Intensive training programme for ultrasound-guided minimally invasive synovial tissue biopsy on knees and wrists in different phases of inflammation

OBJECTIVES

To develop an intensive training programme for ultrasound (US)-guided synovial tissue (ST) biopsy on knees and wrists in inflammatory arthritis and to assess the learning curve, patient tolerability, sample quality and trainees' expectations.

METHODS

Active or remission rheumatoid arthritis patients were enrolled. Nine trainees joined the 4-month programme in a centre experienced in performing US-guided ST biopsies consisting of four sequential phases: (1) observation, (2) performance of guided step-by-step phases, (3) execution of the whole procedure on paired joints (knees or wrists) of the same patient in parallel with the trainer and (4) performance of the procedure autonomously. Sample representativity was assessed by histology, and procedure-related adverse events were recorded. Before and after the programme, trainees' expectations and perceptions were collected.

RESULTS

328 ST biopsy procedures were included. The rate of trainees' informative samples was: (1) comparable to the trainers in active and remission knees, but lower in active wrists (70% for trainees vs 100% for trainers, p=0.06) in phase 3; (2) excellent on active knees and wrists (91.9% and 90.9% respectively) but lower (77.6%, p=0.0089) on remission knees in phase 4. Procedures performed by trainees did not affect patient tolerability. Trainees' expectations about procedure-related invasiveness and pain infliction decreased while the difficulty of procedure execution on active wrists and remission knees remained perceived as moderately difficult.

CONCLUSIONS

This intensive training programme develops advanced skills in the performance of US-guided ST biopsy on knees and wrists, yielding high-quality specimens available for basic and translational studies on inflammatory joint diseases.

COVID-19 illness: Different comorbidities may require different immunological therapeutic targets

BACKGROUND

The SARS-CoV-2 pandemic has led to more than 6,870.000 deaths worldwide. Despite recent therapeutic advances, deaths in Intensive Care Units still range between 34 and 72%, comprising substantial unmet need as we move to an endemic phase. The general agreement is that in the first few days of infection, antiviral drugs and neutralizing monoclonal antibodies should be adopted. When the patient is hospitalized and develops severe pneumonia, progressing to a systemic disease, immune modifying therapy with corticosteroids is indicated. Such interventions, however, are less effective in the context of comorbidities (e.g., diabetes, hypertension, heart failure, atrial fibrillation, obesity and central nervous system-CNS diseases) which are by themselves associated with poor outcomes. Such comorbidities comprise common and some distinct underlying inflammatory pathobiology regulated by differential cytokine taxonomy.

METHODS

Searching in the PubMed database, literature pertaining to the biology underlying the different comorbidities, and the data from the studies related to various immunological treatments for the Covid-19 disease were carefully analyzed.

RESULTS

Several experimental and clinical data have demonstrated that hypertension and atrial fibrillation present an IL-6 dependent signature, whereas diabetes, obesity, heart failure and CNS diseases may exhibit an IL-1a/b predominant signature. Distinct selective cytokine targeting may offer advantage in treating severe COVID-19 illness based on single or multiple associated comorbidities. When the patient does not immediately respond, a broader target range through JAKs pathway inhibitors may be indicated.

CONCLUSIONS

Herein, we discuss the biological background associated with distinct comorbidities which might impact the SARS-CoV-2 infection course and how these should to be addressed to improve the current therapeutic outcome.

Bosentan Does Not Affect Renal Resistive Index in Scleroderma/Systemic Sclerosis Patients

INTRODUCTION

If properly evaluated, chronic kidney disease can be found in up to 50% of patients with systemic sclerosis (SSc). The renal resistive index (RRI) is a marker of intrarenal vascular resistance and can predict SSc-associated vasculopathy. This study aimed to determine the impact of bosentan, a nonselective endothelin-1 receptor antagonist, on RRI and kidney function in SSc patients with recurrent digital ulcers.

METHODS

Twenty-one patients (age 57 ± 9 years, 19 females) were recruited in a 16-week prospective open-label uncontrolled study. Standardized procedures were used to measure general clinical and laboratory characteristics, systolic, diastolic, and mean arterial pressure (MAP), pulse pressure (PP), diastolic to systolic blood pressure (D/S) ratio, and urinary endothelin-1 levels. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was used to calculate kidney function as an estimated glomerular filtration rate (eGFR). RRI was measured by Doppler ultrasound as the average of three samplings of intrarenal blood flow in different kidney regions of both kidneys. Patients with secondary causes of kidney disease or kidney diseases associated with albuminuria were excluded.

RESULTS

Bosentan treatment for 16 weeks did not change RRI (0.731 ± 0.049-0.730 ± 0.054, p = 0.925), but increased urine endothelin-1 to creatinine ratio (0.27 ± 0.15-0.49 ± 0.57 pg/mg, p = 0.032) and reduced MAP (123 ± 10-101 ± 11 mm Hg, p < 0.001), PP (76 ± 11-68 ± 10 mm Hg, p = 0.003), D/S ratio (0.563 ± 0.044-0.538 ± 0.031, p = 0.006), and eGFR (92 ± 20-84 ± 24 mL/min/1.73 m2, p = 0.003).

DISCUSSION/CONCLUSION

In conclusion, in patients with SSc complicated by digital ulcers and normal to mildly diminished kidney function, bosentan had no effect on intrarenal hemodynamics, but reduced blood pressure levels and kidney function.

Effects of house dust mite subcutaneous immunotherapy in real-life. Immunological and clinical biomarkers and economic impact analysis

Background

Etiology of allergic rhinitis and asthma is frequently associated with house dust mite sensitization and allergen immunotherapy (AIT) represents the only disease modifying treatment. In a real world setting, clinicians would benefit from biomarkers to monitor or predict response to AIT.

Methods

Twenty-four consecutive house dust mite (HDM) mono-sensitized rhinitic patients, treated with subcutaneous immunotherapy (SCIT) as per clinical practice, were enrolled. Multiple in vitro biomarkers such as basophil activation (BAT), IL-10 levels, and molecular allergen-specific IgE were performed during HDM SCIT, to monitor the effects of AIT and then correlated to in vivo scores (VAS, CMSS, RQLQ). Nasal cytology was performed at baseline and after 6 and 12 months of treatment. Finally, the economic impact of SCIT in this cohort of patients was evaluated.

Results

Clinical biomarkers confirmed to be useful to monitor AIT efficacy. As for laboratory biomarkers, BAT showed a reduction trend, particularly for D2C1, suggesting that this is a useful parameter in monitoring patients. IL-10 levels tend to remain stable or slightly decrease during treatment. The economic analysis confirmed the favorable impact of immunotherapy.

Conclusions

In this cohort of patients, SCIT confirmed its effectiveness in reducing symptoms and drug utilization. Clinical scores confirmed to be valid in monitoring patients and their response. BAT demonstrated to be useful in monitoring more than predicting response. Further studies are needed to better explore the usefulness of these biomarkers in AIT.

Ecology and Machine Learning-Based Classification Models of Gut Microbiota and Inflammatory Markers May Evaluate the Effects of Probiotic Supplementation in Patients Recently Recovered from COVID-19

Gut microbiota (GM) modulation can be investigated as possible solution to enhance recovery after COVID-19. An open-label, single-center, single-arm, pilot, interventional study was performed by enrolling twenty patients recently recovered from COVID-19 to investigate the role of a mixed probiotic, containing Lactobacilli, Bifidobacteria and Streptococcus thermophilus, on gastrointestinal symptoms, local and systemic inflammation, intestinal barrier integrity and GM profile. Gastrointestinal Symptom Rating Scale, cytokines, inflammatory, gut permeability, and integrity markers were evaluated before (T0) and after 8 weeks (T1) of probiotic supplementation. GM profiling was based on 16S-rRNA targeted-metagenomics and QIIME 2.0, LEfSe and PICRUSt computational algorithms. Multiple machine learning (ML) models were trained to classify GM at T0 and T1. A statistically significant reduction of IL-6 (p < 0.001), TNF-α (p < 0.001) and IL-12RA (p < 0.02), citrulline (p value < 0.001) was reported at T1. GM global distribution and microbial biomarkers strictly reflected probiotic composition, with a general increase in Bifidobacteria at T1. Twelve unique KEGG orthologs were associated only to T0, including tetracycline resistance cassettes. ML classified the GM at T1 with 100% score at phylum level. Bifidobacteriaceae and Bifidobacterium spp. inversely correlated to reduction of citrulline and inflammatory cytokines. Probiotic supplementation during post-COVID-19 may trigger anti-inflammatory effects though Bifidobacteria and related-metabolism enhancement.

Effects of l-Arginine Plus Vitamin C Supplementation on l-Arginine Metabolism in Adults with Long COVID: Secondary Analysis of a Randomized Clinical Trial

Altered l-arginine metabolism has been described in patients with COVID-19 and has been associated with immune and vascular dysfunction. In the present investigation, we determined the serum concentrations of l-arginine, citrulline, ornithine, monomethyl-l-arginine (MMA), and symmetric and asymmetric dimethylarginine (SDMA, ADMA) in adults with long COVID at baseline and after 28-days of l-arginine plus vitamin C or placebo supplementation enrolled in a randomized clinical trial, compared with a group of adults without previous history of SARS-CoV-2-infection. l-arginine-derived markers of nitric oxide (NO) bioavailability (i.e., l-arginine/ADMA, l-arginine/citrulline+ornithine, and l-arginine/ornithine) were also assayed. Partial least squares discriminant analysis (PLS–DA) models were built to characterize systemic l-arginine metabolism and assess the effects of the supplementation. PLS–DA allowed discrimination of participants with long COVID from healthy controls with 80.2 ± 3.0% accuracy. Lower markers of NO bioavailability were found in participants with long COVID. After 28 days of l-arginine plus vitamin C supplementation, serum l-arginine concentrations and l-arginine/ADMA increased significantly compared with placebo. This supplement may therefore be proposed as a remedy to increase NO bioavailability in people with long COVID.

Case report: Dupilumab treatment improved type 2 disorders in a patient with IPEX syndrome diagnosis

We described a case of IPEX syndrome successfully controlled with dupilumab, an anti-IL4 receptor alpha subunit inhibitor. IPEX syndrome is a rare and generally fatal genetic disorder characterized by immune dysregulation, polyendocrinopathy and enteropathy, mostly diagnosed in early childhood. Nonetheless, cases reported in the last 20 years demonstrated that IPEX clinical spectrum encompasses more than the classical triad of early-onset intractable diarrhea, type 1 diabetes and eczema. Atypical cases of IPEX include patients with late-onset of symptoms, single-organ involvement, mild disease phenotypes or rare clinical features. A 21-year-old caucasian man presented with immune dysregulation (hypereosinophilia and elevated IgE), protein-losing enteropathy, polyendocrinopathy (thyroiditis, osteoporosis, delayed puberty), weight loss, eczema manifestations and celiac disease. IPEX syndrome was diagnosed because of the presence of a hemizygous mutation in FOXP3 gene (c.543C>T (p.S181S) in the exon 5). During the course of the disease, the patient developed erosive proctitis, pyoderma gangrenosum, and erythema nodosum. Symptoms improved only after enteral and parenteral corticosteroid therapy and the patient soon developed steroid-dependence. Notwithstanding various therapies including azathioprine, sirolimus, tacrolimus, adalimumab, vedolizumab, the patient failed to achieve a good control of symptoms without steroids. Almost exclusive enteral nutrition with a hypoallergenic, milk-protein free, amino acid-based food for special medical purposes. He continued to lose weight (BMI 14.5 kg/m2) with a consequent high limitation of physical activity and a progressive worsening of the quality of life. In consideration of the poor response to conventional immunosuppressants and the presence of type 2 inflammatory manifestations, treatment with dupilumab at an initial dose of 600 mg, followed by a maintenance dose of 300 mg every other week, according to atopic dermatitis labeled dose, was started and combined to oral budesonide 6 mg/day and 6-mercaptopurine 75 mg/day. The patient experienced a rapid improvement in bowel and skin symptoms, leading to a progressive tapering of steroids. By our knowledge, this is the first report of IPEX syndrome successfully treated by antiIL-4/IL-13 therapy. In this case dupilumab demonstrated to be an effective, safe and steroid-sparing option.

The forgotten key players in rheumatoid arthritis: IL-8 and IL-17 - Unmet needs and therapeutic perspectives

Despite the relevant advances in our understanding of the pathogenetic mechanisms regulating inflammation in rheumatoid arthritis (RA) and the development of effective therapeutics, to date, there is still a proportion of patients with RA who do not respond to treatment and end up progressing toward the development of joint damage, extra-articular complications, and disability. This is mainly due to the inter-individual heterogeneity of the molecular and cellular taxonomy of the synovial membrane, which represents the target tissue of RA inflammation. Tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) are crucial key players in RA pathogenesis fueling the inflammatory cascade, as supported by experimental evidence derived from in vivo animal models and the effectiveness of biologic-Disease Modifying Anti-Rheumatic Drugs (b-DMARDs) in patients with RA. However, additional inflammatory soluble mediators such as IL-8 and IL-17 exert their pathogenetic actions promoting the detrimental activation of immune and stromal cells in RA synovial membrane, tendons, and extra-articular sites, as well as blood vessels and lungs, causing extra-articular complications, which might be excluded by the action of anti-TNFα and anti-IL6R targeted therapies. In this narrative review, we will discuss the role of IL-8 and IL-17 in promoting inflammation in multiple biological compartments (i.e., synovial membrane, blood vessels, and lung, respectively) in animal models of arthritis and patients with RA and how their selective targeting could improve the management of treatment resistance in patients.

