Valvular changes following anthracycline therapy: is it time to look beyond ejection fraction?

Background

Advancements in early detection and treatment of breast cancer have improved survival, but with the costs of side effects, with cardiotoxicity being the most significant one. Anthracycline (ANT) is the most recognized therapy leading to cardiotoxicity, mainly manifested as left ventricle (LV) dysfunction. While the changes in LV ejection fraction (LVEF) are well studied, little is known about the effect of ANT on valvular function. We aimed to evaluate the change in valvular function following ANT therapy in patients diagnosed with breast cancer.

Methods

The study population is part of the Israel Cardio-Oncology Registry (ICOR). All patients performed serial echocardiography; before (T1), during (T2), at the end (T3), and following (T4) ANT therapy, assessing valvular changes. Exclusion criteria included age below 18 and baseline LVEF <55%.

Results

The study included 141 female patients diagnosed with breast cancer and treated with ANT with a mean age of 51±12 years (Table 1). During a median follow-up of 255 [IQR 214–313] days, from T1 to T4, we observed a significant increase in the portion of patients developing new mitral regurgitation (MR) (3.5% to 18.7%, p<0.0001), with a trend for developing moderate and above MR (0.7% to 3.3%, p=0.13). While a statistically significant reduction in mean LVEF (60.2%±1.5 to 59.2%±2.7, p=0.0004) and median LV global longitudinal strain (LV GLS) (−21.6% [−20.0 to −23.0] to −20.0% [−19.1 to −21.1], p<0.0001) was observed (Figure 1), the values remain within the normal range with no significant clinical change. In a multivariate binary logistic regression model, age (OR 1.06, 95% CI: 1.01–1.11) and trastuzumab therapy (OR 5.59, 95% CI: 1.95–16.6) were strong independent predictors for MR development, while medical history was not.

Conclusions

MR development following ANT exposure is frequent, increasingly after the completion of ANT therapy. The parallel reduction in LV function might imply a functional mechanism. Larger trials are needed to evaluate the MR prognostic clinical role in cancer patients.

Funding Acknowledgement

Type of funding sources: None.

OP0250 BREAKTHROUGH INFECTIONS AND PREDICTING SEVERE COVID OUTCOMES DURING RITUXIMAB THERAPY IN AUTOIMMUNE RHEUMATIC DISEASES

Background

As rituximab (RTX) is a B-cell depleting agent, there are concerns regarding its safety during the COVID pandemic. Data from registries during pre-vaccination period reported increased risk of poor outcomes in RTX-treated patients vs TNFi. However, registry data could be limited by reporting bias in determining true incidence. There are also limited data on breakthrough infections following COVID vaccination.

Objectives

To assess the incidence of breakthrough infections and predictors of severe COVID outcomes in RTX-treated autoimmune rheumatic diseases (ARDs) with a view to establishing a treatment algorithm for safe RTX administration.

Methods

An observational cohort study was undertaken in the first consecutive 300 ARD patients in a single centre between index date 01/09/2019 (i.e. 6 months prior to pandemic) and 31/01/2022. Only PCR positive cases were included. COVID outcomes were categorised as Mild (i.e. not hospitalised) or Moderate/Severe (i.e. hospitalised and requiring at least oxygenation or death). Predictors of moderate/severe outcomes were analysed using Cox-regression proportional hazard.

Results

Mean (SD) at index date was 59 (14) years, 226/300 (75%) patients were female and 254 (85%) were Caucasians. The diagnoses were RA=212 (71%), SLE=33 (11%), AAV=26 (9%), Sjogren=9 (3%), IIM=8 (3%) and others=12 (4%). Therapy included concomitant DMARDs = 205 (68%) and oral prednisolone = 84 (28%). Median (range) no. of previous RTX courses was 4 (0-19). 534 RTX courses were administered. Of 294 patients with available vaccine data, 17 (6%) were unvaccinated, 4 (1%) had a single dose, 47 (16%) were double-vaccinated, 217 (74%) triple-vaccinated and 9 (3%) quadruple-vaccinated. Of those who were vaccinated, for the first dose, 11% were given within 12 weeks post-RTX, 15% within 26 weeks and 74% were >26 weeks post-RTX. The rate of overall COVID and moderate/severe infections were 11.2/100 PYs and 2.6/100 PYs respectively. Vaccinated patients had lower rate of moderate/severe infection (2.6/100 PYs) vs unvaccinated (18.6/100 PYs) [Table 1]. Over 650.7 PY follow-up, 17/300 patients (5.7%) had moderate/severe COVID including 2 deaths. Factors associated with time-to-infection in imputed multivariable analysis were number of comorbidities [HR 1.46 (95% CI 1.05-2.04)] and low IgG (<6g/L) [6.15 (1.95-19.41)]. A history of COVID vaccination reduced risk [HR 0.13 (0.03-0.51)]. Demographics including concomitant prednisolone, RTX- and vaccine-associated factors (e.g. RTX dose, time from RTX to vaccine, vaccine mode, peripheral B-cell depletion) were not predictive.

Table 1.

Incidence of COVID infection

Pre-Vaccination ProgrammePost-Vaccination ProgrammeOverall Follow-upOverall COVID rate3.3/100 PYNon-vaccinated = 37.7/100 PY73 cases in 650.7 years] = 11.2/100 PYVaccinated = 18.6/100 PYModerate/Severe COVID rate2.1/100 PYNon-Vaccinated = 15.1/100 PY17 cases in 650.7 years] = 2.6/100 PYVaccinated = 2.6/100 PY

Conclusion

The rate of moderate/severe COVID infection in this cohort is comparable to the pre-pandemic severe infection rate in rituximab trials in RA. The high vaccination uptake in our cohort was effective in preventing severe infection despite the termination of national shielding programme in March 2021 and the spread of the Delta and Omicron variants. Individualised risk–benefit assessment should be undertaken in those with comorbidities, low IgG and unvaccinated when scheduling rituximab therapy.

