Beyond the Scalpel: Assessing ChatGPT's potential as an auxiliary intelligent virtual assistant in oral surgery

AI has revolutionized the way we interact with technology. Noteworthy advances in AI algorithms and large language models (LLM) have led to the development of natural generative language (NGL) systems such as ChatGPT. Although these LLM can simulate human conversations and generate content in real time, they face challenges related to the topicality and accuracy of the information they generate. This study aimed to assess whether ChatGPT-4 could provide accurate and reliable answers to general dentists in the field of oral surgery, and thus explore its potential as an intelligent virtual assistant in clinical decision making in oral surgery. Thirty questions related to oral surgery were posed to ChatGPT4, each question repeated 30 times. Subsequently, a total of 900 responses were obtained. Two surgeons graded the answers according to the guidelines of the Spanish Society of Oral Surgery, using a three-point Likert scale (correct, partially correct/incomplete, and incorrect). Disagreements were arbitrated by an experienced oral surgeon, who provided the final grade Accuracy was found to be 71.7%, and consistency of the experts' grading across iterations, ranged from moderate to almost perfect. ChatGPT-4, with its potential capabilities, will inevitably be integrated into dental disciplines, including oral surgery. In the future, it could be considered as an auxiliary intelligent virtual assistant, though it would never replace oral surgery experts. Proper training and verified information by experts will remain vital to the implementation of the technology. More comprehensive research is needed to ensure the safe and successful application of AI in oral surgery.

ChatGPT performance in prosthodontics: Assessment of accuracy and repeatability in answer generation

STATEMENT OF PROBLEM

The artificial intelligence (AI) software program ChatGPT is based on large language models (LLMs) and is widely accessible. However, in prosthodontics, little is known about its performance in generating answers.

PURPOSE

The purpose of this study was to determine the performance of ChatGPT in generating answers about removable dental prostheses (RDPs) and tooth-supported fixed dental prostheses (FDPs).

MATERIAL AND METHODS

Thirty short questions were designed about RDPs and tooth-supported FDP, and 30 answers were generated for each of the questions using ChatGPT-4 in October 2023. The 900 generated answers were independently graded by experts using a 3-point Likert scale. The relative frequency and absolute percentage of answers were described. Accuracy was assessed using the Wald binomial method, while repeatability was evaluated using percentage agreement, Brennan and Prediger coefficient, Conger generalized Cohen kappa, Fleiss kappa, Gwet AC, and Krippendorff alpha methods. Confidence intervals were set at 95%. Statistical analysis was performed using the STATA software program.

RESULTS

The performance of ChatGPT in generating answers related to RDP and tooth-supported FDP was limited. The answers showed a reliability of 25.6%, with a confidence range between 22.9% and 28.6%. The repeatability ranged from substantial to moderate.

CONCLUSIONS

The results show that currently ChatGPT has limited ability to generate answers related to RDPs and tooth-supported FDPs. Therefore, ChatGPT cannot replace a dentist, and, if professionals were to use it, they should be aware of its limitations.

Type I interferon pathway activation across the antiphospholipid syndrome spectrum: associations with disease subsets and systemic antiphospholipid syndrome presentation

Introduction

While the type I interferon (IFN-I) pathway is crucial in autoimmunity, its role in antiphospholipid antibody (aPL)-positive subjects, including aPL carriers and antiphospholipid syndrome (APS) patients, is poorly understood. This study aims at characterizing IFN-I pathway activation within the spectrum of aPL-positive subsets.

Methods

A total of 112 patients [29 aPL carriers, 31 primary APS (PAPS), 25 secondary APS (SAPS), 27 systemic lupus erythematosus (SLE) patients without aPL, and 44 healthy controls (HCs)] were recruited. IFI6, IFI44, IFI44L, MX1, IFI27, OAS1, and RSAD2 gene expression was evaluated in whole blood, and a composite index (IFN score) was calculated.

Results

An overall activation of the IFN-I pathway was observed across the entire APS spectrum, with differences among genes based on the specific disease subset. The composite score revealed quantitative differences across subsets, being elevated in aPL carriers and PAPS patients compared to HCs (both p < 0.050) and increasing in SAPS (p < 0.010) and SLE patients (p < 0.001). An unsupervised cluster analysis identified three clusters, and correspondence analyses revealed differences in clusters usage across APS subsets (p < 0.001). A network analysis revealed different patterns characterizing different subsets. The associations between IFN-I pathway activation and clinical outcomes differed across APS subsets. Although no differences in gene expression were observed in systemic APS, the network analyses revealed specific gene-gene patterns, and a distinct distribution of the clusters previously identified was noted (p = 0.002).

Conclusion

IFN-I pathway activation is a common hallmark among aPL-positive individuals. Qualitative and quantitative differences across the APS spectrum can be identified, leading to the identification of distinct IFN-I signatures with different clinical values beyond traditional categorization.

Comparative study of torsional and bending stress in NiTi, graphene, and GUM metal endodontic files by finite element analysis

INTRODUCTION

This study investigates the behavior of graphene and GUM in terms of cyclic fatigue resistance and torsion through a finite element analysis on a file with an eccentric rectangular cross section and variable taper, and on a file with a centered triangular cross section, constant taper, and constant pitch.

METHODS

Root canals and endodontic files were created using Catia V5R21 software. For torsional analysis, the tip of the file was fixed at 1 and 3 mm, and a moment of 2.5 N-mm was generated at the handle. For the bending analysis in curved canals (45° and 60°), the handle was kept fixed and a force of 1 N was applied at the tip while the file was kept fixed at 9 mm.

RESULTS

GUM metal instruments showed better torsional resistance. On the other hand, NiTi and graphene performed better under the applied loads during flexion at 45° and 60°.

CONCLUSION

GUM metal is emerging as a promising material in the field of endodontic instrument design due to its physical properties.

Unveiling the ChatGPT phenomenon: Evaluating the consistency and accuracy of endodontic question answers

AIM

Chatbot Generative Pre-trained Transformer (ChatGPT) is a generative artificial intelligence (AI) software based on large language models (LLMs), designed to simulate human conversations and generate novel content based on the training data it has been exposed to. The aim of this study was to evaluate the consistency and accuracy of ChatGPT-generated answers to clinical questions in endodontics, compared to answers provided by human experts.

METHODOLOGY

Ninety-one dichotomous (yes/no) questions were designed and categorized into three levels of difficulty. Twenty questions were randomly selected from each difficulty level. Sixty answers were generated by ChatGPT for each question. Two endodontic experts independently answered the 60 questions. Statistical analysis was performed using the SPSS program to calculate the consistency and accuracy of the answers generated by ChatGPT compared to the experts. Confidence intervals (95%) and standard deviations were used to estimate variability.

RESULTS

The answers generated by ChatGPT showed high consistency (85.44%). No significant differences in consistency were found based on question difficulty. In terms of answer accuracy, ChatGPT achieved an average accuracy of 57.33%. However, significant differences in accuracy were observed based on question difficulty, with lower accuracy for easier questions.

CONCLUSIONS

Currently, ChatGPT is not capable of replacing dentists in clinical decision-making. As ChatGPT's performance improves through deep learning, it is expected to become more useful and effective in the field of endodontics. However, careful attention and ongoing evaluation are needed to ensure its accuracy, reliability and safety in endodontics.

