Chagas Disease in People with HIV: A Narrative Review

Many questions remain unanswered regarding the epidemiology, pathophysiology, diagnosis, treatment, and monitoring of Trypanosoma cruzi infection in people with HIV (PWH). The reported prevalence of T. cruzi infection in PWH living in endemic countries ranges from 1–28% and is likely similar in at-risk US populations. While classic cardiac and gastrointestinal presentations of chronic Chagas disease occur in PWH, PWH are additionally at risk for a severe and often fatal form of T. cruzi-mediated disease called reactivation disease. T. cruzi reactivation typically occurs in PWH with low CD4 counts and poor virologic control. National HIV guidelines in several endemic South American countries recommend that all PWH be screened for T. cruzi infection at the time of HIV diagnosis; however, this recommendation is not widely implemented. The early detection of T. cruzi infection in PWH is critical as the sequelae of Chagas disease, including T. cruzi reactivation, may be preventable through the restoration of robust cellular immunity via the initiation of antiretroviral therapy and the appropriate use of antitrypanosomal therapy.

Blocking α4β7 integrin delays viral rebound in SHIVSF162P3-infected macaques treated with anti-HIV broadly neutralizing antibodies

Anti-HIV broadly neutralizing antibodies (bNAbs) may favor development of antiviral immunity by engaging the immune system during immunotherapy. Targeting integrin α4β7 with an anti-α4β7 monoclonal antibody (Rh-α4β7) affects immune responses in SIV/SHIV-infected macaques. To explore the therapeutic potential of combining bNAbs with α4β7 integrin blockade, SHIVSF162P3-infected, viremic rhesus macaques were treated with bNAbs only (VRC07-523LS and PGT128 anti-HIV antibodies) or a combination of bNAbs and Rh-α4β7 or were left untreated as a control. Treatment with bNAbs alone decreased viremia below 200 copies/ml in all macaques, but seven of eight macaques (87.5%) in the bNAbs-only group rebounded within a median of 3 weeks (95% CI: 2 to 9). In contrast, three of six macaques treated with a combination of Rh-α4β7 and bNAbs (50%) maintained a viremia below 200 copies/ml until the end of the follow-up period; viremia in the other three macaques rebounded within a median of 6 weeks (95% CI: 5 to 11). Thus, there was a modest delay in viral rebound in the macaques treated with the combination antibody therapy compared to bNAbs alone. Our study suggests that α4β7 integrin blockade may prolong virologic control by bNAbs in SHIVSF162P3-infected macaques.

Non-neutralizing Antibodies May Contribute to Suppression of SIVmac239 Viremia in Indian Rhesus Macaques

The antiviral properties of broadly neutralizing antibodies against HIV are well-documented but no vaccine is currently able to elicit protective titers of these responses in primates. While current vaccine modalities can readily induce non-neutralizing antibodies against simian immunodeficiency virus (SIV) and HIV, the ability of these responses to restrict lentivirus transmission and replication remains controversial. Here, we investigated the antiviral properties of non-neutralizing antibodies in a group of Indian rhesus macaques (RMs) that were vaccinated with vif, rev, tat, nef, and env, as part of a previous study conducted by our group. These animals manifested rapid and durable control of viral replication to below detection limits shortly after SIVmac239 infection. Although these animals had no serological neutralizing activity against SIVmac239 prior to infection, their pre-challenge titers of Env-binding antibodies correlated with control of viral replication. To assess the contribution of anti-Env humoral immune responses to virologic control in two of these animals, we transiently depleted their circulating antibodies via extracorporeal plasma immunoadsorption and inhibition of IgG recycling through antibody-mediated blockade of the neonatal Fc receptor. These procedures reduced Ig serum concentrations by up to 80% and temporarily induced SIVmac239 replication in these animals. Next, we transferred purified total Ig from the rapid controllers into six vaccinated RMs one day before intrarectal challenge with SIVmac239. Although recipients of the hyperimmune anti-SIV Ig fraction were not protected from infection, their peak and chronic phase viral loads were significantly lower than those in concurrent unvaccinated control animals. Together, our results suggest that non-neutralizing Abs may play a role in the suppression of SIVmac239 viremia.