Effects of l-Arginine Plus Vitamin C Supplementation on Physical Performance, Endothelial Function, and Persistent Fatigue in Adults with Long COVID: A Single-Blind Randomized Controlled Trial

Long COVID, a condition characterized by symptom and/or sign persistence following an acute COVID-19 episode, is associated with reduced physical performance and endothelial dysfunction. Supplementation of l-arginine may improve endothelial and muscle function by stimulating nitric oxide synthesis. A single-blind randomized, placebo-controlled trial was conducted in adults aged between 20 and 60 years with persistent fatigue attending a post-acute COVID-19 outpatient clinic. Participants were randomized 1:1 to receive twice-daily orally either a combination of 1.66 g l-arginine plus 500 mg liposomal vitamin C or a placebo for 28 days. The primary outcome was the distance walked on the 6 min walk test. Secondary outcomes were handgrip strength, flow-mediated dilation, and fatigue persistence. Fifty participants were randomized to receive either l-arginine plus vitamin C or a placebo. Forty-six participants (median (interquartile range) age 51 (14), 30 [65%] women), 23 per group, received the intervention to which they were allocated and completed the study. At 28 days, l-arginine plus vitamin C increased the 6 min walk distance (+30 (40.5) m; placebo: +0 (75) m, p = 0.001) and induced a greater improvement in handgrip strength (+3.4 (7.5) kg) compared with the placebo (+1 (6.6) kg, p = 0.03). The flow-mediated dilation was greater in the active group than in the placebo (14.3% (7.3) vs. 9.4% (5.8), p = 0.03). At 28 days, fatigue was reported by two participants in the active group (8.7%) and 21 in the placebo group (80.1%; p < 0.0001). l-arginine plus vitamin C supplementation improved walking performance, muscle strength, endothelial function, and fatigue in adults with long COVID. This supplement may, therefore, be considered to restore physical performance and relieve persistent symptoms in this patient population.

Peripheral blood CD4posCD25posFoxP3pos cells and inflammatory cytokines as biomarkers of response in rheumatoid arthritis patients treated with CTLA4-Ig

BACKGROUND

Prognostic biomarkers of treatment response to distinct biologic disease-modifying anti-rheumatic drugs (b-DMARDs) are still lacking within the management of rheumatoid arthritis (RA).

METHODS

Thirty-four b-DMARDs naive RA patients, divided by disease duration into early (cohort 1) and long standing (cohort 2), received CTLA4-Ig. At study entry, and every 3 months for 1 year, each patient underwent peripheral blood (PB)-derived CD4^pos cell subpopulation assessment by flow cytometry, STAT3 and STAT5 expression by RT-PCR and IL-6, IL-12p70, TGFβ, and IL-10 serum levels by ELISA. The DAS and CDAI remission was assessed at 6 and 12 months.

RESULTS

DAS- and CDAI-defined remission within 12 months was achieved by 16 (47.1%) and 8 (23.5%) RA patients, respectively. Considering the whole RA cohort, CTLA4-Ig induced a significant decrease of IL-6 serum levels from baseline to 6 and 12 months, as well as of PB CD4^posCD25^posFoxP3^pos cells at 6 and 12 months, and of CD4^posIL17^pos cells after 12 months. PB CD4^pos cells of RA patients showed higher STAT3 and STAT5 expression than healthy controls, which remained unchanged within 12 months of treatment. At study entry, RA patients achieving DAS remission had significantly lower IL-6 serum levels than RA patients not achieving this outcome. In particular, having baseline IL-6 serum levels ≤ 8.4 pg/ml, significantly identified naïve to b-DMARDs RA patients more likely to achieve DAS-remission under CTLA4-Ig at 6 months (66.7%) compared to RA patients with baseline IL-6 serum levels > 8.4 pg/ml [15.4%, OR (95%Cis) 11.00 (1.75-55.82)]. Moreover, having CD4^posCD25^posFoxP3^pos cells rate ≥ 6.0% significantly identifies naïve to b-DMARDs early RA patients more likely to achieve DAS remission at 6 months (83.3%) compared to RA patients with baseline CD4^posCD25^posFoxP3^pos cells < 6.0% [16.7%, OR (95% Cis) 25.00 (1.00-336.81)].

CONCLUSIONS

Baseline IL-6 serum levels and peripheral blood-derived CD4^pos subpopulations are putative novel prognostic biomarkers of CTLA4-Ig response in RA patients.

POS0316 SEMIQUANTITATIVE ASSESSMENT OF SYNOVITIS ON US-GUIDED SYNOVIAL MEMBRANE BIOPSIES IS CONTINGENT ON DISEASE PHASE AND PREDICTIVE OF TREATMENT RESPONSE IN NAIVE TO TREATMENT PSORIATIC ARTHRITIS

Background

Ultrasound (US)-guided minimally invasive Synovial Tissue (ST) biopsy serves as a safe and well tolerated procedure for basic and translational research on chronic inflammatory joint disease.

Objectives

(i) to assess the diagnostic value of the Krenn score (KSS) on ST samples obtained from US-guided biopsies in a large bio-samples dataset of patients with Psoriatic Arthritis (PsA) across different disease phases; (ii) to develop a multiparametric nomogram integrating clinical and histological characteristics enabling treatment response prediction in naïve to treatment PsA.

Methods

410 patients fulfilling the CASPAR criteria for PsA who underwent US-guided ST biopsy were enrolled. At baseline, patients were categorized based on their disease phase and treatment: n=207 naïve to DMARDs; n=101 resistant to c-DMARDs; n=48 resistant to b-DMARDs and n=54 in sustained clinical and ultrasound remission or in low disease activity (LDA) state (DAPSA ≤ 4 or among 4-14, respectively). Clinical, demographic, and immunological characteristics were recorded for each patient. All ST specimens were stained with H&E and classified by a pathologist, blinded to clinical characteristics, using the Krenn score to assess ST inflammation degree (1) implemented with the determination of lymphocytes, plasma cells, granulocytes and tissue oedema presence. Each naive to treatment PsA was treated according to the EULAR recommendations (2) and DAPSA remission rate at 6 months was recorded.

Results

Considering the whole enrolled cohort, the distribution of KSS was significantly different among patients across the different PsA phases (ANOVA p<0.001). In particular, among the different phases, KSS was significantly higher in b-DMARDs resistant (p<0.0001) and c-DMARDs resistant (p<0.0001) compared to remission/LDA disease patients as well as naive to treatment PsA (p<0.0001). Interestingly, regardless to the disease phase, KSS of the biopsied joint directly correlated to disease activity in terms of DAPSA (r=0.476, p<0.001) and DAS28 scores (r=0.476, p<0.001). Considering the naïve to treatment PsA cohort, patients achieving DAPSA defined-LDA/remission had, before treatment, significantly lower KSS (p<0.001), lower rate of ST plasmacells presence (p<0.001) and shorter symptoms duration (p=0.01) as compared to naïve to treatment PsA not achieving this clinical outcome. Moreover, considering distinct clinical phenotype domains, naive to treatment PsA patients with concomitant dactylitis and skin disease were less likely to achieve DAPSA LDA/remission (p<0.001), regardless of treatment scheme. On logistic regression, at baseline, having a KSS <5 [OR: 5.30 (95%CI:2.21-12.74) p<0.001], absence of plasma cells ST infiltrate [OR: 3.87 (2.11-7.10 95%CI) p<0.001], concomitant dactylitis [OR: 2.55 (95%CI:1.24-5.25) p=0.01] and skin involvement [OR: 2.06 (95%CI:1.17-3.62) p=0.01] were independent factors associated with DAPSA score-LDA/remission achievement at 6 months. Finally, a multiparametric nomogram integrating baseline clinical and histological characteristics of naïve PsA enabling to predict up to 75% of probability to achieve DAPSA remission at 6 months was developed.

Conclusion

KSS is a reliable tool for synovitis assessment in PsA, being contingent on disease phases, related to disease burden and included within a treatment response predictive multiparametric nomogram in naïve PsA.

References

[1]Krenn V, et al. Histopathology 2006

[2]Gossec L, et al. Annals of the Rheumatic Diseases 2020

Disclosure of Interests

None declared

OP0284 IMMUNOPHENOTYPIC CHARACTERIZATION OF PERIPHERAL BLOOD-DERIVED B LYMPHOCYTES OF PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS DURING B-CELL TARGETED THERAPY WITH ANTI-BLyS

Background

Belimumab, the first biological drug approved for the treatment of patients with Systemic Lupus Erythematosus (SLE), is a fully human IgG1λ monoclonal antibody directed against BlyS (B Lymphocyte Stimulator). BLyS inhibition is associated with a reduction in circulating B subsets and short-lived plasmacells

Objectives

The aim of this study was to characterize the B cell phenotype in SLE patients at baseline and after B-cell targeted therapy with Belimumab in a cohort of active SLE patients.

Methods

Fifty-four SLE patients diagnosed according to the 2012 SLICC criteria (49 females, mean age 40.6±13.2 years, disease duration 12.3±9.0 years, SLEDAI-2K 6.6±3.1) who received belimumab were enrolled. Phenotyping of peripheral blood (PB)- derived B lymphocytes (using as phenotypic markers IgD, CD27 and CD38) was performed at six (T6) and twelve (T12) months in 38 SLE patients, together with the expression of BAFF and BAFF- R by flow cytometry.

Results

In the whole SLE cohort, a reduction over time was observed in the percentage of CD19pos[T0:11.1±6.1% vs T6:6.4±3.4%,p<0.01;T12:4.2±3.4%,p<0.01] and naïve B cells (IgDposCD27neg) [T0:55.8±28.7% vs T6:34.9±22.2%,p<0.01;T12:30.0±19.4%;p=0.04] and an increase of switched memory B cells (IgDnegCD27pos)[T0:21.0±20.2% vs T6:37.5±21.4%,p<0.01;T12:42.2±21.%7,p=0.02] after B-cell targeted therapy with anti-BLyS. Moreover, a reduction of IgDnegCD27neg memory B cells at T6(p=0.01) was observed. Conversely, BAFF and BAFFR expression in peripheral blood-derived CD19pos cells remained unchanged during therapy with anti-BLyS. Stratifying SLE patients based on severe (renal and/or neurological) and mild (articular and/or cutaneous) organ involvement, a significant reduction of CD19pos percentage[T0:10.7±4.6% vs 6:6.8±2.4%,p=0.03;T12:4.5±3.5%,p=0.03] and naïve B cells[T0:61.0±24.6% vs T6:38.9±17.5%,p<0.01;T12:36.9±16.0%,p=0.03] was found in SLE patients with mild organ involvement and a significant increase of switched memory B cell subsets in both subgroups [(severe T0:24.1±25.0% vs T6:44.9±27.4%,p=0.01) (mild T0:18.9±18.3 vs T6:31.2±12.7%,p<0.01)]. Evaluating the B cell subsets regarding the response to treatment (based on the reduction of the SLEDAI-2K), a significant reduction of naïve B cells was observed at T6 in both SLE group,[(responders T0:55.4±29.3 vs T6:32.3±19.9,p<0.01)(no responders T0:63.1±41.3% vs T6:41.4±33.5%,p=0.05)] and switched memory B cells[(responders T0:22.4±21.2% vs T6:39.6±19.4%,p<0.01)(no responders T0:20.6±26.1% vs T6:38.6±35.3%,p<0.05)], with a significant higher percentage at baseline of switched memory B cells in responder SLE than in no-responder SLE group (22.4±21.2% vs 20.6±26.1%,p=0.02). ROC curve analysis of IgDnegCD27pos subset [AUC(95% CIs):0.761:(0.566-0.957)p=0.023] identified a cut-off of 9.94% associated with response at 6 months. Moreover, having a IgDnegCD27pos rate ≥9.94% [OR:4.5(95% CIs:0.9-17.2)]; and the presence of anti-dsDNA antibodies at baseline[OR:5.2(95%CIs:1.2-22.1)], identified SLE patients who achieved early response within 6 months from belimumab therapy initiation.

Conclusion

Anti BLyS therapy significantly impacts on the composition of peripheral blood B-cell subpopulations in SLE patients in relation with the distinct organ involvement. Moreover, baseline immunological features and IgDnegCD27pos B cell subset rate are novel putative biomarkers of response to anti-BLyS therapy in SLE patients.

References

[1]D. Ramsköld et al. B cell alterations during BAFF inhibition with belimumab in SLE. EBioMedicine. 2019 Feb;40:517-527.

[2]S. Piantoni et al. Characterization of B- and T-cell compartment and B-cell related factors belonging to the TNF/TNFr superfamily in patients with clinically active systemic lupus erythematosus: baseline BAFF serum levels are the strongest predictor of response to belimumab after twelve months of therapy. Front Pharmacol. 2021 May 21;12:666971.

Disclosure of Interests

None declared

POS0105 IMMUNOLOGICAL AND TISSUE DERIVED BIOMARKERS OF EARLY RESPONSE IN MODERATE-TO-SEVERE RHEUMATOID ARTHRITIS TREATED WITH JAK-INHIBITORS

Background

Among Janus kinase inhibitors (JAKi) approved for Rheumatoid Arthritis (RA) treatment, tofacitinib and baricitinib are considered as pan-JAKi (pJAKi) while upadacitinib and filgotinib as selective anti-JAK1 (sJAKi) drugs. To date, despite ≈30% of RA patients exposed to JAKi achieve DAS28-CRP remission at 12 weeks, there is still lack of predictive biomarkers of response in RA treated with distinct JAKi.

Objectives

To determine whether pre-treatment immunological and synovial tissue features can predict clinical improvement in moderate-to-severe RA treated with JAKi.

Methods

Among 174 RA patients treated with JAKi, 84 underwent peripheral blood (PB) drawing and US-guided synovial tissue (ST) biopsy. Demographic, clinical and immunological features were collected for each patient at baseline and after 12 weeks. The distribution of PB-derived B lymphocytes subsets was assessed by flow cytometry, using CD27/IgD classification. Synovitis degree assessment was determined using Krenn score (KSS) by trained pathologist, blinded to clinical characteristics.