References

None

Acknowledgements

This research was funded/supported by the the Wellcome Trust Institutional Strategic Support Fund to MYMY (204825/Z/16/Z), National Institute for Health Research (NIHR) Doctoral Research Fellowship to MYMY (DRF-2014-07-155) and NIHR Clinician Scientist to EMV (CS-2013-13-032). PE is a Versus Arthritis Professor of Rheumatology. This article/paper/report also presents independent research funded/supported by the NIHR Leeds Biomedical Research Centre. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

Disclosure of Interests

Md Yuzaiful Md Yusof Consultant of: Aurinia Pharmaceuticals, Jack Arnold: None declared, Benazir Saleem: None declared, Claire Vandevelde: None declared, Shouvik Dass: None declared, Sinisa Savic Speakers bureau: Novartis, Swedish Orphan Biovitrum (SOBI) and Sire, Grant/research support from: Novartis, Swedish Orphan Biovitrum, Octapharma and CSL Behring, Edward Vital Speakers bureau: Roche, GSK and AstraZeneca, Grant/research support from: Roche, GSK and AstraZeneca, Paul Emery Consultant of: BMS, Abbott, Pfizer, MSD, Novartis, Roche and UCB, Grant/research support from: Abbott, BMS, Pfizer, MSD and Roche.

Yusof MY, Vital E. AB0434 EFFICACY AND SAFETY OF OBINUTUZUMAB IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS WITH SECONDARY NON-RESPONSE TO RITUXIMAB

Background

Secondary inefficacy characterized by infusion reactions and anti-drug antibodies occur in 14% of SLE patients treated with repeat rituximab courses(1). Obinutuzumab is a next-generation humanized type-2 anti-CD20 therapy licensed for hematological malignancies which may overcome this issue(2).

Objectives

We set out to evaluate the clinical efficacy and safety of obinutuzumab in a cohort of rituximab resistant SLE patients.

Methods

We collated data from SLE patients receiving obinutuzumab for secondary non-response to rituximab in BILAG centres. Disease activity was assessed using BILAG-2004, SLEDAI-2K and serology before, and 6 months after, obinutuzumab 2x1000mg infusions alongside methylprednisolone 100mg. Flow cytometry where possible was carried out using a multiple gating highly sensitive strategy.

Results

All 9 patients included in the study received obinutuzumab alongside concomitant oral immunosuppression. At 6 months post-obinutuzumab, there were significant reductions in median SLEDAI-2K from 12 to 6 (p=0.014) and total BILAG-2004 score from 21 to 2 (p=0.009). Complement C3 and dsDNA titres improved significantly (both p=0.04). Non statistically significant numerical improvements were seen in C4 levels.

Of 8/9 patients receiving concomitant oral prednisolone at baseline (all >10mg/day), 5/9 had their dose reduced at 6 months; 4/8 were on 5mg/day and were in Lupus Low Disease Activity State. After obinutuzumab, 6/9 patients with peripheral B-cell data achieved complete depletion including 4/4 assessed with highly sensitive assays. 1/9 obinutuzumab non-responder required cyclophosphamide therapy. 1 unvaccinated patient died from COVID-19.

Table 1.

Baseline characteristics, disease activity and steroid doses before and after last obinutuzumab/rituximab.

PatientEthnicityDisease duration (Years)Age (Years)Total BILAG-2004 before ObiTotal BILAG-2004 after ObiSLEDAI-2K before ObiSLEDAI-2K after ObiPrednisolone before Obi (mg)Prednisolone after Obi (mg)1South Asian10.836.41821481052South Asian6.324.424212430103South Asian11.934.829110410104South Asian8.241.92116015155South Asian6.829.43221181450606White European17.537.0128881557White European16.930.01211281058Caribbean6.244.225213010159Caribbean2.621.092166105Median (Q1, Q3)NA8.2 (6, 12)34.8 (29,37)21 (12, 25)2 (1, 2)12 (10, 14)6 (4, 8)10 (10, 15)10 (5, 15)

Conclusion

Obinutuzumab appears to be effective and steroid-sparing in renal and non-renal SLE patients with secondary non-response to rituximab. Obinutuzumab was shown to be effective in patients with severe renal and non-renal disease. Therefore, in those with previous responsiveness to B-cell depletion, switching to humanised type-2 anti-CD20 therapy is a logical approach following loss off efficacy.

References

[1]Vital EM, Dass S, Buch MH, Henshaw K, Pease CT, Martin MF, et al. B cell biomarkers of rituximab responses in systemic lupus erythematosus. Arthritis Rheum [Internet]. 2011 Oct [cited 2020 Oct 12];63(10):3038–47. Available from: https://pubmed.ncbi.nlm.nih.gov/21618204/

[2]Hassan SU, Md Yusof MY, Emery P, Dass S, Vital EM. Biologic Sequencing in Systemic Lupus Erythematosus: After Secondary Non-response to Rituximab, Switching to Humanised Anti-CD20 Agent Is More Effective Than Belimumab. Front Med [Internet]. 2020 Aug 27 [cited 2020 Sep 2];7:498. Available from: https://www.frontiersin.org/article/10.3389/fmed.2020.00498/full

Disclosure of Interests

Jack Arnold: None declared, Shouvik Dass Consultant of: Roche, Abbvie, UCB & Chugai, Employee of: Honoraria from Roche, Abbvie, UCB & Chugai, Sarah Twigg: None declared, Colin Jones: None declared, Benjamin Rhodes: None declared, Peter Hewins: None declared, Mithun Chakravorty: None declared, Philip Courtney: None declared, Michael Ehrenstein Grant/research support from: GSK, Employee of: Has received honoraria from GSK, Md Yuzaiful Md Yusof: None declared, Edward Vital Employee of: Has received honoraria from Roche

AB0510 IMMUNOPHENOTYPIC RECLASSIFICATION OF ANA ASSOCIATED AUTOIMMUNE DISEASE: PRELIMINARY ANALYSIS OF FLOW CYTOMETRIC DATA IN A MULTI-DISEASE COHORT

Background

The heterogeneity within the connective tissue disease patient cohort is not adequately reflected by current diagnostic labels(1,2). An immunophenotypic classification may be more appropriate for targeting therapy and basket therapeutic trials. DEFINITION is a multi-disease cohort (n=300) containing multiple clinical and immune datasets.

