Corticosterone Contributes to Diet-Induced Reprogramming of Post-Metamorphic Behavior in Spadefoot Toads

Stressful experiences in early life can have phenotypic effects that persist into, or manifest during, adulthood. In vertebrates, such carryover effects can be driven by stress-induced secretion of glucocorticoid hormones, such as corticosterone, which can lead to developmental reprogramming of hypothalamic-pituitary-adrenal/interrenal axis activity and behavior. Nutritional stress in the form of early life nutrient restriction is well known to modify later life behaviors and stress activity through corticosterone-related mechanisms. However, it is not known whether corticosterone is also mechanistically involved in carryover effects induced by a different form of nutritional variation: the use of alternate or entirely novel types of dietary resources. The plains spadefoot (Spea bombifrons) presents an excellent system for testing this question, since larvae of this species have evolved to use 2 alternate diet types: an ancestral detritus-based diet and a more novel diet of live shrimp. While previous work has shown that feeding on the novel shrimp diet influences juvenile (i.e., post-metamorphic) behavior and corticosterone levels, it is unclear whether these diet-induced carryover effects are mediated by diet-induced corticosterone itself. To test for the mechanistic role of corticosterone in diet-induced carryover effects, we experimentally treated S. bombifrons larvae with exogenous corticosterone and measured subsequent effects on juvenile behavior and corticosterone levels. We found that while shrimp-fed larvae had elevated corticosterone levels, treatment of larvae with corticosterone itself had effects on juvenile behavior that partially resembled those carryover effects induced by the shrimp diet, such as altered food seeking and higher locomotor activity. However, unlike carryover effects caused by the shrimp diet, larval corticosterone exposure did not affect juvenile corticosterone levels. Overall, our study shows that corticosterone-related mechanisms are likely involved in carryover effects induced by a novel diet, yet such diet-induced carryover effects are not driven by corticosterone alone.

Effectiveness, safety and impact of guselkumab on sexuality and perceived stigmatization in patients with psoriasis in routine clinical practice: Week 28 results from the prospective German multicentre G-EPOSS study

BACKGROUND

G-EPOSS is a prospective, non-interventional, German multicentre study of patients with moderate-to-severe plaque psoriasis receiving guselkumab, a therapeutic monoclonal antibody targeting interleukin-23, in a real-world setting.

OBJECTIVES

The objective of the study was to evaluate the effectiveness and safety of guselkumab, including its impact on skin, health-related quality of life (HRQoL), sexuality, and perceived stigmatization.

METHODS

Patients (≥18 years old) received guselkumab per routine clinical practice. The primary endpoint was the proportion of patients achieving absolute Psoriasis Area and Severity Index (PASI) ≤ 3 at Week (W)28. Secondary endpoint assessments over 28 weeks included the Nail Psoriasis Severity Index (NAPSI), anogenital Physician's Global Assessment (aPGA), and Dermatology Life Quality Index (DLQI). Sexuality and perceived stigmatization were assessed by patients using the Relationship and Sexuality Scale (RSS) and Perceived Stigmatization Questionnaire (PSQ), respectively.

RESULTS

Overall, 293 patients were included in the evaluable set population. Mean age and disease duration were 45.6 and 17.6 years, respectively. At baseline, mean PASI, aPGA and DLQI scores were 15.3, 2.7 and 11.3, respectively. In total, 25.9% of patients had received a prior biologic. Overall, 83.0% of patients achieved PASI ≤ 3, and 56.2%/35.1% achieved PASI ≤ 1/PASI = 0, respectively, at W28. Among those with NAPSI ≥ 1 and aPGA ≥ 1 at baseline, NAPSI = 0 and aPGA = 0 were achieved by 39.2% and 61.1% of patients, respectively, and 61.4% of patients achieved DLQI 0-1 at W28. Improvements were observed over 28 weeks across individual items of the DLQI, RSS and PSQ, indicating improved HRQoL and sex life, and decreased perceived stigmatization. Based on DLQI Question (Q)9, 53.6% of patients experienced sexual difficulties at baseline, which decreased to 12.1% at W28. DLQI Q9 responses were consistent with RSS item responses, highlighting DLQI Q9 as a sentinel for sexual impairment.

CONCLUSIONS

Guselkumab improved overall skin symptoms and HRQoL in patients with psoriasis and decreased sexual impairment and perceived stigmatization. No new safety signals were observed.

STUDY CODE

CNTO1959PSO4008.

Intraarticular treatment with integrin α10β1-selected mesenchymal stem cells affects microRNA expression in experimental post-traumatic osteoarthritis in horses

Osteoarthritis (OA) remains a major cause of lameness in horses, which leads to lost days of training and early retirement. Still, the underlying pathological processes are poorly understood. MicroRNAs (miRNAs) are small non-coding RNAs that serve as regulators of many biological processes including OA. Analysis of miRNA expression in diseased joint tissues such as cartilage and synovial membrane may help to elucidate OA pathology. Since integrin α10β1-selected mesenchymal stem cell (integrin α10-MSC) have shown mitigating effect on equine OA we here investigated the effect of integrin α10-MSCs on miRNA expression. Cartilage and synovial membrane was harvested from the middle carpal joint of horses with experimentally induced, untreated OA, horses with experimentally induced OA treated with allogeneic adipose-derived MSCs selected for the marker integrin α10-MSCs, and from healthy control joints. miRNA expression in cartilage and synovial membrane was established by quantifying 70 pre-determined miRNAs by qPCR. Differential expression of the miRNAs was evaluated by comparing untreated OA and control, untreated OA and MSC-treated OA, and joints with high and low pathology score. A total of 60 miRNAs were successfully quantified in the cartilage samples and 55 miRNAs were quantified in the synovial membrane samples. In cartilage, miR-146a, miR-150 and miR-409 had significantly higher expression in untreated OA joints than in control joints. Expression of miR-125a-3p, miR-150, miR-200c, and miR-499-5p was significantly reduced in cartilage from MSC-treated OA joints compared to the untreated OA joints. Expression of miR-139-5p, miR-150, miR-182-5p, miR-200a, miR-378, miR-409-3p, and miR-7177b in articular cartilage reflected pathology score. Several of these miRNAs are known from research in human patients with OA and from murine OA models. Our study shows that these miRNAs are also differentially expressed in experimental equine OA, and that expression depends on OA severity. Moreover, MSC treatment, which resulted in less severe OA, also affected miRNA expression in cartilage.

Neutrophil gelatinase-associated lipocalin as a potential biomarker for equine asthma

BACKGROUND

Studies in people have found neutrophil gelatinase-associated lipocalin (NGAL) concentrations are increased in asthma and can be used to distinguish between asthma subtypes. NGAL has not yet been investigated in equine asthma (EA).

OBJECTIVES

To investigate the ability of NGAL concentrations in bronchoalveolar lavage (BAL) fluid and serum to distinguish between control horses, horses with mild-moderate EA (MEA) and horses with severe EA (SEA).

STUDY DESIGN

Retrospective cross-sectional study.

METHODS

Details of endoscopic examination including tracheal mucus score (TMS, scale 0-5) and BAL cytology performed on 227 horses were extracted from records and NGAL concentrations were measured on stored serum and BAL fluid samples. The horses were divided into groups (control group n = 73, MEA n = 98, SEA n = 56) based on clinical signs and BAL cytology results. Differences between groups were evaluated with the Mann-Whitney test and correlation between BAL NGAL, serum NGAL, and BAL cytology were evaluated using Spearman's correlation.

RESULTS

BAL NGAL concentrations were higher in EA than in control horses (median: 25.6 and 13.3 μg/L, respectively, p < 0.001). Concentrations of NGAL in BAL differed between groups, with higher concentrations in MEA than in control horses (median: 18.5 and 13.3 μg/L, respectively, p < 0.001), and higher concentrations in SEA than in MEA horses (median: 54.1 and 18.5 μg/L, respectively, p < 0.001). BAL NGAL concentration differed between horses with TMS ≤2 an >2 (median 15.6 and 21.1 μg/L, respectively, p = 0.004). No differences were found in serum NGAL concentration between any of the groups.

MAIN LIMITATION

Only 66 of the 227 (29%) horses had haematology and serum NGAL measured.

CONCLUSION

BAL NGAL concentration differed between control and EA and reflected severity of disease. These results justify further research into the potential of NGAL as a biomarker of EA.

Integrin α10β1-Selected Mesenchymal Stem Cells Reduce Pain and Cartilage Degradation and Increase Immunomodulation in an Equine Osteoarthritis Model

OBJECTIVE

Integrin α10β1-selected mesenchymal stem cells (integrin α10-MSCs) have previously shown potential in treating cartilage damage and osteoarthritis (OA) in vitro and in animal models in vivo. The aim of this study was to further investigate disease-modifying effects of integrin α10-MSCs.

DESIGN

OA was surgically induced in 17 horses. Eighteen days after surgery, horses received 2 × 107 integrin α10-MSCs intra-articularly or were left untreated. Lameness and response to carpal flexion was assessed weekly along with synovial fluid (SF) analysis. On day 52 after treatment, horses were euthanized, and carpi were evaluated by computed tomography (CT), MRI, histology, and for macroscopic pathology and integrin α10-MSCs were traced in the joint tissues.

RESULTS

Lameness and response to carpal flexion significantly improved over time following integrin α10-MSC treatment. Treated horses had milder macroscopic cartilage pathology and lower cartilage histology scores than the untreated group. Prostaglandin E2 and interleukin-10 increased in the SF after integrin α10-MSC injection. Integrin α10-MSCs were found in SF from treated horses up to day 17 after treatment, and in the articular cartilage and subchondral bone from 5 of 8 treated horses after euthanasia at 52 days after treatment. The integrin α10-MSC injection did not cause joint flare.

CONCLUSION

This study demonstrates that intra-articular (IA) injection of integrin α10-MSCs appears to be safe, alleviate pathological changes in the joint, and improve joint function in an equine post-traumatic osteoarthritis (PTOA) model. The results suggest that integrin α10-MSCs hold promise as a disease-modifying osteoarthritis drug (DMOAD).

Multi-Omic Temporal Landscape of Plasma and Synovial Fluid-Derived Extracellular Vesicles Using an Experimental Model of Equine Osteoarthritis

Extracellular vesicles (EVs) contribute to osteoarthritis pathogenesis through their release into joint tissues and synovial fluid. Synovial fluid-derived EVs have the potential to be direct biomarkers in the causal pathway of disease but also enable understanding of their role in disease progression. Utilizing a temporal model of osteoarthritis, we defined the changes in matched synovial fluid and plasma-derived EV small non-coding RNA and protein cargo using sequencing and mass spectrometry. Data exploration included time series clustering, factor analysis and gene enrichment interrogation. Chondrocyte signalling was analysed using luciferase-based transcription factor activity assays. EV protein cargo appears to be more important during osteoarthritis progression than small non-coding RNAs. Cluster analysis revealed plasma-EVs represented a time-dependent response to osteoarthritis induction associated with supramolecular complexes. Clusters for synovial fluid-derived EVs were associated with initial osteoarthritis response and represented immune/inflammatory pathways. Factor analysis for plasma-derived EVs correlated with day post-induction and were primarily composed of proteins modulating lipid metabolism. Synovial fluid-derived EVs factors represented intermediate filament and supramolecular complexes reflecting tissue repair. There was a significant interaction between time and osteoarthritis for CRE, NFkB, SRE, SRF with a trend for osteoarthritis synovial fluid-derived EVs at later time points to have a more pronounced effect.

Towards optimal use of antithrombotic therapy of people with cancer at the end of life: A research protocol for the development and implementation of the SERENITY shared decision support tool

BACKGROUND

Even though antithrombotic therapy has probably little or even negative effects on the well-being of people with cancer during their last year of life, deprescribing antithrombotic therapy at the end of life is rare in practice. It is often continued until death, possibly resulting in excess bleeding, an increased disease burden and higher healthcare costs.

METHODS

The SERENITY consortium comprises researchers and clinicians from eight European countries with specialties in different clinical fields, epidemiology and psychology. SERENITY will use a comprehensive approach combining a realist review, flash mob research, epidemiological studies, and qualitative interviews. The results of these studies will be used in a Delphi process to reach a consensus on the optimal design of the shared decision support tool. Next, the shared decision support tool will be tested in a randomised controlled trial. A targeted implementation and dissemination plan will be developed to enable the use of the SERENITY tool across Europe, as well as its incorporation in clinical guidelines and policies. The entire project is funded by Horizon Europe.

RESULTS

SERENITY will develop an information-driven shared decision support tool that will facilitate treatment decisions regarding the appropriate use of antithrombotic therapy in people with cancer at the end of life.

CONCLUSIONS

We aim to develop an intervention that guides the appropriate use of antithrombotic therapy, prevents bleeding complications, and saves healthcare costs. Hopefully, usage of the tool leads to enhanced empowerment and improved quality of life and treatment satisfaction of people with advanced cancer and their care givers.

Biomechanical performance of a novel light-curable bone fixation technique

Traumatic bone fractures are often debilitating injuries that may require surgical fixation to ensure sufficient healing. Currently, the most frequently used osteosynthesis materials are metal-based; however, in certain cases, such as complex comminuted osteoporotic fractures, they may not provide the best solution due to their rigid and non-customizable nature. In phalanx fractures in particular, metal plates have been shown to induce joint stiffness and soft tissue adhesions. A new osteosynthesis method using a light curable polymer composite has been developed. This method has demonstrated itself to be a versatile solution that can be shaped by surgeons in situ and has been shown to induce no soft tissue adhesions. In this study, the biomechanical performance of AdhFix was compared to conventional metal plates. The osteosyntheses were tested in seven different groups with varying loading modality (bending and torsion), osteotomy gap size, and fixation type and size in a sheep phalanx model. AdhFix demonstrated statistically higher stiffnesses in torsion (64.64 ± 9.27 and 114.08 ± 20.98 Nmm/° vs. 33.88 ± 3.10 Nmm/°) and in reduced fractures in bending (13.70 ± 2.75 Nm/mm vs. 8.69 ± 1.16 Nmm/°), while the metal plates were stiffer in unreduced fractures (7.44 ± 1.75 Nm/mm vs. 2.70 ± 0.72 Nmm/°). The metal plates withstood equivalent or significantly higher torques in torsion (534.28 ± 25.74 Nmm vs. 614.10 ± 118.44 and 414.82 ± 70.98 Nmm) and significantly higher bending moments (19.51 ± 2.24 and 22.72 ± 2.68 Nm vs. 5.38 ± 0.73 and 1.22 ± 0.30 Nm). This study illustrated that the AdhFix platform is a viable, customizable solution that is comparable to the mechanical properties of traditional metal plates within the range of physiological loading values reported in literature.

