Single-Cell RNA-Seq Analysis of Patient Myeloid-Derived Suppressor Cells and the Response to Inhibition of Bruton's Tyrosine Kinase

Myeloid-derived suppressor cell (MDSC) levels are elevated in patients with cancer and contribute to reduced efficacy of immune checkpoint therapy. MDSC express Bruton's tyrosine kinase (BTK) and BTK inhibition with ibrutinib, an FDA-approved irreversible inhibitor of BTK, leads to reduced MDSC expansion/function in mice and significantly improves the antitumor activity of anti-PD-1 antibody treatments. Single-cell RNA sequencing (scRNA-seq) was used to characterize the effect of ibrutinib on gene expression of fluorescence-activated cell sorting-enriched MDSC from patients with different cancer types [breast, melanoma, head and neck squamous cell cancer (HNSCC)]. Melanoma patient MDSC were treated in vitro for 4 hours with 5 μmol/L ibrutinib or DMSO, processed for scRNA-seq using the Chromium 10× Genomics platform, and analyzed via the Seurat v4 standard integrative workflow. Baseline gene expression of MDSC from patients with breast, melanoma, and HNSCC cancer revealed similarities among the top expressed genes. In vitro ibrutinib treatment of MDSC from patients with melanoma resulted in significant changes in gene expression. GBP1, IL-1β, and CXCL8 were among the top downregulated genes whereas RGS2 and ABHD5 were among the top upregulated genes (P < 0.001). Double positive CD14+CD15+ MDSC and PMN-MDSC responded similarly to BTK inhibition and exhibited more pronounced gene changes compared with early MDSC and M-MDSC. Pathway analysis revealed significantly downregulated pathways including TREM1, nitric oxide signaling, and IL-6 signaling (P < 0.004).

IMPLICATIONS

scRNA-seq revealed characteristic gene expression patterns for MDSC from different patients with cancer and BTK inhibition led to the downregulation of multiple genes and pathways important to MDSC function and migration.

A Bayesian multivariate mixture model for high throughput spatial transcriptomics

High throughput spatial transcriptomics (HST) is a rapidly emerging class of experimental technologies that allow for profiling gene expression in tissue samples at or near single-cell resolution while retaining the spatial location of each sequencing unit within the tissue sample. Through analyzing HST data, we seek to identify sub-populations of cells within a tissue sample that may inform biological phenomena. Existing computational methods either ignore the spatial heterogeneity in gene expression profiles, fail to account for important statistical features such as skewness, or are heuristic-based network clustering methods that lack the inferential benefits of statistical modeling. To address this gap, we develop SPRUCE: a Bayesian spatial multivariate finite mixture model based on multivariate skew-normal distributions, which is capable of identifying distinct cellular sub-populations in HST data. We further implement a novel combination of Pólya-Gamma data augmentation and spatial random effects to infer spatially correlated mixture component membership probabilities without relying on approximate inference techniques. Via a simulation study, we demonstrate the detrimental inferential effects of ignoring skewness or spatial correlation in HST data. Using publicly available human brain HST data, SPRUCE outperforms existing methods in recovering expertly annotated brain layers. Finally, our application of SPRUCE to human breast cancer HST data indicates that SPRUCE can distinguish distinct cell populations within the tumor microenvironment. An R package spruce for fitting the proposed models is available through The Comprehensive R Archive Network.

A National Referral Service for Paediatric Brachytherapy: An Evolving Practice and Outcomes Over 13 Years

AIMS

Most children requiring radiotherapy receive external beam treatment and few have tumours suitable for brachytherapy. No paediatric radiotherapy centre will treat enough patients from its own normal catchment population for expertise in brachytherapy to be developed and sustained. Following discussion and agreement in the national paediatric radiotherapy group, a service for paediatric brachytherapy in the UK has been developed. We report the process that has evolved over more than 10 years, with survival and functional outcome results.

MATERIALS AND METHODS

Since 2009, potential patients have been referred to the central paediatric oncology multidisciplinary team meeting, where imaging, pathology and treatment options are discussed. Since 2013, the National Soft Tissue Sarcoma Advisory Panel has also reviewed most patients, with the principal aim of advising on the most suitable primary tumour management for complex patients. Clinical assessment and examination under anaesthetic with biopsies may be undertaken to confirm the appropriateness of brachytherapy, either alone or following conservative surgery. Fractionated high dose rate brachytherapy was delivered to a computed tomography planned volume after implantation of catheters under ultrasound imaging guidance. Since 2019, follow-up has been in a dedicated multidisciplinary clinic.

RESULTS

From 2009 to 2021 inclusive, 35 patients (16 female, 19 male, aged 8 months to 17 years 6 months) have been treated. Histology was soft-tissue sarcoma in 33 patients and carcinoma in two. The treated site was pelvic in 31 patients and head and neck in four. With a median follow-up of 5 years, the local control and overall survival rates are 100%. Complications have been few, and functional outcome is good.

CONCLUSION

Brachytherapy is effective for selected paediatric patients, resulting in excellent tumour control and good functional results. It is feasible to deliver paediatric brachytherapy at a single centre within a national referral service.

Can Anti-Müllerian Hormone levels predict future pregnancy outcomes in recurrent pregnancy loss?

OBJECTIVE

Serum Anti-Müllerian Hormone (AMH) levels have been shown to be lower among women who have experienced recurrent pregnancy loss (RPL) compared with the general population. However, it is unclear whether it can predict livebirth. This study aims to determine whether AMH can predict the likelihood of a livebirth in women with RPL.

STUDY DESIGN

Prospective analysis of a consecutive cohort of women undergoing investigation for RPL in a tertiary referral centre over a seven year period (August 2014 -December 2021). Analysis was performed using descriptive statistics, chi-square models and logistic regression models adjusting for maternal age and previous livebirth. Exclusion criteria for the regression analysis included abnormal parental karyotype and abnormal pelvic ultrasound scan. Pregnancy outcome was defined as livebirth or further pregnancy loss.

RESULTS

There were 488 women who underwent investigation of RPL during the study period. Of these, 65.2% (n = 318) conceived following attendance at the clinic. The majority of these women (69.4%, n = 221) proceeded to have a livebirth. There were no differences in median AMH levels between the livebirth group and the further pregnancy loss group (11 pmol/L vs 9 pmol/L respectively (p = 0.083). AMH did not affect clinical pregnancy rates (p = 0.77, 95% CI = 0.99 [0.98, 1.01]) or pregnancy outcome (p = 0.30, 95% CI = 1.01 [0.99, 1.04]). Abnormal pelvic ultrasonography (p = 0.04) and an abnormal parental karyotype (p = 0.04) were associated with an increased likelihood of a subsequent pregnancy loss.

CONCLUSION

Although AMH levels may have some utility in counselling of some couples with RPL, these contemporaneous data indicate that low AMH does not negatively influence subsequent pregnancy outcome in women with recurrent pregnancy loss.

'Nesting networks': Women's experiences of social network support in high-risk pregnancy

OBJECTIVE

Social support, an individual's social relationships (both online and offline), may provide protection against adverse mental health outcomes, such as anxiety and depression, which are high in women who have been hospitalised with high-risk pregnancy. This study explored the social support available to women at higher risk of preeclampsia during pregnancy by examining personal social networks.

DESIGN

Semi-structured interviews were accompanied by social network mapping using the web-based social networking tool GENIE.

SETTING

England.

PARTICIPANTS

Twenty-one women were recruited, of whom 18 were interviewed both during pregnancy and postnatally between April 2019 and April 2020. Nineteen women completed maps pre-natally, 17 women completed maps pre-natally and post-natally. Women were taking part in the BUMP study, a randomised clinical trial that included 2441 pregnant individuals at higher risk of preeclampsia and recruited at a mean of 20 weeks' gestation from 15 hospital maternity units in England between November 2018 and October 2019.

RESULTS

Women's social networks tightened during pregnancy. The inner network changed most dramatically postnatally with women reporting fewer network members. Interviews revealed networks were primarily 'real-life' rather than online social networks, with members providing emotional, informational, and practical support. Women with a high-risk pregnancy valued the relationships they developed with health professionals during pregnancy, and would like their midwife to have a more central role in their networks by providing informational and, where needed, emotional support. The social network mapping data supported the qualitative accounts of changing networks across high-risk pregnancy.