Results

Among enrolled RA patients, 82.7% was treated with pJAKi and 17.3% with sJAKi. Moreover, 35.6% of RA patients was b/ts-DMARDs naïve, 18.4% b/ts-DMARDs non-responder and 46.0% was difficult-to-treat (D2T) RA. In the whole cohort, 49.2% and 50.8% of RA patients achieved DAS28-CRP and CDAI low disease activity (LDA), respectively, after 12 weeks of JAKi treatment. Moreover, 37.7% and 5.9% of RA patients achieved DAS28-CRP and CDAI remission (REM), respectively, after 12 weeks of JAKi treatment regardless to JAKi category. Considering the immunological profile, RA patients achieving CDAI LDA were more likely rheumatoid factor (60.0%) and ACPA positive (60.5%) compared to RA patients not achieving this outcome (RF: 40.0%, p= 0.03 and ACPA: 39.5%, p= 0.02). Considering PB-derived B cell phenotype, b/ts-DMARDs naïve RA achieving DAS28-CRP LDA at 12 week had pre-treatment lower unswitched memory B (IgDposCD27pos) cell rate (6.91±7.70%) compared to b/ts-DMARDs naïve RA not achieving the same outcome (13.21±5.68%, p= 0.009). ROC analysis identified a cut-off value of 6.89% for IgDposCD27pos cells discriminating b/ts-DMARDs naïve RA achieving DAS28-CRP LDA at 12 week [AUC: 0.174±0.086; p= 0.008; OR(95%CIs): 18.20 (1.761-188.069)]. Furthermore, b/ts-DMARDs naïve RA achieving DAS28-CRP REM at 12-week follow up visit, had PB enrichment of naïve B cells (IgDposCD27neg: 68.08±17.38%) and lower percentage of unswitched memory B lymphocytes (5.10±4.29%) compared to RA not achieving the same outcome (IgDposCD27neg: 54.68±16.16%, p= 0.05; IgDposCD27pos: 13.96±8.34%, p= 0.001) [IgDposCD27neg cut-off: 62.6%, AUC:0.727±0.101, p=0.05; OR(95%CIs): 7.33(1.272-42.294); IgDposCD27pos cut-off: 6.89%, AUC: 0.139±0.073, p= 0.002; OR(95%CIs): 12.37 (1.828-83.767)]. Interestingly, considering the D2T RA subgroup, patients achieving DAS28-CRP LDA at 12 week follow up had lower rates of PB-derived IgDnegCD27neg B cells (3.83±0.96%) compared to RA not achieving the same outcome (7.25±2.83%, p= 0.04; cut-off: 5.46%, AUC: 0.083±0.095, p=0.041). Considering the pre-treatment synovitis degree, b/ts-DMARDs naïve RA achieving CDAI LDA status had significantly higher KSS at baseline (3.8±2.2) compared to RA not achieving the same outcome [1.7±1.4, p= 0.02; KSS cut-off: 3.00, AUC: 0.795±0.097; p=0.018; OR(95%CIs): 14.0 (1.39-141.49)]. Finally, no significant associations were observed between PB-derived B cell subpopulations rate and synovitis degree both in the whole RA cohort as well as stratifying patients for disease phase.

Conclusion

Pre-treatment immunological profile, peripheral blood-derived B cell phenotype and synovitis degree are associated with the early achievement of at least DAS28-CRP/CDAI LDA in RA patients receiving JAKi despite their selectivity.

References

[1]Gremese E et. J Leukoc Biol. 2019

[2]Alivernini S et al. Pharmacol Res. 2019

[3]Alivernini S et al. Arthritis Rheumatol. 2021

Disclosure of Interests

None declared

OP0084 DIGITAL SPATIAL PROFILING REVEALS DISTINCT SYNOVIAL TISSUE MACROPHAGE TRANSCRIPTOMIC SIGNATURE OF SUSTAINED REMISSION IN RHEUMATOID ARTHRITIS PATIENTS AT RISK OF DISEASE FLARE AFTER TREATMENT CESSATION

Background

Sustained remission is the treatment goal for Rheumatoid Arthritis (RA) and once achieved patients are eligible to treatment tapering or discontinuation. However, this exposes patients to the occurrence of unpredictable disease flare, and to date there are no definitive predictive biomarkers of flare for RA in remission that could be used in clinical practice.

Objectives

To assess the impact of clinical classification of remission on synovial tissue (ST) features of RA in sustained remission and to identify predictive biomarkers of disease flare.

Methods

200 RA in sustained clinical (102 RA with DAS<1.6 and 98 RA fulfilling Boolean remission criteria for at least 9 months, respectively) and ultrasound (US) remission (PD negative) under Methotrexate with or without biological-Disease Modifying Anti-Rheumatic Drugs (bDMARDs) were enrolled and underwent to US guided ST biopsy. 373 naive RA were included as comparison. For each patient, synovitis degree was determined using a H&E-based semiquantitative score1. Some ST samples of remission RA were used for synovial tissue macrophage (STMs)(CD206/MerTK) FACS phenotyping and digital spatial profiling (GeoMx DSP, Nanostring) to quantitate transcript abundance of CD68pos cells in 138 spatially distinct ST regions of interest (ROI). After study entry, RA were randomly assigned to tapering/discontinuation (TAP/DISC) (tapering c- or b-DMARD treatment for 6 months and discontinuing c- or bDMARD afterwards) or maintaining the same therapeutic scheme (CONT). Each RA was followed every 3 months to assess flare rate after treatment modifications for 24 months.

Results

Regardless of either DAS- or Boolean-defined, remission patients had significantly lower KSS than naive RA (p<0.0001 for both). However, ST of RA in Boolean remission had lower KSS (p<0.0001) and was enriched in CD206posMerTKpos STMs (p=0.0012) as compared to DAS-defined remission RA. 73(36.5%) RA experienced a disease flare regardless of the treatment change during 24 months follow-up. Stratifying RA in remission based on remission definition and treatment group, DAS-defined remission RA who had a disease flare within at least 6 months follow-up had, at study entry, significantly higher KSS (p<0.0001) than RA who maintained a sustained remission, regardless of the treatment change (CONT:p=0.0027 and TAP/DISC:p=0.0011). Logistic regression analysis revealed that baseline KSS≥3 [AUC:0.748(95%CI:0.649-0.846)p<0.0001] was an independent predictive factor of disease flare [OR:6.9(95%CI:2.82-16.81)] within 24 months follow-up in DAS-defined remission RA. Conversely, RA in Boolean remission did not differ for KSS at study entry in both the CONT (p>0.05) and the TAP/DISC (p>0.05) group in relation to disease flare. However, considering STMs phenotype, RA in Boolean remission in the TAP/DISC group who had low levels of CD206posMerTKpos (<38.1%), experienced more likely a disease flare compared to RA in the CONT subgroup with CD206posMerTKpos≥38.1% (p=0.0014). Logistic regression analysis confirmed that, before treatment change, STMs phenotype (CD206posMerTKpos <38.1%) in RA in remission is an independent predictor of disease flare [OR:6.25(95%CI:1.33-29.43)] within 24 months. Finally, DSP analysis using CD68 morphology marker, revealed that lining and sublining layer CD68pos spatial transcriptomics distinguished, at baseline, remission RA who flared after treatment modification from those who did not.

Conclusion

Disease flare is a common event in RA in sustained remission after treatment modification. KSS and STMs phenotype identified by flow cytometry or by tissue spatial transcriptomic can identify RA in remission at higher risk of flare after treatment modification. Thus, spatial transcriptomic with defined panel of markers on histological biopsy tissues could be a way forward in predicting disease flare.

References

[1]Alivernini S, et al. Arthritis & Rheumatology 2021

Disclosure of Interests

Simone Perniola: None declared, Barbara Tolusso: None declared, Aziza Elmesmari: None declared, Marco Gessi: None declared, Clara Di Mario: None declared, Maria Rita Gigante: None declared, Luca Petricca: None declared, Dario Bruno: None declared, Domenico Somma: None declared, Annamaria Paglionico: None declared, Valentina Varriano: None declared, Laura Bui: None declared, Maria Antonietta D’Agostino: None declared, Mariola Kurowska-Stolarska Grant/research support from: Pfizer, GSK, Novartis, Eli Lilly, Elisa Gremese Speakers bureau: Abbvie, BMS, Novartis, GSK, Galapagos, Eli Lilly, Pfizer., Grant/research support from: Abbvie, BMS., Stefano Alivernini Speakers bureau: Abbvie, BMS, Novartis, Galapagos, Eli Lilly, Pfizer., Grant/research support from: Pfizer, Novartis, GSK.

POS0777 STUDY OF PERIPHERAL BLOOD B CELL IMMUNO-PHENOTYPING IN PATIENTS WITH LUPUS NEPHRITIS: PARAMETERS OF DISEASE ACTIVITY, REMISSION AND FLARE

Background

B cells play a central role in systemic lupus erythematosus (SLE) pathogenesis connecting innate with adaptative immunity.

Objectives

To investigate the peripheral blood B cell phenotype in a cohort of SLE patients with renal involvement (LN-SLE) in relation to disease activity and renal histological lesions compared to healthy controls.

Methods

One hundred LN-SLE patients with active renal involvement, 40 at disease onset (Early) and 60 in whom LN occurred after the disease onset (Long) were enrolled. Thirty-seven healthy controls were included. Clinical, laboratory and demographic data were collected at baseline and at 6 and 12 month of follow-up. Disease activity was recorded using SLEDAI-2K. Ultrasound-guided renal biopsy has been performed for the definition of the nephritic class according to the ISN/RPS classification. The memory B cells immunophenotyping (IgD/CD27 classification) was analyzed in peripheral blood through flow cytometry. To clarify the role of key molecules in the B cells activation, IL-6 and BAFF serum levels were assayed by Enzyme-linked immunosorbent assay (ELISA).

Results

According to the onset of renal symptoms, there were no differences in the distribution of the renal classes and in activity and chronicity indices in the two groups. A direct correlation was observed between chronicity index score and creatinine in the whole cohort (R=0.342;p<0.01) and in LN-SLE Early (R=0.528;p=0.01) and Long (R=0.337;p=0.02). The disease activity index was found to be significantly higher in anti-dsDNA positive than in negative ones (6.6±4.8 vs 2.8±3.5;p=0.01), and in patients with at least one antiphospholipid antibody-APL positivity (6.8±4.8 vs 5.1±4.8;p=0.05). Considering predictive biomarkers of the remission within 12 months, the presence of histological lesions (glomerulosclerosis and fibrocellular crescents) and the positivity for at least one of the APL antibodies were associated to the failure in achieving clinical remission, while baseline 24h-UP levels ≤2750mg were associated to remission achievement [OR:2.6(95%CIs:1.1-5.8)]. Studying the B cells subset, a lower percentage of CD19pos and unswitched memory (IgDposCD27pos) in LN-SLE compared to controls (6.8±5.5% vs 10.5±3.5%;p<0.01 and 11.1±12.0% vs 15.3±8.0%;p<0.01,respectively) was observed. In addition, we found higher levels of double-negative memory B cells (IgDnegCD27neg) and plasmablasts (CD27posCD38pos) in LN-SLE than in controls [(CD27negIgDneg 10.0±8.7% vs 4.1±1.9%;p<0.01)(CD27posCD38pos 4.4±5.3% vs 1.0±0.5%;p<0.01)]. Furthermore, CD19pos and IgDposCD27pos negatively correlated with BAFF [(R=-0.327;p=0.03 and R=-0.305;p=0.04) respectively] while a direct correlation was observed between IgDnegCD27neg B cells and IL-6 serum levels (R=0.302;p<0.01). No correlation was found between B cells subsets and the disease activity parameters. Considering the remission status achievement within 12 months both LN-SLE groups had significantly lower frequencies of IgDposCD27pos than controls [(Remission:10.7±12.4% vs 15.3±8.0%;p<0.01)(No-Remission:9.8±9.5% vs 15.3±8.0%;p<0.01)] conversely had a significantly higher rate of IgDnegCD27neg than controls [(Remission:11.5±10.0% vs 4.1±1.9%;p<0.01;NoRemission:9.6±6.7% vs 4.1±1.9%;p<0.01] and plasmablasts [(Remission 5.2±6.7% vs 1.0±0.5;p=0.05;NoRemission:4.1±3.4 vs 1.0±0.5;p<0.01)]

Conclusion

This study suggests that the active injury and chronic damage histological features of LN do not depend on the SLE duration per se, but could be associated to the failure in achieving clinical remission within 12 months. Furthermore, data on memory B cells immunophenotyping reveals a distinct B cells subset of SLE patients when compared to healthy controls, confirming an alteration of B cells subsets in SLE patients and strengthening the hypothesis of the pathogenetic role played by B lymphocytes in the course of LN.

References

[1]Obris că et al. Int J Mol Sci 2021;22(7):3766.

[2]Zhu L et al. Clin Rheumatol 2018;37(1):205-212.

Disclosure of Interests

None declared

Infectious agents breaking the immunological tolerance: The holy grail in rheumatoid arthritis (RA) reconsidered

Multiple Sclerosis (MS) has been shown to be linked to Epstein Barr Virus (EBV) infection, a virus that infects B cells inside the CNS. The seminal study raises a key interest into the infectious origin of several other autoimmune inflammatory diseases.We will discuss here the infectious agents that have been studied over the years in Rheumatoid Arthritis (RA), a crippling arthritis that was treated a century ago with gold salts (anti mycobacterial agent), with chloroquine (anti malarial agent), or sulphasalazine (an antibacterial-antiinflammatory agent). Several infectious agents have been taken into consideration i.e. Streptococcus group A, Proteus, Mycobacterium tuberculosis-MTB, Parvovirus B19, Epstein Barr virus, Porphyromonas gengivalis-Pg, Aggregatibacter actinomycetescomitans, and finally Haemophilus -Glaesserella parasuis-Hps. Of these agents only three satisfy the Witebski's criteria as possible pathogenetic causes of an autoimmune disease, MTB, Pg, Hps. We will discuss here how the immune tolerance might be broken, which could be the neoantigen or autoantigen involved, how the infectious agent was studied as a trigger capable of inducing arthritis in animal models. The preventive measures that should be adopted to lessen the impact of the infections, to prevent the burden and the severity of the illness are described.