CH bond activation in aromatic ketones mediated by iridium-tris(pyrazolyl)borate complexes

Reaction of complex [TpMe2Ir(η4-CH2C(Me)C(Me)C2)] (1) with a series of aromatic ketones at 130 °C renders, by means of a selective ortho-CH activation, Ir(III)-metallacycles 2-5, which display an Ir-H bond. When [TpMe2Ir(C6H5)2N2] (6) is treated with 2-(trifluoromethyl)acetophenone and 2-fluoroacetophenone at 80 °C, the formation of dimeric (7) and trimeric architectures (8) is achieved through the meta- and para-CH activation of the aromatic ketone, respectively. The generation of complexes 2-5 is proposed to occur by the initial formation of Ir(III) η1-ketone adducts as key intermediates, followed by aromatic CH activations and the release of a butadiene ligand. The formation of complexes 7 and 8 involves an assisted process in which a metal center activation of the less sterically hindered C-H bond of the aromatic ketone takes place (releasing a benzene molecule), followed by the coordination of the carbonyl group, which generates the respective dimeric and trimeric structures. Complexes 7 and 8 are efficient catalysts for the transfer hydrogenation of ketones and aldehydes using isopropanol as the hydrogen source. All complexes have been fully characterized by NMR spectroscopy, FT-IR, elemental analysis and, in the cases of 7 and 8, X-ray crystallography. Details of the reaction conditions, isolation of the products, and proposals for the pathways of formation of complexes 2-5 and 7-8 are discussed.

Immunometabolic Profile Associated with Progressive Damage of the Intestinal Mucosa in Adults Screened for Colorectal Cancer: Association with Diet

Environmental factors such as diet and lifestyle have been shown to influence the development of some intestinal mucosal lesions that may be precursors of colorectal cancer (CRC). The presence of these alterations seems to be associated with misbalanced immunological parameter levels. However, it is still unclear as to which immunological parameters are altered in each phase of CRC development. In this work, we aimed to study the potential relationships of immunological and metabolic parameters with diet in a CRC-related lesion context. Dietary information was obtained using an annual semi-quantitative food-frequency questionnaire (FFQ) from 93 volunteers classified via colonoscopy examination according to the presence of intestinal polyps or adenocarcinoma. Cytokines, chemokines, and adipokines were determined from serum samples. We observed a reduction in adiponectin according to the damage to the mucosa, accompanied by an increase and decrease in C-X-C motif chemokine ligand 10 (CXCL10) and resistin, respectively, in CRC cases. The presence of aberrant crypt foci (ACF) in the polyp group was associated with higher tumor necrosis factor-alpha (TNF-α) concentrations. Vegetables were directly correlated with adiponectin and resistin levels, while the opposite occurred with red meat. A bioactive compound, soluble pectin, showed a negative association with TNF-α. Future dietary strategies could be developed to modulate specific immunological parameters in the context of CRC.

Fitting parameters and therapies of ODE tumor models with senescence and immune system

This work is devoted to introduce and study two quasispecies nonlinear ODE systems that model the behavior of tumor cell populations organized in different states. In the first model, replicative, senescent, extended lifespan, immortal and tumor cells are considered, while the second also includes immune cells. We fit the parameters regulating the transmission between states in order to approximate the outcomes of the models to a real progressive tumor invasion. After that, we study the identifiability of the fitted parameters, by using two sensitivity analysis methods. Then, we show that an adequate reduced fitting process (only accounting to the most identifiable parameters) gives similar results but saving computational cost. Three different therapies are introduced in the models to shrink (progressively in time) the tumor, while the replicative and senescent cells invade. Each therapy is identified to a dimensionless parameter. Then, we make a fitting process of the therapies' parameters, in various scenarios depending on the initial tumor according to the time when the therapies started. We conclude that, although the optimal combination of therapies depends on the size of initial tumor, the most efficient therapy is the reinforcement of the immune system. Finally, an identifiability analysis allows us to detect a limitation in the therapy outcomes. In fact, perturbing the optimal combination of therapies under an appropriate therapeutic vector produces virtually the same results.

Dental injury offenses and compensation imposed by Spanish courts, before and during Covid-19. A cross-sectional study

Injuries to the dentofacial region caused by third parties can affect physiological, sensory and esthetic functions with legal repercussions. The personal and social circumstances generated by Covid-19 and the governmental measures taken to control it, have increased the risk factors for violence and with it, the resulting injury rate. The aim of the present investigation was to compare the amount of civil liability for dental injury crimes agreed by Spanish courts, in certain Autonomous Communities, before and during the pandemic situation caused by Covid-19. For this purpose, a analytic cross-sectional study was carried out by analyzing sentences from the database of the Judicial Documentation Center. A comparison of means (one-way ANOVA) was used on the amount of compensation between the different years, and between the Autonomous Communities of Madrid, Catalonia Cataluña, Andalusia, the Canary Islands and the Valencian Community. It was observed that the year 2020 stood out for the increase in the number of cases of dental injury offenses. For its part, the Autonomous Community of Andalusia showed the highest amount of compensation during the pandemic, although the highest number of cases corresponded to the Community of Madrid. The statistical analysis yielded a probability of more than 0.05, which eliminated the possibility of significant differences in each of the comparisons.

Humoral responses against HDL are linked to lipoprotein traits, atherosclerosis, inflammation and pathogenic pathways during early arthritis stages

OBJECTIVE

Chronic inflammation and immune dysregulation are crucial mechanisms for atherosclerosis in RA. Recent evidence suggests a link via humoral responses against high-density lipoproteins (HDL). This study aimed to characterize the specificity, clinical relevance and emergence of humoral responses against HDL along disease course, especially during the earliest phases of arthritis.

METHODS

IgG and IgM serum levels of antibodies against HDL (anti-HDL) and apolipoprotein A1 (anti-ApoA1) were measured in 82 early RA patients, 14 arthralgia individuals and 96 controls. Established RA patients (n = 42) were included for validation. Atherosclerosis and vascular stiffness were measured by Doppler ultrasound. Lipoprotein content, particle numbers and size were measured by H-NMR. Cytokines were measured by immunoassays. A cardiometabolic-related protein panel was evaluated using high-throughput targeted proteomics.

RESULTS

Anti-HDL and anti-ApoA1 responses were increased in early RA compared with controls (both P < 0.001) and were comparable to established disease. Only anti-ApoA1 antibodies were increased in arthralgia. IgG anti-HDL and anti-ApoA1 were associated with unfavourable lipoprotein traits in RA and arthralgia, respectively. A similar picture was observed for inflammatory mediators. No associations with clinical features or risk factors were found. IgG anti-HDL were independently associated with atherosclerosis occurrence in early RA, and outperformed patient stratification over conventional algorithms (mSCORE) and their anti-ApoA1 counterparts. Anti-HDL antibodies correlated with proteins involved in immune activation, remodelling and lipid metabolism pathways in early RA.

CONCLUSION

Humoral responses against HDL particles are an early event along the arthritis course, although quantitative and qualitative differences can be noticed among stages. These differences informed distinct capacities as biomarkers and underlying pathogenic circuits.

Diagnostic Performance of Anti-dsDNA Tests by Indirect Immunofluorescence and Enzyme-linked Immunosorbent Assay in Patients with Systemic Lupus Erythematosus

BACKGROUND

Several laboratory techniques for anti double-stranded (ds) DNA detection in systemic lupus erythematosus (SLE) are available, with variable diagnostic performance. We aimed to evaluate anti-dsDNA's diagnostic performance by indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (EIA).

METHODS

We conducted a single-center retrospective (2015 to 2020) study. Patients with anti-dsDNA tests by IIF and EIA were included. We evaluated the indications, applications, concordance, positive predictive value (PPV) of anti-dsDNA to confirm SLE diagnosis or flares, and associations of disease manifestations with positivity with each technique.