Serum amyloid A does not predict non-survival in hospitalised adult horses with acute colitis

BACKGROUND

Predicting non-survival in horses with acute colitis improves early decision making. Therefore, this study aimed to determine the prognostic value of serum amyloid A (SAA) and other clinicopathological and clinical variables in adult horses with acute colitis.

METHODS

Clinical variables, SAA and other blood biomarkers, including plasma L-lactate (lactate), were assessed in 176 horses with acute colitis. A multivariate model for the prediction of non-survival was constructed. Icelandic horses were analysed separately.

RESULTS

Admission SAA was similar in survivors (median 548 mg/L; range 0-5453 mg/L) and non-survivors (396 mg/L; 0-5294) (p = 0.43). A model for non-survival included year of admission, lactate, heart rate, age and colic duration of more than 24 hours. Icelandic horses had a relative risk of 2.9 (95% confidence interval = 2.2-3.8) for acute colitis compared to other breeds. Lactate in Icelandic horses was higher than that in other breeds in both survivors (4.0 mmol/L, range 1.0-12.7 vs. 2.0, 0.7-12.5) and non-survivors (10.0, 1.5-26 vs. 5.4, 0.8-22) (p < 0.001).

LIMITATIONS

The prognostic value of repeated measurements of SAA could not be assessed in this study, as 71% of the non-surviving horses died within a day of admission.

CONCLUSION

Admission SAA did not predict non-survival. Breed needs consideration when lactate is evaluated as a predictor for non-survival in horses with colitis.

Use of serum amyloid A in equine medicine and surgery

Serum amyloid A (SAA) has become an indispensable part of the management of equine patients in general practice and specialized hospital settings. Although several proteins possess acute phase properties in horses, the usefulness of SAA exceeds that of other acute phase proteins. This is due to the highly desirable kinetics of the equine SAA response. SAA concentrations exhibit a rapid and pronounced increase in response to inflammation and a rapid decline after the resolution of inflammation. This facilitates the detection of inflammatory disease and real-time monitoring of inflammatory activity. SAA may be used in all stages of patient management: (1) before diagnosis (to rule in/rule out inflammatory disease), (2) at the time of diagnosis (to assess the severity of inflammation and assist in prognostication), and (3) after diagnosis (to monitor changes in inflammatory activity in response to therapy, with relapse of disease, or with infectious/inflammatory complications). By assessing other acute phase reactants in addition to SAA, clinicians can succinctly stage inflammation. White blood cell counts and serum iron concentration change within hours of an inflammatory insult, SAA within a day, and fibrinogen within 2-3 days; the interrelationship of these markers thus indicates the duration and activity of the inflammatory condition. Much research on the equine SAA response and clinical use has been conducted in the last decade. This is the prerequisite for the evidence-based use of this analyte. However, still today, most published studies involve a fairly low number of horses. To obtain solid evidence for use of SAA, future studies should be designed with larger sample sizes.

Differentiating Strongylus vulgaris-associated, non-strangulating intestinal infarctions from idiopathic peritonitis and acute colitis in horses

BACKGROUND

Horses with non-strangulating intestinal infarction (NSII) are often misdiagnosed with idiopathic peritonitis or acute colitis. Early diagnosis is essential to ensure early surgical intervention and improve survival.

METHODS

Clinical and laboratory data from horses admitted to the University of Copenhagen Large Animal Teaching Hospital with NSII, idiopathic peritonitis or acute colitis between 2009 and 2018 were used for univariate comparisons and a multivariable logistic regression model for prediction of NSII.

RESULTS

Two hundred and thirty-one horses were included. A multivariable model for the prediction of NSII included gastric reflux (more than 5 L) (odds ratio [OR] 8.7; 95% confidence interval [CI] 2.1-36.2), abnormal findings palpated per rectum (intestinal dilatations/impactions [OR 4.43; 95% CI 1.43-13.38], colon displacements [OR 23.16; 95% CI 5.26-101.97] or intestinal mass [OR 179.7; 95% CI 23.5-1375.5]), white blood cell count (OR 1.2; 95% CI 1.1-1.4), packed cell volume (OR 0.9; 95% CI 0.8-0.9), age (OR 0.9; 95% CI 0.8-1.0) and heart rate (OR 1.1; 95% CI 1.0-1.1). The model had a low false positive rate (5%), but a high false negative rate (50%).

LIMITATIONS

Due to the retrospective nature of the study, sample collection was inconsistent, resulting in missing values.

CONCLUSION

The model had some capability in predicting NSII. However, the high risk of false negatives means that exploratory laparotomy should be considered in horses with peritonitis of unknown aetiology in areas where Strongylus vulgaris is prevalent and occurrence of idiopathic peritonitis is low.

Use of admission serum neutrophil gelatinase-associated lipocalin (NGAL) concentrations as a marker of sepsis and outcome in neonatal foals

BACKGROUND

Equine neonatal sepsis can be challenging to diagnose and prognosticate. Neutrophil gelatinase-associated lipocalin (NGAL), a new marker of renal damage and inflammation, can potentially be helpful.

OBJECTIVES

To evaluate NGAL in neonatal foals with sepsis, and assess its relation to outcome.

ANIMALS

Foals ≤ 14 days, with admission blood analysis and stored serum.

METHODS

NGAL was measured on stored serum from 91 foals. Foals were scored for sepsis and survival and categorized according to sepsis status (septic, sick non-septic, healthy, and uncertain sepsis status) and outcome groups (survivors and non-survivors). The septic foals were further sub-categorized according to severity (normal sepsis, severe sepsis and septic shock). A Kruskal-Wallis test was used to compare serum NGAL concentrations in survivors and non-survivors, in the sepsis status groups, and in the sepsis severity groups. Optimal cut-off values for serum NGAL concentrations to diagnose sepsis and outcome were determined with receiver operating characteristic (ROC) curves. NGAL was compared to creatinine and SAA.

RESULTS

Median serum NGAL concentrations were significantly higher in septic than non-septic foals. However, serum NGAL concentrations did not differ between sepsis severity subgroups. Serum NGAL concentrations were significantly lower in survivors than in non-survivors. Optimal cut-off values of serum NGAL concentrations were 455 μg/L (sensitivity 71.4%, specificity 100%) and 1104 μg/L (sensitivity 39.3%, specificity 95.2%) for predicting sepsis and non-survival, respectively. NGAL correlated to SAA, but not to creatinine. NGAL performed similarly to SAA to diagnose sepsis.

CONCLUSION

Serum NGAL concentrations may be useful for diagnosing sepsis and predicting outcome.

Serum amyloid A as a marker to detect sepsis and predict outcome in hospitalized neonatal foals

BACKGROUND

Serum amyloid A (SAA) has been reported to hold promise as diagnostic and prognostic marker in foals. This has not been investigated thoroughly.

OBJECTIVES

Evaluate admission SAA concentrations as predictor of sepsis and outcome.

ANIMALS

Five hundred and ninety hospitalized foals <14 days old.

METHODS

Retrospective multicenter study. Foals were scored with sepsis and survival scores, grouped according to health category (septic, sick but nonseptic, uncertain sepsis status) and outcome; septic foals were further categorized according to severity (normal sepsis, severe sepsis, and septic shock). SAA was compared between groups using Mann-Whitney test and Kruskal-Wallis test. Receiver operating characteristic curves identified optimal SAA cut off values for detecting sepsis and predicting outcome.

RESULTS

Admission SAA concentrations differed significantly between sick nonseptic foals (312.1 ± 685.4 mg/L) and septic foals (1079.7 ± 1254.5 mg/L) and increased with increasing sepsis score. SAA did not differ between sepsis severity groups. The optimal cut off for sepsis detection was 1050 mg/L (sensitivity 30.2%, specificity 90.7%). Admission SAA concentrations were lower in surviving (435.0 ± 723.6 mg/L) compared to nonsurviving foals (1062.7 ± 1440.1 mg/L) and decreased with increasing survival score. The optimal cut off for nonsurvival prediction was 1250 mg/L (sensitivity 22.1%, specificity 90.8%).

CONCLUSIONS AND CLINICAL IMPORTANCE

SAA concentration was higher in septic foals and nonsurviving foals. Even though optimal cut offs for SAA to detect sepsis and predict outcome had low sensitivity, they had good specificity. SAA can therefore be used as a marker to rule out sepsis and nonsurvival.

A detailed macroscopic scoring system for experimental post-traumatic Osteoarthritis in the equine middle carpal joint

OBJECTIVE

Osteoarthritis (OA) is a significant health issue in humans as well as horses. Experimental models of equine carpal OA have been used to investigate OA pathogenesis and potential therapeutic candidates. A 5-scale scoring system (OARSI) for macroscopic pathological cartilage changes already exists, but there is a need for a scoring system with better differentiation of severity. The aim of this study was therefore to develop and validate such a scoring system.

RESULTS

New scoring system were developed for cartilage erosions (Copenhagen Equine Total Cartilage Score, CEqTCS) along with synovial membrane pathology and osteochondral fragment healing (Copenhagen Equine Carpal Osteoarthritis Score, CEqCOAS). For the CEqTCS there was excellent intraclass agreement (ICC = 0.993; CI 0.985-0.996; p = 1.08e-31) and consistency (ICC = 0.992; CI 0.985-0.996; p = 4.61e-31), as well as excellent interclass agreement (ICC = 0.974; CI 0.948-0.987, p = 2e-22) and consistency (ICC = 0.973; CI 0.946-0.987; p = 2.77e-22), while the OARSI system had moderate (κ = 0.47) and weak (κ = 0.28) inter- and intra-class agreement, respectively. The OARSI score and the CEqTCS correlated excellently, but every OARSI grade encompassed a wide range of CEqTCS grades. The new score for assessment of equine OA provides means to a better differentiation of OA changes than the existing OARSI system.

AB0466 DYSFUNCTION OF THE AUTONOMIC NERVOUS SYSTEM IS ASSOCIATED WITH LOW-GRADE INFLAMMATION IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background

Systemic lupus erythematosus (SLE) is characterized by chronic, systemic inflammation, organ damage and -dysfunction. Autonomic nervous system dysfunction is highly prevalent in SLE patients (up to 54%); compared to controls the prevalence may be up to 12 times increased.1 These numbers parallel findings in other chronic conditions such as diabetes.2

Heart rate variability (HRV) reflects autonomic activity, and low variability indicates impaired activity, denoted as autonomic dysfunction (AD). AD is associated with low-grade inflammation in healthy subjects and patients with diabetes or cardiovascular disease.3 The causality hereof is not fully understood: AD may impair the vagally mediated anti-inflammatory reflex, thus leading to increased systemic inflammation, but inflammatory mediated microvascular and neuronal damage may also impair autonomic function.

Objectives

To determine if markers of low-grade inflammation are associated with AD in SLE patients.

Methods

SLE patients (n=111) from the Copenhagen based PLUSheart (Prospective Lupus Study on Cardiovascular Risk Factors) cohort were included for this cross-sectional analysis. The cohort has previously been described1 with the following characteristics in 2018-2019: 89.2% women, mean age: 51.5 (SD ±12.7) years, mean BMI: 25.1 (±5.0), mean disease duration: 19.9 (±9.5) years, median SLEDAI 2K score: 3 (IQR 1-4), and median SLE Damage Index score: 2 (1-4).

Low-grade inflammation was evaluated by plasma levels of C-reactive protein (CRP) and soluble urokinase-type plasminogen activator receptor (suPAR). Autonomic function was assessed with 5-min resting lead-I electrocardiograms using the VagusTM device. Subsequent HRV analyses comprised RMSSD (the root mean square of successive interval differences between normal heartbeats), reflecting parasympathetic function, and SDNN (standard deviation of normal-to-normal heartbeat intervals), reflecting mixed parasympathetic-sympathetic function.

Results

All HRV- and inflammatory markers were non-normally distributed. The median SDNN was 30.4 (IQR 24.1-40.4), the median RMSSD was 19.7 (12.6-31.7). The median CRP level was 1 (1-3) and suPAR level was 3.2 (2.5-4.6).

For parametric analyses, all markers were logarithmically transformed. Both SDNN and RMSSD associated with CRP and suPAR levels in univariate analyses. When adjusting for age and SLE disease activity as per the SLEDAI-score, SDNN remained associated with suPAR and CRP and RMSSD with suPAR only (Table 1).

Table 1.

Association between low-grade inflammation and autonomic nervous system function

SDNN *RMSSD *UnivariateAdjustedUnivariateAdjustedβPβPβPβPCRP *-0.2410.011-0.1970.035-0.2150.024-0.1680.072suPAR *-0.2390.014-0.1970.038-0.2680.006-0.2270.016

Univariate and multivariate linear regression analyses adjusted for age and disease activity of correlations between log-transformed (*) low-grade inflammation markers (CRP and suPAR) and heart rate variability markers (RMSSD and SDNN). β=standardized coefficients. Statistically significance (P<0.05) is marked with bold.

Conclusion

In SLE, HRV impairments reflecting both decreased parasympathetic and mixed parasympathetic-sympathetic autonomic function were associated with markers of low-grade inflammation independently of SLE disease activity and age. Longitudinal prospective studies are needed to determine causality.

References

[1]Zinglersen AH, et. al. Characteristics of cardiovascular autonomic dysfunction and association with quality of life in patients with systemic lupus erythematosus. doi:10.1136/lupus-2021-000507

[2]Spallone V. Update on the Impact, Diagnosis and Management of Cardiovascular Autonomic Neuropathy in Diabetes: What Is Defined, What Is New, and What Is Unmet. Diabetes Metab J. doi:10.4093/dmj.2018.0259

[3]Haensel A, et. al. The relationship between heart rate variability and inflammatory markers in cardiovascular diseases. Psychoneuroendocrinology. doi:10.1016/j.psyneuen.2008.08.007

Disclosure of Interests

Amanda Hempel Zinglersen: None declared, Katrine Kjær Iversen: None declared, Jesper Eugen-Olsen Shareholder of: Co-founder, shareholder and CSO of ViroGates (suPAR assay), Jesper Fleischer Shareholder of: Co-inventor of the VagusTM-device (HRV measurement), Søren Jacobsen: None declared

POS0761 TIME-DEPENDENT ANALYSES OF CLINICAL MANIFESTATIONS OF SYSTEMIC LUPUS ERYTHEMATOSUS IDENTIFY PATIENTS AT HIGH RISK OF INCIDENT PROTEINURIA

Background

Nephritis (LN) in systemic lupus erythematosus (SLE) is still a major determinant of poor prognosis[1].