Objectives

To perform preliminary clustering analysis using the flow cytometric dataset from DEFINITION.

Methods

142 patients with comprehensive flow cytometry data available were selected from the DEFINITION cohort. Highly sensitive flow cytometry was used to identify 7 B cell, T cell, NK cell and monocyte subsets and tetherin/SIGLEC1 expression on each subset.

ANA and ENA titres were assessed via the Bioplex assay. Demographic and clinical data was obtained from the DEFINITION cohort. Multiple classification algorithms were applied to flow cytometry data using R. Including K-means, hierachical, model-based and partitioning around medioids (PAM). Output clusters were retrospectively compared to their legacy diagnoses and serology.

Results

In the first 142 patients, PAM identified 3 clusters with memberships of 45, 49 and 48 patients respectively (Table 1).

Table 1.

Key legacy diagnoses and ENA positivity for the identified clusters.

DiagnosisTotalCluster 1Cluster 2Cluster 3P valueSLE57221025>0.01UCTD2512850.06Sjogren’s152490.06Systemic sclerosis70520.07MCTD92430.76Myositis83320.86Antibody positivitydsDNA431611160.33Ro604512726>0.01Ro5236107190.01La182214>0.01Sm141490.02Sm_RNP2375110.23RNP143560.64SCL-7010010.37Jo-141210.80Centromere51400.08Chromatin29108110.68Ribosomal P41120.78

Cluster 1 (UCTD/CD3+ dominant) was characterised by a higher proportion of UCTD patients (27%) and larger populations of CD3+ T cells and NK bright cells.

Cluster 2 (SSc dominant/Tetherin low) was characterised by a higher population of systemic sclerosis (SSc) patients (10%) and a lower proportion of SLE patients (20%). High levels of classical and non-classical monocytes were demonstrated alongside low plasmablast populations and low SIGLEC1/Tetherin expression.

Cluster 3 (SLE/pSS high, Ro/Tetherin high) included a higher proportion of SLE and primary Sjogren’s syndrome (pSS) patients (52% and 19%). This cluster showed larger plasmablast numbers and higher SIGLEC1/Tetherin expression. Serologically this cluster had higher levels of Ro60, Ro52, Sm-RNP and La positivity.

There were statistically significant differences in Ro60, Ro52, La, and Sm antibody positivity between the 3 clusters. Significant differences in CD19+CD27+ memory B cell tetherin expression and CD14+CD16- classical monocyte SIGLEC1 expression were observed (both p < 0.05). A significant difference in SLE distribution was noted between the clusters (p < 0.01).

Conclusion

This preliminary study identified of a flow cytometric dataset identified 3 immunophenotypically distinct subgroups, each comprised of multiple legacy diagnoses within spectrum of ANA+ disease. Future work will evaluate other datasets within the full cohort with a view to conduct basket trials in the baskets defined.

References

[1]Mucke J, Alarcon-Riquelme M, Andersen J, Aringer M, Bombardieri S, Brinks R, et al. What are the topics you care about making trials in lupus more effective? Results of an Open Space meeting of international lupus experts. Lupus Sci Med [Internet]. 2021 May 20 [cited 2021 Jul 12];8(1):506. Available from: /pmc/articles/PMC8141446/

[2]Barturen G, Beretta L, Cervera R, Van Vollenhoven R, Alarcón-Riquelme ME. Moving towards a molecular taxonomy of autoimmune rheumatic diseases [Internet]. Vol. 14, Nature Reviews Rheumatology. Nature Publishing Group; 2018 [cited 2021 Jun 28]. p. 75–93. Available from: https://pubmed.ncbi.nlm.nih.gov/29362467/

Acknowledgements

Funding: AstraZeneca

Disclosure of Interests

Jack Arnold: None declared, Lucy Marie Carter: None declared, Md Yuzaiful Md Yusof: None declared, Zoe Wigston: None declared, Sabih-Ul Hassan: None declared, Katherine Dutton: None declared, Shouvik Dass Speakers bureau: Honoraria from Roche, Consultant of: Roche, Abbvie, UCB & Chugai, Antonios Psarras: None declared, Edward Vital Speakers bureau: GSK, AstraZeneca, Consultant of: AstraZeneca, Lilly, Roche, GSK, Aurinia, Iltoo, Novartis, Grant/research support from: Research grants paid to the employer: AstraZeneca and Sandoz

OP0234 RNA-Seq IN PERIPHERAL BLOOD IMMUNE CELLS IDENTIFIES MODULAR NETWORKS PREDICTIVE AND PROTECTIVE FOR PROGRESSION FROM ANA POSITIVITY TO CLASSIFIABLE SYSTEMIC AUTOIMMUNE DISEASE

Background

Anti-nuclear antibody (ANA) positivity represents a complex ‘At-Risk’ state for development of connective tissue disease (CTD). While ANA may become positive years in advance of clinically manifest CTD, they are also harboured in at least low titre by up to 25% of the wider population, of whom only a small fraction ultimately develop systemic autoimmunity. Complex immune disturbances including plasmacytoid dendritic cell exhaustion and non-haematopoietic interferon (IFN) production are evident even among ANA positive individuals who do not ultimately progress to overt disease [1].

