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

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

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

Interleukin-6 and IgA-rheumatoid factor are crucial for baseline erosiveness, and anti-citrullinated peptide antibodies for radiographic progression in early rheumatoid arthritis treated according to a treat-to-target strategy

OBJECTIVES

To define baseline clinical and immunological characteristics [anti-citrullinated peptide antibodies (ACPAs), immunoglobulin M (IgM)- and IgA-rheumatoid factor (RF), and interleukin-6 (IL-6) levels] involved in determining baseline erosiveness, outcome, and radiographic progression among seropositive and seronegative early rheumatoid arthritis (ERA) patients.

METHOD

The 408 ERA patients enrolled in the study were monitored every 3 months according to the treat-to-target strategy. At baseline and after 12 months, hand and foot radiographs were evaluated using the Sharp/van der Heijde erosion score.

RESULTS

At diagnosis, seronegative patients were older and had higher Disease Activity Scores (DASs) than seropositive patients. A higher risk of erosiveness at baseline was conferred by IgA-RF positivity and IL-6 plasma levels ≥7.6 pg/mL, particularly when simultaneously present. In multivariate analysis, disease duration and IL-6 plasma levels ≥7.6 pg/mL arose as independent variables associated with presence of erosions at onset. Radiographic progression at 1 year follow-up, which occurred in 11.1% of ERA patients, was predicted by ACPA positivity, together with higher age at diagnosis. Despite similar percentages of good European League Against Rheumatism response, DAS and Boolean remission being observed over time among seropositive and seronegative patients and between erosive and non-erosive subjects, ERA patients who were erosive at onset, IgA-RF seropositive, and simultaneously having high baseline IL-6 plasma levels (≥7.6 pg/mL) were treated to a greater extent with tumour necrosis factor blockers after 12 months.

CONCLUSION

IgA-RF positivity and IL-6 plasma levels are crucial for baseline erosiveness, while ACPA positivity represents the strongest risk factor for developing radiographic progression in ERA.