CONCLUSION

Women with a high-risk pregnancy seek to build "nesting networks" to support them through pregnancy into motherhood. Different types of support are sought from trusted sources. Midwives can play a key role.

PRACTICE IMPLICATIONS

As well as highlighting other potential needs during pregnancy and the ways in which they can be met, support from midwives has a key role. Through talking to women early in their pregnancy, signposting information and explaining ways to contact health professionals regarding informational or emotional support would fill a gap that currently is met by other aspects of their network.

Pre-frontal stimulation does not reliably increase reward responsiveness

Depression is the leading cause of disability worldwide and its effects can be fatal, with over 800,000 people dying by suicide each year. Neuromodulatory treatments such as transcranial magnetic stimulation (TMS) are being used to treat depression. Despite its endorsement by two regulatory bodies: NICE (2016) and the FDA (2008), there are major questions about the treatment efficacy and biological mechanisms of TMS. Ahn et al.'s (2013) justified the use of TMS in a clinical context in an important study indicating that excitatory TMS increases reward responsiveness. A pseudo-replication of this study by Duprat et al., (2016) also found a similar effect of active TMS, but only with the addition of an exploratory covariate to the analyses-trait reward responsiveness. Here we replicate Ahn et al.'s (2013) key study, and to test the reliability of the effects, and their dependency on trait reward responsiveness as described by Duprat et al., (2016). Using excitatory and sham TMS, we tested volunteers using the probabilistic learning task to measure their reward responsiveness both before and after stimulation. We also examined affect (positive, negative) following stimulation. Irrespective of TMS, the task was shown to be sensitive to reward responsiveness. However, we did not show TMS to be effective in increasing reward responsiveness and we did not replicate Ahn et al., (2013) or Duprat et al., (2016)'s key findings for TMS efficacy, where we provide evidence favouring the null. Moreover, exploratory analyses suggested following active stimulation, positive affect was reduced. Given our findings, we question the basic effects, which support the use of TMS for depression, particularly considering potential deleterious effects of reduced positive affect in patients with depression.

Novelty-induced locomotor behavior predicts heroin addiction vulnerability in male, but not female, rats

RATIONALE

The ongoing rise in opioid use disorder (OUD) has made it imperative to better model the individual variation within the human population that contributes to OUD vulnerability. Using animal models that capture such variation can be a useful tool. Individual variation in novelty-induced locomotion is predictive of substance use disorder (SUD) propensity. In this model, rats are characterized as high-responders (HR) or low-responders (LR) using a median split based on distance travelled during a locomotor test, and HR rats are generally found to exhibit a more SUD vulnerable behavioral phenotype.

OBJECTIVES

The HR/LR model has commonly been used to assess behaviors in male rats using psychostimulants, with limited knowledge of the predictive efficacy of this model in females or the use of an opioid as the reward. In the current study, we assessed several behaviors across the different phases of drug addiction (heroin taking, refraining, and seeking) in over 500 male and female heterogeneous stock rats run at two geographically separate locations. Rats were characterized as HRs or LRs within each sex for analysis.

RESULTS

Overall, females exhibit a more OUD vulnerable phenotype relative to males. Additionally, the HR/LR model was predictive of OUD-like behaviors in male, but not female rats. Furthermore, phenotypes did not differ in anxiety-related behaviors, reacquisition of heroin-taking, or punished heroin-taking behavior in either sex.

CONCLUSIONS

These results emphasize the importance of assessing females in models of individual variation in SUD and highlight limitations in using the HR/LR model to assess OUD propensity.

Migrating Type 2 Dendritic Cells Prime Mucosal Th17 Cells Specific to Small Intestinal Commensal Bacteria

Dendritic cells (DCs) are professional APCs equipped with MHC-restricted Ags, costimulations, and cytokines that effectively prime and differentiate naive T cells into distinct functional subsets. The immune signals that DCs carry reflect the route of Ag uptake and the innate stimuli they received. In the mucosal tissues, owing to the great variety of foreign Ags and inflammatory cues, DCs are predominantly activated and migratory. In the small intestine, CD4 Th17 cells are abundant and have been shown to be regulated by DCs and macrophages. Using a mouse commensal bacteria experimental model, we identified that the early priming step of commensal-driven Th17 cells is controlled by bona fide Zbtb46-expressing DCs. CCR7-dependent migration of type 2 DCs (DC2s) from the small intestine to the mesenteric lymph nodes (MLNs) is essential for the activation of naive CD4 T cells. The migratory DC2 population in the MLNs is almost exclusively Esam+ cells. Single-cell RNA sequencing highlighted the abundance of costimulatory markers (CD40 and OX40) and chemokines (Ccl22 and Cxcl16) on MLN migratory DCs. Further resolution of MLN migratory DC2s revealed that the Th17-polarizing cytokine IL-6 colocalizes with DC2s expressing CD40, Ccl17, and Ccl22. Thus, early Th17 cell differentiation is initiated by a small subset of migratory DC2s in the gut-draining lymph nodes.

Define and visualize pathological architectures of human tissues from spatially resolved transcriptomics using deep learning

Spatially resolved transcriptomics provides a new way to define spatial contexts and understand the pathogenesis of complex human diseases. Although some computational frameworks can characterize spatial context via various clustering methods, the detailed spatial architectures and functional zonation often cannot be revealed and localized due to the limited capacities of associating spatial information. We present RESEPT, a deep-learning framework for characterizing and visualizing tissue architecture from spatially resolved transcriptomics. Given inputs such as gene expression or RNA velocity, RESEPT learns a three-dimensional embedding with a spatial retained graph neural network from spatial transcriptomics. The embedding is then visualized by mapping into color channels in an RGB image and segmented with a supervised convolutional neural network model. Based on a benchmark of 10x Genomics Visium spatial transcriptomics datasets on the human and mouse cortex, RESEPT infers and visualizes the tissue architecture accurately. It is noteworthy that, for the in-house AD samples, RESEPT can localize cortex layers and cell types based on pre-defined region- or cell-type-enriched genes and furthermore provide critical insights into the identification of amyloid-beta plaques in Alzheimer's disease. Interestingly, in a glioblastoma sample analysis, RESEPT distinguishes tumor-enriched, non-tumor, and regions of neuropil with infiltrating tumor cells in support of clinical and prognostic cancer applications.

Migratory type 2 dendritic cells mediate mucosal Th17 response to gut commensal bacteria

Dendritic cells (DCs) are professional antigen-presenting cells equipped with MHC-restricted antigens, co-stimulations, and cytokines that effectively prime and differentiate naïve T cells into distinct functional subsets. The immune signals that DCs carry reflect the route of antigen uptake and the innate stimuli they received. In the mucosal tissues, owing to the great variety of foreign antigens and inflammatory cues, DCs are predominantly activated and migratory. The gut commensal bacteria contribute to immune health by educating the immune system at this unique location interfacing with the outside environment. In the small intestine, CD4 Th17 cells are abundant and play a critical role in mucosal defense against bacterial and fungal infections. We identified that the early priming step of commensal-driven Th17 cells is controlled by bona fide Zbtb46-expressing DCs. CCR7-dependent migration of DC2s from the small intestine to the mesenteric lymph nodes is essential for the activation of naïve CD4 T cells. The migratory DC2 population in the MLN are almost exclusively Esam+ cells. Single-cell RNA sequencing highlighted the abundance of co-stimulatory markers (CD40 and OX40) and chemokines (Ccl22 and Cxcl16) on MLN migratory DCs. Further resolution of MLN migratory DC2s revealed that the Th17-polarizing cytokine IL-6 colocalizes with DC2s expressing CD40, Ccl17, and Ccl22. Our study indicates that the mucosal Th17 cell response is regulated by a restricted subset of migratory DC2s in the gut draining lymph nodes.