In a prospective observational cohort of ANA positive individuals At-Risk for CTD we have shown that a validated blood IFN-Score was predictive of progression to classifiable SLE [2]. However, the wider transcriptional fingerprint of the At-Risk state and other factors modifying risk of progression are not known. We hypothesise that diverse immune processes, both independent and interacting with IFN pathway activation, could modulate risk of progression.

Objectives

To investigate how peripheral blood immune cell transcriptional signatures derived by RNA Seq associate with progression or non-progression from At-Risk ANA positivity to clinically apparent CTD.

Methods

Peripheral blood mononuclear cells (PBMCs) were isolated at baseline from ANA-positive At-Risk individuals demonstrating ≤1 clinical criterion for classifiable CTD, symptom duration <12 months and naive of glucocorticoid or immunosuppressive therapy. Progression was prospectively adjudicated at 12 months and defined as accrual of clinical/ immunological criteria sufficient to meet classification for SLE (SLICC 2012) or other relevant CTDs. Bulk RNASeq was performed on PMBCs from 16 progressors and 19 non-progressors. Weighted gene co-expression network analysis (WGCNA) was performed using WGCNA package and gene ontology enrichment was evaluated using ClusterProfiler, in R Bioconductor. The top 20% genes ranked by connectivity were defined as hub genes. Major cell subsets were quantified in parallel by multiparameter flow cytometry.

Results

29 modules were identified by WGCNA. Eigengenes for 3 modules were significantly associated with progression status. A single, 152 gene module showed strong positive correlation with progression (R=0.55, p<0.001). Hub genes were significantly enriched for type I IFN-signalling pathway and included established interferon stimulated genes such as IFI44 and IRF7.

Two further modules had a negative, i.e. protective, association with progression; a smaller 37 gene module, correlated negatively with both blood interferon score (R=-0.46, p=0.005) and with progression (R=-0.43, p=0.01). A larger 252 gene module was also negatively related to progression (R=-0.43, p=0.009) and demonstrated significant pathway enrichment for regulation of cell morphogenesis and actin cyctoskeleton organisation.

Conclusion

We identify novel modular transcriptomic signatures implicated in SLE disease initiation. We show (i) IFN-pathway activation is the single strongest transcriptomic risk marker of progression from the ANA positive At Risk state and (ii) we identify 2 novel protective signatures in peripheral blood immune cells for which further network-based characterization is ongoing.

References

[1]Psarras et al. 2020 Nat Commun 11: 6149.

[2]Md Yusof MY, et al. Ann Rheum Dis 2018;77:1432–1439.

Disclosure of Interests

Lucy Marie Carter: None declared, Md Yuzaiful Md Yusof Consultant of: Aurinia Pharmaceuticals, Darren Plant: None declared, Adewonuola Alase: None declared, Jack Arnold: None declared, Antonios Psarras: None declared, Zoe Wigston: None declared, Edward Vital Consultant of: AstraZeneca, Genentech, Aurinia, Lilly, ILTOO and Modus Therapeutics., Grant/research support from: Astra Zeneca and Sandoz

Epilepsy and the smell of fear

OBJECTIVE

In our canine scent detection research involving a specific volatile organic compound (VOC) associated with human epileptic seizure, we began to suspect involvement of the primitive neural networks associated with production of a previously undescribed human alarm pheromone as the origin of our seizure scent. We hypothesized that if we presented fear-scented sweat to our canine seizure scent detection team, and they identified the fear scent as their seizure scent, then that would suggest that they are identical compounds.

METHODS

Following consent and approval, sweat samples taken from volunteers associated with the Brooke Gordon Comprehensive Epilepsy Center at Denver Health were processed by the Canine Assistants (CA) service dog team that had been imprinted to recognize the unique seizure scent from our previous study. In part one, sweat samples were collected from subjects, who had no prior history of epilepsy or seizures, under two different testing environments: watching a scary movie (It) and a neutral/comedy movie (Airplane!). In part two, a larger follow-up study utilizing fear sweat, exercise sweat, epilepsy sweat, and other distractor scents were provided in a multiple choice paradigm to better understand the inter-rater reliability of the canine responses.

RESULTS

In part one, our canine seizure scent detection team identified fear-scented sweat samples as their seizure scent in 4 of 5 study participants. There was almost perfect agreement of seizure scent detection during fear scent trials between the canine seizure scent detectors with a kappa value of 0.814 (95% CI: 0.668-0.960). In part two, (utilizing eleven different subjects) our canine scent detection team identified samples of either fear or seizure sweat with a sensitivity of 82% and a specificity of 100% (no false positives) from among the multiple choices offered. Additionally, there was 92% agreement between the members of the canine scent detection team.

SIGNIFICANCE

While this hypothesis testing study is small and deserves replication, it confirms that the Canine Assistants seizure scent detection team consistently and accurately identified fear-scented sweat as their seizure scent, implying that the VOC, menthone, is common to both conditions. This further implies that human seizure propagation and fear network circuitry may share a common anatomy, and that menthone may not only be an early seizure biomarker, but a newly described human alarm pheromone.

AB0293 IDENTIFYING PREDICTORS OF SHORT-TERM RESPONSE TO RITUXIMAB IN PRIMARY SJOGREN’S SYNDROME

Background:

Randomised controlled trials of rituximab (RTX) in primary Sjogren’s syndrome (pSS) have aimed to alleviate glandular symptoms and fatigue with only limited data on efficacy/effectiveness of the initial and repeat cycles of RTX on extra-glandular pSS.