The vast majority of LN occurs in proximity to the SLE diagnosis[2]. Identification of individuals at high risk, especially early onset SLE, is therefore warranted. Inclusion of risk factors prior to the SLE diagnosis may thus be of importance to enable sufficient risk factor profiling. SLE-patients seem to cluster according to clinical and serological phenotypes suggesting distinct disease trajectories[3-5].

Objectives

To determine if incident proteinuria associated with the debut age of non-renal SLE characteristics.

Methods

Data of SLE patients from six Danish centers were obtained from the Danbio-database from 2017 – 2020. The occurrence and timing of proteinuria was compared with first time onset of any non-renal manifestations as defined by the 1997 American College of Rheumatology Classification Criteria. Cox-regression models were used to identify risk factors for incident proteinuria. Time from first occurring non-renal manifestation to incident proteinuria or censoring defined time at risk. Covariates were eliminated if p >0.01 in a ‘backwards’ manner. After the model reduction process p-values <0.05 were considered statistically significant.

Results

586 SLE patients, mainly white (94%) women (88%), mean age at inclusion of 34.6 years (standard deviation, SD = 0.6 years) and observed for a mean of 14.9 years (SD =0.5 years), were recruited. The cumulative prevalence of proteinuria was 40%. Male gender hazard ratio, HR = 1.35 (range 0.77-2.35), p=0.009, lymphopenia HR = 1.77 (range 1.24-2.52), p=0.005 were associated with incident proteinuria. In contrast, patients with discoid rash had lower risk of incident proteinuria HR 0.42 (range 0.21-0.83), p=0.01. Male patients with lymphopenia had the highest risk of proteinuria with a one-, 5- and 10-year risk of proteinuria ranging from 9-27%, 34-75% and 51-89 %, depending on the age at presentation (debut at 20, 30, 40 or 50 years). The corresponding risk-profiles for women with lymphopenia were 3-9%, 8-34% and 12-58%, respectively, as illustrated in Figure 1.

Conclusion

The occurrences of lymphopenia and discoid rash were oppositely associated with risk of incident proteinuria and the risk effects varied according to gender and patient age at onset of these manifestations. Thus, the risk of proteinuria may not be constant but could vary according to presentation of non-renal manifestations that may call for a differentiated clinical follow-up. Based on these findings, we suggest that the debut age of known prognostic factors, even prior to the SLE diagnosis should be considered when designing prognostic statistical models.

References

[1]Faurschou, M., et al., Prognostic factors in lupus nephritis: diagnostic and therapeutic delay increases the risk of terminal renal failure. J Rheumatol, 2006. 33(8): p. 1563-9.

[2]Hanly, J.G., et al., The frequency and outcome of lupus nephritis: results from an international inception cohort study. Rheumatology (Oxford), 2016. 55(2): p. 252-62.

[3]Diaz-Gallo, L.M., et al., Four Systemic Lupus Erythematosus Subgroups, Defined by Autoantibodies Status, Differ Regarding HLA-DRB1 Genotype Associations and Immunological and Clinical Manifestations. ACR Open Rheumatol, 2022. 4(1): p. 27-39.

[4]Jacobsen, S., et al., A multicentre study of 513 Danish patients with systemic lupus erythematosus. II. Disease mortality and clinical factors of prognostic value. Clin Rheumatol, 1998. 17(6): p. 478-84.

[5]Leffers, H.C.B., et al., Smoking associates with distinct clinical phenotypes in patients with systemic lupus erythematosus: a nationwide Danish cross-sectional study. Lupus Sci Med, 2021. 8(1).

Disclosure of Interests

Martin Andersen Employee of: Novo Nordisk A/S: 2010-2014, Anders Stockmarr: None declared, Henrik Leffers: None declared, Anne Troldborg: None declared, Anne Voss: None declared, Salome Kristensen: None declared, Bent Deleuran: None declared, Lene Dreyer Speakers bureau: Speakers bureau: Eli Lilly, Galderma and Janssen, Grant/research support from: Grant from BMS outside the present work, Laura Johnsen: None declared, Ada Colic: None declared, Søren Jacobsen: None declared

AB0478 LUPUS ANTICOAGULANT IS ASSOCIATED WITH PROSPECTIVE ECHOCARDIOGRAPHIC CHANGES IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: A FIVE-YEAR FOLLOW-UP STUDY

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease with increased risk of cardiovascular complications such as coronary artery disease, myocarditis, pericarditis, and valvular dysfunction (1─3). The pathophysiological mechanisms are poorly understood and markers to identify high risk patients are warranted.

Objectives

We aimed to identify SLE-characteristics that are associated with progressive cardiac dysfunction.

Methods

A total of 108 patients with SLE (90 % female, mean age 46±13 years, median disease duration of 14 (7-21) years) were included from 2013 to 2014. Blood samples were collected with inclusion of biomarkers, and a standard echocardiography was performed at baseline and at a five-year follow-up. Multivariate regression analyses with five independent lupus-specific baseline variables of interest (disease activity, lupus nephritis, anti-cardiolipin and/or anti-beta-2 glycoprotein I antibodies, and lupus anticoagulant (LAC)) were performed for the association with baseline echocardiographic parameters as well as for changes during follow-up.

Results

During the five-year follow-up period, left ventricular (LV) end-diastolic volume index increased from 43.5±13.9 to 52.5±15.7 ml/m2 (p <0.001) (Figure 1 A1), and LV diastolic parameters declined (E/A ratio 1.4±0.5 vs. 1.3±0.5, p=0.002; e’ velocity 12.8±3.8 vs. 12.0±3.7 cm/s, p=0.02; mitral valve deceleration time 227.9 vs. 200.8 ms, p=<0.001), except for E/e’ (7.5±3.8 vs. 6.8±3.4, p=0.02) (Figure 1B1) in the entire SLE population. LV ejection fraction remained stationary (59.5±6.8 vs. 59.6±6.4 %, p=0.81). Presence of LAC was associated with progressive LV dilatation during the follow-up period (p=0.005) (Figure 1 A2) but not baseline LV volumes (p=0.35). LAC was associated with lower E/A ratio at baseline (p=0.006) but did not predict a decrease of E/A ratio during follow-up (p=0.09) (Figure 1 B2). Follow-up changes of other echocardiographic parameters were not associated with any of the lupus-specific variables.

Figure 1.

Left ventricular end-diastolic volume index (LVEDVI) (A) and E/A ratio (B) at baseline and follow-up (A1, B1) as well as paired longitudinal changes as density plots (A2, B2) with mean values (dashed lines) according to the presence of LAC (blue). LVEDVI and E/A ratio at baseline were log-transformed due to non-normality.

Conclusion

Presence of LAC was associated with lower E/A ratio at baseline as well as progressive left ventricular dilatation during a five-year follow-up period. Hence, LAC might be a predictor of progressive cardiac dysfunction in SLE patients. LAC is known to have implications for the microvascular circulation, but the clinical significance of the present findings is yet to be elucidated.

References

[1]Yafasova A, Fosbøl EL, Schou M, Baslund B, Faurschou M, Docherty KF, et al. Long-Term Cardiovascular Outcomes in Systemic Lupus Erythematosus. J Am Coll Cardiol. 2021 Apr 13;77(14):1717–27.

[2]Aviña-Zubieta JA, To F, Vostretsova K, De Vera M, Sayre EC, Esdaile JM. Risk of Myocardial Infarction and Stroke in Newly Diagnosed Systemic Lupus Erythematosus: A General Population-Based Study. Arthritis Care Res. 2017 Jun;69(6):849–56.

[3]Zuily S, Regnault V, Selton-Suty C, Eschwège V, Bruntz J-F, Bode-Dotto E, et al. Increased risk for heart valve disease associated with antiphospholipid antibodies in patients with systemic lupus erythematosus: meta-analysis of echocardiographic studies. Circulation. 2011 Jul 12;124(2):215–24.

Disclosure of Interests

None declared

POS0142 DISTINCT EXPRESSION CLUSTERS OF INTERFERON-REGULATED GENES ASSOCIATE DIFFERENTLY WITH DISEASE ACTIVITY IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background

Systemic lupus erythematosus (SLE) is a complex multiorgan autoimmune disease that primarily affects women during child-bearing years. The aetiology of SLE involves inadequate clearance of nuclear material released from apoptotic cells. The persistence of host DNA and RNA triggers the immune system to react as seen in a viral infection, causing persistent activation of antiviral interferon (IFN) signalling pathways. Aberrant production of IFN cytokines, type 1 in particular, results in elevated levels of >1000 IFN-regulated gene (IRG) expression in the blood, termed an IFN signature. The IFN signature is typically measured as a score combining the expression levels of a subset of 3-4 IRGs. Several cross-sectional studies have pointed to an association between the IFN signature and disease activity, however subsequent longitudinal studies and a recent systematic review by our group[1] have failed to reproduce these findings. It was suggested that the lack of association between the IFN signature and disease activity was because the IRGs that are sensitive to disease activity are not typically included in the subset of IRGs used to determine an IFN score[2]. Uncovering the significance of the IFN signature in SLE disease activity is particularly relevant for evaluating the scope of IFN pathway inhibitors and may explain why these fail to have a significance for the primary endpoint in clinical trials[3].

Objectives

-Determine the mRNA expression of a broad subset of IRGs (>100) in a cross-sectional study of SLE patients with diverse clinical manifestations

-Investigate the association between IRG expression and disease activity

-Validate the findings from a cross-sectional study in a longitudinal study of SLE patients with fluctuating disease activity

Methods

In a cross-sectional study, peripheral blood samples from 34 SLE patients and 15 healthy controls were collected in PAXgene tubes. Ten SLE patients were followed longitudinally, and peripheral blood samples were collected in PAXgene tubes at time of inclusion and after 12 months. Disease activity was assessed by SJ in all patients and determined by means of SLE Disease Activity Index 2000 (SLEDAI-2K) and European Consensus Lupus Activity Measurement Index (ECLAM). RNA from peripheral blood cells (PBCs) was extracted using the PAXgene Blood RNA kit. The mRNA transcripts of 128 IRGs were measured using the multiplexed NanoString nCounter Gene Expression platform. Bioinformatics and statistical analyses were performed using nSolver and SPSS software.

Results

Out of 128 IRGs, 46 were highly expressed in SLE patients as compared to controls and seemed to co-express in mainly two distinct clusters, Figure 1. Expression scores for cluster K1 did not correlate with SLEDAI or ECLAM in a cross-sectional setting, whereas K2 expression scores did (p<0.01). These findings were confirmed by correlation analysis of changes in K1 and K2 expression scores with scores of disease activity in a longitudinal setting.

Conclusion

Interferon signatures may express differentially with varying associations with disease activity.

References

[1]Siddiqi KZ, et al. Transl Res. 2021

[2]Chiche L, et al. Arthritis Rheumatol. 2014;66:1583-95

[3]Morand EF, et al. N Engl J Med. 2020;382:211-21

Figure 1.

Disclosure of Interests

None declared

AB0006 ESTABLISHED RISK LOCI FOR SYSTEMIC LUPUS ERYTHEMATOSUS AT NCF2, STAT4, TNPO3, IRF5 AND ITGAM ASSOCIATE WITH DISTINCT CLINICAL MANIFESTATIONS: A DANISH GENOME-WIDE ASSOCIATION STUDY

Background

Systemic lupus erythematosus (SLE) has been associated with more than 100 genetic loci. This parallels positively to the clinical diversity that is reflected by the classification of SLE.

Objectives

We aimed to investigate associations between disease manifestations of SLE and risk gene variants relevant to Danish subjects of European ancestry.

Methods

We included 427 SLE patients of European ancestry similar to previous reports.[1] We also included 89,699 controls from the Danish Blood Donor Study Genomic Cohort. SLE risk loci in this population were identified by genome-wide association methodology and hereafter correlated to cumulative occurrence of SLE classification items.

Results

Fourteen variants mapped to the following genes: NCF2, STAT4, TNPO3/TPI1P2, IRF5, and ITGAM, were significantly associated (p<5E-8) with SLE.

The five lead variants were associated (p<0.05) with the following manifestations; NCF2: proteinuria and anti-phospholipid antibodies, STAT4: arthritis, serositis, neurologic disorder, lymphopenia, and anti-Smith antibodies, IRF5: seizures and proteinuria, TNPO3: proteinuria, and ITGAM: photosensitivity (Table 2).

Conclusion

Our findings support the future use of select, relevant genetic markers in predicting various SLE phenotypes.

References

[1]Leffers HCB, Troldborg A, Voss A, et al. Smoking associates with distinct clinical phenotypes in patients with systemic lupus erythematosus: a nationwide Danish cross-sectional study. Lupus Sci Med 2021;8(1).

Table 1.

Associations between five SLE risk loci and specific disease manifestations in 427 Danish patients with SLE*.