Supported by NIAID U01AI125859

Androgen conspires with the CD8+ T cell exhaustion program and contributes to sex bias in cancer

Sex bias exists in the development and progression of non-reproductive organ cancers, but the underlying mechanisms are enigmatic. Studies so far have focused largely on sexual dimorphisms in cancer biology and socioeconomic factors. Here, we establish a role for CD8⁺ T cell-dependent anti-tumor immunity in mediating sex differences in tumor aggressiveness, which is driven by the gonadal androgen but not sex chromosomes. A male bias exists in the frequency of intratumoral antigen-experienced Tcf7/TCF1⁺ progenitor exhausted CD8⁺ T cells that are devoid of effector activity as a consequence of intrinsic androgen receptor (AR) function. Mechanistically, we identify a novel sex-specific regulon in progenitor exhausted CD8⁺ T cells and a pertinent contribution from AR as a direct transcriptional trans-activator of Tcf7/TCF1. The T cell intrinsic function of AR in promoting CD8⁺ T cell exhaustion in vivo was established using multiple approaches including loss-of-function studies with CD8-specific Ar knockout mice. Moreover, ablation of the androgen-AR axis rewires the tumor microenvironment to favor effector T cell differentiation and potentiates the efficacy of anti-PD-1 immune checkpoint blockade. Collectively, our findings highlight androgen-mediated promotion of CD8⁺ T cell dysfunction in cancer and imply broader opportunities for therapeutic development from understanding sex disparities in health and disease.

242 The Importance of Frailty Assessment as a Mortality Indicator and Surgical Decision-Making Tool

Background

Frailty is a multidimensional syndrome, which can lead to poorer health outcome. Frailty score is a proven reliable indicator of post-operative morbidity and mortality; however, its application in clinical practice is limited.

Aim

The study aimed to assess the association between frailty marker and one- year mortality rate and explore its impact in clinical decision making in patients with abdominal aortic aneurysms.

Method

Consecutive patients with abdominal, thoracic, and thoracoabdominal aortic aneurysms presented at dedicated aortic clinic between July 2019 and April 2020 were included. Markers for frailty and sarcopenia using Rockwood Clinical Frailty Scale, SARC-F questionnaire, morphometric analysis for sarcopenia, one-year mortality and fitness were recorded. Multi-disciplinary team (MDT) was blinded to frailty and sarcopenia data; surgical decisions made by MDT were recorded separately.

Results

We assessed 83 patients (median age 75 [72,82], 85% male; median aneurysm diameter 6cm [5.8,7.0]. Sixteen patients were deemed frail, five patients had sarcopenia and thirty-one patients had myopenia. Seventeen patients were deemed not fit for surgery; 41% of these were frail compared with 14% out of those who were deemed fit. The odds ratio of being frail and unfit for surgery was 4.33 (95% CI 1.27–14.82, p = 0.010). Frailty was significantly associated with one-year mortality irrespective of fitness for surgery, sarcopenia and myopenia (OR 10.28, 95%CI 1.82–57.93, p = 0.009). SARC-F and myopenia was not associated with one-year mortality at (OR 1.66, 95%CI 0.03–19.25, p = 0.523) and (OR 0.59, 95%CI 0.09–2.85, p = 0.514), respectively.

Conclusions

Frailty score was associated with both one-year mortality and fitness for surgery decision made by MDT.

233 A Closed-Loop Audit Assessing the Compliance of General Surgery Department in Completing Treatment Escalation Plan (TEP)

Aim

In the event of clinical deterioration, a treatment escalation plan describes individualized interventions that would be appropriate for a patient. Likewise, it allows clear communication amongst staff members and the patient about the limits of treatment. This audit aimed to evaluate the compliance of the General Surgery department during the pandemic.

Method

A closed-loop audit was conducted by looking at notes of General Surgery patients retrospectively and identifying those who’s had their treatment escalation plan form filled out during their admission. Data were collated, analysed, and presented in our local audit meeting. Thereafter, we disseminated the results to the department and modified our admission clerking proforma to ensure this is done. Afterwards, a re-audit was done to assess the improvement of compliance.

Results

A total of 24 patients were included. Before the modification of the clerking proforma, only 21% of TEP were completed. After the added changes, 36% of admitted patients had their form completed.

Conclusions

Our department was generally doing poorly with regards to ensuring our patients had TEP forms completed. Even though we generally have young, fit and well patients, according to our trust guidelines, all patients are meant to have their forms filled out. This ensures clear communication among staff and proper allocation of resources if there will be any shortages in the services that could be provided. By shining light on this topic, our department had been more compliant and proactive with ensuring that patients, especially the elderly, had a TEP form filled out.

Treatment with soluble CD24 attenuates COVID-19-associated systemic immunopathology

Background

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) through direct lysis of infected lung epithelial cells, which releases damage-associated molecular patterns and induces a pro-inflammatory cytokine milieu causing systemic inflammation. Anti-viral and anti-inflammatory agents have shown limited therapeutic efficacy. Soluble CD24 (CD24Fc) blunts the broad inflammatory response induced by damage-associated molecular patterns via binding to extracellular high mobility group box 1 and heat shock proteins, as well as regulating the downstream Siglec10-Src homology 2 domain–containing phosphatase 1 pathway. A recent randomized phase III trial evaluating CD24Fc for patients with severe COVID-19 (SAC-COVID; NCT04317040) demonstrated encouraging clinical efficacy.

Methods

Using a systems analytical approach, we studied peripheral blood samples obtained from patients enrolled at a single institution in the SAC-COVID trial to discern the impact of CD24Fc treatment on immune homeostasis. We performed high dimensional spectral flow cytometry and measured the levels of a broad array of cytokines and chemokines to discern the impact of CD24Fc treatment on immune homeostasis in patients with COVID-19.

Results

Twenty-two patients were enrolled, and the clinical characteristics from the CD24Fc vs. placebo groups were matched. Using high-content spectral flow cytometry and network-level analysis, we found that patients with severe COVID-19 had systemic hyper-activation of multiple cellular compartments, including CD8⁺ T cells, CD4⁺ T cells, and CD56⁺ natural killer cells. Treatment with CD24Fc blunted this systemic inflammation, inducing a return to homeostasis in NK and T cells without compromising the anti-Spike protein antibody response. CD24Fc significantly attenuated the systemic cytokine response and diminished the cytokine coexpression and network connectivity linked with COVID-19 severity and pathogenesis.

Conclusions

Our data demonstrate that CD24Fc rapidly down-modulates systemic inflammation and restores immune homeostasis in SARS-CoV-2-infected individuals, supporting further development of CD24Fc as a novel therapeutic against severe COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13045-021-01222-y.

Association of SARC-F Score and Rockwood Clinical Frailty Scale with CT-Derived Muscle Mass in Patients with Aortic Aneurysms

OBJECTIVES

Patients with aortic aneurysms (AA) are often co-morbid and susceptible to frailty. Low core muscle mass has been used as a surrogate marker of sarcopenia and indicator of frailty. This study aimed to assess association between core muscle mass with sarcopenia screening tool SARC-F and Clinical Frailty Scale (CFS) in patients with AA.

METHODS

Prospective audit of patients in pre-operative aortic clinic between 01/07/2019-31/01/2020 including frailty assessment using Rockwood CFS and sarcopenia screening using SARC-F questionnaire. Psoas and sartorius muscle area were measured on pre-operative CT scans and adjusted for height. Association was assessed using Spearman's rank correlation coefficient.

RESULTS

Of 84 patients assessed, median age was 75 years [72,82], 84.5% were men, 65.5% were multimorbid and 63.1% had polypharmacy. Nineteen percent were identified as frail (CFS score >3) and 6.1% positively screened for sarcopenia (SARC-F score 4 or more). Median psoas area (PMA) at L3 was 5.6cm2/m2 [4.8,6.6] and L4 was 7.4cm2/m2 [6.3,8.6]. Median sartorius area (SMA) was 1.8 cm2/m2 [1.5,2.2]. CFS demonstrated weak but statistically significant negative correlation with height-adjusted PMA at L3 (r=-0.25, p=0.034) but not at L4 (r=-0.23, p=0.051) or with SMA (r=-0.22, p=0.065). No association was observed between SARC-F score and PMA or SMA (L3 PMA r=-0.015, p=0.9; L4 PMA r=-0.0014, p= 0.99; SMA r=-0.051, p=0.67).

CONCLUSION

CFS showed higher association with CT-derived muscle mass than SARC-F. Comprehensive pre-operative risk-stratification tools which incorporate frailty assessment and body composition analysis may assist in decision making for surgery and allow opportunity for pre-habilitation.