Pro Nerve Growth Factor and Its Receptor p75NTR Activate Inflammatory Responses in Synovial Fibroblasts: A Novel Targetable Mechanism in Arthritis

We have recently provided new evidence for a role of p75NTR receptor and its preferential ligand proNGF in amplifying inflammatory responses in synovial mononuclear cells of chronic arthritis patients. In the present study, to better investigate how activation of the p75NTR/proNGF axis impacts synovial inflammation, we have studied the effects of proNGF on fibroblast-like synoviocytes (FLS), which play a central role in modulating local immune responses and in activating pro-inflammatory pathways. Using single cell RNA sequencing in synovial tissues from active and treatment-naïve rheumatoid arthritis (RA) patients, we demonstrated that p75NTR and sortilin, which form a high affinity receptor complex for proNGF, are highly expressed in PRG4pos lining and THY1posCOL1A1pos sublining fibroblast clusters in RA synovia but decreased in RA patients in sustained clinical remission. In ex vivo experiments we found that FLS from rheumatoid arthritis patients (RA-FLS) retained in vitro a markedly higher expression of p75NTR and sortilin than FLS from osteoarthritis patients (OA-FLS). Inflammatory stimuli further up-regulated p75NTR expression and induced endogenous production of proNGF in RA-FLS, leading to an autocrine activation of the proNGF/p75NTR pathway that results in an increased release of pro-inflammatory cytokines. Our data on the inhibition of p75NTR receptor, which reduced the release of IL-1β, IL-6 and TNF-α, further confirmed the key role of p75NTR activation in regulating inflammatory cytokine production. In a set of ex vivo experiments, we used RA-FLS and cultured them in the presence of synovial fluids obtained from arthritis patients that, as we demonstrated, are characterized by a high concentration of proNGF. Our data show that the high levels of proNGF present in inflamed synovial fluids induced pro-inflammatory cytokine production by RA-FLS. The blocking of NGF binding to p75NTR using specific inhibitors led instead to the disruption of this pro-inflammatory loop, reducing activation of the p38 and JNK intracellular pathways and decreasing inflammatory cytokine production. Overall, our data demonstrate that an active proNGF/p75NTR axis promotes pro-inflammatory responses in synovial fibroblasts, thereby contributing to chronic synovial inflammation, and point to the possible use of p75NTR inhibitors as a novel therapeutic approach in chronic arthritis.

Depression and Endothelial Dysfunction in Psoriatic Arthritis: Is There Any Possible Relationship?

Background: Cardiovascular events (CVEs) are the first cause of death in patients with psoriatic arthritis (PsA). Depression is a recognized risk factor in cardiovascular events and is frequently associated with PsA. Flow-mediated dilatation (FMD) is a widely used method for assessing endothelial dysfunction, a parameter with strong prognostic implications for CVEs. The study aims to explore the relationship between FMD, depressive symptoms and serum cytokines in a cohort of patients with PsA. Patients and Methods: FMD was assessed in 50 consecutive PsA patients aged between 30 and 75 years without known cerebrovascular and coronary heart disease or diabetes. Depressive symptoms were reported using the related subscale of the Hospital Anxiety and Depression Scale (HDS). Disease features, activity indexes, and adjusted Framingham risk score (aFRS) were calculated. Serum level of IL-6, TNF-α, and IL-17A were also assessed. Results: In PsA patients (age 50.7 ± 10.2 years, male 42%, disease duration 5.9 ± 3.3 years, Disease Activity in PSoriatic Arthritis (DAPSA) score 14.0 ± 9.4) FMD inversely correlated with the severity of depressive symptoms according to HDS (ρ = -0.339, p = 0.016), age (ρ = -0.507, p = 0.001), aFRS (rs = -0.453, p < 0.001), duration of PsA (ρ = -0.507, p = 0.001), intensity of pain (ρ = -0.507, p = 0.001), and DAPSA (ρ = -0.507, p = 0.001). No statistically significant correlation was found between FMD or HDS and serum cytokines concentrations. HDS predicted FMD in a model adjusted for age, aFRS, PsA duration, and pain intensity (β = -0.271, p = 0.008), with depressive symptoms contributing directly to 6.4% of the variance. Conclusions: Depressive symptoms correlate with endothelial dysfunction with an exposure-response pattern in our cohort of PsA patients.

Haemophilus parasuis (Glaesserella parasuis) as a Potential Driver of Molecular Mimicry and Inflammation in Rheumatoid Arthritis

Background:Haemophilus parasuis (Hps; now Glaesserella parasuis) is an infectious agent that causes severe arthritis in swines and shares sequence similarity with residues 261–273 of collagen type 2 (Coll_261−273), a possible autoantigen in rheumatoid arthritis (RA).

Objectives/methods: We tested the presence of Hps sequencing 16S ribosomal RNA in crevicular fluid, synovial fluids, and tissues in patients with arthritis (RA and other peripheral arthritides) and in healthy controls. Moreover, we examined the cross-recognition of Hps by Coll_261−273-specific T cells in HLA-DRB1^*04^pos RA patients, by T-cell receptor (TCR) beta chain spectratyping and T-cell phenotyping.

Results:Hps DNA was present in 57.4% of the tooth crevicular fluids of RA patients and in 31.6% of controls. Anti-Hps IgM and IgG titers were detectable and correlated with disease duration and the age of the patients. Peripheral blood mononuclear cells (PBMCs) were stimulated with Hps virulence-associated trimeric autotransporter peptide (VtaA10_755−766), homologous to human Coll_261−273 or co-cultured with live Hps. In both conditions, the expanded TCR repertoire overlapped with Coll_261−273 and led to the production of IL-17.

Discussion: We show that the DNA of an infectious agent (Hps), not previously described as pathogen in humans, is present in most patients with RA and that an Hps peptide is able to activate T cells specific for Coll_261−273, likely inducing or maintaining a molecular mimicry mechanism.

Conclusion: The cross-reactivity between VtaA10_755−766 of a non-human infectious agent and human Coll_261−273 suggests an involvement in the pathogenesis of RA. This mechanism appears emphasized in predisposed individuals, such as patients with shared epitope.

COVID-19 and RA share an SPP1 myeloid pathway that drives PD-L1+ neutrophils and CD14+ monocytes

We explored the potential link between chronic inflammatory arthritis and COVID-19 pathogenic and resolving macrophage pathways and their role in COVID-19 pathogenesis. We found that bronchoalveolar lavage fluid (BALF) macrophage clusters FCN1+ and FCN1+SPP1+ predominant in severe COVID-19 were transcriptionally related to synovial tissue macrophage (STM) clusters CD48hiS100A12+ and CD48+SPP1+ that drive rheumatoid arthritis (RA) synovitis. BALF macrophage cluster FABP4+ predominant in healthy lung was transcriptionally related to STM cluster TREM2+ that governs resolution of synovitis in RA remission. Plasma concentrations of SPP1 and S100A12 (key products of macrophage clusters shared with active RA) were high in severe COVID-19 and predicted the need for Intensive Care Unit transfer, and they remained high in the post-COVID-19 stage. High plasma levels of SPP1 were unique to severe COVID-19 when compared with other causes of severe pneumonia, and IHC localized SPP1+ macrophages in the alveoli of COVID-19 lung. Investigation into SPP1 mechanisms of action revealed that it drives proinflammatory activation of CD14+ monocytes and development of PD-L1+ neutrophils, both hallmarks of severe COVID-19. In summary, COVID-19 pneumonitis appears driven by similar pathogenic myeloid cell pathways as those in RA, and their mediators such as SPP1 might be an upstream activator of the aberrant innate response in severe COVID-19 and predictive of disease trajectory including post-COVID-19 pathology.

Loss of α2-6 sialylation promotes the transformation of synovial fibroblasts into a pro-inflammatory phenotype in arthritis

In healthy joints, synovial fibroblasts (SFs) provide the microenvironment required to mediate homeostasis, but these cells adopt a pathological function in rheumatoid arthritis (RA). Carbohydrates (glycans) on cell surfaces are fundamental regulators of the interactions between stromal and immune cells, but little is known about the role of the SF glycome in joint inflammation. Here we study stromal guided pathophysiology by mapping SFs glycosylation pathways. Combining transcriptomic and glycomic analysis, we show that transformation of fibroblasts into pro-inflammatory cells is associated with glycan remodeling, a process that involves TNF-dependent inhibition of the glycosyltransferase ST6Gal1 and α2-6 sialylation. SF sialylation correlates with distinct functional subsets in murine experimental arthritis and remission stages in human RA. We propose that pro-inflammatory cytokines remodel the SF-glycome, converting the synovium into an under-sialylated and highly pro-inflammatory microenvironment. These results highlight the importance of glycosylation in stromal immunology and joint inflammation.

Inclusion of Synovial Tissue-Derived Characteristics in a Nomogram for the Prediction of Treatment Response in Treatment-Naive Rheumatoid Arthritis Patients

Objective

This study applied a synovitis score obtained during routine care from ultrasound (US)–guided biopsies of synovial tissue (ST) in patients with rheumatoid arthritis (RA) and patients with other inflammatory and noninflammatory joint diseases to identify pretreatment synovial biomarkers associated with disease characteristics, and to integrate the findings into a multiparameter nomogram for use in baseline prediction of diagnosis and treatment response in treatment‐naive rheumatoid arthritis (RA) patients.

Methods

The study enrolled a total of 1,015 patients with various autoimmune diseases (545 patients with RA, 167 patients with psoriatic arthritis [PsA], 199 patients with undifferentiated peripheral inflammatory arthritis [UPIA], 18 patients with crystal‐induced arthritis, 26 patients with connective tissue diseases, and 60 patients with osteoarthritis [OA] [as part of the SYNGem cohort]). All patients underwent a US‐guided ST biopsy at baseline, and patients were then stratified according to disease phase. The KSS, along with disease characteristics and clinical outcomes, were incorporated into a nomogram for prediction of achievement of clinical remission in RA patients who were previously naive to treatment. In patients in whom a treat‐to‐target strategy was applied, remission was defined as change in the Disease Activity Score in 28 joints (DAS28) at 6 months after treatment initiation.

Results

The KSS significantly differed among RA patients, as well as PsA patients and UPIA patients, when compared to OA patients. In RA, the KSS directly correlated with the DAS28 and was related to autoantibody positivity in treatment‐naive RA patients. Moreover, at baseline, treatment‐naive RA patients achieving 6‐month remission according to DAS28 had a lower KSS, shorter duration of symptoms (very early RA [VERA]), and lower disease activity than treatment‐naive RA patients not achieving remission according to DAS28. Results of logistic regression analysis identified the following synergistic predictive factors of achievement of DAS28‐based disease remission at 6 months: having a short disease duration (VERA), not having high disease activity, and having a KSS of <5 at baseline. A nomogram integrating these baseline clinical and histologic characteristics in treatment‐naive RA patients yielded an up to 81.7% probability of achieving 6‐month remission according to the DAS28.

Conclusion

The KSS is a reliable tool for synovitis assessment on US‐guided ST biopsy, contingent on the phase of the disease and the autoimmune profile of each patient. This tool could be integrated within a therapeutic response–predictive nomogram for the prediction of treatment response in RA patients who were previously naive to treatment.

Systemic Bone Density at Disease Onset Is Associated With Joint Erosion Progression in Early Naive to Treatment Rheumatoid Arthritis: A Prospective 12-Month Follow-Up Open-Label Study

Objectives: Osteoporosis and bone erosions are hallmarks of rheumatoid arthritis (RA) since disease onset is underpinned by the inflammatory burden. In this observational study, we aimed to dissect the putative RA-related parameters and bone-derived biomarkers associated with systemic and focal bone loss at disease onset and with their progression.

Methods: One-hundred twenty-eight patients with early rheumatoid arthritis (ERA) were recruited at disease onset. At study entry, demographic, clinical, and immunological parameters were recorded. Each ERA patient underwent plain X-rays of the hands and feet at study entry and after 12 months to assess the presence of erosions. After enrollment, each patient was treated according to the recommendations for RA management and followed up based on a treat-to-target (T2T) strategy. At baseline, blood samples for soluble biomarkers were collected from each patient, and plasma levels of osteoprotegerin (OPG), receptor activator of nuclear factor κB ligand (RANKL), Dickkopf-1 (DKK1), and interleukin 6 (IL-6) were assessed by enzyme-linked immunosorbent assay (ELISA). Seventy-one ERA patients underwent bone mineral density (BMD) measurement at the left femoral neck and second to fourth lumbar spine vertebrae (L2–L4) by dual-energy X-ray absorptiometry (DXA).

Results: Among the whole cohort, 34 (26.6%) ERA patients with bone erosions at study entry had a higher disease activity (p = 0.02) and IL-6 plasma levels (p = 0.03) than non-erosive ones. Moreover, at DXA, 33 (46.5%) ERA patients had osteopenia, and 16 (22.5%) had osteoporosis; patients with baseline bone erosions were more likely osteopenic/osteoporotic than non-erosive ones (p = 0.03), regardless of OPG, RANKL, and DKK1 plasma levels. Obese ERA patients were less likely osteopenic/osteoporotic than normal weight ones (p = 0.002), whereas anti-citrullinated protein antibodies (ACPA) positive ERA patients were more likely osteopenic/osteoporotic than ACPA negative ones (p = 0.034). At logistic regression analysis, baseline Disease Activity Score measured on 44 joints (DAS44) [OR: 2.46 (1.11–5.44)] and osteopenic/osteoporosis status [OR: 7.13 (1.27–39.94)] arose as independent factors of erosiveness. Baseline osteopenic/osteoporotic status and ACPA positivity were associated with bone damage progression during the follow-up.

Conclusions: Bone erosions presence is associated with systemic bone loss since the earliest phases of RA, suggesting that the inflammatory burden and autoimmune biology, underpinning RA, represent crucial enhancers of bone remodeling either locally as at systemic level.