NCF2STAT4IRF5TNPO3ITGAMrs17849502_Trs7574865_Trs4728142_Ars13239597_Ars11860650_TN (%)Malar rash233 (55%)1.28 (0.84-1.96)0.83 (0.62-1.11)1.01 (0.74-1.38)1.44 (0.97-2.12)1.14 (0.80-1.61)Discoid rash46 (11%)1.49 (0.81-2.73)0.90 (0.56-1.45)1.01 (0.62-1.66)1.16 (0.63-2.12)0.76 (0.42-1.41)Photosensitivity219 (51%)0.96 (0.63-1.46)1.09 (0.81-1.47)0.98 (0.71-1.34)0.84 (0.57-1.25)0.67 (0.47-0.97)Oral ulcers132 (31%)0.96 (0.61-1.50)0.90 (0.65-1.23)0.83 (0.60-1.16)1.30 (0.87-1.96)1.43 (0.99-2.05)Non-erosive Arthritis342 (80%)0.84 (0.52-1.37)1.49 (1.02-2.18)0.93 (0.63-1.36)1.04 (0.64-1.68)1.16 (0.74-1.80)Serositis-Pleuritis124 (29%)0.63 (0.38-1.05)1.38 (1.01-1.89)1.22 (0.87-1.72)0.85 (0.56-1.29)0.84 (0.57-1.24)-Pericarditis72 (17%)0.75 (0.41-1.40)1.35 (0.93-1.96)1.05 (0.70-1.58)1.15 (0.70-1.89)1.09 (0.70-1.72)Persistent proteinuria158 (37%)1.63 (1.07-2.49)1.08 (0.80-1.46)0.68 (0.49-0.94)1.74 (1.16-2.61)1.09 (0.76-1.57)Neurologic disorder-Seizures23 (5%)1.58 (0.75-3.35)1.49 (0.80-2.76)2.10 (1.04-4.25)0.61 (0.26-1.44)0.93 (0.42-2.06)-Psychosis8 (2%)0.76 (0.097-5.87)2.77 (0.94-8.15)0.35 (0.10-1.23)0 (0)2.96 (0.85-10.3)Haematologic disorder-Haemolytic anaemia38 (9%)0.78 (0.34-1.76)1.37 (0.85-2.22)0.75 (0.44-1.29)1.11 (0.57-2.19)1.24 (0.70-2.20)-Leukopenia130 (30%)1.04 (0.67-1.61)1.19 (0.87-1.63)1.00 (0.72-1.39)0.90 (0.60-1.37)0.94 (0.64-1.37)-Lymphopenia228 (53%)0.95 (0.63-1.44)1.35 (1.01-1.81)0.95 (0.70-1.29)1.16 (0.79-1.70)1.09 (0.77-1.54)-Thrombocytopenia102 (24%)1.42 (0.91-2.22)0.84 (0.60-1.18)0.83 (0.58-1.18)1.35 (0.86-2.11)0.91 (0.60-1.37)Immunologic disorder-anti-DNA ab.330 (77%)0.69 (0.44-1.09)1.02 (0.72-1.44)0.94 (0.65-1.35)0.97 (0.62-1.53)1.08 (0.71-1.65)-anti-Smith ab.44 (10%)1.44 (0.79-2.64)1.58 (1.00-2.49)1.23 (0.73-2.07)1.47 (0.80-2.69)1.07 (0.61-1.84)-anti-phospholipid ab.183 (43%)1.63 (1.07-2.49)1.05 (0.79-1.41)0.84 (0.61-1.14)1.14 (0.77-1.68)1.14 (0.80-1.62)

* Logistic regression models for each manifestation included all five lead variants (multivariate) and were adjusted for age and sex

Disclosure of Interests

Henrik Leffers: None declared, David Westergaard: None declared, Saedis Saevarsdottir: None declared, Ingileif Jonsdottir: None declared, Ole Birger Pedersen: None declared, Anne Troldborg: None declared, Anne Voss: None declared, Salome Kristensen: None declared, Jesper Lindhardsen: None declared, Prabhat Kumar: None declared, Asta Linauskas: None declared, Lars Juul: None declared, Niels Steen Krogh: None declared, Bent Deleuran: None declared, Lene Dreyer Speakers bureau: Speakers bureau: Eli Lilly, Galderma and Janssen, Grant/research support from: from BMS outside the present work, Michael Schwinn: None declared, Lise wegner Thørner: None declared, Lotte Hindhede: None declared, Christian Erikstrup: None declared, Henrik Ullum: None declared, Søren Brunak Shareholder of: SB has ownerships in Intomics A/S, Hoba Therapeutics Aps, Novo Nordisk A/S, Lundbeck A/S, Kari Stefansson: None declared, Karina Banasik: None declared, Søren Jacobsen: None declared

Concentrations of Neutrophil Gelatinase-Associated Lipocalin are increased in serum and peritoneal fluid from horses with inflammatory abdominal disease and non-strangulating intestinal infarctions

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is produced in response to inflammation in horses, but it has not yet been investigated as a biomarker in horses with abdominal disease.

OBJECTIVES

To investigate NGAL in serum and peritoneal fluid in horses with abdominal disease.

STUDY DESIGN

Retrospective clinical study.

METHODS

Data from medical records of 270 horses admitted with acute abdominal disease (simple obstructions [n=43], strangulating obstructions [n=104], inflammatory abdominal disease [n=99], non-strangulating intestinal infarction [NSII, n=24]) and 9 healthy control horses were reviewed, and serum and peritoneal fluid samples were retrieved from a biobank. NGAL was measured in serum and peritoneal fluid by ELISA. Differences in NGAL concentrations between groups were assessed.

RESULTS

Healthy horses had low serum and peritoneal fluid concentrations of NGAL (median = 21.0 and 9.5 μg/L, respectively). Neither serum nor peritoneal fluid NGAL concentrations (median serum, peritoneal fluid) differed between healthy horses and horses with simple (28.1 μg/L, 13.0 μg/L) and strangulating intestinal obstructions (34.7 μg/L, 38.4 μg/L). Horses with NSII (308.0 μg/L, 2163.0 μg/L) and inflammatory abdominal disease (171.1 μg/L, 314.1 μg/L) had higher serum and peritoneal fluid concentrations of NGAL than the other groups (P<0.001). Peritoneal fluid NGAL concentrations in horses with NSII were higher than in horses with inflammatory abdominal disease (P=0.03).

MAIN LIMITATIONS

Retrospective study design; small group of control horses.

CONCLUSIONS

NGAL is a marker of inflammation in horses with abdominal disease. The high peritoneal fluid concentration of NGAL in horses with NSII compared to all other groups may render NGAL useful for identifying this condition, which is otherwise difficult to differentiate from other types of peritonitis. Thereby, NGAL may potentially facilitate timely surgical intervention in this group of patients. The results of this study must be evaluated in larger, and preferably prospective, studies to obtain a more comprehensive evaluation of the diagnostic utility of NGAL. This article is protected by copyright. All rights reserved.

OP0235 GENOME-WIDE DNA METHYLATION ANALYSIS IN MULTIPLE IMMUNE CELL POPULATIONS REVEALS WIDESPREAD PROMOTER AND INTERGENIC B CELL HYPERMETHYLATION IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background

Patients with systemic lupus erythematosus (SLE) display an aberrant DNA methylation (DNAm) pattern with a predominant interferon signature. However, the DNAm patterns in purified immune cell populations are not well described.

Objectives

To examine genome-wide DNAm changes in sorted CD4+ T cells, monocytes, granulocytes and B cells in SLE patients compared to healthy controls (HC).

Methods

Genome-wide analysis was performed in 20 SLE patients with active lupus nephritis (LN) and 20 age-, sex- and ethnicity-matched HCs. Peripheral blood was processed using gradient density centrifugation for the granulocyte fraction, and CD4+ T-cells, monocytes and B cells were isolated from the mononuclear cell fraction using a RoboSep device (Stemcell Technologies). DNA was extracted using the DNA/RNA/miRNA Universal kit (Qiagen). Genome-wide DNAm was evaluated using Infinium MethylationEPIC BeadChips (Illumina Inc.). Top differentially methylated CpG sites (DMC) were validated using pyrosequencing, and further analysed in follow-up samples, as well as extended to another 36 SLE patients with inactive LN, 36 SLE with never-LN and 20 HCs. Patients and HCs were compared using a paired t-test stratified by cell type. A false discovery rate (FDR) <0.05 was considered statistically significant. Clustering of non-gene annotated CpGs was defined as distance <5000 bp with proximity to neighbouring genes <1x105 bp, identified through mapping of Entrez Gene Identifiers.

Results

Overall, SLE patients with active LN compared to HCs exhibited DMCs in 22, 46, 312 and 78,068 probes in CD4+ T cells, monocytes, granulocytes and B cells, respectively. In CD4+ T cells, monocytes and granulocytes, the majority of DMCs were hypomethylated and related to interferon-regulated genes. In B cells, the majority of DMCs were hypermethylated with 1360 genes in the promoter region restricted to differential methylation >10% and ≥2 DMCs, of which 1087 were hypermethylated. Of these, the most significantly hypermethylated CpGs in the promoter region included CABYR, TMPRSS7, SLC6A2, KLK10/KLK11, WIZ, LPAR1, ZNF385B and IL1R1 (Figure 1). Top hypomethylated genes included IFI44L and MX1. Ingenuity Pathway Analysis (IPA) predicted top upstream regulators in B cells to be IL4, TNF and IFNG. In addition, we identified 1437 DMCs associated with ncRNA and 4626 DMCs with no genic association. The non-gene associated DMCs were related to 275 non-coding clusters. Top non-coding clusters were in proximity to BMP7, ARHGEF10, PRDM1, RIN2 and CCR6, which themselves were differentially methylated. IPA predicted IL2, CD40LG and NFKB1 as the most important upstream regulators for neighbouring genes of non-coding clusters.

Pyrosequencing confirmed B cell hypermethylation in CXCR5, DDR1, MTA3, RAB30 and TRAF5, and in non-coding clusters located on chromosome 3 upstream of FGF12 and chromosome 22 downstream of XPNPEP3 and RBX1. Hypermethylation in CXCR5, DDR1, MTA3, RAB30 and hypomethylation in IFI44L, LGALS3BP and PARP9 was stable at follow-up as well as in patients with inactive and never-LN. Patients in the active LN group exhibited significantly more pronounced hypomethylation in PLSCR1 in CD4+ T-cells, granulocytes and B-cells compared to the other patient groups. Greater β2 microglobulin, anti-DNA antibodies and disease activity were significantly associated with greater B cell CXCR5 hypermethylation (p<0.001), IFI44L hypomethylation in all but CD4+ T cells, LGALS3BP hypomethylation in granulocytes (p<0.0001), PARP9 hypomethylation in all but B cells and PLSCR1 hypomethylation in all but monocytes. Proteinuria was related to PLSCR1 hypomethylation in all but monocytes, as well as hypermethylation at the non-coding cluster in chromosome 3 (p=0.05) and MTA3 (p=0.03) in B cells.

Conclusion

B cell hypermethylation in SLE patients is widespread, and may indicate a novel mechanism for SLE pathogenesis. Differential methylation of several interferon-regulated genes may be associated with disease activity.

Disclosure of Interests

None declared

Human integrin α10β1-selected mesenchymal stem cells home to cartilage defects in the rabbit knee and assume a chondrocyte-like phenotype

BACKGROUND

Mesenchymal stem cells (MSCs) have shown promising results in stimulating cartilage repair and in the treatment of osteoarthritis (OA). However, the fate of the MSCs after intra-articular injection and their role in cartilage regeneration is not clear. To address these questions, this study investigated (1) homing of labeled human adipose tissue derived integrin α10β1-selected MSCs (integrin α10-MSCs) to a cartilage defect in a rabbit model and (2) the ability of the integrin α10-MSCs to differentiate to chondrocytes and to produce cartilage matrix molecules in vivo.

DESIGN

Integrin α10-MSCs were labeled with superparamagnetic iron oxide nanoparticles (SPIONs) co-conjugated with Rhodamine B to allow visualization by both MRI and fluorescence microscopy. A cartilage defect was created in the articular cartilage of the intertrochlear groove of the femur of rabbits. Seven days post-surgery, labeled integrin α10-MSCs or vehicle were injected into the joint. Migration and distribution of the SPION-labeled integrin α10-MSCs was evaluated by high-field 9.4 T MRI up to 10 days after injection. Tissue sections from the repair tissue in the defects were examined by fluorescence microscopy.

RESULTS

In vitro characterization of the labeled integrin α10-MSCs demonstrated maintained viability, proliferation rate and trilineage differentiation capacity compared to unlabeled MSCs. In vivo MRI analysis detected the labeled integrin α10-MSCs in the cartilage defects at all time points from 12 h after injection until day 10 with a peak concentration between day 1 and 4 after injection. The labeled MSCs were also detected lining the synovial membrane at the early time points. Fluorescence analysis confirmed the presence of the labeled integrin α10-MSCs in all layers of the cartilage repair tissue and showed co-localization between the labeled cells and the specific cartilage molecules aggrecan and collagen type II indicating in vivo differentiation of the MSCs to chondrocyte-like cells. No adverse effects of the α10-MSC treatment were detected during the study period.

CONCLUSION

Our results demonstrated migration and homing of human integrin α10β1-selected MSCs to cartilage defects in the rabbit knee after intra-articular administration as well as chondrogenic differentiation of the MSCs in the regenerated cartilage tissue.

Postpartum dysgalactia syndrome in sows: effects on behavior of sows and piglets

BACKGROUND

To investigate if specific sow and piglet behavioral characteristics could be used diagnostically, this case-cohort study of the behavior of sows and piglets during the periparturient period (from 24 h before the birth of first piglet to 24 h after the birth of last piglet) was conducted. Data included 32 sows diagnosed with PDS (PDS+) vs. 37 healthy matched controls (PDS-) and their litters.

RESULTS

A significant change from active behavior with many postural changes to a more passive behavior was noted in connection with parturition. Sow nesting behavior was less frequent in PDS+ sows compared to PDS- sows during (p = 0.04) and after parturition (p = 0.0004). No difference was found between PDS+ and PDS- in the number of postural changes, interval from last time standing to the birth of the first piglet, interval from last time eating/drinking to the birth of the first piglet, interval from the birth of the first piglet to the sow standing after farrowing, interval from the birth of the last piglet until eating/drinking, occurrence of bar biting, or frequency or duration of eating/drinking during the observation period. Piglets of PDS+ sows stayed outside the creep areas more often than piglets of PDS- sows (p < 0.0001), but there was no difference in the mean number of piglets observed massaging the udder every 10 min.

CONCLUSION

These results confirm that sow behavior changes from active before parturition to more passive after parturition. Being diagnosed with PDS affected the periparturient behavior of sows as well as their piglets. The observed reduction in nesting behavior in PDS+ sows may suggest that a highly motivated piglet-oriented behavior was affected. However, classical sickness behaviors like lethargy and passivity seem to be poor markers for PDS.

Validation of ultrasonography for measurement of cartilage thickness in the equine carpus

Articular cartilage thinning is an important hallmark of osteoarthritis (OA), and ultrasonography (US) is a clinically accessible tool potentially suitable for repeated evaluation. The aim of the present prospective methods comparison study was to validate US as a tool for measuring cartilage thickness in the carpus of the horse. Eight Standardbred trotters underwent US examination with 9 and 15 MHz linear transducers. Six anatomical locations in the radiocarpal joint (RCJ) and middle carpal joint (MCJ) were examined. The same joints were assessed by ultrahigh field (9.4 Tesla) magnetic resonance imaging (MRI) and histology. Associations between measurements obtained by the different modalities were assessed by ANOVA, Deming regression, Pearson correlation and Bland–Altman plots. Histologically assessed total cartilage thickness (the noncalcified cartilage (NCC) plus the calcified cartilage zone (CCZ)) overestimated thickness compared to MRI (P < 0.01) and US (P < 0.01). US 15 MHz had substantial agreement with MRI and NCC histology, and repeatability was acceptable (coefficient of variation = 8.6–17.9%) when used for assessment of cartilage thickness in the RCJ. In contrast, 9 MHz US showed poorer agreement with MRI and NCC histology, as it overestimated the thickness of thin cartilage and underestimated the thickness of thicker cartilage in the RCJ and MCJ. Moreover, repeatability was suboptimal (coefficient of variation = 10.4–26.3%). A 15 MHz transducer US is recommended for detecting changes in RCJ cartilage thickness or monitoring development over time, and it has the potential for noninvasive assessment of cartilage health in horses.