Coronary Vasculature and Myocardial Structure in HIV: Physiologic Insights from the Renin-Angiotensin-Aldosterone System

The landscape of HIV medicine dramatically changed with the advent of contemporary antiretroviral therapies (ART) which has allowed persons with HIV (PWH) to achieve good virologic control, essentially eliminating HIV-related complications and increasing life expectancy. As PWH are living longer, non-communicable diseases, such as cardiovascular disease (CVD), have become a leading cause of morbidity and mortality in PWH with rates that are 50-100% higher than in well-matched persons without HIV. In this review, we focus on disease of the coronary microvasculature and myocardium in HIV. We highlight a key hormonal system important to cardiovascular endocrinology, the renin-angiotensin-aldosterone system (RAAS), as a potential mediator of inflammatory driven-vascular and myocardial injury and consider RAAS blockade as a physiologically-targeted strategy to reduce CVD in HIV.

Social Vulnerability among Foreign-Born Pregnant Women and Maternal Virologic Control of HIV

Objective The aim of this study was to assess whether social vulnerability among foreign-born pregnant women living with HIV is associated with maternal viremia during pregnancy. Study Design This retrospective cohort study included all foreign-born pregnant women living with HIV who received prenatal care in a multidisciplinary prenatal clinic between 2009 and 2018. A licensed clinical social worker evaluated all women and kept detailed clinical records on immigration status and social support. Social vulnerability was defined as both living in the United States for less than 5 years and reporting no family or friends for support. The primary outcome was evidence of viral non-suppression after achievement of initial suppression. Secondary outcomes were the proportion of women who required > 12 weeks after starting antiretroviral therapy to achieve viral suppression, median time to first viral suppression (in weeks) after initiation of antiretroviral therapy, and the proportion who missed ≥ 5 doses of antiretroviral therapy. Bivariable analyses were performed. Results A total of 111 foreign-born women were eligible for analysis, of whom 25 (23%) were classified as socially vulnerable. Social and clinical characteristics of women diverged by social vulnerability categorization but no differences reached statistical significance. On bivariable analysis, socially-vulnerable women were at increased risk for needing > 12 weeks to achieve viral suppression (relative risk: 1.78, 95% confidence interval: 1.18–2.67), though there was no association with missing ≥ 5 doses of antiretroviral therapy or median time to viral suppression after initiation of antiretroviral therapy. Conclusion Among foreign-born, pregnant women living with HIV, markers of virologic control during pregnancy were noted to be worse among socially-vulnerable women. Insofar as maternal viremia is the predominant driver of perinatal transmission, closer clinical surveillance and support may be indicated in this population. Key Points

HTA and HIV: The Case of Dual NRTI Backbones in the Italian Setting

The aim of this study is to analyze the potential advantages of emtricitabine/tenofovir alafenamide (FTC/TAF) introduction, creating evidence-based information to orient strategies to reduce costs, thus preserving effectiveness and appropriateness. An Health Technology Assessment (HTA) was implemented in the years 2017–2018 comparing the dual backbones available in the Italian market: FTC/TAF, FTC/TDF (tenofovir disoproxil fumarate/emtricitabine) and ABC/3TC (abacavir/lamivudine). From an efficacy point of view, FTC/TAF ensured a higher percentage of virologic control and a better safety impact than FTC/TDF (improving the renal and bone safety profile, as well as the lipid picture). From an economic point of view, the results revealed a 4% cost saving for the Italian National Healthcare Service NHS with FTC/TAF introduction compared with the baseline scenario. Qualitative perceptions’ results showed that FTC/TAF would decrease the burden of adverse events management, increasing the accessibility of patients to healthcare providers (FTC/TAF: 0.95, FTC/TDF: 0.10, ABC/3TC: 0.28; p-value: 0.016) and social costs (FTC/TDF: −0.23, FTC/TAF: 1.04, ABC/3TC: 0.23; p-value < 0.001), improving patient quality of life (FTC/TDF: 0.31, FTC/TAF: 1.85, ABC/3TC: 0.38; p-value < 0.001). Healthcare services may consider the evidence provided by the present study as an opportunity to include HIV patients in a more adequate antiretroviral treatment arm, guaranteeing a personalized clinical pathway, thus becoming more efficient and effective over time.