687 MDSC gene expression analysis in patients with cancer and the response to inhibition of Bruton's tyrosine kinase

Background

Myeloid-derived suppressor cells (MDSC) are an immunosuppressive immature population of myeloid cells that are elevated in cancer patients. Increased levels of MDSC has been linked to dysregulated anti-tumor responses and reduced efficacy of immune checkpoint therapies thus making them an attractive target. MDSC express Bruton's tyrosine kinase (BTK) and can be depleted using ibrutinib, an FDA-approved irreversible inhibitor of BTK. BTK inhibition leads to reduced MDSC expansion/function in murine models and significantly improved activity of anti-PD-1 antibodies. In this study, single cell RNA-seq (scRNA-seq) was used to characterize the gene expression of MDSC from different cancer types and the effect of ibrutinib on MDSC gene expression.

Methods

Peripheral blood mononuclear cells were isolated from patients with melanoma (n=2), head & neck (n=1), and breast cancer (n=1). MDSC were isolated via fluorescence activated cell sorting. MDSC isolated from melanoma patients (n=2) were treated in vitro for 4h with 1 uM ibrutinib or DMSO and scRNA-seq was performed using the Chromium 10x Genomics platform. ScRNA-seq samples were analyzed using the standard integrative workflow of Seurat v3, which addresses the sample heterogeneity. Cell clusters were identified using Seurat and annotated using SingleRversion3.12. Identification of gene markers for each cell cluster and cell-cluster-specific differential expression analyses were conducted using Seurat.

Results

Baseline gene expression of MDSC from patients with breast and head & neck cancer revealed similarities among the top expressed genes (S100A8, VCAN, and LYZ). In vitro ibrutinib treatment of MDSC from patients with melanoma resulted in significant changes in gene expression within the MDSC cluster compared to DMSO treatment. GBP1(-1.72 log fold change), IL 1β(-1.27 log fold change), and CXCL8(-0.63 log fold change) were among the top downregulated genes (p<0.001) and RGS2 (0.68 log fold change) and ABHD5(0.52 log fold change) were among the top upregulated genes (p<0.001). MDSC subset (PMN-MDSC, M-MDSC, early-MDSC, and CD14+/CD15+ double positive) gene expression changes mirrored total MDSC gene changes. Ingenuity pathway analysis revealed significant downregulated pathways including TREM1 (p<0.001), nitric oxide signaling (p<0.003), and IL-6 signaling (p<0.004). Multiple genes associated with cellular movement (CXCL8, CXCL10) and activation of macrophages (CXCL10, CCL3) were downregulated (p<0.001). PCR analysis on isolated melanoma MDSC (n=2) treated in vitro with ibrutinib verified downregulation of CXCL8 (0.42 fold decrease, p<0.05) and CXCL10 (0.40 fold decrease, p<0.001).

Conclusions

Analysis via scRNA-seq revealed similar gene expression patterns for MDSC from different cancer patients. There was downregulation of multiple genes and pathways important to MDSC function and migration after BTK inhibition.

Ethics Approval

The study obtained ethics approval.

IRB# 1999C0348

IMMUNOLOGICAL INSIGHTS INTO THE THERAPEUTIC ROLES OF CD24Fc AGAINST SEVERE COVID-19

BACKGROUND.

SARS-CoV-2 causes COVID-19 through direct lysis of infected lung epithelial cells, which releases damage-associated molecular patterns (DAMPs) and induces a pro-inflammatory cytokine milieu causing systemic inflammation. Anti-viral and anti-inflammatory agents have shown limited therapeutic efficacy. Soluble CD24 (CD24Fc) is able to blunt the broad inflammatory response induced by DAMPs in multiple models. A recent randomized phase III trial evaluating the impact of CD24Fc in patients with severe COVID-19 demonstrated encouraging clinical efficacy.

METHODS.

We studied peripheral blood samples obtained from patients enrolled at a single institution in the SAC-COVID trial (NCT04317040) collected before and after treatment with CD24Fc or placebo. We performed high dimensional spectral flow cytometry analysis of peripheral blood mononuclear cells and measured the levels of a broad array of cytokines and chemokines. A systems analytical approach was used to discern the impact of CD24Fc treatment on immune homeostasis in patients with COVID-19.

FINDINGS.

Twenty-two patients were enrolled, and the clinical characteristics from the CD24Fc vs. placebo groups were matched. Using high-content spectral flow cytometry and network-level analysis, we found systemic hyper-activation of multiple cellular compartments in the placebo group, including CD8⁺ T cells, CD4⁺ T cells, and CD56⁺ NK cells. By contrast, CD24Fc-treated patients demonstrated blunted systemic inflammation, with a return to homeostasis in both NK and T cells within days without compromising the ability of patients to mount an effective anti-Spike protein antibody response. A single dose of CD24Fc significantly attenuated induction of the systemic cytokine response, including expression of IL-10 and IL-15, and diminished the coexpression and network connectivity among extensive circulating inflammatory cytokines, the parameters associated with COVID-19 disease severity.

INTERPRETATION.

Our data demonstrates that CD24Fc treatment rapidly down-modulates systemic inflammation and restores immune homeostasis in SARS-CoV-2-infected individuals, supporting further development of CD24Fc as a novel therapeutic against severe COVID-19.

FUNDING.

NIH

O-073 Perinatal outcomes of infants conceived using partner versus donor sperm - An analysis of singleton and twin pregnancies from the UK national dataset

Study question

Are perinatal outcomes different in pregnancies conceived using donor sperm compared with those with partner sperm?

Summary answer

The perinatal outcomes of singleton and twin pregnancies conceived with donor sperm are better when compared to those conceived with partner sperm

What is known already

There has been a substantial increase in the use of donor sperm in the last 15 years across the world. A recent systematic review and meta-analysis has suggested that there is an increased risk of hypertensive disorders of pregnancy and small for gestational age babies from ART treatment using donor sperm compared to partner`s sperm. This meta-analysis was limited due to poor quality of primary studies often with small sample sizes.

Study design, size, duration

This is a retrospective cohort study on 196,293 singleton and 46,275 twin pregnancies from the Human Fertilisation and Embryology Authority (HFEA) anonymised dataset including all live births from 1991 to 2016. Outcomes were preterm birth ( &lt; 37 weeks); very preterm birth ( &lt; 32 weeks); very low, low, high and very high birth weight ( &lt; 1500g, &lt; 2500g, &gt;4000g and &gt;4500g respectively); congenital anomaly and healthy baby (term live birth with appropriate weight and no congenital anomaly).

Participants/materials, setting, methods

All pregnancies resulting in singleton or twin livebirth were included. Any cycle involving donor oocytes, PGD, gamete intra-fallopian transfer, ectopic pregnancy, miscarriage, stillbirth, or termination was excluded. Logistic regression and generalised estimating equations were used for analysis of singletons and twins, respectively. Odds ratios (aOR) with 95% confidence intervals (CI) for donor versus partner sperm were adjusted for maternal age, previous pregnancy, cause of infertility and year for all outcomes plus gestational age for birthweight.

Main results and the role of chance

Baseline characteristics for donor and partner sperm pregnancies were assessed for singleton and twin livebirths separately. In both analyses there were significant differences between donor and partner sperm pregnancies in terms of maternal age, previous pregnancy status and cause of infertility.

Analysis of singleton births demonstrated an increased odds (aOR, 95% CI) of having a healthy baby (1.09, 1.05 - 1.12) and reduced odds of congenital anomaly (0.34, 0.29 - 0.39), very preterm birth (0.66, 0.58-0.75), preterm birth (0.81, 0.76-0.86), low birthweight 0.89 (0.83 - 0.96) in singleton births using donor sperm compared with those using partner sperm. There was, however, an increased odds of high birthweight (1.10, 1.05 - 1.16) and very high birthweight (1.16, 1.05-1.29) with donor sperm pregnancies.

Analysis of twin births conceived with donor sperm also showed higher odds of having a healthy baby (1.07, 1.01 - 1.15) and lower odds of congenital anomaly (0.52, 0.39 - 0.68) compared with partner sperm. There were no statistically significant differences between the birthweight or birth gestation outcomes for twin pregnancies.

Sensitivity analysis of only cases with complete outcome data showed no significant differences when compared to the primary analysis.

Limitations, reasons for caution

This is a retrospective study of a single nation’s routinely collected data. We could not adjust for confounders such as smoking, BMI and pregnancy complications such as pre-eclampsia, as they are not recorded in HFEA’s dataset.

Wider implications of the findings

Patients and clinicians can be reassured that donor sperm pregnancies are not at higher risk of adverse perinatal outcomes. In fact, they are more likely to result in a healthy baby. Worldwide registries should consider including maternal data to enable a better assessment of outcomes.

