Successful long-term systemic sclerosis treatment by high-frequent low-dose B cell-depleting therapy

OBJECTIVES

Systemic sclerosis (SSc) is a multiorgan disease with a 10-year mortality rate of up to 50 %. B cell-depleting therapy with rituximab (RTX) appears effective in SSc treatment, but data from randomized controlled trials (RCTs) are lacking, and the frequency and dosage of RTX in SSc have no consensus. We aimed to evaluate the long-term efficacy and safety of quarterly RTX administration in SSc.

METHODS

This study retrospectively analyzed 40 patients with SSC treated with RTX twice within 14 days every 3 months from 2010 to 2020. The patients fulfilled the LeRoy and the American College of Rheumatology/European League Against Rheumatism Criteria for SSc. Modified Rodnan skin score (mRSS), lung function test results, and serum immunoglobulin (IgG, IgA, and IgM) concentrations were analyzed.

RESULTS

A total of 40 patients with SSc received RTX over a median time of 3.9 years (range: 1-10 years). The median mRSS (baseline: 19, 24 months: 16, p < 0.001) demonstrated a significant improvement, and the predicted forced vital capacity was stable. No new or unexpected safety signals, especially regarding treatment-related infectious adverse events, were observed. Immunoglobulin concentrations were within normal range, and specific antibodies to pneumococcal polysaccharides were preserved despite long-term B cell-depleting therapy. None of the patients died during the observation period of up to 10 years.

CONCLUSION

SSc was effectively and safely treated with low-dose RTX quarterly. RCTs are warranted to validate the advantage of continuous B cell depletion by quarterly low-dose RTX administration compared to other treatment intervals.

Dissection of Developmental Programs and Regulatory Modules Directing Endosperm Transfer Cell and Aleurone Identity in the Syncytial Endosperm of Barley

Endosperm development in barley starts with the formation of a multinucleate syncytium, followed by cellularization in the ventral part of the syncytium generating endosperm transfer cells (ETCs) as first differentiating subdomain, whereas aleurone (AL) cells will originate from the periphery of the enclosing syncytium. Positional signaling in the syncytial stage determines cell identity in the cereal endosperm. Here, we performed a morphological analysis and employed laser capture microdissection (LCM)-based RNA-seq of the ETC region and the peripheral syncytium at the onset of cellularization to dissect developmental and regulatory programs directing cell specification in the early endosperm. Transcriptome data revealed domain-specific characteristics and identified two-component signaling (TCS) and hormone activities (auxin, ABA, ethylene) with associated transcription factors (TFs) as the main regulatory links for ETC specification. On the contrary, differential hormone signaling (canonical auxin, gibberellins, cytokinin) and interacting TFs control the duration of the syncytial phase and timing of cellularization of AL initials. Domain-specific expression of candidate genes was validated by in situ hybridization and putative protein-protein interactions were confirmed by split-YFP assays. This is the first transcriptome analysis dissecting syncytial subdomains of cereal seeds and provides an essential framework for initial endosperm differentiation in barley, which is likely also valuable for comparative studies with other cereal crops.

POS0829 SPECTRUM OF ANCA-SPECIFICITIES IN EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS IN A RETROSPECTIVE MULTICENTER STUDY

Background

Anti-neutrophil cytoplasmic autoantibodies specific for myeloperoxidase (MPO-ANCA) are found in 10-70% of the patients with eosinophilic granulomatosis with polyangiitis (EGPA) depending on disease activity, methodological aspects and cohort examined [1-3]. Recently, a higher prevalence of anti-pentraxin 3 (PTX3)-ANCA has been reported in EGPA compared to granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) [4].

Objectives

To investigate the spectrum of ANCA specificities in a multicenter cohort of patients with EGPA and identify novel ANCA antigens.

Methods

We conducted a retrospective analysis of 73 patients with EGPA treated between 2015 and 2020 in 3 tertiary referral centers. In addition to in-house ANCA testing with indirect immunofluorescence (IFT) on fixed human granulocytes and antigen-specific enzyme-linked immunosorbent assays (ELISA), ANCA specificities were determined using a cell-based assay (CBA; Euroimmun, Lübeck, Germany). Diagnosis was based on Chapel Hill consensus conference definitions, ACR- and MIRRA-criteria for EGPA. Patient characteristics and clinical manifestations were evaluated and compared based on ANCA status. Fisher`s exact test was employed for comparison of patient groups.

Results

ANCA findings are summarized in Table 1. MPO- and proteinase 3 (PR3)-ANCA positive patients (13.7%) had a higher prevalence of peripheral neuropathy (70% vs. 44.4%, p = 0.0003) and glomerulonephritis (20% vs. 14.3%, not significant). MPO- and PR3-ANCA-negative patients (86.3%) had a higher prevalence of heart (10% vs. 46%, p <0.0001), central nervous system (CNS) (0% vs. 14.3%, p <0.0001) and gastrointestinal (10% vs. 22.2%, p = 0.0327) involvement. PTX3-ANCA were associated with a higher prevalence of ear-nose-throat (ENT) (100% vs. 85.3%, p <0.0001), lung (100% vs. 89.7%, p = 0.0015), gastrointestinal involvement (60% vs. 17.6%, p <0.0001) and peripheral neuropathy (100% vs. 48.5%, p <0.0001). Kidney (0% vs. 16.2%, p <0.0001) and CNS involvement (0% vs. 13.2%, p = 0.0002) occurred less frequently in PTX3-ANCA positive patients. The 2 olfactomedin 4 (OLM4)-ANCA positive patients presented with ENT, lung and kidney involvement, and polyneuropathy, respectively.