Objectives:

To assess the effectiveness of RTX on extra-glandular symptoms and identify predictors of short-term response with a view to personalised B-cell depleting therapy in patients with pSS.

Methods:

An observational study was conducted in 40 consecutive RTX-treated pSS patients in a single centre for over 15 years. All patients fulfilled the 2002 AEG criteria and were CCP negative. Clinical response at 6 months was defined as ≥3 reduction of ESSDAI from baseline. B-cell subsets were measured using highly sensitive flow cytometry. Predictors of short-term response were analysed using penalised logistic regression.

Results:

38/40 (95%) patients were female, mean (SD) Age 54 (13.7) years, median (IQR) disease duration 5 (2-9) years, 39/40 (98%) had positive ANA, 26/40 (65%) were on concomitant immunosuppressant (IS). Mean (SD) ESSDAI at RTX initiation was 11.5 (6.7); main domains for RTX were articular (73%), skin (23%), PNS (15%) and muscular (15%). 169 RTX cycles were administered with a total follow-up of 165PY. In Cycle 1 (C1) RTX, the proportion of patient achieving ESSDAI response from baseline was 29/40 (73%; 95% CI 58-87). There were significant reductions in ESSDAI, daily prednisolone dose and IgG levels at 6 months (all p<0.05). Of C1 responders, 23/29 received retreatment on clinical relapse; of which 8/23 (35%) lost response [secondary non-depletion non response (2NDNR) associated with anti-RTX antibodies=4 (17%) as we previously observed in SLE[1], side effects=2, ineffective=2]. Of C1 non-responders, 9/11 were retreated but only 2/9 responded in C2. Overall, 13/40 (33%) discontinued RTX within two cycles. In multivariable analysis, concomitant IS and achieving compete B-cell depletion in C1 reduced non-response to RTX (Table 1).

Conclusion:

All pSS patients should be prescribed concomitant immunosuppressant with RTX and therapy should aim to achieve complete depletion. About 1 in 6 pSS patients lose response in repeat cycles which is associated with 2NDNR phenomenon. The use of humanised or type 2 anti-CD20mAbs should overcome these issues and improve the clinical response of extra-glandular pSS.

References:

[1]Md Yusof et al. ARD 2017 (2520 characters – allowed around 2600 as Table 1 is included too)

Table 1.

MVA logistic regression of risk factors for RTX non-response

PredictorsContinued Response (N=27)Non-response within 2 RTX Cycles (N=13)UnivariableOR (95% CI); p-valueMultivariableOR (95% CI); p-valueAge, mean (SD) per 10 years55 (14)52 (12)0.87 (0.53-1.41); 0.572Excluded from final modelDisease duration, median (IQR)5 (2-9)6 (3-9)0.97 (0.87-1.08); 0.565Excluded from final modelConcomitant IS, %81.5%30.8%0.10 (0.02-0.46); 0.0030.07 (0.01-0.52); 0.010IgG, mean (SD), g/L15.5 (6.3)18.4 (5.8)1.08 (0.97-1.20); 0.1751.13 (0.97-1.32); 0.116Clinical ESSDAI, median (IQR)10 (6-16)8 (6-10)0.96 (0.85-1.08); 0.4870.91 (0.79-1.05); 0.185Baseline Plasmablast (x1000),109 cells/L, median(IQR)2.6 (1 -5.2)2.3 (1.6-9.5)1.00 (0.94-1.07); 0.885Excluded from final modelComplete B-cell depletion post-RTX, %55.6%8.5%0.07 (0.01-0.64); 0.0180.04 (0.02-0.82); 0.036

Disclosure of Interests:

Sophanit Pepple: None declared, Jack Arnold: None declared, Edward Vital Grant/research support from: Dr Vital has received honoraria and research grant support from Roche, Andrew Rawstron: None declared, Colin Pease: None declared, Shouvik Dass Grant/research support from: Dr Dass has received honoraria from Roche, Paul Emery Consultant of: Professor Emery has received consultant fees from Roche., Grant/research support from: Professor Emery has received research grants paid to his employer from Roche., Md Yuzaiful Md Yusof: None declared

OP0057 A PERSONALISED RITUXIMAB RETREATMENT APPROACH BASED ON CLINICAL AND B-CELL BIOMARKERS IN ANCA-ASSOCIATED VASCULITIS

Background:

Time-to-relapse after rituximab for ANCA-associated vasculitis (AAV) is variable and optimal retreatment strategy has been unclear. We previously showed that repopulation of naïve B-cells at 6 months predicts sustained response [1].

Objectives:

In AAV following rituximab induction, to evaluate clinical and B-cell predictors of relapse in order to develop a retreatment algorithm.

Methods:

An observational study was conducted in 60 rituximab-treated AAV patients followed for over 10 years. Complete response (CR) was defined as Birmingham Vasculitis Activity Score v3.0 = 0. Retreatment was given on clinical relapse, defined as new features or worsening of persistent disease (not by biomarker status). Peripheral B-cell subsets were measured using highly sensitive flow cytometry. Predictors were tested using multivariable Cox-Regression.

Results:

Median times-to-retreatment for rituximab cycles 1-5 were 87, 71, 65, 59 and 86 weeks. Over 417 patient-years follow-up, 137 relapses occurred in 50 patients; 16 (in 14 patients) were major (renal=7, neurological=4, ENT=3 and respiratory=2). The major-relapse rate was 3.8/100 patient-years. In multivariable analysis, concomitant immunosuppressant [HR 0.48 (95% CI 0.24–0.94)], achieving CR [0.24 (0.12–0.50)] and naïve B-cell repopulation at 6 months [0.43 (0.22–0.84)] were associated with longer time-to-relapse. Higher baseline memory B-cells [1.01 (1.00–1.02)] were associated with a shorter time-to-relapse. AUROC for prediction of time-to-relapse was greater if guided by naïve B-cell repopulation than if ANCA and/or CD19+ return at 6 months had been used, 0.82 and 0.52 respectively.