RESULTS

A total of 1368 reports of anti-dsDNA tests by IIF and EIA and the corresponding medical records of the patients were analyzed. The main indication for anti-dsDNA testing was to help in the diagnosis of SLE in 890 (65%) of the samples, and the main application after obtaining the results was SLE exclusion in 782 (57.2%) cases. The combination with the highest frequency was the negativity result by both techniques in 801 (58.5%) cases (Cohen kappa 0.57). Both methods were positive in 300 patients with SLE (Cohen kappa 0.42). The PPVs of anti-dsDNA tests to confirm diagnosis/flare was 79.64% (95% CI, 75.35-83.35) by EIA, 78.75% (95% CI, 74.27-82.62) by IIF, and 82% (95% CI, 77.26-85.93) when both were positive.

CONCLUSIONS

Anti-dsDNA detection by IIF and EIA are complementary and may indicate different clinical patterns in patients with SLE. The detection of anti-dsDNA antibodies by both techniques has a higher PPV than either separately for confirming SLE diagnosis or flares. These results highlight the need for evaluating both methods in clinical practice.

Influence of the use of social media on patients changing dental practice: a web-based questionnaire study

BACKGROUND

Recent years have seen an increase in the use of social media, by the healthcare sector, including dentistry. Indeed, social media may now be important communication tools for dental practices and patients. This work analyzes the influence of patient (male and female) use of dental practice social media on their decision to change practice. The results also provide insight into the factors patients considered important when choosing a dental practice.

METHODS

This study was approved by the Ethics Committee of the Universidad Europea de Madrid (No. CIPI/22.022). Using a web-based questionnaire, a cross-sectional study was undertaken involving a Spanish population that made use of dental services. The questionnaire consisted of four parts covering provision of informed consent, the collection of sociodemographic data, patient use of dental practice social media, and the factors considered important when changing dental practice.

RESULTS

All participants gave their informed consent regarding inclusion. No compensation was provided for participation. 588 people responded to the questionnaire, of whom 503 were eligible for inclusion. Most respondents were female (312/503; 62%). Most (151/503; 30%) last changed dental practice during the previous 2-5 years. 208/503 (41.4%) indicated that they had visited dental practice social media. 118/503 (23.5%) indicated that they had made use of such the last time they changed dental practice; 102 of these 118 (85.6%) reported their experience to have influenced their decision to change. Respondents who had changed practice in the last 5 years had interacted with dental practice social media more than those who changed over 11 years ago (p < .05), and those who changed practice in the present/past year were more influenced by these media (p < .05). The factor considered most important was 'Facilities and technology'. No gender-based differences were seen for any measured variable (p < .05).

CONCLUSIONS

Different factors affect the selection of a new dental practice, but respondents who changed practice in the last few years were more likely to have made use of dental practice social media, which, for some, influenced their final decision to change. Dental practices might do well to consider using social media as communication and marketing tools.

In-stent restenosis is associated with proliferative skin healing and specific immune and endothelial cell profiles: results from the RACHEL trial

Introduction

In-stent restenosis (ISR) is a major challenge in interventional cardiology. Both ISR and excessive skin healing are aberrant hyperplasic responses, which may be functionally related. However, the cellular component underlying ISR remains unclear, especially regarding vascular homeostasis. Recent evidence suggest that novel immune cell populations may be involved in vascular repair and damage, but their role in ISR has not been explored. The aims of this study is to analyze (i) the association between ISR and skin healing outcomes, and (ii) the alterations in vascular homeostasis mediators in ISR in univariate and integrative analyses.

Methods

30 patients with ≥1 previous stent implantation with restenosis and 30 patients with ≥1 stent without restenosis both confirmed in a second angiogram were recruited. Cellular mediators were quantified in peripheral blood by flow cytometry. Skin healing outcomes were analyzed after two consecutive biopsies.

Results

Hypertrophic skin healing was more frequent in ISR patients (36.7%) compared to those ISR-free (16.7%). Patients with ISR were more likely to develop hypertrophic skin healing patterns (OR 4.334 [95% CI 1.044-18.073], p=0.033), even after correcting for confounders. ISR was associated with decreased circulating angiogenic T-cells (p=0.005) and endothelial progenitor cells (p<0.001), whereas CD4+CD28null and detached endothelial cells counts were higher (p<0.0001 and p=0.006, respectively) compared to their ISR-free counterparts. No differences in the frequency of monocyte subsets were found, although Angiotensin-Converting Enzyme expression was increased (non-classical: p<0.001; and intermediate: p<0.0001) in ISR. Despite no differences were noted in Low-Density Granulocytes, a relative increase in the CD16- compartment was observed in ISR (p=0.004). An unsupervised cluster analysis revealed the presence of three profiles with different clinical severity, unrelated to stent types or traditional risk factors.

Conclusion

ISR is linked to excessive skin healing and profound alterations in cellular populations related to vascular repair and endothelial damage. Distinct cellular profiles can be distinguished within ISR, suggesting that different alterations may uncover different ISR clinical phenotypes.

Assessment of the Use of Common Juniper (Juniperus communis L.) Foliage following the Cascade Principle

Juniperus communis L. is a species commonly grown in regions of the Northern Hemisphere, and is a good candidate to be cultivated in marginal lands. Plants coming from a pruning performed in a natural population located in Spain were used to assess the yield and quality of different products obtained following the cascade principle. A total of 1050 kg of foliage biomass were crushed, steam-distilled, and separated into fractions to produce biochar and absorbents for the pet industry using pilot plants. The obtained products were analysed. The essential oil, with a yield of 0.45% dry basis and a qualitative chemical composition similar to that described for the berries in international standards or monographs, showed antioxidant activity with promising CAA results (inhibition of 89% of the cell's oxidation). However, regarding antibacterial and antifungal activities, it only inhibited the growth of microorganisms at the maximum concentration tested, 2.5%. Concerning the hydrolate, it did not show bioactivity. Regarding the biochar, whose yield was 28.79% dry basis, interesting results were obtained for its characterisation as a possible soil improver for agronomic purposes (PFC 3(A)). Finally, promising results were obtained regarding the use of common juniper as absorbent, taking into account the physical characterisation and odour control capacity.

Sociodemographic and psycho social Differences Between Hate Crime Offenders and Other Non-Bias-Motivated Criminals: Implications for Prison Rehabilitation Programs

Hate crimes have severe consequences for the victims and for all members of the victim's social category. Prison programs must address the criminogenic needs of the participants, especially in this kind of crime, in order to prevent recidivism. This study seeks to understand the role of prejudice and aggression in the execution of hate crimes, in order to design effective interventions for hate crime offenders. Sociodemographic, criminological, and psychosocial variables were assessed in a sample of 33 hate crime offenders sentenced to prison or community service and in a group of 38 non-bias-motivated criminals (n = 71). The individuals convicted of hate crimes have higher reactive and proactive aggression, subtle prejudice, homophobia, and social dominance orientation. The implications of these results for the Penitentiary Administration programs will be discussed.

P-119 A MODIFIED CHEVREL AS AN ALTERNATIVE WALL CLOSURE TECHNIQUE FOR PATIENTS WITH ABDOMINAL HYPERTENSION

 

Abdominal compartment syndrome is a pontentially life-threatening condition seen in critically ill patients, and most often caused by acute pancreatitis, postoperative abdominal vacular thrombosis or mesenteric ischemia. A descompressive laparotomy is sometimes required, often resulting in hernias, and subsequent definitive wall closure is challenging.