Association of intestinal and systemic inflammatory biomarkers with immune reconstitution in HIV+ patients on ART

Background HIV infection is characterized by CD4+ T-cells depletion related to gut damage, microbial translocation, immune activation and intestinal and systemic low-grade inflammation. With the use of antiretroviral treatment, these alterations in HIV+ patients reach similar levels to HIV- controls. However, almost 20% patients have deficient immune reconstitution of CD4+ T-cells, which make them more susceptible to develop non-AIDS and AIDS comorbidities. Methods HIV+ patients on ART, with sustained virologic control were grouped according to their immune reconstitution as: immunological responders (n = 18) and immunological non-responders (n = 18); also, HIV- controls were enrolled (n = 14). CD4+ and CD8+ T-cell activation (HLA-DR+ and CD38+ single and co-expression) were measured by flow cytometry. Serum levels of sCD14, sCD163, lipopolysaccharide, I-FABP, sST2, as well as fecal levels of calprotectin, lactoferrin and secretory IgA were evaluated by ELISA. Levels of C-reactive protein were determined by a high sensibility singleplex bead-based immunoassay. Serum and fecal concentrations of proinflammatory cytokines were quantified by multiplex bead-based immunoassay. Results HLA-DR+ and CD38+ co-expression, as well as median fluorescence intensity in CD4+ and CD8+ T-cells subpopulations was greater in immunological non-responders group, after normalization and fold change calculation. Similarly, this group presented higher levels of sCD14, C-reactive protein, as well as fecal calprotectin and lactoferrin. Furthermore, both HIV+ groups showed elevated levels of proinflammatory cytokines in stool. Conclusions Our data suggests that despite the virologic control, HIV+ patients under treatment with deficient immune reconstitution showed elevation of both innate and T-cells immune activation, as well as intestinal and systemic inflammation. However, some patients with CD4+ T-cells count above 350 cells/μL also presented these alterations. Future studies are necessary to evaluate the dynamics of multiple systemic and intestinal biomarkers in diverse types of HIV+ patients, as such as their clinical impact.

1009. Dolutegravir and Doravirine in Combination: When Standard Antiretroviral Regimens are Unacceptable

Background A drug-drug interaction study between dolutegravir and doravirine in healthy volunteers found no evidence of untoward interaction. Whilst we hypothesize that the combination would be safe and effective, there is no supportive clinical data. We aimed to assess the rationale for use of dolutegravir and doravirine in combination and clinical outcomes among persons with HIV infection (PWH) receiving care at the Washington DC VAMC. Methods A quality improvement initiative utilized the clinical case registry to identify all PWH receiving both dolutegravir and doravirine. We conducted chart review to examine (a) the reasons for switch from other ART to dolutegravir and doravirine, and comorbidities, HIV resistance mutations or drug interactions precluding the use of standard ART, (b) adverse events or side effects and (c) achievement of virologic suppression. Results A case registry search revealed 21 individuals receiving combination dolutegravir doravirine from 2018–2020 (Table 1 and Figure 1). Side effects were not noted except one patient developed mild diarrhea that improved with continuation of therapy. Four patients were hospitalized during the follow-up period for reasons unrelated to the medications. One patient who was admitted to the ICU with shock and multi-organ failure was switched on admission but died four days later and therefore was not included in the analysis of viral outcome (Table 2). One patient had cardiac arrest following missed dialysis, hyperkalemia and rectal hemorrhage from metastatic rectal cancer. Table 1: Patient Demographics. Figure 1: Reasons for Switching to Dolutegravir with Doravirine. Table 2: Virologic Control Before and After Switching to Dolutegravir with Doravirine. Conclusion In an era of abundant ART options, we identified a subset of older PWH whose treatment options are defined by extensive comorbidities, viral resistance, and medication interactions or toxicities. Doravirine is attractive for this population as it can be used in renal impairment, moderate hepatic impairment, is unaffected by timing of meals, and (unlike rilpivirine) has no interaction with proton pump inhibitors. Dolutegravir is included in NRTI-sparing regimens that HHS guidelines suggest should be considered in older PWH, especially with CKD. We found that dolutegravir with doravirine is well tolerated, and achieves virologic suppression in the majority of PWH, indicating this combination is useful when other ART options cannot be used. Disclosures All Authors: No reported disclosures