Trial registration number

Not applicable

P–775 Obstetric and perinatal outcomes of singleton pregnancies after blastocyst-stage embryo transfer: a systematic review and cumulative meta-analysis

Study question

Are obstetric/perinatal outcomes different in singleton pregnancies following blastocyst-stage embryo transfer when compared to cleavage-stage embryo transfer and have results changed over time?

Summary answer

Pregnancies following blastocyst are consistently associated with higher risk of large for gestational age and lower risk of small for gestational age babies

What is known already

Extended embryo culture to blastocyst-stage is widely used to select best embryos in in vitro fertilisation (IVF) cycles to improve pregnancy rates. Transfer of blastocyst-stage embryos is increasing with this being the default strategy in most clinics. As blastocysts are kept in culture until day 5, 6 or 7 after oocyte fertilisation, there are suggestions that longer exposure to culture media may have a negative impact on pregnancy outcomes. More recent primary studies have challenged some of the initial findings. We therefore conducted an updated systematic review and cumulative meta-analysis (CMA) to examine if these results have changed over time.

Study design, size, duration

Systematic review of studies published between 1980 and 2020, followed by aggregated meta-analysis and CMA to track the accumulation of evidence over the period of time. Exposed group: singleton pregnancies following blastocyst transfer. Non-exposed group: singleton pregnancies following cleavage-stage transfer. Sub-group analyses were conducted on fresh and frozen-thawed embryo transfers. Perinatal (categories of preterm birth and birth weight) and obstetric outcomes (hypertensive disorders of pregnancy, gestational diabetes, c-section, placental anomalies) were compared between the groups.

Participants/materials, setting, methods

Medline, EMBASE, CINHAL, Web of Science, Cochrane Central Register of Clinical Trials and International Clinical Trials Registry Platform databases were searched. Relevant journals were searched for advance access publications. Critical Appraisal Skills Programme (CASP) checklists were used to assess study quality. Two independent reviewers extracted data in 2 × 2 tables. Aggregated and CMA were performed using Comprehensive Meta-Analysis software. Risk ratio (RR) with 95% confidence interval (CI) were calculated.

Main results and the role of chance

A total of 33 observational studies were included (n = 574,756 singleton pregnancies). Pregnancies following blastocyst-stage embryo transfer are associated with a higher risk of preterm birth (PTB) (RR 1.09; 95% CI 1.01–1.17), very preterm birth (VPTB) (RR 1.15; 95% CI 1.07–1.24), large for gestational age (LGA) babies (RR 1.13; 95% CI 1.08–1.19), c-section (RR 1.05; 95% CI 1.02–1.09), and with a lower risk of small for gestational age (SGA) babies (RR 0.86; 95% CI 0.81–0.93) as compared to singleton pregnancies following cleavage-stage embryo transfer.

These findings were maintained in both fresh and frozen-thawed sub-groups for LGA and SGA. PTB was not significantly different in both sub-group analyses. The risk of VPTB was higher after blastocyst-stage embryo transfer only in the sub-group analysis of fresh embryo transfers (RR 1.17; 95% CI 1.09–1.27) and that of c-section only in the frozen-thawed sub-group (RR 1.08; 95% CI 1.04–1.12).

No other statistically significant differences for the other outcomes were noted.

The CMA suggests that for SGA and LGA subsequent studies have increased the precision of the point estimate with no change in the direction or magnitude of the treatment effect since 2014.

Limitations, reasons for caution

This analysis was constrained by the intrinsic limitations of observational studies with some of them receiving a CASP score &lt; 10. Adjustment for confounders was not possible and a high degree of clinical and statistical heterogeneity was noted among studies.

Wider implications of the findings: Blastocyst is associated with a higher risk of LGA and a lower risk of SGA with a stable body of evidence since 2014. We may need to revisit the default position of extending embryo culture and individualise care, until further high-quality data from individual-patient-data of large registries are available.

Trial registration number

Not applicable

POS1449 SEGMENTED SHORT-FORMAT ONLINE EDUCATION SIGNIFICANTLY INCREASES PREDICTION, PROGNOSIS, AND MANAGEMENT OF FIBROSING INTERSTITIAL LUNG DISEASE ASSOCIATED WITH CONNECTIVE TISSUE DISEASE

Background:

Identifying fibrosing interstitial lung disease (ILD) at the earliest opportunity remains one of the most urgent challenges for the effective management of this potentially rapidly progressive and burdensome condition, which is frequently associated with several connective tissue diseases (CTDs). However, knowledge on how to identify early hallmarks and predictors of fibrosing ILD, as well as knowing which steps to take next is frequently lacking in clinical practice.

Objectives:

This study was conducted to determine whether online independent medical education could improve rheumatologists’ and pulmonologists’ knowledge and competence in identifying and managing progressive fibrosing ILDs earlier in the disease course.

Methods:

Rheumatologists and pulmonologists participated in five ~10-min presentations about the early identification of fibrosing ILD in patients with or without CTDs and completed all pre- and post-questions.1 The effects of the education on knowledge and competence were assessed using a 3-question, repeated pairs, pre-assessment/post-assessment study design. For all questions combined, the chi-square test assessed differences from pre- to post-assessment. P values <.05 are statistically significant. The activity launched on October 9, 2020, and data were collected through December 18, 2020.

Results:

Overall significant improvements were seen after participation for both rheumatologists (average correct response rate of 28% at pre-assessment vs 74% at post-assessment; P<.001, representing a 165% relative percentage change [RPC]; N=39), and pulmonologists (average correct response rate of 39% at pre-assessment vs 67% at post-assessment; P<.001, representing a 72% RPC; N=102). Specifically, significant improvements were observed in clinicians’ knowledge of predictors of fibrosing ILD in patients with CTD, as well as competence in selecting the right HRCT parameters to assess prognosis and select a treatment approach to reduce the risk of disease progression (Figure 1).

Figure 1.

After participating in the activity, 59% of rheumatologists and 50% of pulmonologists had measurable improved confidence related to identifying early disease progression in patients with progressive fibrosing ILDs.

Given the very low rates of correct responses at baseline regarding predictors of fibrosing ILD and assessing prognosis, it will be important to continue to reinforce these learnings in ongoing educational programs.

Conclusion:

This study demonstrates the success of segmented online education in improving rheumatologists’ and pulmonologists’ knowledge and competence in evaluating risk and prognosis of fibrosing ILD and managing patients with CTD-ILDs. This could lead to earlier changes in therapeutic approach for those with signs of progression and result in improved overall outcomes for these patients.

References:

[1]Kolb M, Maher T, Smith V, Jacob J, Rimekasten G. Catching and Managing Progressive Fibrosing Interstitial Lung Disease Progression Earlier. Launched: Oct 9, 2020. Data as of Dec 18, 2020. Available at www.medscape.org/viewarticle/938826

Disclosure of Interests:

Christy Rohani-Montez: None declared, Marinella Calle: None declared, Chris Allen: None declared, Toby Maher Speakers bureau: Astra Zeneca, Bayer, Blade Therapeutics, Boehringer Ingelheim, Bristol-Myers Squibb, Galapagos, Galecto, GlaxoSmithKline R&D, Indalo, IQVIA, Pliant, Respivant, Roche and Theravance, Consultant of: Astra Zeneca, Bayer, Blade Therapeutics, Boehringer Ingelheim, Bristol-Myers Squibb, Galapagos, Galecto, GlaxoSmithKline R&D, Indalo, IQVIA, Pliant, Respivant, Roche and Theravance, Grant/research support from: Astra Zeneca and GlaxoSmithKline R&D, Vanessa Smith Speakers bureau: Boehringer-Ingelheim Pharma GmbH&Co and Janssen-Cilag NV, Consultant of: Boehringer-Ingelheim Pharma GmbH&Co, Grant/research support from: Research Foundation - Flanders (FWO), Belgian Fund for Scientific Research in Rheumatic diseases (FWRO), Boehringer-Ingelheim, Pharma GmbH&Co, and Janssen-Cilag NV, Joseph Jacob Speakers bureau: Boehringer-Ingelheim; Roche, Consultant of: Boehringer-Ingelheim, Grant/research support from: GlaxoSmithKline, Gabriela Riemekasten Speakers bureau: AbbVie; Actelion; Boehringer-Ingelheim, Consultant of: Actelion; CellTrend; Janssen, Grant/research support from: AbbVie; Actelion, Martin Kolb Speakers bureau: AstraZeneca; Boehringer-Ingelheim; Novartis; Roche, Consultant of: AbbVie Inc.; Algernon Pharma; AstraZeneca;, Boehringer-Ingelheim; Cipla; Covance; EPG Health; Galapagos NV; Gilead; GlaxoSmithKline; Indalo; MitoImmune Therapeutics Inc; Novartis; Pieris; Prometic (now Liminal Biosciences); Roche; Third Pole Inc.; TwoXAR Inc., Grant/research support from: Boehringer-Ingelheim; GlaxoSmithKline; Novartis; Prometic; Roche; Avalyn

Seven-year retrospective study understanding the latent TB infection treatment cascade of care among adults in a low incidence country

Background

Prevention of TB is paramount to achieving elimination targets as recommended by the World Health Organization’s action framework for low incidence countries striving to eliminate TB. Although the rates of TB in Canada are low, understanding the latent TB infection (LTBI) cascade is paramount to identifying gaps in care and treatment barriers, thereby increasing the effectiveness of preventive strategies. The purpose of this study was to examine the LTBI cascade of care and identify barriers to treatment completion in adults referred from primary care to a regional tertiary care TB clinic in Ottawa, Canada.