Lupus anticoagulant in patients with systemic lupus erythematosus is associated with lower E/A ratio and progressive left ventricular dilatation: a five-year follow-up study

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): Copenhagen University Hospital

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease with increased risk of cardiovascular complications such as coronary artery disease, myocarditis, pericarditis and valvular dysfunction. The pathophysiological mechanisms are poorly understood and clinical, biochemical and/or imaging markers to identify high risk patients are warranted.

Purpose

We aimed to identify SLE-characteristics that are associated with progressive cardiac dysfunction during a five-year follow-up period in patients with SLE.

Methods

A total of 147 patients with SLE were included from 2013 to 2014. All patients underwent standard echocardiography at baseline as well as a collection of blood samples, including a selection of biomarkers. Patients were invited to a five-year follow-up with a total of 108 patients (90 % female, mean age 46 ± 13 years, median disease duration of 14 (7-21) years) completing a full echocardiographic, laboratory, and clinical examination. Multivariate regression analyses with eight independent baseline variables of interest (age, sex, disease activity (SLEDAI-2K), lupus nephritis, ischemic heart disease (IHD), antiphospholipid antibodies (IgM and IgG), and lupus anticoagulant(LAC)) were performed as for the association with baseline echocardiographic parameters as well as for changes during follow-up. Only echocardiographic measurements that changed significantly (p &lt; 0.01) during follow-up were selected for the regression analyses. Left ventricular end-diastolic volume index (LVEDVI) and E/A ratio were log-transformed at baseline in the regression analyses due to non-normality.

Results

During a five-year follow-up period, LVEDVI increased from 43.5 ± 13.9 to 52.5 ± 15.7 ml/m2 (p &lt;0.001), and left ventricular diastolic measures declined (E/A ratio 1.4 ± 0.5 vs. 1.3 ± 0.5, p = 0.002; e’ velocity 12.8 ± 3.8 vs. 12.0 ± 3.7 ms, p = 0.02; mitral valve deceleration time 227.9 vs. 200.8 ms, p &lt; 0.001), except for E/e’ (7.5 ± 3.8 vs. 6.8 ± 3.4, p = 0.02). Left ventricular ejection fraction remained stationary (59.5 ± 6.8 vs. 59.6 ± 6.4 %, p = 0.81). In multivariate regression analyses, presence of LAC was significantly associated with progressive left ventricular dilation during the follow-up period (p = 0.003) but not with higher baseline levels (p = 0.64) (Fig. A1 & A2). LAC was associated with lower E/A ratio at baseline (p = 0.005) but did not predict a decrease of E/A ratio during follow-up (p = 0.24) (Fig. B1 & B2). IHD was associated with higher LVEDVI at baseline (p = 0.004), but not with further progression of dilation (p = 0.07).

Conclusion

Presence of LAC was associated with lower E/A ratio at baseline as well as progressive left ventricular dilation during a five-year follow-up period. Hence, LAC might be a predictor of progressive cardiac dysfunction in patients with SLE. LAC is known to have implications for the microvascular circulation, but the clinical significance of the present findings is yet to be elucidated. Abstract Figure A  Abstract Figure B

Temporal extracellular vesicle protein changes following intraarticular treatment with integrin α10β1-selected mesenchymal stem cells in equine osteoarthritis

Introduction

Equine osteoarthritis (OA) is a heterogeneous, degenerative disease of the musculoskeletal system with multifactorial causation, characterized by a joint metabolic imbalance. Extracellular vesicles are nanoparticles involved in intracellular communication. Mesenchymal stem cell (MSC) therapy is a form of regenerative medicine that utilizes their properties to repair damaged tissues. Despite its wide use in veterinary practice, the exact mechanism of action of MSCs is not fully understood. The aim of this study was to determine the synovial fluid extracellular vesicle protein cargo following integrin α10β1-selected mesenchymal stem cell (integrin α10-MSC) treatment in an experimental model of equine osteoarthritis with longitudinal sampling.

Methods

Adipose tissue derived, integrin α10-MSCs were injected intraarticularly in six horses 18 days after experimental induction of OA. Synovial fluid samples were collected at day 0, 18, 21, 28, 35, and 70. Synovial fluid was processed and extracellular vesicles were isolated and characterized. Extracellular vesicle cargo was then analyzed using data independent acquisition mass spectrometry proteomics.

Results

A total of 442 proteins were identified across all samples, with 48 proteins differentially expressed (FDR ≤ 0.05) between sham-operated control joint without MSC treatment and OA joint treated with MSCs. The most significant pathways following functional enrichment analysis of the differentially abundant protein dataset were serine endopeptidase activity (p = 0.023), complement activation (classical pathway) (p = 0.023), and collagen containing extracellular matrix (p = 0.034). Due to the lack of an OA group without MSC treatment, findings cannot be directly correlated to only MSCs.

Discussion

To date this is the first study to quantify the global extracellular vesicle proteome in synovial fluid following MSC treatment of osteoarthritis. Changes in the proteome of the synovial fluid-derived EVs following MSC injection suggest EVs may play a role in mediating the effect of cell therapy through altered joint homeostasis. This is an important step toward understanding the potential therapeutic mechanisms of MSC therapy, ultimately enabling the improvement of therapeutic efficacy.

Small non-coding RNA landscape of extracellular vesicles from a post-traumatic model of equine osteoarthritis

Extracellular vesicles comprise an as yet inadequately investigated intercellular communication pathway in the field of early osteoarthritis. We hypothesised that the small non-coding RNA expression pattern in synovial fluid and plasma would change during progression of experimental osteoarthritis. In this study, we conducted small RNA sequencing to provide a comprehensive overview of the temporal expression profiles of small non-coding transcripts carried by extracellular vesicles derived from plasma and synovial fluid for the first time in a posttraumatic model of equine osteoarthritis. Additionally, we characterised synovial fluid and plasma-derived extracellular vesicles with respect to quantity, size, and surface markers. The different temporal expressions of seven microRNAs in plasma and synovial fluid-derived extracellular vesicles, eca-miR-451, eca-miR-25, eca-miR-215, eca-miR-92a, eca-miR-let-7c, eca-miR-486-5p, and eca-miR-23a, and four snoRNAs, U3, snord15, snord46, and snord58, represent potential biomarkers for early osteoarthritis. Bioinformatics analysis of the differentially expressed microRNAs in synovial fluid highlighted that in early osteoarthritis these related to the inhibition of cell cycle, cell cycle progression, DNA damage and cell proliferation as well as increased cell viability and differentiation of stem cells. Plasma and synovial fluid-derived extracellular vesicle small non-coding signatures have been established for the first time in a temporal model of osteoarthritis. These could serve as novel biomarkers for evaluation of osteoarthritis progression or act as potential therapeutic targets.

Effective protein extraction combined with data independent acquisition analysis reveals a comprehensive and quantifiable insight into the proteomes of articular cartilage and subchondral bone

OBJECTIVE

The objectives of this study was to establish a sensitive and reproducible method to map the cartilage and subchondral bone proteomes in quantitative terms, and mine the proteomes for proteins of particular interest in the pathogenesis of osteoarthritis (OA). The horse was used as a model animal.

DESIGN

Protein was extracted from articular cartilage and subchondral bone samples from three horses in triplicate by pressure cycling technology or ultrasonication. Digested proteins were analysed by data independent acquisition based mass spectrometry. Data was processed using a pre-established spectral library as reference database (FDR 1%).

RESULTS

We identified to our knowledge the hitherto most comprehensive quantitative cartilage (1758 proteins) and subchondral bone (1482 proteins) proteomes in all species presented to date. Both extraction methods were sensitive and reproducible and the high consistency of the identified proteomes (>97% overlap) indicated that both methods preserved the diversity among the extracted proteins. Proteome mining revealed a substantial number of quantifiable cartilage and bone matrix proteins and proteins involved in osteogenesis and bone remodeling, including ACAN, BGN, PRELP, FMOD, COMP, ACP5, BMP3, BMP6, BGLAP, TGFB1, IGF1, ALP, MMP3, and collagens. A number of proteins, including COMP and TNN, were identified in different protein isoforms with potential unique biological roles.

CONCLUSION

We have successfully developed two sensitive and reproducible non-species specific workflows enabling a comprehensive quantitative insight into the proteomes of cartilage and subchondral bone. This facilitates the prospect of investigating the molecular events at the osteochondral unit in the pathogenesis of OA in future projects.

Changes of adenosine deaminase activity in serum and saliva around parturition in sows with and without postpartum dysgalactia syndrome

BACKGROUND

Postpartum dysgalactia syndrome (PDS) is associated with a significantly higher activation of the inflammatory and stress response at parturition than in the healthy sow. Therefore, reliable and possibly non-invasive biomarkers for substantial increases of inflammation are searched to support the PDS diagnosis. This report studies the possible changes of the inflammatory marker enzyme adenosine deaminase (ADA) in serum and saliva of 38 PDS positive sows (PDS+) and 38 healthy sows (PDS-). Sampling was performed every 24 h from 60 h before to 36 h after parturition. Isoenzyme 1 (ADA1) and isoenzyme 2 (ADA2), as well as total ADA (tADA), were measured and their statistical association with several serum and saliva biomarkers of inflammation and stress was investigated.

RESULTS

Compared to a baseline (60 to 36h prepartum), salivary activities of ADA1, ADA2 and tADA increased significantly over time in both PDS+ and PDS- sows, reaching their peaks after parturition. In serum from PDS- sows, no changes were observed over time in either ADA1, ADA2 or tADA. In PDS+ sows, serum ADA2 activity decreased temporarily after parturition followed by a significant increase compared to baseline. ADA1, ADA2 and tADA were all significantly associated with several inflammatory biomarkers and ADA1 in serum was associated with serum cortisol. Although serum activity was higher in PDS+ than in PDS- sows, the differences were not statistically significant. Further, no difference was noted between the groups in the analyses of saliva.

CONCLUSIONS

Salivary ADA1 and ADA2 increased in all sows after parturition, potentially as a response to the postpartum inflammation. However, no difference in the activity of ADA1, ADA2 and tADA were found between PDS+ and PDS- sows indicating inability to diagnose PDS under the conditions described in this report.

Effect of exercise on serum neutrophil gelatinase-associated lipocalin concentration in racehorses

Serum neutrophil gelatinase-associated lipocalin (sNGAL) is a marker of renal injury, and its concentrations are affected by inflammation. Therefore, it could serve as a useful biomarker of disease or fitness in high-level competition. However, it has not yet been determined if sNGAL concentrations are affected by exercise. The aim of this study was to determine whether concentrations of equine sNGAL were affected by 1000 m galloping as the form of exercise used in the study. Pre- and post-gallop sNGAL, serum amyloid A, and creatinine concentrations were evaluated in 14 healthy Thoroughbred racehorses. The results showed that short, high-intensity exercise did not significantly affect sNGAL concentrations in healthy horses (P = .42), and no significant difference was found in either creatinine or serum amyloid A before and after galloping (P > .05). Therefore, it was determined that sNGAL was not influenced by the type of exercise used in the study and could have the potential to be used as a routine laboratory screening tool in horses even after strenuous exercise. Future research should clarify its use in a larger population and a broader range of equine sport disciplines, including endurance-related exercise.

Dynamics of local gene regulations in synovial fluid leukocytes from horses with lipopolysaccharide-induced arthritis

The role of resident cells such a synoviocytes and chondrocytes in intra-articular inflammation is well-characterized, however the in vivo gene expression patterns of cells (predominantly leukocytes) in the synovial fluid (SF) of an inflamed joint have never previously been investigated. The aim of this study was to investigate gene expression in SF leukocytes from the inflamed joint cavity after intra-articular lipopolysaccharide (LPS) injection in horses to improve our understanding of the temporal regulation of the intra-articular inflammatory response. Gene expression was investigated in SF samples available from six horses 2, 4, 8 16 and 24 h after experimental induction of inflammation in the radiocarpal joint by lipopolysaccharide (LPS) injection. Leukocytic expression of 43 inflammation-related genes was studied using microfluidic high throughput qPCR (Fluidigm®). Expression of 26 genes changed significantly over the 24 h study period, including pro- and anti-inflammatory genes such as interleukin (IL)1, IL6, tumor necrosis factor (TNF), cyclooxygenase 2 (COX2), IL1 receptor antagonist (IL1RN), IL10, and superoxide dismutase 2 (SOD2), chemokine genes, apoptosis-related genes, and genes related to cartilage turnover (matrix metalloproteinase 8 and tissue inhibitor of metalloproteinase 1). The inflammatory responses appeared to be regulated, as an early increase (at 2 h) in expression of the pro-inflammatory genes IL1, IL6, TNF and COX2 was rapidly followed by increased expression (at 4 h) of several anti-inflammatory genes (IL10, IL1RN and SOD2). Similarly, both pro- and anti-apoptotic gene expression as well as expression of chondrodegenerative and chondroprotective genes were activated in SF leukocytes. Thus, the inflammatory response in leukocytes infiltrating the joint in the acute stage of arthritis was well orchestrated in this single-hit LPS-induced arthritis model. This study is the first to describe gene expression patterns in SF-derived leukocytes in vivo during severe joint inflammation, and the results thus expand our knowledge of basic inflammatory mechanisms in the early local response in an inflamed joint.

Birthweight, body size, and growth during childhood and risks of rheumatoid arthritis: a large Danish cohort study

Objectives: Adult obesity may be positively associated with risks of rheumatoid arthritis (RA), but associations with early life body size are unknown. We examined whether birthweight, childhood body mass index (BMI), height, and changes in BMI and height were associated with risks of adult RA.Method: A cohort of 346 602 children (171 127 girls) from the Copenhagen School Health Records Register, born in 1930-1996, with measured weights and heights from 7 to 13 years of age, were included. Information on RA, including serological status, came from national registers from 1977 to 2017. Cox regressions were performed.Results: During a median of 35.1 years of observation time per person, 4991 individuals (3565 women) were registered with RA. Among girls, per BMI z-score, risks of RA and seropositive RA increased by 4-9% and 6-10%, respectively. Girls with overweight had higher risks of RA than girls without overweight. Girls who became overweight by 13 years of age had increased risks of RA compared to girls without overweight at 7 or 13 years (hazard ratio = 1.40, 95% confidence interval 1.19-1.66). For boys, associations between BMI and RA (including seropositive RA) were not statistically significant. Height was not associated with RA (any type) in girls. Taller boys had higher risks of RA, especially seropositive RA. Birthweight was not associated with RA.Conclusions: Among women, childhood adiposity was associated with increased risks of RA. Among men, childhood height was positively associated with risks of RA. These findings support the hypothesis that early life factors may be important in the aetiology of RA.

