Delivering a dietetic intervention to cardiovascular patients in the Covid era

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Department of Health

Introduction

Healthy diet and body composition are core components of cardiac rehabilitation. Following the COVID outbreak in March 2020, our face-to-face cardiac rehabilitation programme (Our Hearts Our Minds) was suspended. The programme was then quickly moved to a virtual platform to continue to deliver the programme.

Purpose

Here we describe how the OHOM programme adapted our service to deliver the dietetic assessment and intervention on a virtual platform.

Methods

Pre-Covid the dietary component of OHOM consisted of a face-to-face Initial Assessment (IA) with a dietitian, group education sessions and an End of Programme assessment (EOP). Anthropometric measures and dietary habits were assessed including adherence to the Mediterranean diet via the Mediterranean Diet Score (MDS) toolkit. Using behaviour change techniques, tailored dietary advice was provided and goals agreed to educate on healthier food choices, increase adherence to Mediterranean diet and (if appropriate) promote weight loss and reduce central obesity. The assessment and intervention is now delivered virtually via telephone or video. Anthropometrics are self-reported with tape-measures supplied to assess waist circumference and advice provided on home-weighing. MDS is still assessed. The programme includes fortnightly coaching telephone consultations to review and reset goals, the option to attend a dietitian-led virtual group education session, access to a filmed educational video and submission of food diaries via the Fitbit app.

Results

From April to November 2020, 114 patients completed the virtual programme (65 telephone, 39 video). Dietetic outcomes are outlined in Table 1 with inclusion of data for a similar period one year previously (face-to-face) for comparison. Reductions in anthropometric measures and increased adherence to a cardio-protective diet were noted and the results for the two time periods are remarkably similar.

Conclusion

Delivery of a virtual dietetic component in cardiac rehabilitation is feasible, acceptable and just as effective as face-to-face based on preliminary data.

Table 1: Dietary outcomes at IA and EOP Face-to-face assessments (April - March 2019) Virtual assessments (April - November 2020) IA EOP Change IA EOP Change Mean weight (in those with BMI >25kg/m2) 86.5 85.2 -1.3 91.4 88.6 -2.8 Waist circumference (cm) 104.3 103 -1.3 107 102 -5 Mean MDS (Range 1-14) 4.4 7.5 +3.1 4.8 7.8 +3 % Consuming oily fish once per week 20 57 +37 25 68 +43 Achieving fruit and vegetable target 16 61 +45 21 57 +36

Abstract Figure. Dietitian waist circumference tutorial

Features of Recently Transmitted HIV-1 Clade C Viruses that Impact Antibody Recognition: Implications for Active and Passive Immunization

The development of biomedical interventions to reduce acquisition of HIV-1 infection remains a global priority, however their potential effectiveness is challenged by very high HIV-1 envelope diversity. Two large prophylactic trials in high incidence, clade C epidemic regions in southern Africa are imminent; passive administration of the monoclonal antibody VRC01, and active immunization with a clade C modified RV144-like vaccines. We have created a large representative panel of C clade viruses to enable assessment of antibody responses to vaccines and natural infection in Southern Africa, and we investigated the genotypic and neutralization properties of recently transmitted clade C viruses to determine how viral diversity impacted antibody recognition. We further explore the implications of these findings for the potential effectiveness of these trials. A panel of 200 HIV-1 Envelope pseudoviruses was constructed from clade C viruses collected within the first 100 days following infection. Viruses collected pre-seroconversion were significantly more resistant to serum neutralization compared to post-seroconversion viruses (p = 0.001). Over 13 years of the study as the epidemic matured, HIV-1 diversified (p = 0.0009) and became more neutralization resistant to monoclonal antibodies VRC01, PG9 and 4E10. When tested at therapeutic levels (10ug/ml), VRC01 only neutralized 80% of viruses in the panel, although it did exhibit potent neutralization activity against sensitive viruses (IC50 titres of 0.42 μg/ml). The Gp120 amino acid similarity between the clade C panel and candidate C-clade vaccine protein boosts (Ce1086 and TV1) was 77%, which is 8% more distant than between CRF01_AE viruses and the RV144 CRF01_AE immunogen. Furthermore, two vaccine signature sites, K169 in V2 and I307 in V3, associated with reduced infection risk in RV144, occurred less frequently in clade C panel viruses than in CRF01_AE viruses from Thailand. Increased resistance of pre-seroconversion viruses and evidence of antigenic drift highlights the value of using panels of very recently transmitted viruses and suggests that interventions may need to be modified over time to track the changing epidemic. Furthermore, high divergence such as that observed in the older clade C epidemic in southern Africa may impact vaccine efficacy, although the correlates of infection risk are yet to be defined in the clade C setting. Findings from this study of acute/early clade C viruses will aid vaccine development, and enable identification of new broad and potent antibodies to combat the HIV-1 C-clade epidemic in southern Africa.