Methods

Electronic medical records between January 2010 and December 2016 were reviewed retrospectively and an LTBI cascade of care was constructed from The Ottawa Hospital TB clinic and surrounding primary care clinics. A cohort of 2207 patients with untreated LTBI was used to ascertain the associations between demographic and clinical factors for both treatment non-initiation and non-completion using log-binomial univariable and multivariable regression models.

Results

Of 2207 patients with untreated LTBI who were seen in the clinic during the study period, 1771 (80.2%) were offered treatment, 1203 (67.9% of those offered) started treatment, and 795 (66.1% of those started) completed treatment. In multivariable analysis, non-initiation of treatment was associated with older age (adjusted risk ratio [aRR] 1.06 per 5-year increase, 95% CI: 1.03–1.08) and female gender (aRR 1.28, 95% CI: 1.11–1.47). Non completion of treatment was associated with referral from the TB Clinic back to the primary care team following initial consult (aRR 1.62, 95% CI: 1.35–1.94) and treatment with the standard of 9 months of Isoniazid (9H) compared to 4 months of Rifampin (4R) (aRR 1.45, 95% CI:1.20–1.74).

Conclusions

LTBI treatment completion was significantly decreased among patients who were referred back to primary care from the TB clinic. The 4R regimen resulted in more people completing LTBI treatment compared to 9H in keeping with a recently published RCT. Improved education, communication, and collaboration between tertiary care TB clinics and primary care teams may improve treatment completion rates and address the TB burden in low incidence communities in Canada.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10733-9.

IRIS-FGM: an integrative single-cell RNA-Seq interpretation system for functional gene module analysis

SUMMARY

Single-cell RNA-Seq (scRNA-Seq) data is useful in discovering cell heterogeneity and signature genes in specific cell populations in cancer and other complex diseases. Specifically, the investigation of condition-specific functional gene modules (FGM) can help to understand interactive gene networks and complex biological processes in different cell clusters. QUBIC2 is recognized as one of the most efficient and effective biclustering tools for condition-specific FGM identification from scRNA-Seq data. However, its limited availability to a C implementation restricted its application to only a few downstream analysis functionalities. We developed an R package named IRIS-FGM (Integrative scRNA-Seq Interpretation System for Functional Gene Module analysis) to support the investigation of FGMs and cell clustering using scRNA-Seq data. Empowered by QUBIC2, IRIS-FGM can effectively identify condition-specific FGMs, predict cell types/clusters, uncover differentially expressed genes and perform pathway enrichment analysis. It is noteworthy that IRIS-FGM can also take Seurat objects as input, facilitating easy integration with the existing analysis pipeline.

AVAILABILITY AND IMPLEMENTATION

IRIS-FGM is implemented in the R environment (as of version 3.6) with the source code freely available at https://github.com/BMEngineeR/IRISFGM.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Network-Based Discovery of Opioid Use Vulnerability in Rats Using the Bayesian Stochastic Block Model

Opioid use disorder is a psychological condition that affects over 200,000 people per year in the U.S., causing the Centers for Disease Control and Prevention to label the crisis as a rapidly spreading public health epidemic. The behavioral relationship between opioid exposure and development of opioid use disorder (OUD) varies greatly between individuals, implying existence of sup-populations with varying degrees of opioid vulnerability. However, effective pre-clinical identification of these sub-populations remains challenging due to the complex multivariate measurements employed in animal models of OUD. In this study, we propose a novel non-linear network-based data analysis workflow that employs seven behavioral traits to identify opioid use sub-populations and assesses contributions of behavioral variables to opioid vulnerability and resiliency. Through this analysis workflow we determined how behavioral variables across heroin taking, refraining and seeking interact with one another to identify potentially heroin resilient and vulnerable behavioral sub-populations. Data were collected from over 400 heterogeneous stock rats in two geographically distinct locations. Rats underwent heroin self-administration training, followed by a progressive ratio and heroin-primed reinstatement test. Next, rats underwent extinction training and a cue-induced reinstatement test. To enter the analysis workflow, we integrated data from different cohorts of rats and removed possible batch effects. We then constructed a rat-rat similarity network based on their behavioral patterns and implemented community detection on this similarity network using a Bayesian degree-corrected stochastic block model to uncover sub-populations of rats with differing levels of opioid vulnerability. We identified three statistically distinct clusters corresponding to distinct behavioral sub-populations, vulnerable, resilient and intermediate for heroin use, refraining and seeking. We implement this analysis workflow as an open source R package, named mlsbm.

Diagnostic Challenges And Clinical Implications For Systemic EBV-Associated T-Cell Lymphoproliferative Disorders Of Childhood

Introduction/Objective

Systemic EBV-associated T-cell lymphoproliferative disorders of childhood (S-EBV-T-LPD) comprise three major forms: EBV-positive hemophagocytic lymphohistiocytosis (EBV-HLH), systemic EBV-positive T- cell lymphoma (S-EBV-TCL), and systemic T-cell chronic active EBV infection (S-T-CAEBV). These disorders are rare in children and young adults in Western countries and are associated with poor outcomes. Frequently patients were treated initially for EBV-HLH and subsequently found to have relapsed/refractory EBV-HLH vs S-EBV-TCL or overt EBV+ TCL, the latter of which requires different therapy than EBV-HLH. We report the clinicopathologic findings of 13 cases, including 8 previously reported. (PMID: 31099136)

Methods

Thirteen cases of S-EBV-T-LPD were identified at Texas Children’s Hospital from 1990 to 2020. Clinicopathologic and relevant laboratory parameters were recorded.

Results

Patients included six females and seven males of Hispanic (n=6), Asian (4), and Caucasian origins (3) ages 1-22 years (median 2). All had fever, hepatosplenomegaly, cytopenias, abnormal EBV serologies, and significantly elevated peripheral blood EBV- DNA load by quantitative PCR. Histologic features were variable ranging from EBV+ T-cell infiltrates with subtle architectural distortion and mild atypia to overt morphologic appearance of lymphoma.

Consistent findings were aberrant T-cell populations identified by immunohistochemistry (n=4) or bone marrow flow cytometry (n=9, 1-50%, mean 16%). Five patients were classified as overt EBV+ TCL with abnormal karyotyping identified in 3. Seven patients had pathology findings indistinguishable between EBV-HLH and S-EBV-TCL and were classified as EBV-HLH/S-EBV-TCL. One patient had S-T-CAEBV. Outcomes were dismal after HLH-directed immuno/chemotherapy protocols with/without bone marrow transplant as only three EBV-HLH/S-EBV-TCL patients were alive at 1.5, 2.5 months, and 9 years follow-up.

Conclusion

This series from North America demonstrate challenges in the diagnosis and management of S-EBV-T- LPD cases. Particularly, EBV-HLH and S-EBV-TCL, which require vastly different treatment strategies, may initially present with overlapping clinicopathological features. Further studies are needed to address clear diagnostic criteria to guide appropriate management.

Household Food Security and Infant Adiposity

OBJECTIVES

Food insecurity has been associated with obesity, but previous studies are inconsistent and few included infants. We examined associations between household food security and infant adiposity and assessed the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and Supplemental Nutrition Assistance Program (SNAP) as effect modifiers. We hypothesized that infants from food-insecure households would have greater adiposity, with attenuation by WIC and SNAP.