OP0289 LLDAS (LOW LUPUS DISEASE ACTIVITY STATE), LOW DISEASE ACTIVITY (LDA) AND REMISSION (ON- OR OFF-TREATMENT) PREVENT DAMAGE ACCRUAL IN SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) PATIENTS IN A MULTINATIONAL MULTICENTER COHORT

Background:

Remission, LDA and LDAS have been proposed as treatment goals for SLE. However, the independent impact of these states on damage accrual has not been fully evaluated.

Objectives:

To determine the independent impact of remission (both off & on treatment), LDA, and LLDAS on damage accrual.

Methods:

We studied a long-term longitudinal multinational SLE cohort, including patients completing at least two annual assessments. Remission off-treatment was defined as a SLEDAI (excluding serology) =0, without prednisone and immunosuppressive (IS) drugs. Remission on-treatment was defined as a SLEDAI (excluding serology) =0, prednisone daily dose<=5 mg/d and maintenance IS drugs. LDA was defined as a SLEDAI (excluding serology) <=2, without prednisone or IS drugs. LLDAS was defined as a SLEDAI <=4 with no activity in major organ systems, with no new features of lupus disease activity compared to the previous assessment, prednisone daily dose<=7.5 mg/d and maintenance IS drugs. Antimalarials were allowed in all groups. Damage accrual was ascertained with the SLICC/ACR damage index (SDI). Univariable and multivariable generalized estimated equation (GEE) negative binomial regression models were used. To create mutually exclusive groups, disease activity was divided into five states: remission off-treatment, remission on-treatment (minus remission off treatment), LDA (minus remission), LLDAS (minus remission and LDA) and not-optimally controlled. The proportion of the time that patients were in the specific state at each visit since cohort entry was determined. Possible effect modifiers and confounders adjusted for included sex, age at diagnosis, race/ethnicity, education, baseline disease duration, follow-up time, the highest-ever glucocorticoid dose prior to cohort entry, antimalarials and SDI. Time-dependent covariates were determined at the same annual visit as disease activity state; the outcome was the increase in the SDI and it was assessed at the subsequent visit.

Results:

There were 1,652 patients, 1464 (88.6%) were female, mean age at diagnosis was 34.6 (SD 13.4) years and mean baseline disease duration was 5.5 (SD 4.1) months. Patients had a mean follow-up of 6.5 (SD 4.3) years, 11686 visits were included. 763 patients (46.2%) had an increase in SDI score ≥1 during follow-up. 2483 (21.2%) of the visits were classified as remission off-treatment, 2276 (19.5%) as remission on-treatment, 544 (4.7%) as LDA, 657 (5.6%) as LLDAS and 5726 (49.0%) as not-optimally controlled. Being in remission off-treatment, remission on-treatment, LDA and LLDAS were predictive of a lower probability of damage accrual [remission off-treatment IRR=0.403, 95% CI 0.301-0.541); remission on-treatment IRR=0.313 (95% CI 0.218-0.451) LDA: IRR=0.469 (CI 95% CI 0.272-0.809); LLDAS IRR=0.440 (95% CI 0.241-0.803)]. The multivariable model is summarized in Table 1.

Table 1.

Multivariable GEE model of the impact of disease activity states on damage accrual.

Incidence Rate Ratio95% CIDisease activity stateRemission off treatment0.4030.301-0.541Remission on treatment0.3130.218-0.451LDA0.4690.272-0.809LLDAS0.4400.241-0.803Gender, male1.2741.086-1.495Age at diagnosis1.0241.020-1.029EthnicityCaucasian USRef.Caucasian other1.0170.849-1.217African1.4671.211-1.776Asian0.8630.693-1.075Hispanic1.2661.034-1.550Other1.1210.759-1.656Educational level, years0.9770.957-0.996Disease duration at baseline0.9600.801-1.150Follow-up time0.9420.923-0.960Antimalarial use0.7860.681-0.908Highest prednisone dose before baseline1.0021.001-1.007SDI before1.1001.050-1.1152

LLDAS: Low lupus disease activity state LDA: Low disease activity SDI: SLICC/ACR Damage Index

Conclusion:

Remission on- and off-treatment, LDA and LLDAS were associated with less damage accrual, even adjusting for possible confounders and effect modifiers. This highlights the importance of treating to target in SLE.

Disclosure of Interests:

Manuel F. Ugarte-Gil Grant/research support from: Pfizer, Janssen, John Hanly: None declared, Murray B Urowitz: None declared, Caroline Gordon Speakers bureau: UCB, Consultant of: Center for Disease Control, Astra-Zeneca, MFP, Sanofi, UCB, Sang-Cheol Bae: None declared, Juanita Romero-Diaz: None declared, Jorge Sanchez-Guerrero: None declared, Sasha Bernatsky: None declared, Ann E Clarke Consultant of: AstraZeneca, BristolMyersSquibb, GlaxoSmithKline, and Exagen Diagnostics, Daniel J Wallace Grant/research support from: Exagen, David Isenberg: None declared, Anisur Rahman: None declared, Joan T Merrill: None declared, Paul Fortin: None declared, Dafna D Gladman Consultant of: Abbvie, Janssen, Pfizer, Novartis, Amgen, Grant/research support from: Abbvie, Janssen, Pfizer, Novartis, Amgen, Ian N. Bruce: None declared, Michelle A Petri: None declared, Ellen M Ginzler Grant/research support from: Aurinia pharmaceutical, M.A. Dooley: None declared, Rosalind Ramsey-Goldman: None declared, Susan Manzi: None declared, Andreas Jonsen: None declared, Ronald van Vollenhoven Speakers bureau: AbbVie, Galapagos, GSK, Janssen, Pfizer, UCB, Consultant of: Abbvie, AstraZeneca, Biogen, Biotest, Celgen, Galapagos, Gilead, Janssen, Pfizer, Sanofie, Servier, UCB, Vielabo, Grant/research support from: BMS, GSK, Lilly, UCB, Cynthia Aranow: None declared, Meggan Mackay: None declared, Guillermo Ruiz-Irastorza: None declared, S. Sam Lim: None declared, Murat Inanc: None declared, Kenneth C Kalunian Consultant of: Roche, Biogen, Janssen, AstraZeneca, Eli Lilly, Genetech, Gilead, ILTOO, Nektar, Viela, Equillium, Bristol-Meyers Squibb, Soren Jacobsen Grant/research support from: BMS, Christine Peschken: None declared, Diane L Kamen: None declared, Anca Askanase Consultant of: Abbvie, Grant/research support from: Glaxo Smith Kline, Astra Zeneca, Janssen, Eli Lilly and Company, Mallinckrodt, Pfizer, Bernardo Pons-Estel Consultant of: GSK, Janssen, Graciela S Alarcon: None declared.

Long-term athletic performance in sport horses after desmotomy of the accessory ligament of the deep digital flexor tendon

BACKGROUND

Outcome after desmotomy of the accessory ligament of the deep digital flexor tendon (AL-DDFT) to treat flexural deformity of the distal interphalangeal joint has been reported to be excellent. However, no studies have compared long-term athletic performance of sport horses exposed to desmotomy of the AL-DDFT to that of matched controls.

OBJECTIVES

The objective of this study is to compare long-term athletic performance in sports horses subjected to desmotomy of the AL-DDFT with the performance of matched controls.

STUDY DESIGN

This is an observational multicentre retrospective matched cohort study.

METHODS

Records from horses undergoing desmotomy of the AL-DDFT between 2004 and 2015 were reviewed. Various databases were used to identify age-matched siblings as unexposed controls and data on the horses' athletic careers.

RESULTS

Seventy-four exposed and 194 matched unexposed horses were included. Although not significantly different, the proportion of exposed horses entering competition (28%, 95% CI 16%-38%) had a substantial risk difference compared with the proportion of unexposed horses entering competition (38%, 95% CI 26%-44%) (P = .2). Career longevity was significantly better for unexposed (15.6 competitions [95% CI 10.7-22.5] over a median of 570 days [IQR 210-1340]) than for exposed horses (9.7 competitions [95% CI 6.4-14.6] over a median of 219 days [IQR 2-1159] for horses operated in one limb and 6.1 competitions [95% CI 3.6-9.9] over a median of 446 days [IQR 23-603 days] for horses operated in two limbs, P < .001). Age at surgery and whether the condition was unilateral or bilateral did not affect chance of competing.

MAIN LIMITATIONS

Small sample size, varying quality of medical records, stage of contraction not noted in many records and missing information on reasons for not entering into competition.

CONCLUSIONS

Desmotomy of the AL-DDFT is associated with decreased long-term athletic performance in sport horses compared with matched unexposed horses.

Tandem Mass Tag (TMT) Proteomic Analysis of Saliva in Horses with Acute Abdominal Disease

Simple Summary

This study shows for the first time the variation of the salivary proteome in horses with acute abdominal disease (AAD) compared with healthy horses through a high-throughput proteomic approach. A total of 118 proteins were identified, and 17 showed significant changes between the two groups. The changes observed in proteins were closely related to an impaired primary immune defense and antimicrobial capacity in the mucosa, and one salivary protein (lactoferrin) was successfully verified. These results may increase the background and knowledge of saliva composition in horses with AAD and further understanding of the physiopathological changes occurring in the organism in this disease.

Abstract

The aim of this study was to investigate the changes in the salivary proteome in horses with acute abdominal disease (AAD) using a tandem mass tags (TMT)-based proteomic approach. The saliva samples from eight horses with AAD were compared with six healthy horses in the proteomic study. Additionally, saliva samples from eight horses with AAD and eight controls were used to validate lactoferrin (LF) in saliva. The TMT analysis quantified 118 proteins. Of these, 17 differed significantly between horses with AAD and the healthy controls, 11 being downregulated and 6 upregulated. Our results showed the downregulation of gamma-enteric smooth muscle actin (ACTA2), latherin isoform X1, and LF. These proteins could be closely related to an impaired primary immune defense and antimicrobial capacity in the mucosa. In addition, there was an upregulation of mucin 19 (MUC19) and the serine protease inhibitor Kazal-type 5 (SPINK5) associated with a protective effect during inflammation. The proteins identified in our study could have the potential to be novel biomarkers for diagnosis or monitoring the physiopathology of the disease, especially LF, which decreased in the saliva of horses with AAD and was successfully measured using a commercially available immunoassay.

Colonic Health in Hospitalized Horses Treated with Non-Steroidal Anti-Inflammatory Drugs - A Preliminary Study

Non-steroidal anti-inflammatory drugs (NSAIDs) can cause right dorsal colitis, but longitudinal clinical studies are lacking. This study investigates whether NSAID treated horses develop right dorsal colonic pathology in a clinical setting. Non-gastrointestinal hospitalized horses treated with NSAIDs >4 days, and untreated hospital-owned teaching horses and non-gastrointestinal client-owned hospitalized horses were included. All horses were monitored over time with clinical examinations (focusing on presence of colic, depression, reduced appetite, unstructured feces), ultrasonographic intestinal wall measurements, fecal occult blood tests (semi-quantitative results), and blood analysis (total protein and albumin concentrations, white blood cell and neutrophil counts). Outcomes were recorded as "ultrasonographically thickened right dorsal colon (RDC) walls", "colitis" and "right dorsal colitis". Findings over time were compared to baseline values and to control horses. Seventeen NSAID treated horses and 5 controls were included. NSAID treated horses developed thickened RDC walls (4/9), and subclinical and mild colitis (9/11) and right dorsal colitis (4/10), whereas all control horses remained healthy. The first changes were identified on treatment day 2. RDC walls of treated horses were significantly thicker compared to their own baseline values and compared to control horses. In conclusion, presumptive colon pathology was identified with a high incidence, starting early in the course of treatment, but with low severity. Appropriate monitoring should be advised throughout NSAID treatment. Additional research for noninvasive diagnostic tests for colon pathology is required.

Influence of clinical and experimental intra-articular inflammation on neutrophil gelatinase-associated lipocalin concentrations in horses

Objective

To investigate neutrophil gelatinase‐associated lipocalin (NGAL) concentrations in serum and synovial fluid (SF) from horses with joint inflammation.

Study design

Experimental studies and retrospective clinical study.

Sample population

Serum and SF samples were available from healthy horses (n = 19), clinical cases, and horses with experimental joint inflammation. Clinical cases included horses with (n = 10) or without (n = 10) septic arthritis. Experimental intra‐articular inflammation was induced by lipopolysaccharide (LPS; n = 7, severe inflammation), lidocaine (n = 6, moderate inflammation), or mepivacaine (n = 6, mild inflammation).

Methods

Availability of samples was based on approval from the local ethical committee and from the Danish Animal Experiments Inspectorate. Neutrophil gelatinase‐associated lipocalin was measured with a previously validated enzyme‐linked immunosorbent assay. Repeated‐measurements one‐ and two‐way analysis of variance and correlation analysis were used to analyze NGAL concentrations and white blood cell counts (WBC).

Results

After injection of LPS or lidocaine, SF NGAL concentrations increased 343‐ (P = .0035) and 60‐fold (P = .0038) relative to baseline, respectively. Serum NGAL also increased in both groups (P < .05) but to lower concentrations than in SF. Concentrations were higher after injection of lidocaine SF NGAL than after injection of mepivacaine (P < .05) at 6 and 12 hours. Synovial fluid concentrations of NGAL were higher in horses with septic arthritis than in the nonseptic group (P = .0070) and in healthy controls (P = .0071). Concentrations of NGAL correlated with WBC in SF (P < .0001, R² = 0.49) and in blood (P = .0051, R² = 0.27).

Conclusion

Neutrophil gelatinase‐associated lipocalin concentrations increased in SF in response to experimentally induced and naturally occurring joint inflammation. Synovial fluid NGAL concentration correlated with WBC and, thus, seems to reflect intensity of joint inflammation.

Clinical significance

Neutrophil gelatinase‐associated lipocalin may prove to be a useful biomarker of joint inflammation and infection in horses.

Establishing research priorities related to osteoarthritis care via stakeholder input from patients

INTRODUCTION

Stakeholder involvement in research is emphasised to improve relevance. We aimed to identify, define and prioritise important research topics seen from the point of view of people with osteoarthritis (OA).

METHODS

We invited 1,315 members of the user panel of the Danish Rheumatism Association to answer an electronic survey that included; 1) an open-ended question about important research topics (free-text response option), 2) 15 predefined research topics to be rated for importance and 3) predefined topics grouped into four categories in which the most important was prioritised. Free-text responses were analysed using content analysis.

