Formation of robust bound states of interacting microwave photons

Systems of correlated particles appear in many fields of modern science and represent some of the most intractable computational problems in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles1. The lack of general solutions for the three-body problem and acceptable theory for strongly correlated electrons shows that our understanding of correlated systems fades when the particle number or the interaction strength increases. One of the hallmarks of interacting systems is the formation of multiparticle bound states2-9. Here we develop a high-fidelity parameterizable fSim gate and implement the periodic quantum circuit of the spin-½ XXZ model in a ring of 24 superconducting qubits. We study the propagation of these excitations and observe their bound nature for up to five photons. We devise a phase-sensitive method for constructing the few-body spectrum of the bound states and extract their pseudo-charge by introducing a synthetic flux. By introducing interactions between the ring and additional qubits, we observe an unexpected resilience of the bound states to integrability breaking. This finding goes against the idea that bound states in non-integrable systems are unstable when their energies overlap with the continuum spectrum. Our work provides experimental evidence for bound states of interacting photons and discovers their stability beyond the integrability limit.

Comparative Sensitivity of Solid-Phase Versus PEG Enhancement Assays for Detection and Identification of Red Blood Cell Antibodies

Introduction/Objective

Identifying antibodies to red blood cell (RBC) antigens is one of transfusion medicine’s most critical and challenging issues. There are 354 RBC antigens recognized by the International Society of Blood Transfusion. Accurate identification of clinically significant alloantibodies is imperative for identifying and preventing hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. We compared the performance of the tube (polyethylene glycol–indirect antiglobulin test [PEG-IAT]) and solid-phase techniques for antibody identification.

Methods/Case Report

We performed a retrospective study on all antibody screens and identifications performed between 2007–2021 at Stanford Hospital. Over this period, 631,535 antibody screens were performed predominantly using an automated solid-phase technique. Subsequent antibody identification studies were performed using manual tube testing (PEG-IAT) and automated solid-phase techniques.

Results (if a Case Study enter NA)

Antibody screening resulted in 28,316 (4.5%) positive samples with at least one antibody. Antibody identification performed on both platforms identified 50 discordant [DMH1] samples. 8 anti-Jka, 2 anti-Jkb, 1 anti-S, and 1 anti-M were detected by automatic solid-phase technique but were not detected by PEG-IAT. 20 anti-E, 6 anti-K, 2 anti-Fya, 2 anti-c , 2 anti-C, 2 anti-Fyb, 1 anti-cE[DMH2] , 1 anti-e,1 anti-M, and 1 anti-S were detected by PEG-IAT but were negative by automated solid-phase technique. Anti-E had the least sensitivity (98.99%) in the automated solid-phase technique, while anti-Jkb had the least sensitivity (98.78%) in PEG-IAT.

Conclusion

This is the first robust 15-year study comparing methodologic sensitivity to detect clinically significant alloantibodies. The incidence of discordant results between the PEG-IAT and solid-phase technique was low. Among discordant samples, anti-Jka was commonly detected by solid-phase but not by PEG-IAT. In contrast, anti-E was commonly detected by PEG-IAT but not by the solid phase.

Workflow Improvement after Implementing Remote Blood Allocation Devices at an Academic Medical Center Blood Bank

Introduction/Objective

Patients with hematological cancer routinely receive red blood cell (RBC) transfusions in the outpatient infusion clinical setting as part of their clinical therapy. Typically, RBCs are delivered to the outpatient infusion clinic via the pneumatic tube (P-tube). However, due to the recent expansion of the hospital footprint and the new location of the transfusion services, the P-tube encountered challenges that impacted the reliability of the delivery of RBC, which can delay patient care and affect patient satisfaction. This study’s purpose is to evaluate the pre-and post-implementation of the Haemobank-20 (HB20), remote blood storage and dispensing device, by reviewing the turn-around time (TAT) and the number of orders fulfilled outside of the transfusion service.

Methods/Case Report

Blood products are stocked to the HB in the infusion center. An electronic transfusion schedule is reviewed the night before scheduled transfusions to ensure appropriate inventory. When a patient is ready for the transfusion, the clinical nurse will use the device to retrieve blood products for the patient from the HB20. The average timed delivery time from the transfusion service to the outpatient infusion center is about 11 minutes. Data was retrospectively gathered from a 10-month interval before and after HB20 implementation to evaluate the number of orders fulfilled by the HB20.