Conclusion:

These data suggest that all patients should receive concomitant oral immunosuppressant. Those with incomplete response or with absent naïve B-cells should be retreated at 6 months. Patients with complete response and naïve repopulation at 6 months should not receive fixed retreatment. This algorithm could reduce hypogammaglobulinaemia due to unnecessary retreatment.

Figure 1.

A personalised retreatment algorithm for rituximab in ANCA-associated vasculitis

References:

[1]Md Yusof et al. Annals of rheumatic diseases (2015) PMID: 25854586.

Disclosure of Interests:

Jack Arnold: None declared, Edward Vital Speakers bureau: Roche, GSK and AstraZeneca, Consultant of: Roche, GSK and AstraZeneca, Grant/research support from: Roche, GSK and AstraZeneca, Shouvik Dass Speakers bureau: Roche and GSK, Aamir Aslam: None declared, Andrew Rawstron: None declared, Sinisa Savic: None declared, Paul Emery Speakers bureau: BMS, Abbott, Pfizer, MSD, Novartis, Roche and UCB, Consultant of: BMS, Abbott, Pfizer, MSD, Novartis, Roche and UCB, Grant/research support from: Abbott, BMS, Pfizer, MSD and Roche., Md Yuzaiful Md Yusof: None declared

Prevalence of microvascular dysfunction and association with clinical outcomes in heart failure with preserved ejection fraction

Introduction

Heart failure with preserved ejection fraction (HFpEF) accounts for approximately 50% of symptomatic heart failure. A recently proposed paradigm for the pathophysiology of HFpEF postulates a central inflammatory aetiology with coronary microvascular function at its core. However, the pathophysiological and clinical significance of microvascular dysfunction in HFpEF remains uncertain.

Purpose

Utilising cardiovascular magnetic resonance (CMR), we sought to (1) quantify coronary microvascular function, (2) evaluate the impact of microvascular dysfunction and fibrosis on long-term clinical outcomes and (3) examine the relationship between myocardial perfusion and fibrosis.

Methods

In a prospective, observational study, 147 subjects (104 HFpEF without a prior history or CMR evidence of coronary artery disease, and 43 asymptomatic controls) underwent multiparametric CMR, comprising left ventricular volumetric assessment, absolute quantitation of myocardial blood flow [MBF] during adenosine stress (140mcg/kg/min) and at rest, and evaluation of diffuse myocardial fibrosis (extracellular volume [ECV]). The primary endpoint was the composite of death or hospitalisation with heart failure.

Results

104 HFpEF patients (mean age 73±9 years, mean ejection fraction 56%) and 43 controls (mean age 73±5 years, mean ejection fraction 58%) were studied. There was no significant difference in resting MBF (1.10±0.42ml/min/g in HFpEF subjects vs 1.00±0.38 ml/min/g in controls, p=0.23), though hyperaemic MBF was lower in HFpEF subjects (1.66±0.68 ml/min/g vs 1.97±0.59 ml/min/g, p=0.01). Myocardial perfusion reserve [MPR] was also lower in HFpEF subjects (1.73±0.75 vs 2.22±0.76; p&lt;0.01). Microvascular dysfunction (defined as MPR&lt;2.0) was present in 70% of HFpEF patients (versus 33% of controls, p&lt;0.01). During median follow-up of 3.4 years, there were 46 composite events. MPR was predictive of clinical outcome (one unit increase – hazard ratio [HR] 0.57; 95% CI 0.35–0.92; p=0.02), as was ECV (one standard deviation [SD] increase – HR 1.65; 95% CI 1.14–2.39; p=0.01). However, there was no significant linear correlation between MPR and diffuse fibrosis (r&lt;0.01, p=0.99).

Conclusion

Microvascular dysfunction is highly prevalent in HFpEF and is associated with adverse clinical outcomes. The lack of correlation between abnormal myocardial perfusion and fibrosis challenges the assertion of a direct causal link between these entities.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): NIHR, BHF

Boot camps in neonatal-perinatal medicine fellowship programs: A national survey

BACKGROUND

Simulation is widely used in graduate medical education. A prior survey showed that 80% of Neonatal-Perinatal Medicine (NPM) fellowship programs in the U.S. use simulation. There are multiple ways to provide simulation-based education. One such method is through intensive simulation-based education sessions held at the beginning of a training program, common called 'boot camps'. The aim of this study was to describe the use of simulation-based boot camps in NPM fellowship programs.

METHODS

Survey study of Accreditation Council for Graduate Medical Education (ACGME) accredited NPM fellowships in the U.S.

RESULTS

Fifty-nine of 98 programs (60%) responded. Thirty six (61%) participated in 1st year fellow boot camps, which focused on procedural skills and newborn resuscitation. Nearly half of programs participated in regional boot camps. Most boot camps were one or two days long. Eleven programs (19%) held 2nd or 3rd year fellow boot camps, which focused on advanced resuscitation and communication. Barriers included lack of faculty protected time (57%), funding (39%), and lack of faculty experience (31%).

CONCLUSIONS

A majority of ACGME accredited NPM fellowships participate in 1st year fellows' boot camps. Many participate in regional boot camps. A few programs have 2nd or 3rd year fellow boot camps. Lack of time, funding, and faculty experience were common barriers.