Aim

This study aims to describe short term results after a modified Chevrel technique for midline incisional repair in patients witch abdominal hypertension.

Materials & Methods

We performed a modified Chevrel as an abdominal closure technique in 9 patients between January 2016 and January 2022. All patients presented varying degrees of abdominal hypertension.

Results

Nine patients were treated with new technique (6 male and 3 female), all of whom had conditions that precluded unfolding the contralateral side as a means for closure. The reasons for this were diverse, including presence of ileostomies, intra-abdominal drainages, Kher tubes or an inverted T scar from previous transplant. The use of mesh was initially dismissed in 6 of the patients (66.7%) because they required subsequent abdominal surgeries. None of the patients developed a hernia, although two died 6 months after the procedure. Only one patient developed buldging. A decrease in intrabdominal pressure was achieved in all patients.

Conclusion

The modified Chevrel technique can be used as a closure option for midline ventral hernias in cases where the entire abdominal wall cannot be used.

Using a Virtual Patient via an Artificial Intelligence Chatbot to Develop Dental Students’ Diagnostic Skills

Knowing how to diagnose effectively and efficiently is a fundamental skill that a good dental professional should acquire. If students perform a greater number of clinical cases, they will improve their performance with patients. In this sense, virtual patients with artificial intelligence offer a controlled, stimulating, and safe environment for students. To assess student satisfaction after interaction with an artificially intelligent chatbot that recreates a virtual patient, a descriptive cross-sectional study was carried out in which a virtual patient was created with artificial intelligence in the form of a chatbot and presented to fourth and fifth year dental students. After several weeks interacting with the AI, they were given a survey to find out their assessment. A total of 193 students participated. A large majority of the students were satisfied with the interaction (mean 4.36), the fifth year students rated the interaction better and showed higher satisfaction values. The students who reached a correct diagnosis rated this technology more positively. Our research suggests that the incorporation of this technology in dental curricula would be positively valued by students and would also ensure their training and adaptation to new technological developments.

POS0600 ANGIOGENIC T-CELL DEPLETION OCCURS DURING THE EARLIEST PHASES OF RHEUMATOID ARTHRITIS LINKED TO SUBCLINICAL VASCULAR STIFFNESS

Background

vascular insult accounts for the cardiovascular (CV) risk excess in rheumatoid arthritis (RA). Angiogenic T cells (Tang), which are responsible of vascular repair, have been described to be reduced in established RA with overt CV disease. However, whether Tang are altered during the earliest stage of the disease and related to subclinical CV findings is unknown.

Objectives

to evaluate circulating Tang levels in the very early stage of RA, including clinically suspect arthralgia (CSA), and their associations with subclinical CV endpoints (subclinical atherosclerosis and vascular stiffness).

Methods

84 RA patients (2010 EULAR/ACR classification criteria), 14 CSA individuals (EULAR criteria) and 28 matched healthy controls (HC) were recruited. All patients were untreated at the time of sampling. Tang (CD3+CD31+CXCR4+) frequency was assessed by flow cytometry in peripheral blood samples. Plaque occurrence, cIMT and stiffness parameters were analyzed by Doppler ultrasound in internal carotid, middle cerebral and basilar arteries. Lipoprotein analyses were performed by NMR.

Results

Tang were decreased in RA and CSA groups compared to HC (both p<0.010). Whereas Tang frequency was negatively correlated with very low density lipoproteins features (cholesterol and triglyceride content, size distribution and particle number) in HC and positively with HDL (cholesterol content and particle number), these associations were lacking in RA and CSA groups. Tang levels were not related to individual traditional CV risk factors, body mass index, wait circumference (all p>0.050) nor with the modified SCORE (r=-0.070, p=0.542) or Framingham Risk Score (r=-0.013, p=0.907). On the contrary, disease activity accounted for the Tang depletion observed in RA (b[95% CI]; DAS28: -0.436 [-0.306, -0.109], p=<0.001; SDAI: -0.020 [-0.032, -0.008], p=0.002). Tang levels were unrelated to the duration of the symptoms both in RA and CSA.

In RA patients, Tang frequency was not associated with atherosclerosis plaque occurrence (p=0.556) or cIMT (r=0.136, p=0.245). However, Tang paralleled stiffness parameters: vascular strain (VS, r=0.373, p=0.013), vascular distensibility (VD, r=0.479, p=0.004), vascular stiffness (VSf, r=-0.400, p=0.007) and pressure-strain elastic modulus (PSEM, r=-0.373, p=0.013). Finally, Tang frequency was an independent predictor of stiffness parameters after adjusting for mSCORE, body mass index, DAS28, RF and ACPA positivity: VS (β=0.415, p=0.035), VD (β =0.361, p=0.028), VSf (β =-0.322, p=0.033) and PSEM (β =-0.346, p=0.016).

Conclusion

Tang depletion is an early event along RA development, associated with disease-related parameters and unrelated to traditional risk factors. Tang may be the missing, functional link between disease activity and CV outcomes. Altered Tang levels may be an early biomarker of premature vascular stiffness during the first stages of the disease.

REFERENCES

Disclosure of Interests

None declared

POS0092 HETEROGENEITY OF THE TYPE I INTERFERON SIGNATURE AMONG ANTIPHOSPHOLIPID SYNDROME PATIENTS: A CLUSTER AND CORRESPONDENCE ANALYSIS APPROACH

Background

Type I Interferons (IFN) are central players in the pathogenesis, disease activity and evolution of several autoimmune conditions. To date, a limited number of evidences is available on the specific role of IFN activation in antiphospholipid antibodies (aPL) positive patients, including aPL carriers, primary antiphospholipid syndrome (PAPS) and those APS subjects who presented with an associated autoimmune disease (secondary APS, SAPS), such as systemic lupus erythematosus (SLE).

Objectives

The aim of this study was to evaluate the differential expression of IFN stimulated genes (ISG) among different subsets of aPL positive subjects and SLE patients.

Methods

For the purpose of the study, a total of 112 patients attending the San Giovanni Bosco Hospital (Turin, Italy) were enrolled, including 31 PAPS, 25 SAPS, 27 SLE patients without aPL, 29 aPL carriers (mean age 48.3±13.3 years, 76% female)1,2. Nineteen subjects were also recruited as healthy controls (HCs). Complete demographic, clinical, and laboratory data were collected at the time of the inclusion. Gene expression was evaluated by RT-PCR in whole blood for the following genes: IFI6, IFI44, IFI44L, MX1,IFI27, OAS1 and RSAD2. Normalized gene expression levels (Z-scores) were averaged into a global IFN signature (IFN score). Differences were measured by Kruskal-Wallis tests and associations among genes were studied by cluster and correspondence analyses. Correlations among genes were plotted by network analyses.

Results

An overall activation of ISG was noted across APS subsets, but certain differences were noted among genes. Whereas some ISG were already upregulated in the aPL positive group compared to HC (IFI44, IFI44L, MX1, IFI27, OAS1 and RSAD2, all p<0.050), other ISG were only in increased SLE (IFI6), MX1 differed between SLE and SAPS, and IFI27 and OAS1 showed differences between PAPS and SAPS. The composite IFN score revealed quantitative differences in the IFN pathway activation across APS subsets, being elevated in aPL carriers/PAPS groups compared to HCs (both p<0.050) and increasing in SAPS (p<0.010) and SLE (p<0.001) groups. Network analyses (Figure 1A) revealed qualitative differences in the gene-gene correlation networks: (i) weaker structures were found in HCs and aPL carriers, compared to stronger and higher-degree networks in SAPS and SLE groups; and (ii) the influence of each node was different across groups. Unsupervised cluster analysis identified 3 clusters (I to III) based on ISG patterns (Figure 1B). Clusters usage differed among APS subsets, thus correlating clinical status (Figure 1C). Distinct groups of ISG positively correlate to aPS/PT IgG titre in aPL carriers and PAPS groups (all rho>0.500), whereas no associations were retrieved in SAPS or SLE. No associations with previous thrombotic events were observed in any subset, although IFN composite score and several ISG correlate with the number of thrombotic recurrences under anticoagulation (all rho>0.400). No associations with GAPSS were observed.