Results (if a Case Study enter NA)

The HB has helped maintain nurse-to-patient ratios, reduced traffic at the blood bank issue window, and significantly sped up the turnaround time of RBCs from 11 minutes to less than 60 seconds. Before HB implementation, staff at the blood bank received 2853 units of RBCs through the blood bank window. This has been decreased by 61.2 percent to 1136 RBCs.

Conclusion

Implementing the Haemobank-20 in the outpatient infusion center has successfully reduced the turnaround time and the workload within the Transfusion Services. The current results study demonstrate that the remote blood-release system is safe and helpful in improving the efficiency of blood issue for patients in remote outpatient locations.

Localized recharge processes in the NE Mekong Delta and implications for groundwater quality

Understanding recharge in the Mekong Delta is critical for the delta's groundwater resources, and requires the investigation of recharge processes at the local scale. In this study of the north eastern area of the Mekong Delta, time-series of environmental tracer data (δ¹⁸O, δ²H, major ions and ³H) and markers of rural pollution (NH₄ and NO₃) were used to highlight localized recharge and impacts on groundwater quality. Results highlighted new hydrological insights into recharge processes, including that the Pleistocene aquifer receives recent recharge (< 60 years), predominantly during high rainfall months (> 100 mm/month). However, due to shallow clay layers there are significant spatial variations in these recharge processes, which were observed in the seasonal fluctuation of groundwater δ¹⁸O values in groundwater. Wet season δ¹⁸O changes ranged from below analytical uncertainty (≤ 0.10 ‰) to up to 0.56 ‰, and the calculated fraction of rainfall contribution to the aquifer is ≤5 % to 16 %. Rainfall recharge via the acrisol soils results in low groundwater EC (20-55 μS/cm), acidic groundwater (pH 3.6-5.6), and may also have resulted in the low groundwater NO₃ concentrations (≤ 5.3 mg NO₃/L) at many sites due to adsorption, therefore delaying not reducing NO₃ contamination. Site specific variations in nitrogen processes includes increased NO₃ (to 29.7 mg/L) from fertiliser transfers or nitrification, and increased NH₄ (to 1.4 mg/L) likely due to the recharge of irrigation waters. Unlike other recharge areas across the northern Mekong Delta, this north-eastern region provides a groundwater resource unaffected by arsenic contamination. Therefore, these results should inform on priority areas for protection from further contamination by rural anthropogenic activities.

Concomitant left atrial appendage closure with left ventricular assist device surgery can reduce ischemic cerebrovascular accidents

Background

It remains unknown if concomitant left atrial appendage closure (LAAC) at the time of left ventricular assist device (LVAD) surgery can reduce ischemic cerebrovascular accidents.

Purpose

The purpose of this study is to assess the impact of LAAC at LVAD surgery on the incidence of ischemic cerebrovascular accidents.

Methods

Between January 2012 and November 2021, 310 patients underwent LVAD surgery with HeartMate II or III. Out of 310 patients, 98 patients (31.6%) underwent concomitant LAAC. The cohort was divided into two groups: patients with LAAC (Group A, n=98) and without LAAC (Group B, n=212). To minimize device bias, LVAD surgery with HeartWare HVAD device was excluded. The ischemic cerebrovascular accident was defined as ischemic stroke, hemorrhagic stroke or transient ischemic attack. We reviewed early and long-term clinical outcomes. The incidence of ischemic cerebrovascular accidents was compared between two groups using the Kaplan-Meier method. We also investigated if LAAC was associated with ischemic cerebrovascular accidents by Cox proportional hazards analysis.