RESULTS

Out of 850 (65%) respondents, 483 had OA (mean ± standard deviation age 60.3 ± 10.2 years, 91% female). From the free-text responses, we identified seven research topics; 1) diagnostics, 2) prevention, 3) side effects, 4) treatment, 5) aetiology, 6) being young with OA and 7) quality of life. For "treatment", we identified seven subtopics. Out of all topics and subtopics, "pain management" was the most frequently highlighted. All predefined topics were rated as "very important" or "somewhat important" by more than 75% of the respondents. The top prioritised topics within each category were 1) improving the diagnosis, 2) individualised treatment, 3) shared decision-making and 4) cross-sector collaboration and collaboration between professionals.

CONCLUSIONS

We identified research topics that were important in the eyes of people with OA and found that "pain management" was particularly emphasised.

FUNDING

none.

TRIAL REGISTRATION

not relevant.

Microvesicles in active lupus nephritis show Toll-like receptor 9-dependent co-expression of galectin-3 binding protein and double-stranded DNA

Circulating microvesicles (MVs) from patients with systemic lupus erythematosus (SLE) express the type 1 interferon (IFN)-inducible protein galectin-3 binding protein (G3BP), which may enhance their deposition in the glomerular basement membrane. The release of G3BP-expressing MVs from normal peripheral blood mononuclear cells (PBMCs) is induced by Toll-like receptor 9 (TLR-9) ligands, and these vesicles contain autoantibody-accessible double-stranded DNA (dsDNA). This study compares the release of MVs expressing G3BP and dsDNA from PBMCs derived from SLE patients with or without active lupus nephritis (LN) and from healthy donors, and taps further into the potential dependency on IFN-α for their generation and impacts of TLR-7/TLR-9 co-stimulation. PBMCs from 10 healthy donors and 12 SLE patients, six of whom had active LN at study inclusion, were stimulated in-vitro with recombinant human IFN-α and the TLR-9 agonists oligodeoxynucleotide (ODN)2216 or ODN2395 alone or in combination with the TLR-7 agonist gardiquimod. MVs in the supernatants were subsequently isolated by differential centrifugation and their expression of G3BP and dsDNA was quantified by flow cytometry. Stimulation with ODN2395 significantly increased the release of MVs co-expressing G3BP and dsDNA from PBMCs isolated from healthy donors and SLE patients. The expression of G3BP on individual MVs and the proportion of G3BP and dsDNA double-positive MVs released were increased in active LN patients. Neither co-stimulation with gardiquimod nor with the IFN-α inhibitor IN-1 had any effect on the MV release induced by ODN2395. In conclusion, the TLR-9-mediated inducibility of MVs co-expressing G3BP and dsDNA is increased in SLE patients with active LN.

Bidirectional knotless barbed versus conventional smooth suture for closure of surgical wounds in inguinal castration in horses

Background

Castration of the stallion is one of the most frequently performed surgical procedures in the horse. Recently barbed suture materials for surgical wound closure were introduced to the market with manufacturers claiming that these sutures enhance speed and security as they eliminate the need to tie knots. Recently, it has been suggested that this type of suture may increase postoperative complications. This study aimed at investigating and comparing a bidirectional absorbable knotless barbed suture (KBS) to a conventional smooth suture (SS) for wound closure of inguinal castrations in the horse. This was done by evaluating short-term and post-discharge complications and by comparing the time spent on suturing the surgical wounds after bilateral inguinal castration, which was performed on 45 horses undergoing castration at The Large Animal Teaching Hospital at University of Copenhagen from September 2017 to May 2019.

Results

Short-term complications were few; at 24 h minor swelling occurred in 29 and 33% of horses sutured with KBS and SS respectively and cutaneous dehiscence during recovery occurred in two horses of each group. Post-discharge follow-up revealed that three horses needed veterinary attention for treatment of complications (scrotal swelling (n = 1, KBS); wound exudation (n = 1, SS) and wound dehiscence after return to pasture (n = 1, SS)). Wound closure was achieved 6 min faster with KBS than with SS (P < 0.0001).

Conclusions

Use of the KBS suture did not result in increased occurrence of postoperative complications. Wound closure was faster with KBS than with SS in equine bilateral inguinal castration. Our results show that KBS can safely be used in the horse following bilateral inguinal castrations without adverse effects and with a reduction in suturing time.

Histologic changes and gene expression patterns in biopsy specimens from bacteria-inoculated and noninoculated excisional body and limb wounds in horses healing by second intention

OBJECTIVE

To evaluate histologic changes and gene expression patterns in body and limb wounds in horses in response to bacterial inoculation.

SAMPLE

Wound biopsy specimens from 6 horses collected on days 7, 14, 21, and 27 after excisional wounds (20 wounds/horse) were created over the metacarpal and metatarsal region and lateral thoracic region (body) and then inoculated or not inoculated on day 4 with Staphylococcus aureus and Pseudomonas aeruginosa.

PROCEDURES

Specimens were histologically scored for the amount of inflammation, edema, angiogenesis, fibrosis organization, and epithelialization. Quantitative PCR assays were performed to quantify gene expression of 10 inflammatory, proteolytic, fibrotic, and hypoxia-related markers involved in wound healing.

RESULTS

Except for gene expression of interleukin-6 on day 27 and tumor necrosis factor-α on day 14, bacterial inoculation had no significant effect on histologic scores and gene expression. Gene expression of interleukin-1β and -6, serum amyloid A, and matrix metalloproteinase-9 was higher in limb wounds versus body wounds by day 27. Gene expression of cellular communication network factor 1 was higher in limb wounds versus body wounds throughout the observation period.

CONCLUSIONS AND CLINICAL RELEVANCE

The lack of clear markers of wound infection in this study reflected well-known difficulties in detecting wound infections in horses. Changes consistent with protracted inflammation were evident in limb wounds, and gene expression patterns of limb wounds shared similarities with those of chronic wounds in humans. Cellular communication network factor warrants further investigation and may be useful in elucidating the mechanisms underlying poor limb wound healing in horses.

THU0271 PERFORMANCE OF THE EULAR/ACR 2019 CLASSIFICATION CRITERIA FOR SYSTEMIC LUPUS ERYTHEMATOSUS IN EARLY DISEASE, ACROSS SEXES AND ETHNICITIES

Background:

EULAR/ACR 2019 SLE Classification Criteria were validated in an international cohort.

Objectives:

To evaluate performance characteristics of SLE classification systems in sex, race/ethnicity, and disease duration subsets.

Methods:

Sensitivity and specificity of the EULAR/ACR 2019, SLICC 2012 and ACR 1982/1997 criteria were evaluated in the validation cohort.

Results:

The cohort consisted of female (n=1098), male (n=172), Asian (n=118), Black (n=68), Hispanic (n=124) and White (n=941) patients; and patients with an SLE duration of 1-3 years (n=196), 3-5 years (n=157), and ≥5 years (n=879). Among patients with 1-3 years disease duration, the EULAR/ACR criteria had better sensitivity than the ACR criteria (97% (95%CI 92-99%) vs 81% (95%CI 72-88%). The new criteria performed well in men (sensitivity 93%, specificity 96%) and women (sensitivity 97%, specificity 94%). The new criteria had better sensitivity than the ACR criteria in White (95% vs 83%), Hispanic (100% vs 86%) and Asian patients (97% vs 77%).

Conclusion:

The EULAR/ACR 2019 criteria perform well in patients with early disease, and across sexes and ethnicities.

Disclosure of Interests:

Sindhu Johnson Grant/research support from: Boehringer Ingelheim, Corbus Pharmaceuticals, GlaxoSmithKline, Roche, Merck, Bayer, Consultant of: Boehringer Ingelheim, Ikaria, Ralph Brinks: None declared, Karen Costenbader Grant/research support from: Merck, Consultant of: Astra-Zeneca, David Daikh: None declared, Marta Mosca: None declared, Rosalind Ramsey-Goldman: None declared, Josef S. Smolen Grant/research support from: AbbVie, Eli Lilly, Janssen, Merck Sharp & Dohme, Pfizer, Roche – grant/research support, Consultant of: AbbVie, Amgen Inc., AstraZeneca, Astro, Celgene Corporation, Celtrion, Eli Lilly, Glaxo, ILTOO, Janssen, Medimmune, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Samsung, Sanofi, UCB – consultant, Speakers bureau: AbbVie, Amgen Inc., AstraZeneca, Astro, Celgene Corporation, Celtrion, Eli Lilly, Glaxo, ILTOO, Janssen, Medimmune, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Samsung, Sanofi, UCB – speaker, David Wofsy: None declared, Dimitrios Boumpas Grant/research support from: Unrestricted grant support from various pharmaceutical companies, Diane L Kamen Consultant of: Consulted on SLE survey development for Lilly and consulted on SLE trial protocol development for EMD Serono in 2019, David Jayne Grant/research support from: ChemoCentryx, GSK, Roche/Genentech, Sanofi-Genzyme, Consultant of: Astra-Zeneca, ChemoCentryx, GSK, InflaRx, Takeda, Insmed, Chugai, Boehringer-Ingelheim, Ricard Cervera: None declared, Nathalie Costedoat-Chalumeau Grant/research support from: UCB to my institution, Betty Diamond: None declared, Dafna D Gladman Grant/research support from: AbbVie, Amgen Inc., BMS, Celgene Corporation, Janssen, Novartis, Pfizer, UCB – grant/research support, Consultant of: AbbVie, Amgen Inc., BMS, Celgene Corporation, Janssen, Novartis, Pfizer, UCB – consultant, Bevra H. Hahn Grant/research support from: Janssen Research & Development, LLC, Falk Hiepe: None declared, Soren Jacobsen: None declared, Dinesh Khanna Shareholder of: Eicos Sciences, Inc./Civi Biopharma, Inc., Grant/research support from: Dr Khanna was supported by NIH/NIAMS K24AR063120, Consultant of: Acceleron, Actelion, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Corbus Pharmaceuticals, Horizon Therapeutic, Galapagos, Roche/Genentech, GlaxoSmithKline, Mitsubishi Tanabe, Sanofi-Aventis/Genzyme, UCB, Kirsten Lerstrom: None declared, Elena Massarotti: None declared, William Joseph McCune: None declared, Guillermo Ruiz-Irastorza: None declared, Jorge Sanchez-Guerrero: None declared, Matthias Schneider: None declared, Murray B Urowitz: None declared, George Bertsias Grant/research support from: GSK, Consultant of: Novartis, Bimba F. Hoyer: None declared, Nicolai Leuchten: None declared, Chiara Tani: None declared, Sara Tedeschi: None declared, Zahi Touma: None declared, Gabriela Schmajuk Grant/research support from: Pfizer, Branimir Anic: None declared, Florence Assan: None declared, Tak Chan: None declared, Ann E Clarke: None declared, Mary K. Crow: None declared, László Czirják Consultant of: Actelion, BI, Roche-Genentech, Lilly, Medac, Novartis, Pfizer, Bayer AG, Andrea Doria Consultant of: GSK, Pfizer, Abbvie, Novartis, Ely Lilly, Speakers bureau: UCB pharma, GSK, Pfizer, Janssen, Abbvie, Novartis, Ely Lilly, BMS, Winfried Graninger: None declared, Bernadett Halda-Kiss: None declared, Sarfaraz Hasni: None declared, Peter Izmirly: None declared, Michelle Jung: None declared, Gabor Kumanovics Consultant of: Boehringer, Teva, Speakers bureau: Roche, Lilly, Novartis, Xavier Mariette: None declared, Ivan Padjen: None declared, Jose M Pego-Reigosa: None declared, Juanita Romero-Diaz Consultant of: Biogen, Iñigo Rua-Figueroa: None declared, Raphaèle Seror Consultant of: BMS, Medimmune, Novartis, Pfizer, GSK, Lilly, Georg Stummvoll: None declared, Yoshiya Tanaka Grant/research support from: Asahi-kasei, Astellas, Mitsubishi-Tanabe, Chugai, Takeda, Sanofi, Bristol-Myers, UCB, Daiichi-Sankyo, Eisai, Pfizer, and Ono, Consultant of: Abbvie, Astellas, Bristol-Myers Squibb, Eli Lilly, Pfizer, Speakers bureau: Daiichi-Sankyo, Astellas, Chugai, Eli Lilly, Pfizer, AbbVie, YL Biologics, Bristol-Myers, Takeda, Mitsubishi-Tanabe, Novartis, Eisai, Janssen, Sanofi, UCB, and Teijin, Maria Tektonidou Grant/research support from: AbbVie, MSD, Novartis and Pfizer, Consultant of: AbbVie, MSD, Novartis and Pfizer, Carlos Vasconcelos: None declared, Edward Vital Grant/research support from: AstraZeneca, Roche/Genentech, and Sandoz, Consultant of: AstraZeneca, GSK, Roche/Genentech, and Sandoz, Speakers bureau: Becton Dickinson and GSK, Daniel J Wallace: None declared, Sule Yavuz: None declared, Pier Luigi Meroni: None declared, Marvin Fritzler: None declared, Raymond Naden: None declared, Thomas Dörner Grant/research support from: Janssen, Novartis, Roche, UCB, Consultant of: Abbvie, Celgene, Eli Lilly, Roche, Janssen, EMD, Speakers bureau: Eli Lilly, Roche, Samsung, Janssen, Martin Aringer Consultant of: Boehringer Ingelheim, Roche, Speakers bureau: Boehringer Ingelheim, Roche

FRI0155 Α MULTICENTER “AT-RISK” COHORT FOR THE DISCOVERY OF ENVIRONMENTAL, CLINICAL AND MOLECULAR PREDICTORS FOR THE TRANSITION INTO SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)

Background:

SLE onset is preceded by a preclinical phase evidenced by the presence of anti-nuclear and other autoantibodies (autoAbs), which however, have low predictive value for development of clinical SLE.

Objectives:

To define the subgroup of autoAbs-positive individuals who are at high risk for progression into SLE by integrating environmental, clinical/serological, genetic and transcriptome data.

Methods:

A multicenter, across five European countries, inception cohort of autoAbs-positive individuals or first-degree relatives (FDRs) of SLE patients who are monitored prospectively over five years for possible transition to SLE according to the classification criteria. Structured data collection on demographics, family and medical history, clinical (criteria and selected non-criteria manifestations) and serological parameters, use of medications, hydroxyvitamin D levels and lifestyle (tobacco, alcohol use, physical activity, adherence to Mediterranean diet). Blood samples are stored for RNA-sequencing and genotyping.