METHODS

We repeatedly measured 666 infants from the southeastern United States in 2013-2017. We categorized households as high, marginal, low, or very low using the US Household Food Security Survey Module. Outcomes were BMI z score, subscapular and triceps skinfold-for-age z score, the sum of subscapular and triceps skinfolds, the ratio of subscapular and triceps skinfolds, and BMI z score ≥1 (at risk for overweight). We used covariate-adjusted repeated-measures linear and logistic regressions.

RESULTS

Of infants, 68.6% were Black and 60.5% had household incomes <$20 000. Interactions between food security and WIC and/or SNAP were not significant. Compared with infants from high food security households, infants from very low food security households had higher BMI z scores (0.18 U; 95% confidence interval [CI] 0.01 to 0.35), higher subscapular skinfold-for-age z scores (0.31 U; 95% CI 0.04 to 0.59), a higher sum of subscapular and triceps skinfolds (0.53 mm; 95% CI 0.002 to 1.07), and greater odds of being at risk for overweight (odds ratio 1.55; 95% CI 1.14 to 2.10). Infants from low food security households had greater odds of being at risk for overweight (odds ratio 1.72; 95% CI 1.17 to 2.10).

CONCLUSIONS

In larger and longer studies, researchers should examine food security and adiposity in young children.

A Bayesian multivariate mixture model for skewed longitudinal data with intermittent missing observations: An application to infant motor development

In studies of infant growth, an important research goal is to identify latent clusters of infants with delayed motor development-a risk factor for adverse outcomes later in life. However, there are numerous statistical challenges in modeling motor development: the data are typically skewed, exhibit intermittent missingness, and are correlated across repeated measurements over time. Using data from the Nurture study, a cohort of approximately 600 mother-infant pairs, we develop a flexible Bayesian mixture model for the analysis of infant motor development. First, we model developmental trajectories using matrix skew-normal distributions with cluster-specific parameters to accommodate dependence and skewness in the data. Second, we model the cluster-membership probabilities using a Pólya-Gamma data-augmentation scheme, which improves predictions of the cluster-membership allocations. Lastly, we impute missing responses from conditional multivariate skew-normal distributions. Bayesian inference is achieved through straightforward Gibbs sampling. Through simulation studies, we show that the proposed model yields improved inferences over models that ignore skewness or adopt conventional imputation methods. We applied the model to the Nurture data and identified two distinct developmental clusters, as well as detrimental effects of food insecurity on motor development. These findings can aid investigators in targeting interventions during this critical early-life developmental window.

AB1272 ONLINE EDUCATION BOOSTS CLINICIAN KNOWLEDGE ABOUT EMERGING THERAPIES FOR PATIENTS WITH SYSTEMIC SCLEROSIS-ASSOCIATED INTERSTITIAL LUNG DISEASE

Background:

Systemic sclerosis-associated interstitial lung disease (SSc-ILD) has traditionally been treated with therapies such as cyclophosphamide, mycophenolate mofetil, and hematopoietic stem cell transplantation. However, these therapies are limited by potential toxicity, as well as duration and magnitude of effect. Clinicians need awareness of emerging therapies in late-stage clinical trials that may address these limitations.

Objectives:

This study was conducted to determine whether online independent medical education could improve rheumatologists’ and pulmonologists’ knowledge of emerging therapies for the management of SSc-ILD.

Methods:

Physicians (N = 2,076) participated in a 30-minute, 2-faculty, video-based, online CME with synchronized slides.1The majority of participants were rheumatologists (n = 522) or pulmonologists (n = 557), but the cohort also included clinical immunologists (n = 132) and other physicians with an interest in the topic (n = 865). This study focuses on the 120 rheumatologists and 111 pulmonologists who completed all pre- and post-questions. The effects of the education on knowledge was assessed using a 3-question, repeated pairs, pre-assessment/post-assessment study design. For all questions combined, the chi-square test assessed differences from pre- to post-assessment. P values <.05 are statistically significant. The activity launched on September 17, 2019, and data were collected through November 5, 2019.

Results:

Overall significant improvements were seen after participation for both rheumatologists (average correct response rate of 55% at pre-assessment vs 75% at post-assessment; P<.001, N=120), and pulmonologists (average correct response rate of 60% at pre-assessment vs 77% at post-assessment; P<.001, N=111). Specifically, significant improvements were observed in clinicians’ knowledge of clinical trial data for emerging SSc-ILD therapies (figure).

Figure.

Clinicians from APAC (n = 67) and Europe (n = 79) made up the majority of the cohort, and had similar rates of correct responses without significant differences, indicating consistent effects, independent of the region of origin. After participating in the activity, 48% of pulmonologists and rheumatologists had measurable improved confidence related to their knowledge of emerging therapies for patients with SSc-ILD.

Despite the increases in knowledge and confidence observed, the rates of correct responses suggest there is still room for improvement; therefore, ongoing education will be needed to reinforce knowledge of the latest data evaluating new therapies for SSc-ILD and what they will mean for future practice.

Conclusion:

This study demonstrates the success of online, video-based education in improving rheumatologists’ and pulmonologists’ knowledge of the latest clinical data on emerging therapies for SSc-ILD. This could lead to earlier adoption of new, efficacious therapies that may slow disease progression and improve overall outcomes for these patients.

References:

[1]Distler O, Hoffmann-Vold A-M. How Can We Meet the Treatment Needs of Patients With Systemic Sclerosis-Interstitial Lung Disease? Launched: 9/17/2019. Data as of 11/5/2019. Available atwww.medscape.org/viewarticle/917034

Disclosure of Interests:

Christy Rohani-Montez: None declared, Marinella Calle: None declared, Chris Allen: None declared, Anna-Maria Hoffmann-Vold Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Actelion, Bayer, GlaxoSmithKline, Speakers bureau: Boehringer Ingelheim, Actelion, Roche, Oliver Distler Grant/research support from: Grants/Research support from Actelion, Bayer, Boehringer Ingelheim, Competitive Drug Development International Ltd. and Mitsubishi Tanabe; he also holds the issued Patent on mir-29 for the treatment of systemic sclerosis (US8247389, EP2331143)., Consultant of: Consultancy fees from Actelion, Acceleron Pharma, AnaMar, Bayer, Baecon Discovery, Blade Therapeutics, Boehringer, CSL Behring, Catenion, ChemomAb, Curzion Pharmaceuticals, Ergonex, Galapagos NV, GSK, Glenmark Pharmaceuticals, Inventiva, Italfarmaco, iQvia, medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Roche, Sanofi and UCB, Speakers bureau: Speaker fees from Actelion, Bayer, Boehringer Ingelheim, Medscape, Pfizer and Roche

THU0584 CASE-BASED ONLINE EDUCATION SIGNIFICANTLY INCREASES CLINICIAN COMPETENCE IN ASSESSING SSC-ILD DISEASE PROGRESSION AND IMPLEMENTING APPROPRIATE THERAPY

Background:

Due to the heterogeneity in both the initial manifestations of systemic sclerosis (SSc) and progression with SSc-associated interstitial lung disease (SSc-ILD), diagnosis and prognosis can be challenging in clinical practice. Clinicians need expert case-based guidance on how best to monitor patients with SSc and the treatment implications.

Objectives:

This study was conducted to determine whether online case-based independent medical education could improve rheumatologists’ and pulmonologists’ competence in evaluating and monitoring SSc-ILD progression and initiating the right treatments when progression is identified.

Methods:

Rheumatologists and pulmonologists participated in two comprehensive online case studies, using a ‘test then teach’ approach and completed all pre- and post-questions.1The effects of the education on knowledge and competence were assessed using a 3-question, repeated pairs, pre-assessment/post-assessment study design. For all questions combined, the chi-square test assessed differences from pre- to post-assessment. P values <.05 are statistically significant. The activity launched on September 24, 2019, and data were collected through December 9, 2019.

Results:

Overall significant improvements were seen after participation for both rheumatologists (average correct response rate of 65% at pre-assessment vs 97% at post-assessment; P<.001, N=89), and pulmonologists (average correct response rate of 64% at pre-assessment vs 95% at post-assessment; P<.001, N=71). Specifically, significant improvements were observed in clinicians’ competence in assessing response to therapy and monitoring for disease progression; and managing evidence of disease worsening (figure).