Results

There were no significant differences in baseline characteristics between two groups including age (Group A: 55.0±12.3 years old, Group B: 56.9±14.1 years old, p=0.26), preoperative CHADS2 score (Group A: 2.40±1.1, Group B: 2.58±1.1, p=0.19) and history of atrial fibrillation (Group A: 42.9%, Group B: 42.5%, p=0.95). In-hospital mortality was not significantly different between the two groups (Group A: 7.1%, Group B: 12.3%, p=0.16). In terms of postoperative complications, there were no significant differences between two groups in requiring extracorporeal membrane oxygenation, re-exploration for bleeding and newly required hemodialysis. Median follow up period was 474 days. Thirty-five patients (11.2%) developed ischemic cerebrovascular accidents (5 patients in Group A and 30 patients in Group B). The rate of freedom from ischemic cerebrovascular accidents in Group A (94.1% at 500 days and 94.1% at 1500 days) was significantly higher than that in Group B (88.2% at 500 days and 77.4% at 1500 days; log rank=0.024). In a Cox proportional hazards regression analysis including LAAC, age, history of atrial fibrillation, diabetes mellitus and Heartmate 3 device implantation, LAAC was associated with reducing the incidence of ischemic cerebrovascular accidents (hazard ratio 0.37, 95% CI 0.13–0.89, p=0.02).

Conclusion

Concomitant LAAC at the time of LVAD surgery can reduce ischemic cerebrovascular accidents without increasing perioperative mortality and complications.

Funding Acknowledgement

Type of funding sources: None.

Commercial outdoor plant nurseries as a confounder for electromagnetic fields and childhood leukemia risk

BACKGROUND

Close residential proximity to powerlines and high magnetic fields exposure may be associated with elevated childhood leukemia risks as reported by prior studies and pooled analyses. Magnetic fields exposure from high-voltage powerlines is associated with proximity to these powerlines and consequently with any factor varying with distance. Areas underneath powerlines in California may be sites for commercial plant nurseries that can use pesticides, a potential childhood leukemia risk factor.

OBJECTIVES

Assess if potential pesticide exposure from commercial plant nurseries is a confounder or interacts with proximity or magnetic fields exposure from high-voltage powerlines to increase childhood leukemia risk.

METHODS

A comprehensive childhood leukemia record-based case-control study with 5788 cases and 5788 controls (born and diagnosed in California, 1986-2008) was conducted. Pesticide, powerline, and magnetic field exposure assessment utilized models that incorporated geographical information systems, aerial satellite images, site visits and other historical information.

RESULTS

The relationship for calculated fields with childhood leukemia (odds ratio (OR) 1.51, 95% confidence interval (CI) 0.70-3.23) slightly attenuated when controlling for nursery proximity (OR 1.43, 95% CI 0.65-3.16) or restricting analysis to subjects living far (>300 m) from nurseries (OR 1.43, 95% CI 0.79-2.60). A similar association pattern was observed between distance to high-voltage powerlines and childhood leukemia. The association between nursery proximity and childhood leukemia was unchanged or only slightly attenuated when controlling for calculated fields or powerline distance; ORs remained above 2 when excluding subjects with high calculated fields or close powerline proximity (OR 2.16, 95% CI 0.82-5.67 and OR 2.15, 95% CI 0.82-5.64, respectively). The observed relationships were robust to different time periods, reference categories, and cut points.

DISCUSSION

Close residential proximity to nurseries is suggested as an independent childhood leukemia risk factor. Our results do not support plant nurseries as an explanation for observed childhood leukemia risks for powerline proximity and magnetic fields exposure, although small numbers of subjects concurrently exposed to high magnetic fields, close powerline proximity and plant nurseries limited our ability to fully assess potential confounding.

Risk Factors for Retinal Detachment Repair After Pediatric Cataract Surgery in the United States

Purpose

To determine the cumulative incidence of retinal detachment (RD) repair following pediatric cataract surgery and identify the associated risk factors.

Design

US population-based insurance claims retrospective cohort study.

Participants

Patients ≤ 18 years old who underwent cataract surgery in 2 large databases: Optum Clinformatics (2003-2021) and IBM MarketScan (2007-2016).

Methods

Individuals with ≥ 6 months of prior enrollment were included, and those with a history of RD, RD repair, traumatic cataract, spherophakia, or ectopia lentis were excluded. The primary outcome was time between initial cataract surgery and RD repair. The risk factors investigated included age, sex, persistent fetal vasculature (PFV), prematurity, intraocular lens (IOL) placement, and pars plana lensectomy approach.

Main Outcome Measures

Kaplan-Meier estimated cumulative incidence of RD repair 5 years after cataract surgery and hazard ratios (HRs) with 95% confidence intervals (CIs) from multivariable Cox proportional hazards regression models.

