Single-cell RNAseq identifies clonally expanded antigen-specific T-cells following intradermal injection of gold nanoparticles loaded with diabetes autoantigen in humans

Gold nanoparticles (GNPs) have been used in the development of novel therapies as a way of delivery of both stimulatory and tolerogenic peptide cargoes. Here we report that intradermal injection of GNPs loaded with the proinsulin peptide C19-A3, in patients with type 1 diabetes, results in recruitment and retention of immune cells in the skin. These include large numbers of clonally expanded T-cells sharing the same paired T-cell receptors (TCRs) with activated phenotypes, half of which, when the TCRs were re-expressed in a cell-based system, were confirmed to be specific for either GNP or proinsulin. All the identified gold-specific clones were CD8+, whilst proinsulin-specific clones were both CD8+ and CD4+. Proinsulin-specific CD8+ clones had a distinctive cytotoxic phenotype with overexpression of granulysin (GNLY) and KIR receptors. Clonally expanded antigen-specific T cells remained in situ for months to years, with a spectrum of tissue resident memory and effector memory phenotypes. As the T-cell response is divided between targeting the gold core and the antigenic cargo, this offers a route to improving resident memory T-cells formation in response to vaccines. In addition, our scRNAseq data indicate that focusing on clonally expanded skin infiltrating T-cells recruited to intradermally injected antigen is a highly efficient method to enrich and identify antigen-specific cells. This approach has the potential to be used to monitor the intradermal delivery of antigens and nanoparticles for immune modulation in humans.

Prescribing costs of hypoglycaemic agents and associations with metabolic control in Wales; a national analysis of primary care data

AIMS

There has been a dramatic increase in hypoglycaemic agent expenditure. We assessed the variability in prescribing costs at the practice level and the relationship between expenditure and the proportion of patients achieving target glycaemic control.

METHODS

We utilized national prescribing data from 406 general practices in Wales. This was compared against glycaemic control (percentage of patients achieving a HbA1c level < 59 mmol/mol in the preceding 12 months). Analyses were adjusted for the number of patients with diabetes in each general practice and the Welsh Index of Multiple Deprivation.

RESULTS

There was considerable heterogeneity in hypoglycaemic agent spend per patient with diabetes, Median = £289 (IQR 247-343) range £31.1-£1713. Higher total expenditure was not associated with improved glycaemic control B_(std)  = -0.01 (95%CI -0.01, 0.002) p = 0.13. High-spend practices spent more on SGLT2 inhibitors (16 vs. 9% p < 0.001) and GLP-1 agonists (13 vs. 11% p < 0.001) and less on insulin (34 vs. 42% p < 0.001), biguanides (9 vs. 11% p = 0.001) and sulphonylureas (2 vs. 3% p < 0.001) than low spend practices. There were no differences in the pattern of drug prescribing between high spend practices with better glycaemic control (mean 68% of patients HbA1c <59 mmol/mol) and those with less good metabolic control (mean 58% of patients HbA1c <59 mmol/mol).

CONCLUSIONS

Spend on hypoglycaemic agents is highly variable between practices and increased expenditure per patient is not associated with better glycaemic control. Whilst newer, more expensive agents have additional benefits, in individuals where these advantages are more marginal widespread use of these agents has important cost implications.

Incidence of Acute Cerebrovascular Events in Patients with Rheumatic or Calcific Mitral Stenosis: A Systematic Review and Meta-analysis

BACKGROUND

Patients with mitral stenosis (MS) may be predisposed to acute cerebrovascular events (ACE) and peripheral thromboembolic events (TEE). Concomitant atrial fibrillation (AF), mitral annular calcification (MAC) and rheumatic heart disease (RHD) are independent risk factors. Our aim was to evaluate the incidence of ACEs in MS patients and the implications of AF, MAC, and RHD on thromboembolic risks.

METHODS

This systematic review was registered on PROSPERO (CRD42021291316). Six databases were searched from inception to 19th December 2021. The clinical outcomes were composite ACE, ischaemic stroke/transient ischaemic attack (TIA), and peripheral TEE.

RESULTS

We included 16 and 9 papers, respectively, in our qualitative and quantitative analyses. The MS cohort with AF had the highest incidence of composite ACE (31.55%; 95%CI 3.60-85.03; I²=99%), followed by the MAC (14.85%; 95%CI 7.21-28.11; I²=98%), overall MS (8.30%; 95%CI 3.45-18.63; I²=96%) and rheumatic MS population (4.92%; 95%CI 3.53-6.83; I²=38%). Stroke/TIA were reported in 29.62% of the concomitant AF subgroup (95%CI 2.91-85.51; I²=99%) and in 7.11% of the overall MS patients (95%CI 1.91-23.16; I²=97%). However, the heterogeneity of the pooled incidence of clinical outcomes in all groups, except the rheumatic MS group, were substantial and significant. The logit-transformed proportion of composite ACE increased by 0.0141 (95% CI 0.0111-0.0171; p<0.01) per year of follow-up.

CONCLUSION

In the MS population, MAC and concomitant AF are risk factors for the development of ACE. The scarcity of data in our systematic review reflects the need for further studies to explore thromboembolic risks in all MS subtypes.