Figure 1.

Conclusion

An overall IFN pathway activation has been observed in aPL positive patients and across all APS subsets. Qualitative and quantitative differences across the APS spectrum can be identified, leading to the identification of distinct IFN signatures with different clinical value.

References

[1]Miyakis S, et al. J Thromb Haemost (2006). 2. Aringer M, et al. Arthritis Rheumatol (2019).

Disclosure of Interests

None declared

Possible Association of Periodontal Diseases With Helicobacter pylori Gastric Infection: A Systematic Review and Meta-Analysis

Some research has suggested that dental plaque and saliva could be reservoirs of Helicobacter pylori (H. pylori) and be capable of infecting or re-infecting the gastric mucosa after eradication, with certain studies showing a significant association between PD and gastric infection by this bacterium. An electronic search was performed in PubMed, EMBASE, and Web of Science databases with the terms “Helicobacter pylori AND periodontal diseases”; “Helicobacter pylori AND gingivitis”; “Helicobacter pylori AND chronic periodontitis”; “Helicobacter pylori AND periodontitis”; “Helicobacter pylori AND dental plaque”, to identify articles up to September 2021. The Newcastle-Ottawa scale was used to assess study quality. A meta-analysis was performed using RevMan 2020 (Cochane Collaboration) software. A total of 1,315 studies were identified and 12 were included, analyzing 226,086 patients with mean age between 10.5 and 63.4 years. The prevalence of H. pylori in the oral cavity ranged from 5.4 to 83.3%. A random-effects model was used to analyze the presence of H. pylori and subgroups were made according to the method of evaluation (PCR or RUT). Statistical significance was found in the overall analysis (p = 0.01). There is no clear evidence that H. pylori present in oral bacterial plaque causes gastric infection and vice versa.

Role of Probiotics in Halitosis of Oral Origin: A Systematic Review and Meta-Analysis of Randomized Clinical Studies

Halitosis or oral malodor is a condition caused by the putrefaction of sulfur-containing amino acids. It affects 30–50% of the population and causes social rejection, reducing quality of life, and self-esteem. Probiotics, especially Lactobacillus species, have been proposed for the treatment of genuine halitosis, due to their ability to reduce bacterial colonization. Our objective was to evaluate their use for the treatment of oral halitosis. Applying the PRISMA statement guidelines, we searched PubMed, EMBASE, and Web of Science databases for scientific articles from the last 15 years, up to July 2021. The keywords used were “Probiotics”; “Halitosis”; “Mouth diseases”; “Oral health”; “Humans”; “Randomized Clinical Trials” according to the question, “Are probiotics effective for the reduction or elimination of oral halitosis?” Fourteen studies were identified, although only four met the inclusion criteria. We evaluated 283 participants treated with two different probiotics, with a follow-up of at least 2 weeks. Risk of bias was assessed using the Cochrane Collaboration tool. A fixed-effects meta-analysis was performed. No statistical significance was found (p = 0.53). Despite the limitations of this meta-analysis, we believe that some probiotics have a beneficial effect on halitosis, although more clinical trials are needed to establish real evidence on this aspect.

Systematic Review Registration:https://doi.org/10.37766/inplasy2021.9.0009, identifier: INPLASY20211900.

Malondialdehyde-modified HDL particles elicit a specific IgG response in abdominal aortic aneurysm

High Density Lipoprotein (HDL) plays a protective role in abdominal aortic aneurysm (AAA); however, recent findings suggest that oxidative modifications could lead to dysfunctional HDL in AAA. This study aimed at testing the effect of oxidized HDL on aortic lesions and humoral immune responses in a mouse model of AAA induced by elastase, and evaluating whether antibodies against modified HDL can be found in AAA patients. HDL particles were oxidized with malondialdehyde (HDL-MDA) and the changes were studied by biochemical and proteomics approaches. Experimental AAA was induced in mice by elastase perfusion and then mice were treated with HDL-MDA, HDL or vehicle for 14 days. Aortic lesions were studied by histomorphometric analysis. Levels of anti-HDL-MDA IgG antibodies were measured by an in-house immunoassay in the mouse model, in human tissue-supernatants and in plasma samples from the VIVA cohort. HDL oxidation with MDA was confirmed by enhanced susceptibility to diene formation. Proteomics demonstrated the presence of MDA adducts on Lysine residues of HDL proteins, mainly ApoA-I. MDA-modification of HDL abrogated the protective effect of HDL on cultured endothelial cells as well as on AAA dilation in mice. Exposure to HDL-MDA elicited an anti-HDL-MDA IgG response in mice. Anti-HDL-MDA were also detected in tissue-conditioned media from AAA patients, mainly in intraluminal thrombus. Higher plasma levels of anti-HDL-MDA IgG antibodies were found in AAA patients compared to controls. Anti-HDL-MDA levels were associated with smoking and were independent predictors of overall mortality in AAA patients. Overall, MDA-oxidized HDL trigger a specific humoral immune response in mice. Besides, antibodies against HDL-MDA can be detected in tissue and plasma of AAA patients, suggesting its potential use as surrogate stable biomarkers of oxidative stress in AAA.

Oral Manifestations of COVID-19: Updated Systematic Review With Meta-Analysis

There is increasing evidence for oral lesions and manifestations of COVID-19. The aim of this meta-analysis was to investigate the types of oral manifestations of COVID-19 and their prevalence. PubMed/Medline, Scopus, Web of Science, and Google Scholar databases were used to search for publications on oral manifestations in patients with PCR-confirmed COVID-19. A total of 310 records were selected, and 74 were included. Oral lesions in COVID-19 were classified according to their etiologies, including iatrogenic lesions caused by intubation and opportunistic infections. Of the included studies, 35 reported oral lesions probably caused by severe acute respiratory syndrome-Coronavirus-2 (SARS-CoV-2) infection. Meta-analysis of prevalence data on oral manifestations and aphthous lesions indicated high heterogeneity, while meta-analysis of xerostomia prevalence data revealed a pooled prevalence, with considerable heterogeneity. In conclusion, the meta-analysis yielded high heterogeneity between studies: oral lesions yielded a prevalence of 0.33 (95% CI 0.11-0.60), xerostomia lesions a prevalence of 0.44 (95% CI 0.36-0.52) and aphthous lesions 0.10 (95% CI 0.01-0.24). In addition, a gap in the evidence regarding the prevalence of oral lesions in COVID-19 was identified and the need for further observational studies focusing on this issue and on the causal relationships between oral lesions and COVID-19 was highlighted.