The Epithelial to Mesenchymal Transition Promotes Glutamine Independence by Suppressing GLS2 Expression

Identifying bioenergetics that facilitate the epithelial to mesenchymal transition (EMT) in breast cancer cells may uncover targets to treat incurable metastatic disease. Metastasis is the number one cause of cancer-related deaths; therefore, it is urgent to identify new treatment strategies to prevent the initiation of metastasis. To characterize the bioenergetics of EMT, we compared metabolic activities and gene expression in cells induced to differentiate into the mesenchymal state with their epithelial counterparts. We found that levels of GLS2, which encodes a glutaminase, are inversely associated with EMT. GLS2 down-regulation was correlated with reduced mitochondrial activity and glutamine independence even in low-glucose conditions. Restoration of GLS2 expression in GLS2-negative breast cancer cells rescued mitochondrial activity, enhanced glutamine utilization, and inhibited stem-cell properties. Additionally, inhibition of expression of the transcription factor FOXC2, a critical regulator of EMT in GLS2-negative cells, restored GLS2 expression and glutamine utilization. Furthermore, in breast cancer patients, high GLS2 expression is associated with improved survival. These findings suggest that epithelial cancer cells rely on glutamine and that cells induced to undergo EMT become glutamine independent. Moreover, the inhibition of EMT leads to a GLS2-directed metabolic shift in mesenchymal cancer cells, which may make these cells susceptible to chemotherapies.

Future technology on the flight deck: assessing the use of touchscreens in vibration environments

Use of touchscreens in the flight deck has been steadily increasing, however, their usability may be severely impacted when turbulent conditions arise. Most previous research focusses on using touchscreens in static conditions; therefore, this study assessed touchscreen use whilst undergoing turbulent representative motion, generated using a 6-axis motion simulator. Touchscreens were tested in centre, side and overhead positions, to investigate how turbulence affected: (1) error rate, movement times and accuracy, (2) arm fatigue and discomfort. Two touchscreen technologies were compared: a 15" infra-red and a 17.3" projected capacitive touchscreen with force sensing capability. The potential of the force sensing capability to minimise unintentional interactions was also investigated. Twenty-six participants undertook multi-direction tapping (ISO 9241; ISO 2010 ) and gesture tasks, under four vibration conditions (control, light chop, light turbulence and moderate turbulence). Error rate, movement time and workload increased and usability decreased significantly, with screen position and increasing turbulence level. Practitioner Summary: This study evaluated the use of infra-red and projected capacitive touchscreen technologies using multi-directional tapping and gesture tasks, whilst being subjected to different levels of turbulence representative motion. Performance degraded significantly with increasing turbulence level and touchscreen location. This has implications for future flight deck design.

An enhanced set of displacement parameter restraints in CRYSTALS

Crystallographic restraints are widely used during refinement of small-molecule and macromolecular crystal structures. They can be especially useful for introducing additional observations and information into structure refinements against low-quality or low-resolution data (e.g. data obtained at high pressure) or to retain physically meaningful parameter values in disordered or unstable refinements. However, despite the fact that the anisotropic displacement parameters (ADPs) often constitute more than half of the total model parameters determined in a structure analysis, there are relatively few useful restraints for them, examples being Hirshfeld rigid-bond restraints, direct equivalence of parameters and SHELXL RIGU-type restraints. Conversely, geometric parameters can be subject to a multitude of restraints (e.g. absolute or relative distance, angle, planarity, chiral volume, and geometric similarity). This article presents a series of new ADP restraints implemented in CRYSTALS [Parois, Cooper & Thompson (2015), Chem. Cent. J. 9, 30] to give more control over ADPs by restraining, in a variety of ways, the directions and magnitudes of the principal axes of the ellipsoids in locally defined coordinate systems. The use of these new ADPs results in more realistic models, as well as a better user experience, through restraints that are more efficient and faster to set up. The use of these restraints is recommended to preserve physically meaningful relationships between displacement parameters in a structural model for rigid bodies, rotationally disordered groups and low-completeness data.

Abstract 3475: Novel correlation-based network analysis of breast tumor metabolism identifies the glycerol channel protein Aquaporin-7 as a regulator of breast cancer metastasis

The complex yet interrelated connections between cancer metabolism, gene expression, and oncogenic driver genes have the potential to identify novel biomarkers and drug targets with prognostic and therapeutic value. Using GC-MS, LC-MS/MS, and capillary zone electrophoresis (CZE)-MS platforms, we quantified and compared the levels of 374 metabolites in breast tumor tissue from normal tissue and transgenic mouse breast cancer models overexpressing a panel of oncogenes (PyMT, PyMT-DB, Wnt1, Neu, and C3-TAg). Comparison of the metabolite profiles from the tumors identified oncogene-induced metabolic reprogramming of the tumor tissues. To develop a higher order understanding of the driver genes and metabolites in breast cancer, we next developed a discovery-based correlation network analysis that captured interactions between both metabolite and gene expression data. This analysis uniquely identified a metabolic network of metabolites and genes with prognostic value in breast cancer patients, identifying 35 metabolite and 33 gene hubs that are likely integral to breast tumor metabolism. Further MALDI-MS based imaging revealed heterogeneous distribution of hub metabolites between stromal and epithelial tissue in breast tumors from transgenic mouse models, as well as heterogeneity within the tumor epithelium, suggesting complex metabolic landscape even within the tumor epithelium. We initially focused on the gene hub aquaporin-7 (Aqp7), a water and glycerol channel protein, as a novel regulator of breast cancer. AQP7 deficiency in animal models is associated with adipocyte hypertrophy, increased glycerol and triglyceride accumulation, insulin resistance, and obesity. We discovered that AQP7 is a prognostic marker of overall survival and metastasis in breast cancer patients. Aqp7 is expressed in the epithelium and adipocytes in normal and tumor breast tissue. Reduced Aqp7 expression in mouse breast cancer cells decreased both proliferation and lung metastatic burden. These data suggest AQP7 promotes invasive phenotypes of breast cancer progression. Using an unbiased, discovery-based approach, this study shed light on important players in breast cancer metabolism from a new perspective that complements current guided network analyses.