Rituximab Followed by Belimumab Controls Severe Lupus Nephritis and Bullous Pemphigoid in Systemic Lupus Erythematosus Refractory to Several Combination Therapies

Systemic lupus erythematosus (SLE) and bullous pemphigoid (BP) are chronic autoimmune diseases in which B cells play an important pathogenic role in the different stages of the disease. B cell-targeted therapies have been suggested as a new rational approach for treating SLE. Rituximab (RTX), an anti-CD20 chimeric monoclonal antibody, failed to achieve primary endpoints in two clinical trials (EXPLORER and LUNAR) despite multiple observational and retrospective studies showing its beneficial effect on SLE. Moreover, RTX is recommended in cases of BP that is unresponsive to conventional treatments. Belimumab (BLM), a human immunoglobulin G1 λ monoclonal antibody that inhibits soluble B-lymphocyte stimulator (BlyS)/B-cell activating factor (BAFF), is the only biological treatment approved for standard therapy of refractory autoantibody-positive active SLE. Animal models and a few case reports have supported the efficacy of the combined use of RTX followed by BLM as maintenance therapy in severe lupus nephritis (LN), suggesting that their combined use may be more effective than their single use, without compromising safety. In this study, we describe the clinical case of a SLE patient with predominant renal involvement in overlap with BP, refractory to conventional therapy including RTX alone, achieving significant steroid sparing and clinical remission under sequential treatment of RTX-BLM. Moreover, we describe the first case of BP successfully treated with BLM. This case report may encourage further clinical research studies in B lymphocyte targeted combination therapy in patients affected by SLE with major organ involvement or with refractory disease, suggesting that RTX and BLM sequential therapy may be a valid option for the treatment of SLE manifestations, including conventional therapy and RTX-resistant LN.

Switching from IFX originator to biosimilar CT-P13 does not impact effectiveness,safety and immunogenicity in a large cohort of IBD patients

BACKGROUND

Switching from IFX originator to CT-P13 is safe; however, little data on immunogenicity exists.

RESEARCH DESIGN AND METHODS

Consecutive IBD patients on IFX originator were switched to CT-P13 and followed-up for 12 months. Clinical activity, infliximab trough levels (ITLs), anti-drug antibodies (ATIs), and adverse events were recorded at predefined timepoints (baseline, second CT-P13 infusion, 6 and 12 months). The outcomes investigated were immunogenicity, pharmacokinetics, effectiveness and safety.

RESULTS

119 patients were switched to CT-P13 after a median time with IFX of 5.8 years. No changes in mean ITLs were observed. ATIs were detected in 30 patients (25.2%): 14 before and 16 after switch. Mean persistent ATIs were significantly higher compared to mean transient ones (109.74 ng/mL ±84.70 vs 18.22 ng/mL ±11.37, p < 0.001), with significantly lower ITLs associated (mean 0.32 µg/mL ±0.6 vs 3.08 µg/mL ±3.22, p < 0.001). A significant decrease of patients in steroid-fee clinical remission was observed after the switch (p = 0.004), with subsequent improvement at 6 months (p = 0.005). Eighteen patients (15.1%) discontinued IFX, only 6 (5%) for loss of response.

CONCLUSIONS

Switching from infliximab originator to CT-P13 seems safe and effective, without differences in immunogenicity. A temporary reduction of clinical benefit after switching could be potentially explained by a 'nocebo-effect response'.

Sarilumab use in severe SARS-CoV-2 pneumonia

BACKGROUND

Interleukin-6 signal blockade showed preliminary beneficial effects in treating inflammatory response against SARS-CoV-2 leading to severe respiratory distress. Herein we describe the outcomes of off-label intravenous use of Sarilumab in severe SARS-CoV-2-related pneumonia.

METHODS

53 patients with SARS-CoV-2 severe pneumonia received intravenous Sarilumab; pulmonary function improvement or Intensive Care Unit (ICU) admission rate in medical wards, live discharge rate in ICU treated patients and safety profile were recorded. Sarilumab 400 mg was administered intravenously on day 1, with eventual additional infusion based on clinical judgement, and patients were followed for at least 14 days, unless previously discharged or dead.

FINDINGS

Of the 53 SARS-CoV-2pos patients receiving Sarilumab, 39(73·6%) were treated in medical wards [66·7% with a single infusion; median PaO2/FiO2:146(IQR:120-212)] while 14(26·4%) in ICU [92·6% with a second infusion; median PaO2/FiO2: 112(IQR:100-141.5)].Within the medical wards, 7(17·9%) required ICU admission, 4 of whom were re-admitted to the ward within 5-8 days. At 19 days median follow-up, 89·7% of medical inpatients significantly improved (46·1% after 24 h, 61·5% after 3 days), 70·6% were discharged from the hospital and 85·7% no longer needed oxygen therapy. Within patients receiving Sarilumab in ICU, 64·2% were discharged from ICU to the ward and 35·8% were still alive at the last follow-up. Overall mortality rate was 5·7%.

INTERPRETATION

IL-6R inhibition appears to be a potential treatment strategy for severe SARS-CoV-2 pneumonia and intravenous Sarilumab seems a promising treatment approach showing, in the short term, an important clinical outcome and good safety.

Basic immunology may lead to translational therapeutic rationale: SARS-CoV-2 and rheumatic diseases

COVID-19 pandemia is a major concern for patients and healthcare systems. The fear of infection by patients with concomitant rheumatic diseases (either adult or children) and connective tissue diseases is arising worldwide, because of their immunological background and immunological therapies. Analysing the basic biology of single diseases, the data suggest that there is an "immunological umbrella" that seems to protect against the infection, through IFN type 1 and NK cell function. To date, reports from China, United States and Europe did not reveal an higher risk of infection, either for rheumatoid arthritis, juvenile idiopathic arthritis nor for lupus erythematosus. Antimalarials, anti-IL6-Anti-IL6 receptor, anti-IL1, anti-GM-CSF receptor and JAK1/2/3 inhibitors, are under investigation in COVID-dedicated clinical trials to control the inflammation raised by SARS-CoV-2 infection. Initial reports on the occurrence of autoimmune phenomena in the convalescence phase of SARS-CoV-2 infection suggests that the immunological consequences of the infection need to be strictly understood. Reporting of the study conforms to broad EQUATOR guidelines (Simera et al January 2010 issue of EJCI).

Distinct synovial tissue macrophage subsets regulate inflammation and remission in rheumatoid arthritis

Immune-regulatory mechanisms of drug-free remission in rheumatoid arthritis (RA) are unknown. We hypothesized that synovial tissue macrophages (STM), which persist in remission, contribute to joint homeostasis. We used single-cell transcriptomics to profile 32,000 STMs and identified phenotypic changes in patients with early/active RA, treatment-refractory/active RA and RA in sustained remission. Each clinical state was characterized by different frequencies of nine discrete phenotypic clusters within four distinct STM subpopulations with diverse homeostatic, regulatory and inflammatory functions. This cellular atlas, combined with deep-phenotypic, spatial and functional analyses of synovial biopsy fluorescent activated cell sorted STMs, revealed two STM subpopulations (MerTKposTREM2high and MerTKposLYVE1pos) with unique remission transcriptomic signatures enriched in negative regulators of inflammation. These STMs were potent producers of inflammation-resolving lipid mediators and induced the repair response of synovial fibroblasts in vitro. A low proportion of MerTKpos STMs in remission was associated with increased risk of disease flare after treatment cessation. Therapeutic modulation of MerTKpos STM subpopulations could therefore be a potential treatment strategy for RA.

AB1234 MICRO-RNA 155 AND MIR-34A: POSSIBLE BIOMARKERS OF INFLAMMATORY BURDEN AND DISEASE ACTIVITY IN ANCA-ASSOCIATED VASCULITIS WITH RENAL INVOLVEMENT

Background:

Predicting clinical outcomes in ANCA-related glomerulonephritis remains a major challenge. To date, there is no reliable biomarker able to predict renal prognosis in patients with ANCA-associated vasculitis (AAV). Micro-RNA (miRNA) are non-coding RNAs involved in the fine tuning of immune cells biology and this epigenetic modulation associates with different phenotypes and prognosis in several diseases.

Objectives:

To investigate the expression of miR-155 and miR-34a in kidney biopsies of AAV patients according with renal outcome.

Methods:

Fifteen patients with AAV and renal involvement (mean age 63.0 ±13.3 years, disease duration 4.9±2.2 months), who underwent renal biopsy. Demographic, clinical and autoimmune parameters were recorded for each patient. Each kidney biopsy was classified according to the Berden Classification, Risk group (according to the ANCA Renal Risk Score) and the chronicity Classification of the Mayo Clinic’s proposed score.

MiR-155 and miR-34a expression was investigated on kidney biopsy tissue using the miRNeasy FFPE kit (Qiagen). The quantitative expression of miR-155, miR-34a and housekeeping gene U1, used as control, was assessed by Real Time-PCR. MiR-155 and miR-34a expression was correlated with histopathological and clinical-laboratory parameters.

Each patient was followed for 12 months and renal outcome was considered according toKDIGO CKDClassification. Markers of inflammation (ESR, CRP) and urine analysis data were recorded at baseline and after 12 months.

Results:

Six (40%) patients were p-ANCA positive and 9 (60%) c-ANCA positive. Eight patients (53%) also had pulmonary involvement. The mean baseline GFR was 30.7±28.8 ml/min/1.73 m2and 10 patients (66%) showed an active urinary sediment.

At disease onset, the mean expression of miR-155 was 9.5±21.1, while the expression of mir-34a was 13.1±46.2. Considering the autoimmune profile, kidney tissue of p-ANCA positive patients was enriched of mir-155 (19.6±30.6 fold) compared to c-ANCA positive patients (1.9±2.9 fold; p=0.001). Particularly, considering the renal function, kidney tissue of patients with greater impairment of renal function (KDIGO stage 5) was enriched of miR-155 (21.5±38.3 fold) compared to patients with less renal impairment (KDIGO stage 1-4) (4.72±8.16 fold, p=0.004).

Tissue expression of miR-155 and miR-34a did not correlated with the abovementioned histopathological classifications.

After 12 months from kidney biopsy, 3(20%) patients had a worsening of renal function, 5 (33%) still presented elevated markers of inflammation and 3 (20%) still had proteinuria at urine analysis. At baseline, kidney tissue of patients with higher CRP plasma levels and proteinuria at follow-up presented higher expression of miR-155 (p=0.002 and p=0.001), whereas no significant differences were found about miR-34a kidney tissue expression.

Conclusion:

MiRNAs may play a potential role in the pathogenesis of ANCA-related glomerulonephritis. MiR-155 kidney enrichment seems to mirror the disease inflammatory burden and activity at the onset and after 12 months representing a possible biomarker in ANCA vasculitis with renal involvement. This finding may represent the basis for further studies on miRNA expression in blood samples, aiming to identify a non-invasive biomarker of kidney damage, predicting disease’s relapses and patients’ prognosis.

References:

[1]Renauer et al, Clin Rev Allergy Immunol. 2016

Disclosure of Interests:

Dario Bruno: None declared, Pier Giacomo Cerasuolo: None declared, Clara Di Mario: None declared, Silvia Laura Bosello Speakers bureau: Abbvie, Pfizer, Boehringer, Laura Gigante: None declared, Alessia Musto: None declared, Gisella Vischini: None declared, Stefano Costanzi: None declared, Stefano Alivernini: None declared, Barbara Tolusso: None declared, Giuseppe Grandaliano: None declared, Elisa Gremese Speakers bureau: Abbvie, BMS, Celgene, Jannsen, Lilly, MSD, Novartis, Pfizer, Sandoz, UCB

AB0102 SPECIALIZED PRO-RESOLVING MEDIATOR RECEPTORS AS INFLAMMATORY RESOLUTION BIOMARKERS IN RHEUMATOID ARTHRITIS

Background:

The regulation of inflammation is a dynamic process involving several molecules as lipid mediators. The Specialized Pro-resolving Mediators (SPMs), such as Resolvin (RvD and RvE), Protectins, Maresins and Lipoxin A4 (LXA4), are bioactive metabolites of omega-3 and omega-6 fatty acids which drive inflammatory resolution phase and promote tissue repair. ERV, ALX/FPR2 and BLT1 are SPM receptors. Although in Rheumatoid Arthritis (RA) lipid mediators role within pathophysiology is under definition, studies on SPMs receptors role are still lacking in this disease.

Objectives:

Purpose of this study is to define ERV, ALX/FPR2 and BLT1 expression in blood derived leukocytes and synovial cells and to correlate it to disease activity to define SPM receptors ad inflammatory resolution biomarkers in RA patients.

Methods:

A cohort of 52 RA patients was enrolled in the study of which 40 with active disease (DAS28= 5,35 (5,18-6,40)) and 12 in sustained remission status (DAS28= 2,1 (1,83-2,42)). Each enrolled patient underwent peripheral blood (PB) drawing and 46 of them underwent US-guided synovial tissue (ST) biopsy. FACS gating strategy was used for PB and ST processing to evaluate percentage of positive cells and the mean fluorescence intensity (MFI) of ERV+, ALX/FPR2+and BLT1+in CD45+CD3+, CD45+CD19+for PB and ST, CD45+CD14+and neutrophils for PB only and CD45-CD90+, CD45+CD64+CD11b+macrophages (distinct in CD206+and CD206-subpopulations) for ST only. Each included ST was stained with haematoxylin/eosin and categorized by a pathologist, blinded to clinical characteristics, using the Krenn Score (KS) to assess ST inflammation degree. As control group, 11 undifferentiated peripheral inflammatory arthritis (UPIA) patients were enrolled in the study.

Results:

Considering the whole RA cohort, DAS28 inversely correlated with BLT1+positive cells on ST-derived CD45+(r= -0.48; p= 0.048), CD3+(r= -0.56; p= 0.019) and CD19+(r= -0.49; p= 0.042) cells, in contrast with CD90+(r= 0.50; p= 0.041) cells. Similarly, both DAS28 and KS inversely correlated with ALX/FPR2+positive cells in ST-derived CD45+(r= -0.42, p= 0.050 and r= -0,41, p= 0,046 respectively) cells. Evaluating the MFI levels of the SPM receptors along all RA stages (naïve-to-treatment, resistant-to-treatment, sustained remission) compared with UPIA control group, interestingly ST-derived CD45+cells of remission RA were depleted of ERV1 compared to naïve-to-treatment RA (p=0.04), despite comparable ST inflammation. Furthermore, highest ERV1 expression was found in ST-derived CD45+CD3+and CD45+CD19+cells in naïve-to-treatment RA compared with UPIA patients (p= 0,045 and p= 0,012 respectively). Moreover, the lowest BLT1 level was found in remission RA CD3+cells compared with UPIA and naïve-to-treatment RA patients (p= 0,008 and p= 0,023 respectively).

Conclusion:

SPM receptors expression seem to be tightly related to disease activity in the synovial tissue, suggesting an important involvement in the inflammatory process in RA patient.