Knowledge, Attitudes, and Practices among Dental Practitioners Regarding Antibiotic Prescriptions for Pregnant and Breastfeeding Women in the Dominican Republic

In this study, we aimed to explore the trends among dentists in the Dominican Republic of providing antibiotic prescriptions to pregnant/breastfeeding dental patients. A survey was conducted among 98 dentists, using a self-administered questionnaire, about their knowledge and attitudes regarding antibiotic usage in pregnant/lactating women and the translation of these into practice. The majority of the survey population were female dentists (63.3%) aged 45–54 years. A chi-square test showed statistically significant differences in the knowledge sources between older and younger dentists, with a minority having chosen scientific literature as a source (p-value of 0.04). There were statistically significant associations between gender and certain attitudes and practice-based questions, with p-values of 0.04 and 0.01, respectively. The Spearman’s correlation test showed a statistically significant correlation between knowledge and attitude (p-value 0.001), whereas no correlation was found with practice (p-value 0.23). A multiple response analysis showed that the majority of the respondents chose the second and third trimester for antibiotic prescriptions for acute conditions such as cellulitis, periodontal abscess, and pericoronitis. Most dentists had sufficient knowledge about antibiotic usage in pregnant/lactating women, but it did not translate into practice, and a certain proportion of the participants followed incongruent drug prescription. These findings can be used to focus on judicious antibiotic usage by dentists in the Dominican Republic.

Novel Immune Cell Subsets Exhibit Different Associations With Vascular Outcomes in Chronic Kidney Disease Patients-Identifying Potential Biomarkers

Background and Aims: Alterations in novel immune cell subsets, such as angiogenic T cells (Tang), senescent T cells (CD4⁺CD28^null), and monocyte subsets are associated with impaired vascular homeostasis in several inflammatory conditions. However, mediators underlying vascular deterioration in chronic kidney disease (CKD) are poorly characterized. This study assessed their role in the vascular deterioration of CKD using a broad spectrum of surrogate markers ranging from altered functionality to overt calcification.

Methods: Tang (CD3⁺CD31⁺CXCR4⁺), CD4⁺CD28^null cells, and monocytes [CD14/CD16 subsets and angiotensin-converting enzyme (ACE) expression] were measured in peripheral blood by flow cytometry in 33 CKD stage 5 patients undergoing peritoneal dialysis (CKD5-PD) and 15 healthy controls (HCs). Analyses were replicated in a hemodialysis cohort. Vascular surrogate markers (including adventitial vasa vasorum, pulse wave velocity, intima-media thickness, and vascular calcification) were assessed by appropriate imaging methods.

Results: In CKD5-PD, decreased Tang levels (p < 0.001) were unrelated to clinical features or traditional cardiovascular (CV) risk factors but correlated negatively with troponin T levels (r = −0.550, p = 0.003). Instead, CD4⁺CD28^null frequency was increased (p < 0.001), especially in those with vascular calcifications. Quantitative and qualitative differences were also observed within the monocyte pool, a shift toward CD16⁺ subsets and ACE expression being found in CKD. Equivalent results were observed in the replication cohort. Each subset associated distinctly with adverse vascular outcomes in univariate and multivariate analyses: while Tang depletion was linked to poor vascular function and subclinical atherosclerosis, increases in CD4⁺CD28^null were associated with overt vascular thickening and calcification. Monocytes were not independently associated with vascular outcomes in CKD patients.

Conclusions: Novel T cell and monocyte subsets are altered in CKD. Altered T-cell subpopulations, but not monocytes, exhibited distinct associations with different vascular outcomes in CKD. Tang are emerging biomarkers of subclinical vascular deterioration in CKD.

Histomorphometric Comparison between Two Types of Acellular Dermal Matrix Grafts: A Mini Pig Animal Model Study

Acellular dermal matrix grafts (ADMG) have been used as soft tissue graft substitutes for autografts in periodontal plastic surgical procedures. They have benefits like avoiding a second surgical site and patient morbidity that have been associated with autografts, but there is limited evidence available on their tissue response and wound healing process. This histomorphometric animal model study was carried out in mini pigs and it aimed to compare the two types of ADMG materials of porcine derivative with a control group through observation of parameters like epithelial and Keratinized layer thickness, angiogenesis, cellularity, matrix resorption, and inflammatory infiltrate. The surgical technique involved punctures on the edentulous areas stripping the epithelial tissue and exposing the underlying connective tissue, placement of the ADMGs in the appropriate control and test sites. Following this, gingival biopsies were procured at three different time intervals of 15, 45, and 90 days. There were significant differences in epithelial and Keratinized layer thickness among the three groups. This study concluded that there was no clear consensus on which graft material was superior but it gave an insight into the tissue response and wound healing process associated with the graft materials.

Clinical and Histological Differences between Guided Tissue Regeneration with Acellular Dermal Matrix of Porcine Origin and Autologous Connective Tissue: An Animal Study

This research aims to evaluate the clinical and histological parametric differences concerning keratinized tissue that result from two regeneration techniques, the subepithelial autologous connective tissue graft (ACTG) and the acellular dermal matrix (MD) of porcine origin, performed on surgical beds on edentulous spaces in an animal model. The parameters of the MD and ACTG groups were compared with samples of the control group (CG) after 15, 45, and 90 days. Nine female white pigs (Sus scrofa domestica) were used, and each animal provided 20 study areas (12 MD and 8 ACTG). At 15 days, the keratin layer thickness in the MD group was greater than those of the ACTG (25.27 vs. 19.95 μm) and the CG (21.2 μm). After 45 days, the MD and ACTG thickness values decreased but were higher than the CG. At 90 days, MD (19.46 μm) obtained a value close to that of CG, and the ACTG decreased to CG (15.53 μm, p < 0.001). The use of an MD may be a viable alternative to the ACTG because of its ability to provide increased keratinized tissue in comparison to the ACTG.

Relationship Between T-Cell Exosomes and Cellular Subsets in SLE According to Type I IFN-Signaling

Objective: To quantify the levels of circulating exosomes derived from T-cells and monocytes and their possible associations with leukocyte subpopulations and cytokine milieu in Systemic Lupus Erythematosus (SLE).

Methods: Total circulating exosomes (CD9⁺-Ex) and those derived from T-cells (CD3⁺-Ex) and monocytes (CD14⁺-Ex) were quantified by flow cytometry in 82 SLE patients and 32 controls. Leukocyte subsets and serum cytokines were analyzed by flow cytometry or by immunoassays. IFN-score was evaluated by real time RT-PCR in whole blood samples from a subgroup of 73 patients and 24 controls.

Results: Activation markers (IFNR1 and BLyS) on monocytes, neutrophils and B-cells correlated inversely with circulating exosomes (CD9⁺-Ex, CD3⁺-Ex, and CD14⁺-Ex) in controls but directly with CD3⁺-Ex in patients (all p < 0.05). Although CD9⁺-Ex were increased in SLE, no differences were found in CD3⁺-Ex, supporting that exosome content accounts for this opposite role. Interestingly, CD4⁺CD28^null cells correlated with CD3⁺-Ex in patients and controls, and displayed similar associations with leukocyte subsets in both groups. Additionally, CD3⁺-Ex correlated in patients with the expression of CD25 in CD4⁺CD28^null cells. Furthermore, the activated status of this senescent subset was related to IFNα serum levels in controls and to IFN-score in SLE patients. Finally, patients presenting high IFN-score, in addition to elevated CD25⁺CD28^null cells associated with the activation of myeloid cells, displayed higher levels of inflammatory cytokines and chemokines.

Conclusion: Our results support a relationship between T-cell exosomes and cellular subsets in SLE according to type I IFN-signaling, which could amplify chronic immune activation and excessive cytokine/chemokine response.

