. At diagnosis, late latent or unknown duration stage was observed in 51%, and median RPR titer was 1/32. By only considering those PLH with serological response at 12 months (132, 75%), 63 of them (51%) were identified as persistence of serofast status according to our definition. As it could be expected, serofast status was observed in the case of higher initial RPR titers (p=0.005), lower rate of serological response at the first determination (56% vs 35%; p=0.082), longer time of HIV infection (132 vs 84 months; p=0.013), and lower CD4/CD8 ratio at diagnosis (0.88 vs 1.52, p=0.07). Of note, time to indetectable and resolution of serofast state was shorter in subsequent syphilis episodes (p=0.02). In a Cox multivariate analysis, a shorter time of serological response at the first determination (Hazard ratio, HR, 0.89; p=0.034), a higher nadir CD4/CD8 ratio (HR 4.86; p=0.044), and a lower CD4/CD8 ratio at the time of diagnosis (HR 0.24; p=0.04) were associated with shorter time of serofast status. Indeed, 22 out of 63 serofast became indetectable during a median follow up of 35 months (3.6 person-years), decreasing to median RPR titer of 1/2 at the last determination, and without later increases of treponemal test in absence of reinfection. Conclusions: This prospective study clarifies the factors associated with serofast status after a syphilis diagnosis. Importantly, serofast status was related to the intersection of serological presentation and immunological factors, with a trend to decrease progressively. Thus, this study ruled out the need of additional studies and interventions in this population. 1242 No CSF Study in Neuro Asymptomatic Syphilis in People With HIV: Clinical and Serologic Outcomes María L. Otth 1 , Catalina Novoa 2 , Sandra Gonzalez 1 , Camila Jorquera 1 , Rebeca Northland 2 , Marcelo Wolff 2 1 University of Chile, Santiago, Chile, 2 Fundación Arriarán, Santiago, Chile Background: Syphilis is common in people living with HIV, and central nervous system involvement is more frequent, although mostly asymptomatic, in which case it seems to be mostly a benign condition, which has led to a growing trend not to perform a lumbar punction (LP). During the COVID-19 pandemic restrictions, LPs were not performed in neuro asymptomatic patients with low CD4+ cell count and high VDRL titers, as previously done at this HIV care center, and participants received benzathine penicillin, as in no neurologic involvement, generating an opportunity to evaluate outcomes after this noninvasive practice. Methods: Longitudinal, retrospective, observational study. Local records kept from 03/2020 to 08/2022 were reviewed. Eligibility criteria were VDRL ≥1:32, no neurological symptoms and no cerebrospinal fluid (CSF) study at diagnosis. Data was analyzed with Stata 15.1. Results: 203/869 syphilis cases (23.4%) met eligibility criteria, 98.5% were men, median age was 34 years; 79.2% had latent syphilis. Median CD4 count was 533 cells/mL (IQR 400-734, and 21,7% had <350 cells/mL). Median baseline VDRL was 1/32; median follow-up was 20 months. Of 30 patients with VDRL test done at 2 months, 83.3% had VDRL titer drop >2 folds, later that level of titer drop occurred in 56/59 (95%), 82/98 (83.6%) and 50/53 (94.3%) patients at 6, 12 and 24 months, respectively; 21% reached a non-reactive VDRL in a median of 13 months. Six persons required CSF study due to persistent high VDRL titers; none had neurosyphilis. No person presented neurological symptoms during follow up. No statistically significant association was observed between CD4+ cell count, viral load, syphilis stage, and baseline VDRL with its serologic

evolution. Limitations of this study include its non-comparative design, and lack of a more comprehensive neurologic follow up instead of the simpler clinical evaluation used. Conclusions: This work found that people living with HIV with neuro asymptomatic syphilis -VDRL titers that previously were indicative of CSF study- who were treated without LP as if no neurologic involvement, had an adequate serological response and none developed clinical neurosyphilis during follow up. These findings reinforce the present trend not to perform CSF study by lumbar punction in this setting. 1243 Describing the Cascade of Care for Neurosyphilis in People Living With HIV: Finding the Gaps Shaul A. Navarro-Lara, Hector O. Rivera-Villegas, Nancy Sierra-Barajas, Angelina Silva-Casarrubias, Yanink Caro Vega, Alvaro López-Iñiguez, Brenda E. Crabtree Ramírez Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico Background: Incidence of syphilis has increased over the last 20 years. This increase might be followed by a rise in neurosyphilis (NS), especially in the HIV population. Surveillance for NS is heterogeneous and thus the real incidence is not well known. These factors highlight the need for a standardized evaluation process. Therefore, we aim to describe a Cascade of Care of NS to evaluate the missed opportunities of screening and diagnosis, and the time between steps. Methods: We retrospectively evaluated all active adults living with HIV (defined as those with at least one clinic visit/year) from 2021 to 2023 in a tertiary care Hospital in Mexico. At our center, people with a VDRL title ≥1:32 should undergo Lumbar Puncture (LP) and/or ophthalmologic evaluation (OE) in the absence of neurological symptoms (Martínez et al., 2022). We assessed the first event registered per patient. To describe the Cascade of Care, the following steps were reviewed: 1) active patients eligible to be screened with VDRL, 2) the ones screened, 3) asymptomatic patients with VDRL ≥1:32,-of which, 4) those who went through OE and/or LP, and 5) if there was an indication for treatment. Serologic follow-up (defined as any VDRL between 6 and 12 months) was evaluated. Time between each step of the cascade is described. Results: During the study period, a total of 1,267 active people with HIV were registered and from those, 791 (62.4%) were screened for syphilis. 183 (14.4%) had VDRL title ≥1:32 and 123 (66.8%) went through OE and/or LP. 47 had ocular syphilis and/or NS confirmed by fundoscopy and a positive VDRL test in CSF, respectively (representing a 38.2% of positivity). All of them received treatment as inpatients. Median time from a positive VDRL ≥1:32 and OE/LP was 15 days (IQR 7 – 41 days), and from positive evaluation to treatment was 6.5 days (IQR 0 - 11days). (Figure 1). The proportion of those treated with a serological follow up was 89.3%. Conclusions: In this study, the Syphilis Cascade of Care, we found important gaps and missed opportunities of diagnosis with almost 40% of people not screened. Of those screened, two thirds had potential NS or ocular syphilis, with 38.2% of them having a positive result. Our findings support the need for implementing strategies to increase screening and improve the time to diagnosis and treatment.

Poster Abstracts

CROI 2025 410