References:

[1]Serhan CN. Nature, 2014.

[2]Alivernini S, et al. Arthritis Res Ther 2016

[3]Krenn V et al. Histopathology, 2006.

Disclosure of Interests:

Simone Perniola: None declared, Stefano Alivernini: None declared, Barbara Tolusso: None declared, Maria Rita Gigante: None declared, Marco Gessi: None declared, Clara Di Mario: None declared, Luca Petricca: None declared, Annunziata Capacci: None declared, Anna Laura Fedele: None declared, Gianfranco Ferraccioli: None declared, Elisa Gremese Speakers bureau: Abbvie, BMS, Celgene, Jannsen, Lilly, MSD, Novartis, Pfizer, Sandoz, UCB

FRI0574 RENAL TISSUE EPIGENETIC BIOMARKERS’ CHARACTERIZATION IN PATIENTS WITH LUPUS NEPHRITIS AS PARAMETERS OF DISEASE ACTIVITY, REMISSION AND FLARE

Background:

Epigenetic factors such as non-coding RNA (miRNA) have been shown to be deregulated in Systemic Lupus Erythematosus (SLE). In particular, in mouse model (1), different miRNAs have been associated with lupus nephritis (LN), one of the most severe manifestations of the disease.

Objectives:

The aim of the study was to evaluate the expression of miR-155 and miR-34a in renal tissue as biomarkers of organ involvement and inflammatory tissue activity in patients with LN.

Methods:

Thirty-two LN patients with active renal involvement were enrolled (age: 32.2 ± 9.2 years). The nephritic onset of the disease (early-SLE) was present in 13 patients (41%), while 19 patients (59%) showed a renal involvement during the follow-up (long-SLE). Clinical, laboratory and demographic data were collected for each patient. Disease activity was recorded using SLEDAI-2K and renal activity, using the total SLEDAI-2K fraction including the items related to the renal involvement. Ultrasound-guided renal biopsy has been performed for each patients for the definition of the nephritic class according to the ISN / RPS classification of 2003 revised in 2018(2). The expression of miR-155 and miR-34a in renal tissue was carried out by extraction of total RNA from paraffin-preserved biopsies and after a retrotrascription protocol was evaluated using SYBR® Green-based real-time PCR by relative quantification considering the ΔCt (Ct miRNA- Ct housekeeping gene)(3).

Results:

Mir-155 and miR-34a expression in renal tissue were comparable in the different histological classes. Dividing patients on the base of nephritic onset, patients with early SLE showed lower expression of miR-155 (ΔCt 12.8 ± 10.8) and miR-34a (ΔCt 14.6 ± 9.9) than patients with long-SLE (miR-155: ΔCt 6.1 ± 8.7 p = 0.02; miR-34a: ΔCt 7.1 ± 9.0 p = 0.03). Furthermore, a direct correlation was observed between the expression of miR-155 and miR-34a (r = 0.91, p <0.001). Considering patients with early-SLE, the expression of miR-34a was slightly significant in patients who had relapsed (ΔCt 8.2 ± 11.4 vs ΔCt 18.4 ± 7.9 p = 0.08), although no correlation emerged between the expression of miR-155 and miR-34a both at the time of the biopsy and with the disease activity indices. At the histological evaluation, miR-155 and miR-34a were more expressed in Early-SLE patients who had wire loop lesions (miR-155: ΔCt 19.5 ± 7.7 vs ΔCt 7.3 ± 9.6 p = 0.05; miR-34a: ΔCt 21,7 ± 1.1 vs ΔCt 8,8 ± 9.7 p= 0.05) possibly associated with a greater activation of the inflammatory component.

Conclusion:

MiR-155 and miR-34a may represent tissue biomarkers of inflammatory activation in patients with LN in particular the higher expression of these miRNA in Long-SLE patients could indicate a possible role of these biomarkers in renal involvement in patients with SLE with later renal onset. The increased expression of miR-34a could give indications of a disease recurrence suggesting a closer monitoring of the patient.

References:

[1] Leiss H et al. Plosone 2017

[2] Bajema IM et al Kidney Int. 2018

[3] Alivernini S et al. Nat Commun 2018

Disclosure of Interests:

None declared

THU0193 CLINICO-DEMOGRAPHIC, IMMUNOLOGIC AND SYNOVIAL HISTOLOGIC FEATURES INFLUENCING RESPONSE TO JAK-INHIBITORS IN RHEUMATOID ARTHRITIS: A MONOCENTRIC COHORT

Background:

Janus kinase Inhibitors (JAKis) are approved for the treatment of Rheumatoid Arthritis (RA) in over 40 countries. The updated EULAR recommendations for RA treatment revised the preference of bDMARDs over tsDMARDs based on the new data related to JAKis long-term efficacy and safety. [1].

Objectives:

To evaluate the efficacy and safety of JAKis molecules in an observational single center cohort of RA patients in a real life outpatient clinical setting.

Methods:

76 RA patients [mean age: 55.7±12.5 years, 64(84.2%) female, disease duration: 120.7±97.2 months, 43 (61.4%) seropositive (AB+) for ACPA and/or IgM-RF, 34(44.7%) with BMI ≥25.0 kg/m2] were followed after starting JAKis treatment monotherapy or in combination with conventional synthetic DMARDs (csDMARDs). At study entry, and every 3 months, the ACR/EULAR core data set variables were recorded for each patient. Clinical improvement and remission rate were evaluated according to Disease Activity Score (DAS) and Clinical Disease Activity Index (CDAI) and any therapy-related adverse effect was reported. Among the whole RA cohort, 20 patients underwent US-guided synovial tissue (ST) biopsy before JAKis treatment and classified using the Krenn score for the semiquantitative assessment of ST inflammation[2].

Results:

Among the whole RA cohort who started JAKis [mean follow-up (FU) duration: 6.1±3.7 months], 22(28.9%) showed DAS-defined high disease activity. 54(71.1%) patients were previously treated with at least 1 csDMARD and 33(43.4%) were naive to biologic DMARDs (bDMARDs). Among RA previously exposed to b-DMARDs, 23(30.3%) were using anti-TNF and 14(18.4%) anti-IL6R, whereas 6(7.9%) patients received other bDMARD. In particular, 11(14.5%) patients were previously treated only with one bDMARD.

During the FU, 12(15.8%) patients discontinued JAKis [7 due to treatment failure and 5 to adverse events (1 anemia, 2 gastrointestinal intolerance, 2 H.Zoster infection)]. All RA who discontinued JAKis for incomplete or no-response were previously exposed to bDMARDs.

DAS Remission was achieved in 29 of 65(44.6%) patients during the FU, of whom 21(32.5%) achieved remission at 3 months. Similarly, 16(24.6%) patients reached CDAI remission of whom 12(18.5%) patients achieved remission at 3 months.

At baseline, there were no differences of DAS-remission rate based on age, gender, disease duration, BMI and high disease activity. Similarly, concomitant steroid and csDMARDs therapy did not impact on the rate of DAS and CDAI Remission. However, RA reaching DAS remission during FU had more likely a shorter disease duration (p=0.01) and were less previously exposed to bDMARDs (p=0.001) than patients not achieving DAS remission. Conversely, the DAS Remission rate was higher in AB+ (55.3%) than in AB- RA patients (27.3%, p=0.04).

Furthermore, bDMARDs naive RA showed higher probability to reach remission compared to bDMARD previously exposed RA [DAS remission: 66.7% vs 28.9%, respectively, p=0.003; OR(95%): 4.90 (1.69-14.3) and CDAI-remission: 37.0% vs 15.8%, p=0.05; OR(95%CIs): 3.12(0.97-10.10)], regardless to the type of the previous bDMARDs used.Finally, considering the baseline ST features, RA achieving clinical improvement did not differ in terms of Krenn score and microanatomical organization compared to RA not achieving the clinical improvement.

Conclusion:

The efficacy rate of JAKis therapy is not influenced by BMI and baseline high disease activity. Previous exposure to bDMARDs impacts both on the clinical response and on the rate of JAKis therapy discontinuation. Therapy-related adverse effects mainly occurred in bDMARD previously exposed RA patients.

References:

[1]Smolen JS, et al. Ann Rheum Dis 2020

[2]Krenn V, et al. Histopathology 2006

Disclosure of Interests:

Dario Bruno: None declared, Maria Rita Gigante: None declared, Luca Petricca: None declared, Anna Laura Fedele: None declared, Simone Perniola: None declared, Marco Gessi: None declared, Barbara Tolusso: None declared, Stefano Alivernini: None declared, Elisa Gremese Speakers bureau: Abbvie, BMS, Celgene, Jannsen, Lilly, MSD, Novartis, Pfizer, Sandoz, UCB

CO0002 LOSS OF SELF-TOLERANCE IN SARS-COV-2 INFECTION: IMMUNOLOGICAL ASSESSMENT OF A CONVALESCENT COHORT

Background:

Some infectious agents may act as inducers of autoimmune conditions1. Despite SARS-CoV-2 infection can induce autoimmune phenomena in infected people2, individual risk factors or underlining mechanisms leading to loss of immunological tolerance are still unknown.

Objectives:

To assess the rate of development of autoantibodies in convalescent SARS-CoV-2 patients and their relation on infection clinical course and disease parameters.

Methods:

One-hundred and nine convalescent SARS-CoV-2 patients were studied and underwent multidisciplinary assessment in a Day Hospital clinical setting. For each patient, demographic, clinical and immunological data were collected and, at study entry, autoimmune profile [antinuclear antibodies (ANAs), antibodies reacting with extractable nuclear antigens (anti-ENA), antineutrophil cytoplasmic antibodies (ANCAs), Lupus anticoagulant (LA), anticardiolipin antibodies (aCL) IgM and IgG, anti-β2 glycoprotein I (anti-β2GPI) IgM and IgG] was assessed by Fluorescent immunoassay. Moreover, IL-6 plasma levels were assessed by ELISA (ELLA).

Results:

After a median time from hospitalization for SARS-CoV-2 infection of 53.3 ± 0.9 days, 55(50.5%) SARS-CoV-2 convalescent patients showed the positivity (ABpos) of at least one autoantibody. In particular, 31(28.4%) were positive for LA, 11(10.1%) for IgM-RF, 8(7.3%) for ANA and 6(5.5.%) for IgG-aCL whilst less than 2% showed other autoantibody positivities (IgM-aCL, IgG-anti-β2GPI, ENA, ACPA, c-ANCA, Scl70 and RNP). Analyzing the patient-related characteristics associated with the development of autoimmunity, convalescent male patients were more likely characterized by the development of antiphospholipid antibodies (aPL) (37.3%) than female (16.7%; p=0.02). Considering the disease-related characteristics, convalescent SARS-CoV-2 patients who experienced severe pneumonia (i.e., oxygen support need) during hospitalization, more likely received IL-6R-inhibitor administration (47.3%) and developed more than one autoantibody (87.5%) (aPL + another AB) than convalescent SARS-CoV-2 patients who did not need oxygen support [(12.5%; p=0.02) (OR95%IC: 9.5(1.4-109.1)] or IL-6R-inihibitor (1.9%; p<0.001). Finally, assessing cytokines plasma levels in convalescent SARS-CoV-2 patients stratified based on the development of autoantibodies we found that, despite a significant reduction of IL-6 plasma levels from hospitalization, convalescent SARS-CoV-2 patients who developed autoantibody positivity had higher IL-6 plasma levels (8.5 ± 2.5 pg/ml) than convalescent SARS-CoV-2 ABnegpatients (5.6 ± 1.5 pg/ml; p=0.07), mostly if considered autoantibodies other than aPL (15.4 ± 7.7 pg/ml)(p=0.01).

Conclusion:

Loss of self-tolerance is a common phenomenon in the medium-term follow-up of SARS-CoV-2 convalescent patients whose occurrence is dependent by a severe disease course and by an aberrant host inflammatory response. Long-term follow-up will reveal AB persistency and their clinical impact.

References:

[1]Barzilai O, et al. Current Opinion in Rheumatology 2007.

[2]Zhou Y, et al. Clin Transl Sci. 2020.

Disclosure of Interests:

None declared

THU0287 EVALUATION OF PREDICTIVE FACTORS OF WORSE PROGNOSIS IN LUPUS NEPHRITIS: FOCUS ON NEW PATHOGENETIC PATHWAYS

Background:

cytokine dysregulation plays an important role in the pathogenesis of Lupus Nephritis (LN) representing an attractive field of research aiming to find new pathways for new targeted therapies. IL-17, IL-23 axis seems to have a great influence in the development of LN.

Objectives:

to evaluate the strongest prognostic factors in a cohort of patient with LN focusing on of the impact of IL-17, IL 23 axis as new pathogenetic pathway on renal outcome.

Methods:

91 patients with active LN at disease onset or disease flare were enrolled. Laboratory, immunological and disease activity data were collected at the baseline and at 6(T6),12(T12),24(T24) months and at the last follow-up(FU). 84 renal biopsies were evaluated according to ISN/RPS classification, assessing the activity and chronicity indexes and the active interstitial infiltrate using the BANFF score system. Baseline serum levels of IL-17 and IL-23 were assessed by ELISA in 37 patients.

Results:

among the 84 renal biopsies evaluated 77% belonged to class III and IV according to ISN/RPS; 41,8% of patients had an active interstitial infiltrate<5%, 35.2% between 5% and 25% and 15,4% above 25%. Regarding immunological data 35,2% of patients revealed a seropositivity for antiphospholipid antibodies(APL+). The median serum level of IL-17 and IL-23 were 0.12±0.15 pg/ml and 27.7±9.12 pg/ml respectively. Using the ROC curves analysis we found a cut off value of 25.89 pg/ml for IL-23 for remission at T6. Among the 10 patients with a IL-23 level above this cut-off none achieved remission at T6 and the univariate analysis shows that a serum level of IL-23 above the defined cut-off was associated with an active interstitial infiltrate>5% at renal biopsy and with the development of persistent proteinuria. The analysis of IL-17 could not let us to find a cut off value for renal damage progression since a too much high number of patients had a null value. Nevertheless patients with more elevated serum levels of IL-17 at the baseline showed more elevated level of interstitial infiltrate at renal biopsy and a worse renal outcome overall. Finally we conducted an univariate and multivariate analysis for each renal outcome considered. We found that an inflammatory interstitial infiltrate>5% at renal biopsy and APL+ were associated with worse renal outcome in terms of early and persistent remission, chronic damage, persistent proteinuria, and renal flare both in univariate and multivariate analysis. Higher serum level of IL-23 was associated with persistent proteinuria, renal flare and tended to be associated to chronic renal damage and persistent renal activity.