Results

Retinal detachment repair was performed on 47 of 3289 children included in this study. The cumulative incidence of RD repair within 5 years of cataract surgery was 2.0% (95% CI, 1.3%-2.6%). Children requiring RD repair were more likely to have a history of prematurity or PFV and less likely to have an IOL placed (all P < 0.001). Factors associated with RD repair in the multivariable analysis included a history of prematurity (HR, 6.89; 95% CI, 3.26-14.56; P < 0.001), PFV diagnosis (HR, 8.20; 95% CI, 4.11-16.37; P < 0.001), and IOL placement (HR, 0.44; 95% CI, 0.21-0.91; P = 0.03). Age at surgery, sex, and pars plana lensectomy approach were not significantly associated with RD repair after adjusting for all other covariates.

Conclusions

Approximately 2% of patients will undergo RD repair within 5 years of pediatric cataract surgery. Children with a history of PFV and prematurity undergoing cataract surgery without IOL placement are at the greatest risk.

P-580 Cumulative live birth rate of oocyte in-vitro maturation with a pre-maturation step in women with polycystic ovary syndrome or high antral follicle count

Study question

What is the cumulative live birth rate (CLBR) at 24 months of women undergoing oocyte in vitro maturation (IVM) a with pre-maturation step (CAPA-IVM)?

Summary answer

The CLBR at 24 months with CAPA-IVM was 38.2%.

What is known already

IVM with a pre-maturation step, known as capacitation IVM (CAPA-IVM) improves the competence of oocytes matured in-vitro by sustaining meiotic arrest to allow the synchronization of cytoplasmic and genetic maturation of the oocytes. Results from a randomized controlled trial showed that CAPA-IVM resulted in a live birth rate after the first transfer of 35.2% which was non-inferior to IVF. There is a lack of data on cumulative live birth following CAPA-IVM.

Study design, size, duration

A multi-center, retrospective study, performed at IVFMD, My Duc Hospital and IVFMD Phu Nhuan, My Duc Phu Nhuan Hospital from 1 January 2017 to 31 December 2019.

Participants/materials, setting, methods

All women with polycystic ovary syndrome (PCOS) or high antral follicle count (AFC) treated with a CAPA-IVM cycle were recruited to the study. All embryos were frozen at day 3. Cumulative live birth was difined as at least one live birth resulting from initiated CAPA-IVM cycle. If the women did not return for embryo transfer, outcomes were followed up until 24 months from aspiration day. Logistic regression was performed to assess which factors predicted CLBR.

Main results and the role of chance

Between 1 January 2019 and 31 December 2019, there were 374 eligible women included in the study, among them, 368 patients had embryos for transfer (98.4%) and six patients had no embryo for transfer (1.6%). A total of 496 frozen embryo transfer (FET) cycles from 368 patients were performed. Mean age and body max index (BMI) were 29.5±3.21 years and 22.3±3.09, respectively. The maturation rate was 63.2%. The median number of embryos was 4.0 [2.00; 6.00]. The cumulative clinical pregnancy rate was 60.4%, cumulative ongoing pregnancy rate was 51.6%. At 24 months after starting the treatment, the CLBR of CAPA-IVM was 38.2%. Multivariate analysis showed that patient age and number of metaphase II oocytes were the predictive factors for cumulative live birth after CAPA-IVM.

Limitations, reasons for caution

The study limitation derives from its retrospective nature. The generalizability of the study may be limited due to the single ethnicity group.

Wider implications of the findings

In patients with PCOS or high AFC, CAPA-IVM was viable and resulted in acceptable CLBR. CAPA-IVM may be the first-line treatment for women with PCOS or high AFC requiring assisted reproduction.

Trial registration number

not applicable

POS0658 TUMOR NECROSIS FACTOR BLOCKERS INDUCED SARCOIDOSIS: DESCRIPTION OF 31 CASES FROM THE FRENCH PHARMACOVIGILANCE DATABASE

Background

Development of Tumor Necrosis Factor blockers (TNFb) whose drug class has several mechanistic and pharmacologic sub-classes, have improved the management of autoimmune and inflammatory diseases, including sarcoidosis. With their increasing use, paradoxical reactions are described and one of the most frequent is sarcoidosis. However, the description of TNFb-induced sarcoidosis (TIS) remains poor, because reported in few and only short case-series.