Figure.

After participating in the activity, 54% of rheumatologists and 51% of pulmonologists had measurable improved confidence related to communicating with patients with SSc-ILD about the possibility of disease progression.

Given that only around half of clinicians provided correct responses at baseline, it will be important to continue to reinforce these learnings in ongoing education.

Conclusion:

This study demonstrates the success of online, case-based education in improving rheumatologists’ and pulmonologists’ competence in managing patients with SSc-ILD. This could lead to earlier changes in therapeutic approach for those with signs of progression and result in improved overall outcomes for these patients.

References:

[1]Denton C. When SSc-ILD Starts Progressing: Monitoring and Managing Those at Risk for Poor Prognosis. Launched: 9/24/2019. Data as of 12/9/2019. Available atwww.medscape.org/viewarticle/918465

Disclosure of Interests:

Christy Rohani-Montez: None declared, Marinella Calle: None declared, Chris Allen: None declared, Christopher Denton Grant/research support from: GlaxoSmithKline, CSL Behring, and Inventiva, Consultant of: Medscape, Roche-Genentech, Actelion, GlaxoSmithKline, Sanofi Aventis, Inventiva, CSL Behring, Boehringer Ingelheim, Corbus Pharmaceuticals, Acceleron, Curzion and Bayer

Progress in High-Speed Spin Testing of Superconducting Wire and Tapes for High-Field NMR Magnet Qualification

This paper summarizes the status of a 3-year, NIH-funded research project to study the strength of high temperature superconductors under high circumferential hoop stress, in order to qualify these materials for high-field (> 1 GHz-class NMR magnets. The unique approach presented here is to spin test coils at high rotational speeds, approaching 100,000 rpm, in order to induce the necessary hoop stress. Thermal strain compatibility between the Bi-2212 wire and Inconel wire has been qualified, including thermal cycling. Assembly and testing of the first low-speed (< 30,000 rpm) rotor is now in process, and the design of second, higher speed (> 60,000 rpm) rotor, is also underway.

P6484Invasive and non-invasive characterisation of low gradient aortic stenosis

Background

Low gradient severe aortic stenosis (LGAS) is associated with unfavourable outcomes when compared to high gradient aortic stenosis (HGAS), yet the contributing pathophysiology is poorly understood.

Methods

Symptomatic LGAS and HGAS patients undergoing trans-catheter aortic valve implantation (TAVI) underwent 3T stress perfusion cardiac magnetic resonance imaging (CMR) pre-(within 24 hours) and post-(4–6 months) TAVI. Left ventricular (LV) contractility and coronary flow/pressure were measured during hyperaemia and rapid pacing, immediately before and after TAVI, using a conductance LV catheter and dual-pressure and Doppler sensor–tipped guidewire in the mid-left anterior descending coronary artery.

Results

24 patients were recruited resulting in 19 suitable datasets (LGAS N=9, HGAS N=10, equally matched for comorbidities and B-natriuretic peptide level). LGAS patients had a smaller LV end diastolic volume index (p=0.035) and lower LV mass index (LVMI) (p=0.037). Pre-TAVI stress global endocardium-epicardium gradient was 0.88±0.09 and global myocardial perfusion reserve (MPR) 2.0±0.48 in 14 patients (6 LGAS and 8 HGAS patients, no difference between groups). Pre-TAVI, baseline coronary data demonstrated lower augmentation pressure (AP, p=0.035) and augmentation index (AIx, p=0.02) in the LGAS group. LGAS patients also exhibited a shorter ejection time (p=0.015), larger forward compression waves during rest, hyperaemia and rapid pacing, and smaller backward expansion waves (BEW) (p=0.001). Lower baseline end systolic pressure (p=0.004), inotropy (dP/dt+, p=0.045), lusitropy (dP/dt-, p=0.069), and stroke work (p=0.019) were observed in the LGAS group. Whilst LV size was smaller the LGAS group, rapid pacing induced a more significant drop in end systolic volume (p=0.045) and ejection fraction (p=0.015) in patients with HGAS. Post-TAVI, the hyperaemic BEW fell sharply (p<0.001), along with coronary VTI (p=0.02), and average pulse velocity (p=0.028), and AP and AIx remained lower (p=0.034 and p=0.031, respectively). The forward expansion wave was reduced in LGAS during rapid pacing. The HGAS group displayed a more profound drop in dP/dt+ (p=0.011) and dP/dt- p=0.014) at rest following intervention. Repeat CMR demonstrated statistically significant reduction in LV size and LVMI (p=0.012 and p<0.001, respectively) with significant increase in 3D global peak radial, circumferential and longitudinal strain (p=0.004, p=0.001 and p=0.018, respectively). Post-TAVI stress global endocardium-epicardium gradient was 0.88±0.13 and MPR 2.46±0.59 (improved from pre-TAVI, p=0.05). There was no difference in remodelling patterns or perfusion between the two groups.

Conclusion

This is the first study detailing the combined invasive and CMR pathophysiological changes in LGAS. Despite invasive parameters indicating a disease of less severe AS, the level of perfusion abnormality is disproportionate which may in part, relate to their adverse prognosis.

Acknowledgement/Funding

This research is funded by a Clinical Research Training Fellowship grant from the British Heart Foundation (FS/16/51/32365).

Associations of maternal diet with infant adiposity at birth, 6 months and 12 months

OBJECTIVES

To assess associations between maternal prenatal diet quality and infant adiposity.

DESIGN

The design was a prospective birth cohort.

SETTING

We used data from the Nurture study, a cohort of women and their infants residing in the southeastern USA.

PARTICIPANTS AND EXPOSURE ASSESSMENT

Between 2013 and 2015, we enrolled 860 women between 20 and 36 weeks' gestation. After reconsenting at delivery and excluding women with implausible calorie intakes, we measured dietary intake using the Block food frequency questionnaire, and assessed diet quality using a modified Alternate Healthy Eating Index 2010 (AHEI-2010), which assessed intake of 10 food categories, including fruits, vegetables, whole grains, nuts/legumes, fats, meats, beverages and sodium (excluding alcohol).

OUTCOMES

We assessed birth weight for gestational age z-score, small and large for gestational age, low birth weight and macrosomia. Outcomes at 6 and 12 months were weight-for-length z-score, sum of subscapular and triceps skinfold thickness (SS+TR) and subscapular-to-triceps skinfold ratio (SS:TR).

RESULTS

Among mothers, 70.2% were black and 20.9% were white; less than half (45.2%) reported having a high school diploma or less. Among infants, 8.7% were low birth weight and 8.6% were small for gestational age. Unadjusted estimates showed that a higher AHEI-2010 score, was associated with a higher birth weight for gestational z-score (β=0.01; 95% CI 0.002 to 0.02; p=0.02) and a greater likelihood of macrosomia (OR=1.04; 95% CI 1.004 to 1.09; p=0.03). After adjustment, maternal diet quality was not associated with infant adiposity at birth, 6 or 12 months.

CONCLUSIONS

Although poor maternal diet quality during pregnancy was not associated with infant adiposity in our study, maternal diet during pregnancy may still be an important and modifiable factor of public health importance.

GAIL: An interactive webserver for inference and dynamic visualization of gene-gene associations based on gene ontology guided mining of biomedical literature

In systems biology, inference of functional associations among genes is compelling because the construction of functional association networks facilitates biomarker discovery. Specifically, such gene associations in human can help identify putative biomarkers that can be used as diagnostic tools in treating patients. Although biomedical literature is considered a valuable data source for this task, currently only a limited number of webservers are available for mining gene-gene associations from the vast amount of biomedical literature using text mining techniques. Moreover, these webservers often have limited coverage of biomedical literature and also lack efficient and user-friendly tools to interpret and visualize mined relationships among genes. To address these limitations, we developed GAIL (Gene-gene Association Inference based on biomedical Literature), an interactive webserver that infers human gene-gene associations from Gene Ontology (GO) guided biomedical literature mining and provides dynamic visualization of the resulting association networks and various gene set enrichment analysis tools. We evaluate the utility and performance of GAIL with applications to gene signatures associated with systemic lupus erythematosus and breast cancer. Results show that GAIL allows effective interrogation and visualization of gene-gene networks and their subnetworks, which facilitates biological understanding of gene-gene associations. GAIL is available at http://chunglab.io/GAIL/.