Conclusion:

interstitial inflammatory infiltrate and APL+ represent in our study the strongest predictors of worse renal outcome. An higher serum level of IL-23 was found to be a negative prognostic factor pointed out the possibility to consider the IL-17-IL 23 axis as a biomarkers of a more aggressive renal disease.

Disclosure of Interests:

None declared

AB0757 ASSOCIATION BETWEEN DEPRESSIVE SYMPTOMS AND ENDOTHELIAL DYSFUNCTION IN PATIENTS WITH PSORIATIC ARTHRITIS

Background:

Cardiovascular complications are the leading cause of death in patients with psoriatic arthritis (PsA), but current strategies for reducing cardiovascular risk are still inadequate. Depression is a common comorbidity in PsA patients and it is recognized as an independent cardiovascular risk factor in the general population. Endothelial dysfunction, assessed as a reduction in brachial artery Flow Mediated Dilation (FMD), is a predictor of major cardiovascular events in high and low risk populations.

Objectives:

To investigate the relationship between endothelial function and depressive symptoms in a cohort of patients with PsA.

Methods:

Sixty consecutive patients with PsA, aged between 30 and 79 years, with no history of major cardiovascular events, were characterized for traditional cardiovascular risk factors and features of psoriatic disease. The risk of cardiovascular events according to traditional risk factors was calculated using the Framingham Risk Score (FRS) and the presence of depressive symptoms was defined through the Hospital Anxiety and Depression Scale (HDS) using the validated cut-off of 8. Endothelial function was assessed by FMD. Serum IL-6 was quantified by ELISA, IL-17 and TNF-α levels by Luminex method.

Results:

Patients had an average age of 52.1±11.0 years, 43.3% of them were male, 23.3% obese and 25.0% active smokers; 38.3%, 25.0% and 11.7% were treated for high blood pressure, dyslipidemia and diabetes mellitus, respectively. The 10-year risk of major cardiovascular events estimated by FRS was 10.4%. The mean duration of PsA was 9.4 years, 30.0% of patients were in minimal disease activity (MDA) and 61.7% and 46.7% were treated with conventional and biotechnological DMARDs, respectively. The mean HDS value was 6.9±3.2 and 43.4% of patients had significant depressive symptoms. The severity of depressive symptoms according to HDS correlated with disease activity according to DAPSA (r=0.449, p=0.001). The mean FMD was 7.8±3.8%, this value correlated inversely with age (r=-0.408,p<0.001), risk of major cardiovascular events according to FRS (r=-0.327, p=0.011) and severity of depressive symptoms according to HDS (r=-0.285, p=0.027). The correlation between FMD and serum IL-6, IL-17 and TNF-alpha levels was not statistically significant. In multivariate linear regression models, the relationship between FMD and HDS was significant also when corrected for age (β=-0.26, p=0.03, R2=0.23) and FRS normalized through logarithmic transformation (β=-0.32, p=0.009, R2=0.22).

Conclusion:

The degree of endothelial dysfunction quantified by FRS correlates with the severity of the depressive symptoms in patients with PsA, independently of the cardiovascular risk attributable to classical risk factors. The weak relationship between FRS and serum levels of IL-6, IL-17 and TNF-alpha suggests a role of factors independent of inflammation in the regulation of endothelial function in patients with PsA. Systematic research and treatment of depressive symptoms could contribute to a more complete stratification and a better management of cardiovascular risk in patients with PsA.

Disclosure of Interests:

Enrico De Lorenzis: None declared, Angela Di Giorgio: None declared, Gerlando Natalello: None declared, Antonio Nesci: None declared, Dario Bruno: None declared, Donatella Lucchetti: None declared, Giacomo Tanti: None declared, Clara Di Mario: None declared, Pietro Rubortone: None declared, Maria Rosaria Magurano: None declared, Barbara Tolusso: None declared, Angelo Santoliquido: None declared, Giusy Peluso: None declared, Elisa Gremese Consultant of: AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly, Janssen, Merck Sharp & Dohme, Novartis, Sanofi, UCB, Roche, Pfizer, Speakers bureau: AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly, Janssen, Merck Sharp & Dohme, Novartis, Sanofi, UCB, Roche, Pfizer

AB0947 RECIPROCAL IMPACT OF FIBROMYALGIA ON DISEASE CHARACTERISTICS AND PHYSICAL AND PSYCOLOGICAL DOMAINS IN SJOGREN SYNDROME: CROSS SECTIONAL OBSERVATIONAL STUDY

Background:

Sjogren Syndrome (SS) is an autoimmune exocrinopathy, resulting mainly in ocular and oral dryness, with approximately half of patients displaying symptoms from different organ systems, further adding to the heterogeneous clinical phenotype of the disease. Fatigue and pain are common systemic symptoms in patients with primary SS and fibromyalgia is a frequent condition associated with chronic diseases.

Objectives:

The aim of the study was to evaluate the impact of concomitant fibromyalgia in patients with Sjogren Syndrome in terms of clinical features and disease activity.

Methods:

50 patients with Sjogren Syndrome were enrolled in the study (100% female, age: 53.7 ± 13.2 years and disease duration: 8.7 ± 5.3 years), 25(50.0%) with concomitant fibromyalgia (SS/Fibro-group) and 25(50.0%) without (SS-group). 36 patients with primary fibromyalgia (Fibro-group) were included as control group. At study entry, demographic, educational, life-style and clinical parameters were recorded for each patient. SS was diagnosed according to the American College of Rheumatology (ACR) classification criteria (1) and fibromyalgia was diagnosed according to criteria for fibromyalgia defined by ACR (2). Moreover, each patient with fibromyalgia, with and without concomitant SS, was asked to fill a self-reported questionnaire to assess the impact of Fibromyalgia on multiple physical and psycological domains (Italian-FIQR).

Results:

Stratifying the study cohorts based on the demographic and life-style characteristics, no significant differences were found comparing SS-group, Fibro-group and SS/Fibro-group. However, considering the different organ involvement, SS/Fibro-group were more likely reporting arthralgia symptoms (100.0%) than SS-group (76.0% p=0.02), despite similar clinical evidence of arthritis-synovitis among the two groups (12.0% in both groups respectively, p=1.00). Moreover, SS/Fibro-group showed significantly lower ESSDAI score (2.8 ± 1.7) and higher ESSPRI score (7.0 ± 0.9) compared to SS-group (ESSDAI: 7.5 ± 3.7 p<0.001 and ESSPRI: 5.2 ± 1.4, p<0.001 respectively). Finally, analyzing the differential distribution of individual scores of physical and psycological domains of the Italian-FIQR Questionnaire, SS/Fibro-group did not differ compared to Fibro-group (p>0.05 for all the 21 questions included).

Conclusion:

SS is affected by concomitant fibromyalgia in terms of subjective-dependent parameters (i.e. joint complaints) however the concomitant SS does not affect the impact of fibromyalgia on physical and psycological domains, even if disease activity is higher in SS patients without fibromyalgia.

References:

[1]Shiboski SC et al. Arthritis Care Res, 2012

[2]Wolf F. et al. Arthritis Rheum 1990

Disclosure of Interests:

Annunziata Capacci: None declared, Pietro Rubortone: None declared, Valentina Varriano: None declared, Annamaria Paglionico: None declared, Simone Perniola: None declared, Maria Rita Gigante: None declared, Barbara Tolusso: None declared, Stefano Alivernini: None declared, Elisa Gremese Speakers bureau: Abbvie, BMS, Celgene, Jannsen, Lilly, MSD, Novartis, Pfizer, Sandoz, UCB

SAT0224 ANTIPHOSPHOLIPID ANTIBODIES AND VASCULAR RENAL LESIONS AS PROGNOSTIC FACTORS IN LUPUS NEPHRITIS

Background:

Several studies have showed that antiphospholipid antibodies (aPL) positivity represents a predictor of worse renal outcome in patients with Lupus Nephritis (LN). In addition, an association between aPL positivity and the histological data of vascular lesions on the renal biopsies has been reported.

Objectives:

To determine the prognostic role of aPL and vascular renal lesions in the assessment of clinical outcome during the follow up period, in terms of time to achieve remission, number of renal flares and development of chronic renal damage in patients affected by LN.

Methods:

Among 120 patients affected by LN from our Rheumatology Unit, 91 patients (age 43.8 ± 12 years, 74 (81.3%) female, disease duration 7.1 ± 7.9 years) have been evaluated and the follow-up data have been collected at the baseline and at 6, 12, 24 months and at the last follow-up visit. Histopathological data of 41 patients were evaluated according to the 2016 revision of ISN/RPS classification.

Results:

Among the 91 LN patients, 31 (34.1%) were aPL positive (aPL+), 10 (32.2%) of them were affected by Antiphospholipid Antibodies Syndrome (APS), 53.3% showed a single aPL positivity, 23.1% double aPL positivity and 15.4% triple aPL positivity. At the last follow up visit a significant higher number of aPL+ patients showed a persistent complement consumption than aPL negative (aPL-) patients (p=0.001). Evaluating clinical outcome, we observed that aPL- patients showed a remission achievement time slightly earlier than aPL+ patients (13.6 ± 1.0 months vs 16.5 ± 1.5 months; log-rank test: p=0.06, Breslow test: p=0.08) and as expected, patients with a persistent complement consumption achieve remission later (18.2 ± 1.5 months vs 13.0 ± 1 months; log-rank test: p=0.002, Breslow test: p=0.003). Furthermore at the last follow up, a significant higher percentage of aPL+ patients developed persistent proteinuria (p=0.02) and chronic renal failure (p=0.04). Considering histologic features (activity and chronicity index, glomerulonephritis class, presence of mesangiolysis, glomerular wrinkling, glomerular thrombi, interstitial inflammatory infiltrates, interstitial fibrosis and tubular atrophy,tubulitis and vascular lesions) we didn’t observe significant differences between aPL+ and aPL- patients but we found two typical vascular lesions (mesangiolysis and vascular thrombi) only in aPL + patients.

Conclusion:

aPL positivity is a predictor of worse renal outcome but in our cohort of LN patients we didn’t find an association between aPL positivity and vascular renal lesions at renal biopsy. The worse renal outcome and the late time to achieve remission in aPL+ group can be related to a cumulative vascular damage over time as observed in other organ and systems.

Disclosure of Interests:

None declared

SAT0027 DEVELOPMENT AND VALIDATION OF A NOMOGRAM COMBINING CLINICAL AND HISTOPATHOLOGICAL SYNOVIAL FEATURES FOR PREDICTING EARLY TREATMENT RESPONSE IN NAIVE TO TREATMENT RHEUMATOID ARTHRITIS

Background:

Rheumatoid Arthritis (RA) is characterized by synovial tissue (ST) heterogeneity at disease onset in terms of inflammatory degree and microanatomical organization being related to treatment response.

Objectives:

To develop a multiparametric tool for baseline treatment response prediction including disease characteristics and histopathologic features of ST biopsies, using a large single center (SYNGem Unit) naive to treatment RA cohort.

Methods:

240 naive to treatment RA who underwent US-guided ST biopsy, at the first clinical evaluation, were enrolled. Clinical and immunological characteristics were recorded for each patient. All ST FFPE specimens were stained with H&E and classified by a pathologist, blinded to clinical characteristics, using the Krenn score [1] to assess the degree of ST inflammation. All naive to treatment RA were treated according to the T2T scheme and DAS remission rate at 6-12 months was recorded. On the basis of the regression analysis, a nomogram was constructed that incorporated the significant factors predicting the “achievement of DAS-Remission at 6 months follow-up” in naive RA. The performance of the nomogram was assessed by discrimination and calibration.

Results:

Univariate analysis showed that RA who achieved early (6 months) DAS-remission had, at baseline, significantly lower total Krenn score (p<0.001), shorter symptoms duration (p=0.005) and lower disease activity (p<0.001) than RA not achieving this clinical outcome. ROC curve analysis revealed that RA having, at baseline, a total Krenn score <4.5 [(AUC)95%C.I.: 0.67(0.60-0.74),p<0.001] achieved more likely DAS-remission at 6 months (53.1%) than RA with total Krenn score ≥4.5(28.9%,p<0.001). Interestingly, RA whose ST was biopsied within 3 months from joint symptoms beginning showed significantly lower ST inflammation as total Krenn score than RA whose ST was analyzed among 3-12 months (p=0.04) or after 12 months (p=0.002) since symptoms beginning. However, in terms of follicular structure presence, the microanatomical organization of the synovial inflammatory infiltrate did not differ comparing RA whose ST was biopsied within 3 months from joint symptoms beginning (44.4%) and RA whose ST was biopsied among 3-12 months (47.6%, p=0.74) or after 12 months (52.7%,p=0.33) since symptoms beginning.

Logistic regression analysis revealed that, at baseline, being VERA, not having HDA and having a total Krenn score <4.5 were synergistic factors of DAS-remission achievement at 6 months [OR:10.5(95%IC:2.28-48.01);p<0.05]. Based on the regression analysis, a nomogram integrating baseline clinical (disease activity and duration) and histological (total Krenn score) characteristics was developed in which the value of each of the variables was given a point score. A total score was calculated by adding each single point score and, by projecting the value of the “total points” score to the “probability” line up to 87.5%.

Conclusion:

Krenn score is a reliable tool for the semi-quantitative assessment of ST inflammation on US-guided ST biopsies being contingent to baseline disease characteristics and can be integrated within a nomogram to better predict the therapeutic response in naive to treatment RA.