Roles and Functions of a Non-Academic Medical School Facebook Page from the Student Perspective: A Study of Usage and Survey Data

Background: Facebook is a well-established social networking platform that is commonly used by medical schools as an educational resource, but there are few studies assessing the roles of a non-academic Facebook page in medical education. Cardiff University uses Facebook primarily as a student support and engagement platform through its ‘C21’ Facebook Page; this study aimed to explore the use of the page by students, as well as their perceptions on the value of the page and the appropriateness of social media use by the medical school.   Methods:Authors collected and analyzed C21 Facebook Page usage data to obtain descriptive information on reach, engagement and content. They also distributed an anonymized survey to evaluate and explore users’ interest in, experience of and engagement with the content. Results: Of the 1021 posts on the page in 2019, the highest post-engagement rate occurred in the?Student or Staff News?category (13.5%) and the lowest in?Medical Research News?(3.5%). Survey feedback on the page was overwhelmingly positive (n=89; 84.8%), and respondents reported a high degree of trust (n=95; 90.5%) in the page. Students would like to see more ‘Curriculum Vitae (CV)-building’ Opportunities advertised on the page.   Conclusion:The C21 Facebook Page is an important resource in developing community within the medical school and facilitating student engagement with both the C21 course and wider medical opportunities. It is perceived as an appropriate channel of communication between the medical school and students.

Abstract TP208: Prevalence Of Adverse Cerebrovascular Events In Hypertrophic Cardiomyopathy Patients With And Without Atrial Fibrillation: A Systematic Review And Meta-analysis

Introduction: Hypertrophic cardiomyopathy (HCM) predisposes to adverse cerebrovascular events (ACEs) including ischaemic stroke, transient ischaemic attack (TIA), thromboembolic event (TEE) and peripheral embolism (PE). Concomitant atrial fibrillation (AF), which is more prevalent in the HCM population, confers even higher risk. Our aims are to report the prevalence of ACEs in HCM patients and to determine the additional clinical risks of AF on the prognosis of this population.

Methods: A systematic literature search was performed on PubMed, Scopus, Embase/ Ovid and Cochrane library from inception to 20 th March 2021. No limitations on language or date of publication were applied. The primary outcome of this review was to examine and compare the prevalence of ischaemic stroke in the HCM population with or without AF. Secondary outcomes were to identify their risk of non-stroke clinical outcomes such as TIA, non-specified TEE and PE. Non-specified TEE in our paper only referred to thromboembolic events whereby their types were not specified in the included studies. Meta-analysis was performed using StataSE 16 software, and heterogeneity was assessed using I 2 test.

Results: A total of 713 studies were identified, and 35 articles with 42,570 patients were included. The pooled prevalence of stroke/ TIA was 7.45% (95% confidence interval [CI] 5.80 - 9.52, p = 0.000) across 24 studies in the overall HCM population of 37,643 patients. AF contributed to a significantly higher risk of non-specified TEE (Risk ratio [RR] 4.49, 95% CI 1.88 - 10.73, p = 0.0007, I 2 = 87.0) and total stroke/ TIA (RR 3.26, 95% CI 1.75 - 6.08, p = 0.0002, I 2 = 76.0) in our study population. Within the apical HCM (ApHCM) population, the prevalence of stroke/ TIA was 9.30% (95% CI 6.64 - 12.87, p = 0.316).

Conclusion: Our study concludes that concomitant AF diagnosis increases the risk of developing thromboembolic events and the stroke-related mortality rate. Although the prevalence of stroke/ TIA in the ApHCM subtype was slightly higher than the overall HCM population, further studies investigating the clinical outcomes of HCM subtypes are warranted.

Referral rates of patients with diabetes to secondary care are inversely related to the prevalence of diabetes in each primary care practice and confidence in treatment, not to HbA1c level

AIMS

To determine the factors affecting the referral rates of patients with diabetes from primary care to secondary care.

METHODS

A study based on 66 GP surgeries in the Cardiff and Vale University Health Board (population: 515,581) was conducted. We included patients who had an established clinical diagnosis of diabetes (type 1 and type 2) from September 2017 to September 2018. HbA1c outcome data of GP surgeries were obtained from the Quality and Outcomes Framework (QOF) database published for 2018. Referral rates were obtained from the electronic referral database of Cardiff and Vale University Health Board over the same period, and this was adjusted according to the number of patients with diabetes in each GP surgery. Confidence level on the treatment of diabetes among GPs was assessed as a sub-study conducted in nine GP surgeries in the same area, using a self-administered questionnaire. Linear regression was undertaken to assess the relationship between adjusted referral rate and key factors which might influence prescribing rate.

RESULTS

The average adjusted referral rate to secondary care in one year was 4.23% of patients with diabetes in each GP surgery, with a wide variation of 1.24% to 16.28%. The average percentage of patients with diabetes with HbA1c<59mmol/mol was 63.17% (range: 43.19-76.23%). The average confidence score of GPs in treating diabetes was 67% and ranged from 50-85% in the sub-study. Referral rates correlated inversely with the numbers of patients with diabetes in each practice β=-0.32; (95% CI -0.57, -0.08) p=0.01, but there was no significant correlation with the HbA1c outcome β=-0.13; (95% CI -0.39, 0.12); p=0.30. Borderline significant negative correlation was observed between referral rates and overall practice size β=-0.23; (95% CI -0.48, 0.02) p=0.07.

CONCLUSIONS

Referral rates of patients with diabetes to secondary care are determined by the number of patients with diabetes in each practice and confidence level in treatment, not by the overall practice size or HbA1c level. Ensuring quality training in diabetes care for primary care teams as well as the development of integrated diabetes care may be the best way to optimise the volume and appropriateness of referrals to secondary care.