Results:

A total 254 at-risk individuals (93% women, 99% Caucasians, aged [mean ± standard deviation] 36 ± 12 years) have been included and enrolment/monitoring is still ongoing. Forty individuals (16%) have FDR with SLE and 88 individuals (35%) have FDR with another autoimmune disorder. The frequency of active and past use of tobacco was 28% and 20%, respectively. Sedentary lifestyle (moving only for necessary chores or outdoor activity 1-2 times/week) was reported by 54% and adherence to the Mediterranean diet was low (3.4 ± 2.3, maximum score: 9). At enrolment, individuals had 1.9 ± 1.1 ACR-1997 classification criteria, with anti-nuclear antibodies (ANA) being the most frequent (88%), followed by synovitis (39%), photosensitivity (33%) and immunologic disorder (30%) (Table 1). During follow-up of 15.2 ± 7.2 months, a total 15 individuals (5.9%) have progressed into classified SLE, including cases with severe hematological and neurological disease.

Table 1.

Baseline characteristics of the at-risk for SLE cohort

N (%) or mean ± SDACR 1997 classification criteria1.9 ± 1.1 Malar rash68 (27%) Discoid rash29 (11%) Photosensitivity83 (33%) Mucosal ulcers49 (19%) Synovitis100 (39%) Serositis30 (12%) Renal disorder28 (11%) Neurologic disorder31 (12%) Hematologic disorder58 (23%) Immunologic disorder77 (30%) ANA222 (88%)SLICC 2012 classification criteria Clinical criteria1.0 ± 0.9 Immunological criteria1.3 ± 0.9

Conclusion:

Among individuals with positive autoAbs or FDRs with SLE, the short-term risk for transition into clinical SLE is low. Following the study completion, clinical and lifestyle data will be combined with blood transcriptome to define a high-risk subgroup of individuals for progression into SLE.

Acknowledgments:

The study is supported by the Foundation for Research in Rheumatology (FOREUM; preclin016)

Disclosure of Interests:

Christina Adamichou: None declared, Dionysis Nikolopoulos: None declared, Myrto Nikoloudaki: None declared, Zahra Rahme: None declared, Micaela Fredi: None declared, Antigoni Pieta: None declared, ARGYRO REPA: None declared, Alice Parma: None declared, Eleni Kalogiannaki: None declared, Nestor Avgustidis: None declared, Nikolaos Kougkas: None declared, Aggelos Banos: None declared, Anastasios Eskitzis: None declared, Alessandra Bortoluzzi: None declared, Søren Jacobsen: None declared, Prodromos Sidiropoulos: None declared, Emmanouil Dermitzakis: None declared, Marta Mosca: None declared, Luís Inês: None declared, Laura Andreoli: None declared, Angela Tincani: None declared, Antonis Fanouriakis Paid instructor for: Paid instructor for Enorasis, Amgen, Speakers bureau: Paid speaker for Roche, Genesis Pharma, Mylan, George Bertsias Grant/research support from: GSK, Consultant of: Novartis

OP0004 THE EXPRESSION OF INTERFERON-STIMULATED GENES IN PERIPHERAL BLOOD OF PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) ASSOCIATES WITH AFRICAN ANCESTRY

Background:

Type I Interferons (IFNs), and especially INF-alpha, play a crucial role in the pathogenesis of SLE. Interferon-stimulated genes (ISGs) are generally up-regulated in SLE patients. Their pattern of up-regulation is often termed as an IFN signature. Even though composite IFN-scores are already used to express the up-regulation of the IFN-system, e.g. in studies testing therapeutic anti-IFN-antibodies, we are still lacking an in-depth understanding of the IFN signature.

Objectives:

To summarize the available data on the expression of ISGs in peripheral blood of patients with SLE compared to healthy controls; to assess which ISGs are most up-regulated in SLE patients; and to analyse if up-regulations of 6 ISGs typically used in IFN-scores [1,2] are associated with SLE disease activity and ethnicity.

Methods:

The electronic databases PubMed and EMBASE were searched using the terms “interferon signature”, “SLE”, “interferon-stimulated genes”, “microarray” and “gene expression” with inception date until Jan. 28, 2020. Original case-control studies containing quantitative data of ISG expression were included. Exclusion criteria were studies with animal models, clinical trials of drug treatment and studies withexvivo stimulation of cells prior to gene-expression analysis. Fold changes (FCs) (ISG expression in SLE/ISG expression in healthy controls) for the ISGs analysed in each study were extracted. FCs were plotted gene-wise on a heatmap for studies analysing ≥ 7 genes and for genes that were analysed in ≥ 5 studies. Cluster analysis using principle component analysis (PCA) and association analyses using generalized linear modelling (GLM) were performed for 6 ISGs (IFI27, IFI44, IFI44L, RSAD2, PRKR and IFIT1) as well as disease activity and ethnicity (SPSS).

Results:

16 case-control studies comprising a total of 851 SLE patients were included in the analyses, see Tab. 1. 24 ISGs had an average FC of ≥ 4. IFI27, RSAD2, IFI44L, IFI44, HERC5 and IFIT5 had an average FC > 6. The heatmap showed great variation in the expression of ISGs within the individual studies but also gene-wise between the studies, see Fig. 1. The inter-study variation was statistically explored for the selected 6 ISGs. PCA showed that PRKR, RSAD2, IFIT1, IFI44 and IFI44L clustered with African ancestry, see Fig. 2. Subsequent GLM confirmed that RSAD2 and PRKR were positively associated with African ancestry. However, none of the 6 ISGs were positively correlated with disease activity.

Figure 1.

Heatmap of ISG up-regulation.

Figure 2.

Principal component analysis.

Conclusion:

The degree of up-regulation of ISGs in SLE patients shows considerable variation within and between the individual studies. However, a pattern of up-regulation clearly emerges. We find a clustering of 5 prominent genes of the IFN signature (PRKR, RSAD2, IFIT1, IFI44 and IFI44L) and a positive correlation of RSAD2 and PRKR with African ancestry, pointing to the need to take ethnicity into account when using the IFN signature. Our results do not support the use of the IFN signature as traditionally defined as a surrogate marker for disease activity.

References:

[1]Kirou, K.A. et. al. Arthritis Rheum. 52, 1491–1503 (2005)

[2]Morand E.F. et. Al. N Engl J Med. (2019)

Table 1.

Demographics on the studies in the heatmap. Characteristics refer to SLE patients. HC = healthy controls, SLEDAI = SLE Disease Activity Index, BILAG = British Isles Lupus Assessment Group.

PaperSLE (N)HC (N)Female (N)Age (Mean)SLEDAI (Mean)African (N)Caucasian (N)Asian (N)Panousis, N.I. 201914258120405.2138Alcorta, D.A., 200740284035BILAG: 6.72018Assassi, S., 20101721163926Zhu, H., 2016302542912Li, Q.Z.,20092711253912Chaussabel, D., 20082212201412.163Bouquet, J., 201711251151353Wither, J.E. 201817022149348.5408050Mackay, M., 2016112011341314Yao, Y., 20084124394041Lyons, P.A., 201013251347121Lambers, W.M., 201939223243<4351Baechler, E.C., 2003484245Han, G.M., 200310189296.110Ishii, T., 2005313030343.831Tang, J., 200814460132336.4144Ye, S., 20035039452950

Disclosure of Interests:

None declared

Validation of an equine serum amyloid A assay with an unusually broad working range

Background

Serum amyloid A (SAA) is a major equine acute phase protein and of great value in detection and monitoring of inflammation. A new immunoturbidometric assay based on monoclonal antibodies (VET-SAA, Eiken Chemical Co., Japan) may be useful for SAA measurements in routine diagnostic laboratories. The aim of the study was to validate the VET-SAA immunoturbidometric assay and use it to measure serum SAA concentrations in a variety of clinical cases. Precision was assessed by intra- and interassay coefficients of variation of repeated measurements of serum pools (low, intermediate, high concentrations of SAA). Accuracy was estimated by linearity under dilution. Detection limit was determined by replicate determinations of ionized water. Measurements were compared to measurements performed in a previously validated SAA assay (LZSAA assay, Eiken Chemical Co., Japan). Subsequently, the VET-SAA assay was used for measuring serum SAA concentrations in horses with and without inflammation.

Results

Detection limit was 1.2 mg/L. Without modifications, the assay measured SAA concentrations with acceptable reliability in a broad concentration range (0 to > 6000 mg/L). In the 0–3000 mg/L range, the assay demonstrated good precision and accuracy, and concentrations correlated well with those obtained in the LZSAA assay, albeit with a slight systematic bias. Concentrations of SAA assessed in horses with and without inflammation followed the expected pattern, with significantly higher concentrations in horses with systemic inflammation than in healthy horses and horses with non-inflammatory disease.

Conclusions

The assay was unique in its ability to measure SAA concentrations with acceptable reliability over an extreme concentration range. This is relevant in the equine species, where SAA concentrations may reach very high concentrations.

Lymphopenia and neutropenia are associated with subsequent incident proteinuria in Danish patients with systemic lupus erythematosus

Objective: The aim of this study was to investigate whether incident proteinuria in patients with systemic lupus erythematosus (SLE) was preceded by changes in blood lymphocytes and neutrophil counts and/or neutrophil-lymphocyte ratio (NLR).Method: SLE patients with no proteinuria before or at the time of classification were included. Longitudinal data on SLE manifestations, vital status, and SLE-associated medications were collected during clinical visits and chart review. Laboratory data were collected through a nationwide database. Lymphopenia, severe lymphopenia, and neutropenia were defined as values below 0.8 × 10⁹, 0.5 × 10⁹, and 2.0 × 10⁹ cells/L, respectively. High NLR was defined as values above the median. Proteinuria was defined by at least two measurements of elevated urine protein excretion (> 0.5 g/day). Hazard ratios (HRs) were calculated by Cox modelling using time-dependent continuous and binary covariates based on multiple laboratory measurements adjusted for use of immunosuppressants.Results: In total, 260 SLE patients were available for the analysis, of whom 30 (12%) developed incident proteinuria following the diagnosis of SLE. Median follow-up time was 73.5 months. Lymphocyte and neutrophil counts, but not NLR, were associated with incident proteinuria. HRs for incident proteinuria were 2.71 for lymphopenia [95% confidence interval (CI) 1.20-6.11], 4.73 for severe lymphopenia (95% CI 1.93-11.59), and 2.54 for neutropenia (95% CI 1.14-5.65).Conclusion: Lymphopenia and neutropenia predicted the risk of first-time proteinuria independently of immunosuppressants.

Lack of evidence of mastitis as a causal factor for postpartum dysgalactia syndrome in sows

To investigate the prevalence of mastitis in sows suffering from postpartum dysgalactia syndrome (PDS), we examined milk constituents and concentrations of lipopolysaccharides (LPS) obtained from the udder vein (v. epigastrica). As part of a case-cohort study, 109 sows were monitored daily from 60 h antepartum (a.p.) to 36 h postpartum (p.p.). Over time, 38 sows were diagnosed with PDS (PDS+) and were retrospectively matched with 38 healthy sows (PDS-). The study period was divided into 7 smaller time periods (A, B, C, D, E, F, G, H, and E), allowing the studied values, in period B to G, to be compared with period A that served as a baseline, and PDS+ and PDS- sows were compared within the time periods. All sows were subjected to a thorough daily clinical examination and blood was sampled from v. epigastrica for LPS detection. Milk samples were obtained for bacteriological evaluation and detection of N-acetyl-beta-d-glucosaminidase (NAGase), lactate dehydrogenase (LDH), β-glucuronidase (β-glu; for evaluation of mastitis), isocitrate (isoC), free glucose, uric acid (UA; for evaluation of the mammary energy status), β-hydroxybutyrate acid (BHBA; for evaluation of ketosis), and milk urea (for evaluation of the protein status). The results revealed that PDS+ sows had decreased concentrations of UA in milk (P < 0.0001), increased heart rates (P < 0.01), increased mammary edema (P < 0.05), and prolonged capillary refill time in the vulvar mucosa (P < 0.01) compared with PDS- sows. Compared with baseline, feces became more solid 0 to 36 h p.p. (P < 0.0001) and the respiration rate decreased 12 to 24 h p.p. (P < 0.0001) for both PDS+ and PDS- sows. No differences were found between PDS+ and PDS- sows for severe bacterial infections, concentrations of LPS in blood or LDH, NAGase, BHBA, free glucose, isoC, or urea in milk. Concentrations of LPS in blood were not associated with signs of mastitis or edema in the mammary glands. However, a difference over time was seen for redness (P < 0.0001), warmth (P < 0.0001), and hardness (P < 0.05) of the 6 most anterior glands in both PDS+ and PDS- sows from 60 h a.p to 36 h p.p. The PDS- sows had greater concentrations of β-glu than the PDS+ sows, but no change over time was demonstrated for this marker. In conclusion, signs of mastitis were not consistently linked to PDS in sows. However, the cardiovascular system seemed to be compromised in PDS+ sows and the cause should be investigated to elucidate the pathogenesis of PDS.

An Equine Wound Model to Study Effects of Bacterial Aggregates on Wound Healing

Objective: Relevant animal models to study effects of bacterial aggregates on wound healing are lacking. We aimed at establishing an equine wound model with bacterial aggregates to investigate the impact of bacterial inoculation on normal (thorax) and impaired (limb) wound healing. Approach: Wounds were created on three limbs and both thorax sides of six horses. Twelve out of 20 wounds per horse were inoculated with 10⁴ Staphylococcus aureus and 10⁵ Pseudomonas aeruginosa on day 4. Healing was monitored until day 27 by clinical assessment, including wound scoring, surface pH measurements, and digital photography for area determination. Biopsies were used for bacterial culture and for peptide nucleic acid fluorescence in situ hybridization to detect bacterial aggregates. Results: Inoculated limb wounds healed slower than noninoculated limb wounds from day 10 onward (p < 0.0001). Inoculated and noninoculated thorax wounds healed equally well and faster than limb wounds. The odds ratio of detecting bacterial aggregates in inoculated limb wounds was 7.1 (2.4-21.0, p = 0.0086) compared with noninoculated limb wounds and 36.2 (3.8-348, p = 0.0018) compared with thorax wounds. Innovation: This equine wound model with bacterial aggregates might be superior to other animal wound models, as both normal and impaired healing can be studied simultaneously. In this model, many aspects of wound healing, including novel treatments, may be studied. Conclusions: The impaired healing observed in inoculated limb wounds may be related to the persistent bacterial aggregates. Both in capability of clearing inoculated bacteria from the wounds and in healing pattern, thorax wounds were superior to limb wounds.