Comparison of Different Dietary Indices as Predictors of Inflammation, Oxidative Stress and Intestinal Microbiota in Middle-Aged and Elderly Subjects

During the last decades the gut microbiota has been identified as a key mediator in the diet-health interaction. However, our understanding on the impact of general diet upon microbiota is still limited. Dietary indices represent an essential approach for addressing the link between diet and health from a holistic point of view. Our aim was to test the predictive potential of seven dietary ratings on biomarkers of inflammation, oxidative stress and on the composition and metabolic activity of the intestinal microbiota. A cross-sectional descriptive study was conducted on a sample of 73 subjects aged >50 years with non-declared pathologies. Dietary inflammatory index (DII), Empirical Dietary Inflammatory Index (EDII), Healthy Eating Index (HEI), Alternative Healthy Eating Index (AHEI), Mediterranean adapted Diet Quality Index-International (DQI-I), Modified Mediterranean Diet Score (MMDS) and relative Mediterranean Diet Score (rMED) were calculated based on a Food Frequency Questionnaire. Major phylogenetic types of the intestinal microbiota were determined by real time polymerase chain reaction (qPCR) and fecal short chain fatty acids (SCFAs) by gas chromatography. While DII, HEI, DQI-I and MMDS were identified as predictors of Faecalibacterium prausnitzii levels, AHEI and MMDS were negatively associated with Lactobacillus group. HEI, AHEI and MMDS were positively associated with fecal SCFAs. In addition, DII and EDII explained lipoperoxidation level and Mediterranean scores the serum IL-8 concentrations. The lower detection of IL-8 in individuals with higher scores on Mediterranean indices may be partially explained by the increased levels of the anti-inflammatory bacterium F. prausnitzii in such individuals.

Profiling of Serum Oxylipins During the Earliest Stages of Rheumatoid Arthritis

OBJECTIVE

Eicosanoids modulate inflammation via complex networks involving different pathways and downstream mediators, including oxylipins. Although altered eicosanoids are linked to rheumatoid arthritis (RA), suggesting that metabolization is enhanced, the role of oxylipins in disease stratification remains unexplored. This study was undertaken to characterize oxylipin networks during the earliest stages of RA and evaluate their associations with clinical features and treatment outcomes.

METHODS

In total, 60 patients with early RA (according to the American College of Rheumatology/European League Against Rheumatism 2010 criteria), 11 individuals with clinically suspect arthralgia (CSA), and 28 healthy control subjects were recruited. Serum samples were collected at the time of onset. In the early RA group, 50 patients who had not been exposed to disease-modifying antirheumatic drug (DMARD) or glucocorticoid treatment at the time of recruitment were prospectively followed up at 6 and 12 months after having received conventional synthetic DMARDs. A total of 75 oxylipins, mostly derived from arachidonic, eicosapentanoic, and linoleic acids, were identified in the serum by liquid chromatography tandem mass spectrometry.

RESULTS

Univariate analyses demonstrated differences in expression patterns of 14 oxylipins across the RA, CSA, and healthy control groups, with each exhibiting a different trajectory. Network analyses revealed a strong grouping pattern of oxylipins in RA patients, whereas in individuals with CSA, a fuzzy network of oxylipins with higher degree and closeness was found. Partial least-squares discriminant analyses yielded variable important projection scores of >1 for 22 oxylipins, which allowed the identification of 2 clusters. Cluster usage differed among the groups (P = 0.003), and showed associations with disease severity and low rates of remission at 6 and 12 months in RA patients who were initially treatment-naive. Pathway enrichment analyses revealed different precursors and pathways between the groups, highlighting the relevance of the arachidonic acid pathway in individuals with CSA and the lipooxygenase pathway in patients with early RA. In applying distinct oxylipin signatures, subsets of seropositive and seronegative RA could be identified.

CONCLUSION

Oxylipin networks differ across stages during the earliest phases of RA. These distinct oxylipin networks could potentially elucidate pathways with clinical relevance for disease progression, clinical heterogeneity, and treatment response.

Low-density granulocytes and monocytes as biomarkers of cardiovascular risk in systemic lupus erythematosus

OBJECTIVE

The aim was to evaluate the most relevant cell populations involved in vascular homeostasis as potential biomarkers of SLE-related cardiovascular disease (CVD).

METHODS

Low-density granulocytes (LDGs), monocyte subsets, endothelial progenitor cells, angiogenic T (Tang) cells, CD4+CD28null and Th1/Th17 lymphocytes and serum cytokine levels were quantified in 109 SLE patients and 33 controls in relationship to the presence of subclinical carotid atheromatosis or cardiovascular disease. A second cohort including 31 recent-onset SLE patients was also included.

RESULTS

Raised monocyte and LDG counts, particularly those LDGs negative for CD16/CD14 expression (nLDGs), in addition to the ratios of monocytes and nLDGs to high-density lipoprotein-cholesterol (HDLc) molecules (MHR and nLHR, respectively), were present in SLE patients with traditional risk factors or subclinical atheromatosis but not in those who were CV-free, thus revealing their value in the identification of patients at risk of CVD, even at the onset of disease. Accordingly, nLDGs were correlated positively with carotid intima-media thickness (cIMT) and with inflammatory markers (CRP and IL-6). A bias towards more differentiated monocyte subsets, related to increased IFN-α and IL-17 serum levels, was also observed in patients. Intermediate monocytes were especially expanded, but independently of their involvement in CVD. Finally, CD4+CD28null, Th17 and Th1 lymphocytes were increased, with CD4+CD28null and Th17 cells being associated with cIMT, whereas endothelial progenitor and Tang cell levels were reduced in all SLE patients.

CONCLUSION

The present study highlights the potential use of MHR and nLHR as valuable biomarkers of CVD risk in SLE patients, even at diagnosis. The increased amounts of nLDGs, monocytes, Th17 and senescent-CD28null subsets, coupled with reduced pro-angiogenic endothelial progenitor cells and Tang cells, could underlie the development of atheromatosis in SLE.

IgM anti-phosphorylcholine antibodies associate with senescent and IL-17+ T cells in SLE patients with a pro-inflammatory lipid profile

OBJECTIVE

The aim was to evaluate whether T cell subsets and the lipid profile could be linked to the cardioprotective effect of IgM anti-phosphorylcholine (PC) antibodies in SLE.

METHODS

Anti-PC antibodies were quantified by ELISA in 197 patients and 99 controls and analysed in relationship to clinical features, treatments and serum lipids. Carotid atheromatosis was evaluated by ultrasonography; Th1, Th17, Treg and CD4+CD28null cells by flow cytometry; and cytokine serum levels by immunoassays, in a subgroup of 120 SLE patients and 33 controls.

RESULTS

IgM anti-PC serum levels were reduced in SLE patients compared with controls (P < 0.001) and were associated with age (β= -0.252; P = 0.002), high-density lipoprotein (HDL; β = 0.271; P = 0.001), low-density lipoprotein (LDL; β= -0.192; P = 0.017) and glucocorticoid treatment (β= -0.201; P = 0.012), whereas the IgG-to-IgM anti-PC ratio was increased (P = 0.007) and associated with age (β = 0.194; P = 0.028) and SLEDAI (β = 0.250; P = 0.005). Also, patients with clinical or subclinical cardiovascular disease exhibited reduced IgM anti-PC levels compared with their cardiovascular disease-free counterparts, regardless of glucocorticoid usage (P = 0.001). CD4+CD28null and Th17 cells were increased in SLE patients compared with controls (P < 0.01) and correlated inversely with IgM anti-PC levels. These associations were observed in patients displaying high triglyceride or low HDL levels, even after adjusting for clinical parameters and treatments (CD4+CD28null: β = -0.455, P = 0.001; Th17: β= -0.280, P = 0.035), but not in those with a normal lipid profile. High triglyceride and low HDL profiles were related to low IgM anti-PC and Treg levels, respectively, whereas both lipid profiles were associated with inflammatory markers and cytokines.