Optimal Combinations of Broadly Neutralizing Antibodies for Prevention and Treatment of HIV-1 Clade C Infection

The identification of a new generation of potent broadly neutralizing HIV-1 antibodies (bnAbs) has generated substantial interest in their potential use for the prevention and/or treatment of HIV-1 infection. While combinations of bnAbs targeting distinct epitopes on the viral envelope (Env) will likely be required to overcome the extraordinary diversity of HIV-1, a key outstanding question is which bnAbs, and how many, will be needed to achieve optimal clinical benefit. We assessed the neutralizing activity of 15 bnAbs targeting four distinct epitopes of Env, including the CD4-binding site (CD4bs), the V1/V2-glycan region, the V3-glycan region, and the gp41 membrane proximal external region (MPER), against a panel of 200 acute/early clade C HIV-1 Env pseudoviruses. A mathematical model was developed that predicted neutralization by a subset of experimentally evaluated bnAb combinations with high accuracy. Using this model, we performed a comprehensive and systematic comparison of the predicted neutralizing activity of over 1,600 possible double, triple, and quadruple bnAb combinations. The most promising bnAb combinations were identified based not only on breadth and potency of neutralization, but also other relevant measures, such as the extent of complete neutralization and instantaneous inhibitory potential (IIP). By this set of criteria, triple and quadruple combinations of bnAbs were identified that were significantly more effective than the best double combinations, and further improved the probability of having multiple bnAbs simultaneously active against a given virus, a requirement that may be critical for countering escape in vivo. These results provide a rationale for advancing bnAb combinations with the best in vitro predictors of success into clinical trials for both the prevention and treatment of HIV-1 infection.

In recent years, a new generation of monoclonal antibodies has been isolated from HIV-1 infected individuals that exhibit broad and potent neutralizing activity when tested against diverse strains of virus. There is a high level of interest in the field in determining if these antibodies can be used to prevent or treat HIV-1 infection. Because HIV-1 is adept at escaping from immune recognition, it is generally thought that combinations of multiple antibodies targeting different sites will be required for efficacy, much the same as seen for conventional antiretroviral drugs. How many and which antibodies to include in such combinations is not known. In this study, a new mathematical model was developed and used to accurately predict various measures of neutralizing activity for all possible combinations having a total of 2, 3, or 4 of the most promising antibodies. Through a systematic and comprehensive comparison, we identified optimal combinations of antibodies that best complement one another for enhanced anti-viral activity, and therefore may be most effective for the prevention or treatment of HIV-1 infection. These results provide important parameters that inform the selection of antibodies to develop for clinical use.

Glycan-Dependent Neutralizing Antibodies Are Frequently Elicited in Individuals Chronically Infected with HIV-1 Clade B or C

A number of potent broadly neutralizing antibodies against HIV-1 have recently been identified that target epitopes on the viral envelope that contain N-linked glycans. It remains unknown how frequently glycan-dependent neutralizing antibodies generally arise during the course of natural infection or whether particular glycosylation sites are preferentially targeted. We tested sera with a broad range of neutralization activity from individuals infected with HIV-1 clades B or C against panels of HIV-1 Env pseudoviruses that lacked specific glycans in the outer domain glycan cluster (ODGC) or inner domain glycan cluster (IDGC) to determine the presence of glycan-dependent neutralizing antibodies. Overall, 54% of individuals were observed to have neutralizing antibodies targeting these glycan regions. Glycan-specific neutralizing antibodies were readily detected in sera that were selected for having broad, moderate, or weak neutralization potency and breadth. Our results demonstrate that glycan-specific neutralizing antibodies arise with appreciable frequency in individuals chronically infected with HIV-1 clades B and C. Antibody responses that commonly occur during natural infection may be more feasible to induce by vaccination; thus glycan-specific neutralizing antibodies may be desirable responses to elicit with candidate HIV-1 vaccines.

Oxygen free radicals in interleukin-1beta-induced glycosaminoglycan production by retro-ocular fibroblasts from normal subjects and Graves' ophthalmopathy patients

Graves' ophthalmopathy (GO) is attributed to an autoimmune process that results in the accumulation in retro-ocular tissue of glycosaminoglycans (GAG) that are in turn responsible for the development of clinical signs and symptoms. Retro-ocular fibroblasts are thought to be the source of GAG production and deposition in GO. In the present study, we investigated interleukin (IL)-1beta-induced oxygen free radical production and the role of oxygen free radicals in IL-1beta-induced GAG production in retro-ocular fibroblasts from both normal subjects and patients with GO. Normal retro-ocular fibroblasts demonstrated no measurable oxygen free radicals whereas GO retro-ocular fibroblasts showed detectable signals by electron paramagnetic resonance (EPR) spectroscopy. IL-1beta increased the free radical production in both cells. Superoxide dismutase (SOD) activity in GO retroocular fibroblasts was higher than that in normal cells. IL-1beta dose- and time-dependently stimulated the SOD activity in both cells, with GO retro-ocular fibroblasts showing less responsiveness. IL-1beta dose-dependently increased [3H]glucosamine incorporation into GAG by both cells. An exogenous oxygen free radical-generating system failed to increase GAG. Scavenging oxygen free radicals by the use of SOD (100 U/mL) and catalase (300 U/mL) partially blocked the IL-1beta-induced GAG production in both cells. These results suggest that stress related oxygen free radicals are present in the retro-ocular tissue in GO and that oxygen free radicals are involved in GAG accumulation induced by cytokine IL-1beta.