References:

[1] Krenn V, et al. Histopathology 2006

Disclosure of Interests:

Stefano Alivernini: None declared, Barbara Tolusso: None declared, Marco Gessi: None declared, Maria Rita Gigante: None declared, Alice Mannocci: None declared, Luca Petricca: None declared, Simone Perniola: None declared, Clara Di Mario: None declared, Anna Laura Fedele: None declared, Laura Bui: None declared, Annunziata Capacci: None declared, Dario Bruno: None declared, Giuseppe La Torre: None declared, Francesco Federico: None declared, Gianfranco Ferraccioli: None declared, Elisa Gremese Speakers bureau: Abbvie, BMS, Celgene, Jannsen, Lilly, MSD, Novartis, Pfizer, Sandoz, UCB

Severe eosinophilic asthma and aspirin-exacerbated respiratory disease associated to eosinophilic gastroenteritis treated with mepolizumab: a case report

Background

Mepolizumab (MEP) is the first anti Interleukin (IL)-5 add-on therapy approved for the treatment of severe refractory eosinophilic asthma.

Case presentation

We describe here the case of a 49 years-old woman with Aspirin-exacerbated respiratory disease (AERD), chronic rhinosinusitis, nasal polyposis and eosinophilic gastroenteritis successfully treated with MEP. Several laboratory and clinical items improved during therapy; moreover MEP showed to be useful as steroid sparing agent.

Conclusions

This case supports that the use of mepolizumab can be effective also in other eosinophilic conditions different from asthma and this opens to new therapeutic perspectives.

O14 Semi-quantitative assessment of synovial inflammation on US guided synovial membrane biopsy is contingent to disease phase, autoimmune profile and treatment response in RA: a large single center experience

Background

Ultrasound (US)-guided minimally-invasive synovial tissue (ST) biopsy is a well-tolerated procedure for basic and translational studies on chronic inflammatory joint diseases as rheumatoid arthritis (RA), psoriatic arthritis (PsA) and spondyloarthritis (SpA). The aim of the study was to evaluate the utility of histopathologic criteria to differentiate US-guided ST biopsies in daily clinical care in relation to diagnosis, disease characteristics, US parameters and treatment response in a large single center ST biopsy unit.

Methods

1,064 patients [545 RA, 167 PsA, 75 SpA, 199 undifferentiated peripheral inflammatory arthritis (UPIA), 18 crystal arthritis, 26 connective tissue diseases and 34 osteoarthritis (OA) respectively] who underwent US-guided ST biopsy were enrolled. US parameters (Synovial Hyperthrophy and Power Doppler signal respectively) were recorded for each biopsied joint. RA, PsA and SpA patients were stratified based on disease activity phase (naive to DMARDs, DMARDs resistant and in sustained remission, respectively). Clinical, demographic and immunological characteristics were recorded for each patient. All ST FFPE specimens were routinely processed and stained with H&E and classified by a pathologist, blinded to clinical characteristics, using the Krenn score to assess the degree of ST inflammation. Moreover, the presence/absence of lymphocytes, plasmacells, granulocytes and oedema was assessed for each ST. All naive to treatment RA were treated according to the T2T scheme and followed for at least 12 months and DAS remission rate was recorded.

Results

In the cohort, the distribution of synovitis score was significantly different among patients with inflammatory chronic diseases (RA, PsA, SpA and UPIA respectively) compared to OA (ANOVA Test p &lt; 0.001). Moreover, Krenn score directly correlated with synovial hyperthrophy (R = 0.36; p &lt; 0.001) and Power Doppler signal (R = 0.40;p&lt;0.001) of the biopsied joint. Considering the RA cohort, naive RA showed a higher Krenn score compared to resistant RA (p &lt; 0.001) and RA in sustained clinical and US remission (p &lt; 0.001), directly correlating with DAS28 (R = 0.51; p &lt; 0.001). Moreover, ACPA and RF positivity was related to the Krenn score and to ST plasmacells presence at RA onset (p &lt; 0.05 and p &lt; 0.001, respectively) but not at the time of DMARDs-failure or sustained remission achievement (p &gt; 0.05 for both). Stratifying naive RA based on disease duration at ST biopsy, naive RA with symptoms duration &gt;1 year, showed higher Krenn score compared to those with symptoms duration &lt;3 months (p &lt; 0.001). Finally, logistic regression analysis revealed that Krenn score higher or equal to 4.5 at baseline is an independent factor of no DAS remission achievement within 12 months [OR(95%CI):0.37(0.20-0.67)p&lt;0.001] in naive RA.

Conclusion

Krenn score is a reliable tool for the semi-quantitative assessment of ST inflammation on US-guided ST biopsies being differentially distributed among various chronic inflammatory joint diseases and contingent to disease phase, autoimmune profile and therapeutic response in RA.

Disclosures

S. Alivernini None. B. Tolusso None. M. Gessi None. M. Gigante None. L. Petricca None. C. Di Mario None. S. Perniola None. A. Fedele None. G. Peluso None. L. Bui None. A. Capacci None. F. Federico None. G. Ferraccioli None. E. Gremese None.

P234 Characterisation of human synovial tissue dendritic cells in rheumatoid arthritis patients

Background

Dendritic cells (DCs) direct immune responses against pathogens while maintaining tolerance to self-antigens. However, their aberrant activation can lead to autoimmunity and inflammation. DCs consist of two subtypes: plasmacytoid and myeloid DCs. Recently, single-cell sequencing has revealed complex heterogeneity within myeloid DCs. These cells can be divided into CD141pos (DC1), DC2 defined as CD1highCD163neg and DC3 defined as CD1clowCD163high. In addition, a population of CD1cnegCD141negCD16pos (DC4), which share some gene expression with CD16pos monocytes, has been identified. To date, most studies of RA investigated DC precursors in circulation or synovial fluid (SF). However, DCs perform their functions within lymphoid or peripheral tissue. Therefore, in this study, we sought to characterise myeloid DC subsets in synovial tissue (ST) with the prospect of better understanding their role in driving autoimmunity in RA.

Methods

We developed a flow sorting strategy to characterise the phenotype of distinct myeloid DC subsets in multiple biological compartments (PB, SF, and ST). Ultrasound-guided ST biopsies (RA n = 9; Psoriatic arthritis n = 3 with active disease) were digested with liberase prior to analysis. PB DCs (RA n = 19, Psoriatic arthritis n = 16, healthy donors n = 12), and SF DC (n = 3) were used as comparators. ST, SF and PB DCs were sorted then microRNA, pro-inflammatory and regulatory cytokine expression analysed by amplified qPCR. To evaluate the role of miR-155 in RA CD1cpos DC activation, CD1cpos cells were computationally sub-setted from a scRNAseq synovial dataset comparing synovial tissues of healthy individuals (n = 4) with patients with active RA (n = 7) and those in sustained clinical and ultrasound remission (n = 7). To elucidate the role of miR-155, CD1cpos DC from RA patients (n = 10) were sorted then transfected with miR-155 mimic or control mimic and the cytokines expression and produced were evaluated using quantitative RT-PCR and Luminex, respectively.

Results

Our data revealed that whilst all myeloid DCs subsets can be present in inflamed RA synovium they occur with variable frequencies. CD1cpos (DC2/3) being the most abundant, followed by CD16pos DCs (DC4), whilst CD141pos DCs (DC1) occur in low numbers or are absent. CD1cpos DC sorted from RA ST express high levels of epigenetic regulators of inflammatory response miR-155, IL-6, TNF-a and IL-23 as compared to circulating cells.Unsupervised clustering of synovial CD1c cells identified 4 separate clusters including a distinctive miR155 positive CD1c cluster in RA patients. These cells showed significantly higher expression of pro-inflammatory cytokines and co-stimulatory molecules compared to other synovial CD1c clusters. Overexpression of miR-155 in CD1cpos leads to increased production of TNF-a and IL-23.

Conclusion

Our data show that miR-155 is strongly implicated as an epigenetic regulator of the pro-inflammatory synovial CD1cpos DCs sub-cluster and contributes to exacerbating RA.

Disclosures

A. Elmesmari None. L. MacDonald None. D. Vaughan None. B. Tolusso None. L. Bui None. M. Gigante None. F. Federico None. G. Ferraccioli None. E. Gremese None. I. B McInnes None. S. Alivernini None. M. Kurowska-Stolarska None.

Laboratory Monitoring of Biological Therapies in Rheumatology: The Role of Immunogenicity

Biological drugs, such as proteins and immunogens, are increasingly used to treat various diseases, including tumors and autoimmune diseases, and biological molecules have almost completely replaced synthetic drugs in rheumatology. Although biological treatments such as anti-tumor necrosis factor (TNF) drugs seem to be quite safe, they cause some undesirable effects, such as the onset of infections due to weakening of the immune system. Given the biological nature of these drugs, they might be recognized as extraneous; this would induce an immune reaction that neutralizes their effectiveness or lead to more serious consequences. Laboratories play a pivotal role in appropriate therapeutic management. The aim of this review was to underline the production of anti-drug antibodies during treatment with biological drugs and highlight the role of laboratories in ensuring appropriate use of these drugs.

Early vedolizumab trough levels predict treatment persistence over the first year in inflammatory bowel disease

Background

Data from trials of vedolizumab for inflammatory bowel disease and from real-world studies suggest an exposure-response relationship, such that vedolizumab trough levels may predict clinical and endoscopic outcomes.

Objective

The purpose of this study was to evaluate in a prospective observational study the utility of an early vedolizumab trough level assay for predicting the first-year vedolizumab therapy outcome.

Methods

This prospective observational study included consecutive inflammatory bowel disease patients. We measured vedolizumab trough levels and anti-vedolizumab antibodies at weeks 6 and 14. Clinical outcome was assessed at weeks 6, 14, 22 and 54. The primary endpoint was the correlation between early vedolizumab trough levels and vedolizumab persistence over the first year of treatment, defined as the maintenance of vedolizumab therapy due to sustained clinical benefit.

Results

We included 101 patients initiating vedolizumab. A cut-off vedolizumab trough level of 16.55 µg/ml at week 14 predicted vedolizumab persistence within the first year of therapy, with 73.3% sensitivity and 59.4% specificity (p = 0.0009). Week 14 vedolizumab trough level was significantly higher in patients with clinical remission at weeks 14, 22 and 54; and in patients achieving mucosal healing within 54 weeks.

Conclusion

High vedolizumab trough level at week 14 was associated with a higher probability of maintaining vedolizumab therapy over the first year due to sustained clinical benefit.

The B side of rheumatoid arthritis pathogenesis

In the last years, a dramatic amount of research has been performedincreasing the knowledge about the biological mechanism underpinning Rheumatoid Arthritis (RA) inflammation, putting B lymphocytes in the center of RA pathogenesis. Nowadays, B cell phenotypes and autoantibodies positivity arose as important biomarkers in early and long-standing disease. Moreover, comparative analysis of peripheral blood and synovial tissue compartments enables the identification of novel physiopathological mechanisms promoting inflammation. In this narrative review we will discuss the biological relevance of B cell derived autoimmunity and in RA course, from disease onset to remission achievement.

Measuring the T-cell down-regulation of TCR-zeta, ZAP-70 and CD28 in arthritis patients: An old tool for new biomarkers

Low T-cell receptor (TCR)/CD28 signaling lymphocytes are expanded in arthritis. We asked whether the down-expression of TCR-related molecules correlates with specific arthritis characteristics and if it has clinical implications. TCR-ZETA, ZAP-70 and CD28 expression was measured by flow cytometry in synovial fluid (SF) and peripheral blood (PB)-derived T cells. In PB, ZETA-downregulation in CD4⁺ CD28⁺ and consequent CD4⁺ CD28lowZETAlow cell expansion correlate with CRP elevation, leukocyte recruitment into SF and, primarily, disease activity (DAS). In some patients, ZETA-downregulation extends to CD8⁺ CD28null and/or CD8⁺ CD28⁺ cells, and this correlates with enhanced leukocyte recruitment, multiple joint involvement, and disability index (HAQ). ZETA-downregulation in CD4⁺ CD28⁺ may also lead to CD4⁺ CD28⁺ ZETAnull cell expansion, which strongly correlates with HAQ. In SF, ZETA-downregulation in CD8⁺ CD28null and consequent CD8⁺ CD28nullZETAlow/null cell expansion correlate with CRP elevation and neutrophilic influx into SF, whereas ZAP-downregulation in CD8⁺ CD28⁺ and consequent CD8⁺ CD28lowZAPlow cell expansion strongly correlate with HAQ and DAS. ZETA-downregulation is preponderant in SF of seronegative arthritides, with seronegative rheumatoid arthritis showing significant down-regulation in CD8⁺ CD28null, and non-rheumatoid arthritides showing significant down-regulation in CD4⁺ CD28⁺ . Altogether, we identified new molecular and cellular biomarkers of arthritis-related T-cell inflammation, useful for assessing arthritis activity, predicting polyarticular progression and functional impairment, characterizing seronegative arthritides, and possibly tailoring immunotherapies.

JAK inhibition by methotrexate (and csDMARDs) may explain clinical efficacy as monotherapy and combination therapy

Methotrexate (MTX) is recognized as the anchor drug in the algorithm treating chronic arthritis (RA, psoriatic arthritis), as well as a steroid sparing agent in other inflammatory conditions (polymyalgia rheumatica, vasculitis, scleroderma). Its main mechanism of action has been related to the increase in extracellular adenosine, which leads to the effects of A2_A receptor in M1 macrophages that dampens TNFα and IL12 production and increases IL1Ra and TNFRp75. By acting on A2_B receptor on M2 macrophages it enhances IL10 synthesis and inhibits NF-kB signaling. MTX has also been shown to exert JAK inhibition of JAK2 and JAK1 when tested in Drosophila melanogaster as a model of kinase activity and in human cell lines (nodular sclerosis Hodgkin's lymphoma and acute myeloid leukemia cell lines). These effects may explain why MTX leads to clinical effects similar to anti-TNFα biologics in monotherapy, but is less effective when compared to anti-IL6R in monotherapy, which acting upstream exerts major effects downstream on the JAK1-STAT3 pathway. The MTX effects on JAK1/JAK2 inhibition also allows to understand why the combination of MTX with Leflunomide, or JAK1/JAK3 inhibitor leads to better clinical outcomes than monotherapy, while the combination with JAK1/JAK2 or JAK1 specific inhibitors does not seem to exert additive clinical benefit.