Objectives

We aimed to better describe the clinical spectrum of TIS, and the differential involvement of TNFb sub-classes.

Methods

French pharmacovigilance database was used to collect data on TIS, excluding patients with previous idiopathic sarcoidosis. Statistical analyses were performed using the Mann-Whitney test for quantitative data and Fisher test for qualitative data. A p value < 0.05 was considered statistically significant.

Results

Data were obtained from 2002 to 2019 for infliximab, adalimumab, golimumab, certolizumab and etanercept. Thirty-one TIS patients were collected from the database, including 12 women (38.7%). In most cases, TNFb was introduced for ankylosing spondylitis (58%), psoriasis (19.3%) or rheumatoid arthritis (16.1%). Median age at TIS occurrence was 54 [43.5; 61.5] years, with a median time to onset of 24 [6.0; 72.0] months. The most frequent involved TNFb was etanercept (n=21, 67.8%). The two mains clinical TIS manifestations were lymph node (n=27, 87.1%) and lung involvement (n=16, 51.6%). The culprit drug was discontinued in 26 (84%) patients, and a double-barreled inflammatory gun to control both initial and induced disorders was proposed in 19 of them (90.5 %), mostly glucocorticoids (n=13, 68.4%) alone or combined with methotrexate (n=3, 15,8%). Among the 14 patients with the available data, the TIS had completely resolved in 11 (78.6%); for all these lasts, the TNFb was discontinued. No significant differences were observed between the TNFb sub-classes of monoclonal antibodies or fusion proteins, regarding clinical presentation, median time to onset or outcome.

Conclusion

This second largest case-series shows that TIS are mostly encountered with etanercept, but without any difference in clinical or prognostic implications with the other TNFb-subclasses.

References

[1]Aggarwal BB, Gupta SC, Kim JH. Historical perspectives on tumor necrosis factor and its superfamily: 25 years later, a golden journey. Blood. 2012 Jan 19;119(3):651–65.

[2]Cohen Aubart F, Lhote R, Amoura A, Valeyre D, Haroche J, Amoura Z, et al. Drug-induced sarcoidosis: an overview of the WHO pharmacovigilance database. J Intern Med. 2019 Oct 15;

[3]Daïen CI, Monnier A, Claudepierre P, Constantin A, Eschard J-P, Houvenagel E, et al. Sarcoid-like granulomatosis in patients treated with tumor necrosis factor blockers: 10 cases. Rheumatology (Oxford). 2009 Aug;48(8):883–6.

[4]Javot L, Tala S, Scala-Bertola J, Massy N, Trenque T, Baldin B, et al. [Sarcoïdosis and anti-TNF: a paradoxical class effect? Analysis of the French Pharmacovigilance system database and literature review]. Therapie. 2011 Apr;66(2):149–54.

[5]Massara A, Cavazzini L, La Corte R, Trotta F. Sarcoidosis appearing during anti-tumor necrosis factor alpha therapy: a new ‘class effect’ paradoxical phenomenon. Two case reports and literature review. Semin Arthritis Rheum. 2010 Feb;39(4):313–9.

[6]Valeyre D, Prasse A, Nunes H, Uzunhan Y, Brillet P-Y, Müller-Quernheim J. Sarcoidosis. Lancet. 2014 Mar;383(9923):1155–67.

Disclosure of Interests

None declared

AB0615 Clinical impact of ceruloplasmin levels at ANCA-associated vasculitis diagnosis

Background

Myeloperoxidase (MPO) plays a major role in loss of immunological tolerance leading to tissue destruction in ANCA-associated vasculitis (AAV). Ceruloplasmin is a protein with antiproteinase and antioxidant properties that inhibits MPO activity. Whether serum level of ceruloplasmin at AAV diagnosis has an impact is unknown.

Objectives

The objective of this study was to evaluate the prognostic impact of serum level of ceruloplasmin at diagnosis in patients with granulomatosis with polyangiitis or microscopic polyangiitis.

Methods

We conducted a retrospective unicentric study at Caen University Hospital, involving consecutive adult patients with granulomatosis with polyangiitis or microscopic polyangiitis between 2010 and 2021 who had available serum at diagnosis. Data was collected using the health records.