CONCLUSION

The present study provides evidence for an association of IgM anti-PC antibodies with pro-atherogenic T cell subsets in SLE, with a high triglyceride/low HDL lipid profile playing a facilitating major role.

THU0065 OXYLIPIN PROFILING DURING THE VERY EARLY PHASE OF RHEUMATOID ARTHRITIS: ASSOCIATIONS WITH DISEASE STAGE, CLINICAL FEATURES AND TREATMENT RESPONSE

Background:

traditional approaches and lipidomics support the relevance of eicosanoids in rheumatic conditions, such as rheumatoid arthritis (RA). Previous studies from our group and others have revealed altered levels of arachidonic acid in RA, pointing to a possible consumption or enhanced metabolisation. However, the potential alterations of its actual metabolites are difficult to assess with conventional approaches, and new, untargeted, high-throughput technologies are needed. More importantly, whether these alterations are related to the disease course and could be found at the very early stage of the disease is unknown.

Objectives:

to characterize the eicosanoid profiles during the earliest stages of RA and their potential clinical associations.

Methods:

60 very early RA patients (50 recruited at diagnosis and treatment-naïve) fulfilling 2010 ACR/EULAR criteria, 11 clinical suspect arthralgia (CSA) individuals and 28 healthy controls (HC) were recruited. Samples were collected at the moment of the diagnosis. Serum oxylipins profiles were analyzed by mass spectrometry (LC-MS/MS). Treatment-naïve patients underwent csDMARD treatment and were followed for 6 (n=49) and 12 months (n=38). Data analysis was performed in R and MetaboAnalyst.

Results:

A total of 75 oxylipins, mostly derived from arachidonic (AA), eicosapentanoic (EPA) and linoleic (LA) acid, were identified. No effect was observed for age, gender or BMI. Correlation and network analyses revealed different patterns among oxylipins across RA patients, CSA and HC (Figure 1A). The 8-HETrE, PGE3 and 20-HETE showed the pattern (linear increase) HC→CSA→RA (p=1.47·10-4, 5.34·10-4 and 5.68·10-4, respectively; and adjusted FDR<0.050) (Figure 1B). A PLS-DA (explaining 12.3% of the total variance, with a 71.0% cross-validation accuracy and permutation p=5·10-4) confirmed that oxylipins profiles differ among groups, although a certain overlap existed. A total of 22 oxylipins had VIP scores>1 (Figure 1C), which allowed the identification of two clusters (I and II). Cluster usage (I/II) differed among groups (p=0.003): HC (27/1), CSA (7/4) and RA (37/23). Patients exhibiting cluster II showed higher VAS global assessment (p=0.016) and pain (p=0.003) than their cluster I-counterparts. More importantly, cluster II patients were less likely to achieve DAS28 remission at 6 (12/17 vs 10/32, p=0.008) and 12 months (6/9 vs 9/29, p=0.066) upon conventional DMARD treatment compared to those showing cluster I.

OPLS-DA analyses revealed a good discrimination between CSA and HC groups, and 7 compounds (13-HODE, PGB2, 9-oxo-ODE, 12-oxo-ETE, 19,20-di-HDPA, 5-HETrE and 15-HEPE) were associated with the course HC->CSA. Different precursors (2 LA, 3 AAA, 1 EPA and 1 DHA) and pathways were noted (3 LOX, 4 CYP450). Regarding RA subsets, differences were noted by seropositivity. Whereas 9 compounds were associated with the pattern HC→seronegative RA (8-HETrE, PGE3, 20-HETE, 19,20-di-HDPA, PGEM, PGJ2, 12-oxo-LTB4, 14,15-EET and LTB4), a distinct set was observed for the pattern HC→seropositive RA (PGE3, 20-oh-PGE2, 5-HETE, PGE2, 12-oxo-ETE, 20-HETE, PGEM, 4-HDoHE, LTB4, 9-oxo-ODE, 12-oxo-LTB4, 8,9-EET). No differences in the major pathways were noted.

Conclusion:

Oxylipin networks differ across disease stages during the very early phase of RA, and can inform on specific signatures related to the disease progression. Oxylipins can delineate profiles with clinical relevance and are able to predict treatment response.

Figure:

Disclosure of Interests:

None declared

IgG Anti-high-Density Lipoproteins Antibodies Discriminate Between Arterial and Venous Events in Thrombotic Antiphospholipid Syndrome Patients

Introduction: Recurrent thrombotic events are a hallmark of Antiphospholipid Syndrome (APS). However, biomarkers to identify if a patient with antiphospholipid antibodies (aPL) is at higher risk to develop an arterial or a venous event are lacking. Recently, the pathogenic role of anti-high-density lipoproteins antibodies (anti-HDL) in the occurrence of cardiovascular disease (CVD) in autoimmunity has emerged. The aim of the present study was to evaluate the presence of IgG anti-HDL antibodies in a cohort of thrombotic APS patients and to investigate their association with clinical outcomes. Methods: Serum levels of IgG anti-HDL antibodies, total IgG, and complete aPL profile were assessed in 60 APS patients and 80 healthy donors (HDs) by immunoassays. Results: Higher levels of IgG anti-HDL were found in APS patients compared to HDs (p < 0.001), even after correcting for total IgG levels (p < 0.001). No associations with treatments or traditional cardiovascular risk factors, except for smoking habit (p < 0.0001), were found. Patients who experienced at least one arterial event (n = 30) had significantly higher levels of anti-HDL antibodies when compared to patients with venous thrombosis (n = 30, p = 0.046), this difference being stronger when adjusting for total IgG (p = 0.007). Additionally, patients tested positive for antiphosphatidylserine/prothrombin (IgG/IgM) antibodies had significantly higher levels of anti-HDL antibodies (p = 0.045). Conclusions: Increased levels of IgG anti-HDL antibodies can be found in APS, mainly in patients with arterial thrombosis, independently of aPL antibodies and traditional risk factors. These findings point to a role of anti-HDL antibodies in APS and support their use as a potential biomarker for arterial thrombotic events.

A subset of low density granulocytes is associated with vascular calcification in chronic kidney disease patients

Inflammation is central to chronic kidney disease (CKD) pathogenesis and vascular outcomes, but the exact players remain unidentified. Since low density granulocytes (LDGs) are emerging mediators in inflammatory conditions, we aimed to evaluate whether LDGs may be altered in CKD and related to clinical outcomes as biomarkers. To his end, LDGs subsets were measured in peripheral blood by flow cytometry and confocal microscopy in 33 CKD patients undergoing peritoneal dialysis and 15 healthy controls (HC). Analyses were replicated in an additional cohort. DEF3 (marker of early granulopoiesis) gene expression on PBMCs was quantified by qPCR. Total CD15+ LDGs and both CD14lowCD16+ and CD14-CD16- subsets were expanded in CKD. The relative frequency of the CD14-CD16- subpopulation was higher among the CD15+ pool in CKD. This alteration was stable over-time. The increased CD14-CD16-CD15+ paralleled Kauppila scores and DEF3 expression, whereas no association was found with CD14lowCD16+ CD15+. Both subsets differed in their CD11b, CD10, CD35, CD31, CD62L, IFNAR1 and CD68 expression, FSC/SSC features and nuclear morphology, pointing to different origins and maturation status. In conclusion, LDGs were expanded in CKD showing a skewed distribution towards a CD14-CD16-CD15+ enrichment, in association with vascular calcification. DEF3 expression in PBMC can be a marker of LDG expansion.