Citation Format: Chen Dai, Jennifer Arceo, James Arnold, Junmin Wu, Norman J. Dovichi, Arun Sreekumar, Jun Li, Laurie E. Littlepage. Novel correlation-based network analysis of breast tumor metabolism identifies the glycerol channel protein Aquaporin-7 as a regulator of breast cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3475.

Ensemble methods for stochastic networks with special reference to the biological clock of Neurospora crassa

A major challenge in systems biology is to infer the parameters of regulatory networks that operate in a noisy environment, such as in a single cell. In a stochastic regime it is hard to distinguish noise from the real signal and to infer the noise contribution to the dynamical behavior. When the genetic network displays oscillatory dynamics, it is even harder to infer the parameters that produce the oscillations. To address this issue we introduce a new estimation method built on a combination of stochastic simulations, mass action kinetics and ensemble network simulations in which we match the average periodogram and phase of the model to that of the data. The method is relatively fast (compared to Metropolis-Hastings Monte Carlo Methods), easy to parallelize, applicable to large oscillatory networks and large (~2000 cells) single cell expression data sets, and it quantifies the noise impact on the observed dynamics. Standard errors of estimated rate coefficients are typically two orders of magnitude smaller than the mean from single cell experiments with on the order of ~1000 cells. We also provide a method to assess the goodness of fit of the stochastic network using the Hilbert phase of single cells. An analysis of phase departures from the null model with no communication between cells is consistent with a hypothesis of Stochastic Resonance describing single cell oscillators. Stochastic Resonance provides a physical mechanism whereby intracellular noise plays a positive role in establishing oscillatory behavior, but may require model parameters, such as rate coefficients, that differ substantially from those extracted at the macroscopic level from measurements on populations of millions of communicating, synchronized cells.

Interactions of vanadium(iv) with amidoxime ligands: redox reactivity

The use of amidoxime-functionalized polymer fibers as a sorbent for uranium has attracted recent interest for the extraction of uranium from seawater. Vanadium is one of the main competing ions for uranium sorption as V(v) species, however, vanadium is also present as V(iv) in seawater. In the present study, the interactions of V(iv) with amidoxime and similar ligands were explored. Attempts were made to synthesize V(iv) complexes of glutaroimide-dioxime, a molecular analogue of polymer sorbents. However, V(iv) was found to react irreversibly with glutaroimide-dioxime and other oxime groups, oxidizing to the V(v) oxidation state. We have explored the reactions and propose mechanisms, as well as characterized the redox behavior of the vanadium-glutaroimide-dioxime complex.

Metabolomics of oncogene-specific metabolic reprogramming during breast cancer

Background

The complex yet interrelated connections between cancer metabolism and oncogenic driver genes are relatively unexplored but have the potential to identify novel biomarkers and drug targets with prognostic and therapeutic value. The goal of this study was to identify global metabolic profiles of breast tumors isolated from multiple transgenic mouse models and to identify unique metabolic signatures driven by these oncogenes.

Methods

Using mass spectrometry (GC-MS, LC-MS/MS, and capillary zone electrophoresis (CZE)-MS platforms), we quantified and compared the levels of 374 metabolites in breast tissue from normal and transgenic mouse breast cancer models overexpressing a panel of oncogenes (PyMT, PyMT-DB, Wnt1, Neu, and C3-TAg). We also compared the mouse metabolomics data to published human metabolomics data already linked to clinical data.

Results

Through analysis of our metabolomics data, we identified metabolic differences between normal and tumor breast tissues as well as metabolic differences unique to each initiating oncogene. We also quantified the metabolic profiles of the mammary fat pad versus mammary epithelium by CZE-MS/MS. However, the differences between the tissues did not account for the majority of the metabolic differences between the normal mammary gland and breast tumor tissues. Therefore, the differences between the cohorts were unlikely due to cellular heterogeneity. Of the mouse models used in this study, C3-TAg was the only cohort with a tumor metabolic signature composed of ten metabolites that had significant prognostic value in breast cancer patients. Gene expression analysis identified candidate genes that may contribute to the metabolic reprogramming.

Conclusions

This study identifies oncogene-induced metabolic reprogramming within mouse breast tumors and compares the results to that of human breast tumors, providing a unique look at the relationship between and clinical value of oncogene initiation and metabolism during breast cancer.

An overview and recent progress in the chemistry of uranium extraction from seawater

This review provides a brief background on the extraction of uranium from seawater as well as recent work by the United States Department of Energy on this project. The world's oceans contain uranium at 3 parts per billion, and despite this low concentration, there has been historical interest in harvesting it, mainly in Japan in the 1980s and the United States in this decade. Improvements in materials, chemistry, and deployment methods have all been made, with the ultimate goal of lower cost. This has been partially realized, dropping from approximately $2000 per kg U₃O₈ extracted in 1984 to $500 per kg today, although this is not yet competitive with terrestrial uranium. This technology may become cost-competitive if the cost of land-based uranium rises, especially if seawater extraction technology is improved further. The coordination chemistry aspects of the project are described in more detail, exploring the functional groups that are present on typical polymer sorbents as well as small-molecule analogues of these ligands. Selectivity for uranium over other metals, particularly vanadium, remains problematic, and techniques to both quantify binding strength and selectivity in order to overcome this issue are essential for future cost improvements.

Homoleptic U(iii) and U(iv) amidate complexes

Homoleptic U(iv) and U(iii) amidate complexes have been isolated and characterized; these species undergo an unusual and reversible change in coordination number upon reduction/oxidation.