Ceruloplasmin was measured by standardized nephelometry (normal values: 0.15 – 0.50 g/L). Patients in each subgroup (whole cohort, microscopic polyangiitis and anti-MPO patients) were divided into two groups based on the median serum level of ceruloplasmin.

We estimated survival using the Kaplan-Meier survival curve, and between-group differences were evaluated by the log-rank test. The study was approved by the local ethics committee of Caen University Hospital (n° 1947).

Results

Ninety-two patients were included, 46 (50%) granulomatosis with polyangiitis (41 anti-proteinase 3 and 5 anti-MPO) and 46 (50%) microscopic polyangiitis (45 anti-MPO and 1 anti-proteinase 3). The median level of ceruloplasmin was 0.44 g/L. No significant differences in the clinical presentation were observed between patients in the two groups (p>0.05). We observed 9 (19.6%) deaths in the low ceruloplasmin group and 5 (10.9%) in the high ceruloplasmin group (p=0.39). Vasculitis relapse occurred in 10/46 patients (22%) and 11/46 patients (24%) (p=1), renal failure leading to dialysis and/or renal transplant in 6/46 patients (13%) and 8/46 patients (17%) (p=0.77), respectively. No significant difference in survival was found (p=0.07). The same analyses were performed between the low and the high ceruloplasmin group with the microscopic polyangiitis subgroup (n=46), and no significant differences were found (p>0.05). However, within the anti-MPO subgroup (n=50), the survival was worse in the low ceruloplasmin group (p=0.03).

Conclusion

In anti-MPO AAV patients, serum level of ceruloplasmin at diagnosis seems to be associated with a significant impact on survival.

References

[1]Baskin E, et al. Ceruloplasmin levels in antineutrophil cytoplasmic antibody-positive patients. Pediatr Nephrol. 2002;17(11):917–9.

[2]Ara J, et al. Ceruloplasmin in small vessel vasculitis. Nephrol Dial Transplant. févr 1999;14(2):515-7.

isclosure of Interests: None declared

POS0425 METABOLIC ALTERATIONS IN ACTIVATED FIBROBLAST-LIKE SYNOVIOCYTES FROM NON-INFLAMED SUBJECTS - MIMICKING EARLY STAGE OF RHEUMATOID ARTHRITIS

Background

Proliferative cells, such as inflamed cells, depend on altered metabolic pathways to support their active proliferation. Synovial samples from patients with rheumatoid arthritis (RA) show reprogramming of different metabolic pathways such as glucose and glutamine metabolism [1]. However, it is unknown which metabolic pathways are altered in the early phases of RA pathogenesis, when non-inflamed fibroblast-like synoviocytes (FLS) are activated to a pro-inflammatory state. Our group has created an in-vitro cell model using FLS from subjects without inflammatory arthritis (non-inflamed FLS) after activation with adiponectin and tumour necrosis factor (TNF) to mimic the early stage of RA [2].

Objectives

We aim to determine if the stimulation of non-inflamed FLS upregulates the expression of key-enzymes involved in glucose and glutamine metabolism and how the inhibition of those enzymes affects FLS activation.

Methods

FLS (passage 6-8) were isolated from synovial tissues of patients without inflammatory arthritis or osteoarthritis who underwent diagnostic arthroscopy due to a previous injury. FLS were cultured in DMEM medium (high glucose and GlutaMAX) containing 10% FBS and stimulated by known FLS-activators, i.e. TNF, interleukin 1 beta (IL-1 β), or adiponectin. For the inhibition experiments, cells were pre-treated with 25 mM 2-DG or 300 nM CB-839 for 4 hours before stimulation. Expressions of the enzymes were measured by western blot in whole-cell lysates and IL-6 was measured using ELISA in cell culture supernatants at 24 hours after stimulation. Cell proliferation was determined using MTT assay after 48 hours of stimulation.

Results

First, we compared the expression of hexokinase 2 (HK2), glutaminase C (GAC), and PFKFB3 in non-inflamed FLS before and after activation with adiponectin, TNF, and IL-1β. Expression of HK2 and GAC were upregulated in adiponectin- and TNF-activated FLS compared to unstimulated FLS. PFKFB3 was not affected by any of the stimuli. IL-1β did not affect the expression of the analysed enzymes (Figure 1A-C). As IL-1β did not affect the expression of metabolic enzymes, we continued stimulation only with adiponectin and TNF. TNF but not adiponectin significantly enhanced the proliferation of FLS without inhibition (Figure 1D). However, FLS proliferation was significantly reduced by pre-treatment with 2-DG, a glycolysis inhibitor, in unstimulated as well as TNF- and adiponectin-stimulated cells. CB-839, a glutaminase inhibitor, did not affect the proliferation of FLS (Figure 1D). Both TNF and adiponectin significantly upregulated the production of IL-6 in FLS. Pre-treatment with 2-DG significantly reduced the production of IL-6. CB-839 pre-treatment significantly reduced the production of IL-6 only in unstimulated FLS (Figure 1E).

Figure 1.

Metabolic alterations in non-inflamed FLS. Expression of hexokinase 2 (HK2; A), glutaminase C (GAC; B) and PFKFB3 (C) in non-inflamed FLS measured by western blot. Proliferation assay (MTT assay; D) and production of IL-6 (ELISA; E) was performed using cells treated with HK2 inhibitor 2-DG and glutaminase inhibitor CB-839. Statistical significance was determined as by one sample t test (A-C; n=7) or paired t test (D-E; n=4-6).

Conclusion

Our results show that the expression of key-enzymes regulating metabolic pathways can be enhanced by adiponectin and TNF in non-inflamed FLS. Moreover, we also show that inhibition of specific metabolic pathways can affect FLS activation differently depending on the cytokine stimulation. These results provide a deeper understanding of metabolic reprogramming in FLS in early RA.

References

[1]Bustamante, M.F., et al., Fibroblast-like synoviocyte metabolism in the pathogenesis of rheumatoid arthritis. Arthritis Res Ther, 2017. 19(1): p. 110.

[2]Zhang, Y., et al., Recombinant Adiponectin Induces the Production of Pro-Inflammatory Chemokines and Cytokines in Circulating Mononuclear Cells and Fibroblast-Like Synoviocytes From Non-Inflamed Subjects. Front Immunol, 2020. 11: p. 569883.

Disclosure of Interests

None declared.

Short-Term Outcomes of Lung Transplantation for COVID-19 ARDS: A Single Center Experience

Purpose

The outcomes of lung transplant (LTx) for COVID-19 related lung disease are continuing to be examined. This study describes our experience in the first 7 cases.

Methods

This study included all patients received double LTx (DLTx) for COVID-19 acute respiratory distress syndrome (ARDS) between November 2020 and October 2021. Patient pre-LTx and perioperative characteristics as well as post-LTx outcomes are presented.

Results

Seven patients underwent DLTx for COVID-19 ARDS. All required mechanical ventilation (MV) pre-LTx. Six patients were male (85%), 5 Hispanic (71%), with a median age of 48 (IQR 40-53) and median body mass index of 23.6 (IQR 21.7-25.6). Six patients (85%) were on veno-venous extracorporeal membrane oxygenation (VV-ECMO) pre-LTx (one conversion from VV to veno-arterial (VA)). Median duration of MV and ECMO pre-LTx was 140 days (IQR 82-165) and 71.5 days (IQR 58-149), respectively. Two patients developed acute kidney injury pre-LTx requiring continuous renal replacement therapy (CRRT). Median time from listing to transplant was 17 days (IQR 10-24). ECMO was discontinued in all but 1 patient post-LTx. Median length of stay in the hospital post-LTx was 30 days (IQR 15-57). All were discharged from the hospital (43% to rehabilitation facility). Two patients on pre-LTx CRRT remained hemodialysis dependent and had multi-drug resistant (MDR) bacterial infections post-LTx. One readmission occurred for presumed rejection, aspiration and infection with MDR Klebsiella now requiring oxygen. All surgical pathology showed diffuse interstitial fibrosis consistent with the fibrotic sequelae of alveolar damage due to COVID-19. At 3-month follow-up, 6 patients (85%) did not need supplemental oxygen and had good pulmonary function.

Conclusion

Lung transplantation for COVID-ARDS is feasible. However, pre-transplant multi-system involvement may be associated with a protracted post-LTx stay and MDR infection. Further studies are needed to assess the long-term outcomes in this cohort.