Table 1.

ANCA in EGPA cohort (n = 73). BPI = bactericidal permeability-increasing protein.

IFT / ELISANo. of patients (%)P-ANCA11 (15.1)C-ANCA5 (6.8)MPO-ANCA8 (10.9)PR3-ANCA2 (2.7)BPI-ANCA1 (1.4)PTX3-ANCA5 (6.8)OLM4-ANCA2 (2.7)

Conclusion

We report on the detection of PTX3-, BPI- and OLM4-ANCA in addition to MPO- and PR3-ANCA in EGPA. OLM4-ANCA has been reported in 2 patients with non-vasculitic inflammatory symptoms previously [5]. Herein, detection of OLM4-ANCA in EGPA is reported for the first time. Our study shows that the presence of ANCA with various specificities other than MPO and PR3 contribute to a higher prevalence of ANCA in EGPA. Moreover, clinical manifestations differ between ANCA-negative EGPA and ANCA-positive EGPA, and between patients with different ANCA-specificities.

References

[1]Schönermarck U, et al. Prevalence and spectrum of rheumatic diseases associated with proteinase 3-antineutrophil cytoplasmic antibodies (ANCA) and myeloperoxidase-ANCA. Rheumatology 2001;40:178-84.

[2]Bremer P, et al. Getting rid of MPO-ANCA: a matter of disease subtype. Rheumatology 2013:752-4.

[3]Comarmond C, et al. Eosinophilic granulomatosis with polyangiitis (Churg-Strauss): clinical characteristics and long-term followup of the 383 patients enrolled in the French Vasculitis Study Group cohort. Arthritis Rheum 2013;65:270-81.

[4]Padoan R, et al. IgG anti-Pentraxin 3 antibodies are a novel biomarker of ANCA-associated vasculitis and better identify patients with eosinophilic granulomatosis with polyangiitis. J Autoimmun 2021;124:102725.

[5]Amirbeagi F, et al. Olfactomedin-4 autoantibodies give unusual c-ANCA staining patterns with reactivity to a subpopulation of neutrophils. J Leukoc Biol 2015;97:181-9.

Disclosure of Interests

None declared

POS0400 MODULATION OF HUMAN EARLY B CELL DEVELOPMENT THROUGH TARGETED DEGRADATION OF IKAROS AND AIOLOS WITH IBERDOMIDE

Background

B differentiation in the bone marrow (BM) is impaired in patients carrying mutation in the IKFZ1 gene, coding for Ikaros a zinc-finger transcription factor. High Ikaros expression is on the contrary associated with systemic lupus erythematosus[1] and multiple myeloma[2]. Targeted treatment with iberdomide, a cereblon modulator which enhances degradation of Ikaros and Aiolos, is under clinical investigation in multiple myeloma patients and systemic lupus erythematosus. However, consequences of the treatment on human early B cell development remain elusive. Immature B cells develop in the BM from hematopoietic stem cells. An intricate network of transcription factors regulates the maturation process. Ikaros and Aiolos regulate gene expression during B cell development. As reported in mice, Ikaros is essential for the commitment to the lymphoid lineage and later, together with Aiolos, ensures the transition from pre-BII large to pre-BII small cells.

Objectives

Investigate the effect of iberdomide (CC-220) on human early B cell development simulated in vitro.

Methods

We tested the impact of iberdomide on short term culture of BM-derived lymphocytes and in a unique in vitro modeling of early B cell development starting from cord blood (CB)- CD34+ progenitors [3, 4]. We used multi-dimensional spectra flow cytometry (17-color pan-el) to dissect early B cell subpopulations.

Results

Iberdomide treatment led to enhanced degradation of Ikaros and Aiolos in both BM- and CB-derived cultures. Addition of iberdomide early (day 7) to the CB-derived culture impaired the specification to the lymphoid lineage and later also the commitment to the B cell lineage. These observations were confirmed by reduced E2A and PAX5 gene expression, respectively. Treatment with iberdomide on B cell precursors (pro- and pre-B cells, day 28 of culture) on one side it enhanced the proliferation of early progenitors resulting in increased amount of CD10+CD38+ lymphoid-committed cells. On the other side, it resulted in a accumulation of pre-B cells and inefficient development of immature B cells.

Conclusion

Iberdomide impairs the commitment to the lymphoid lineage by enhancing Ikaros’ degrada-tion. When targeting already committed B cells, iberdomide treatment undermines the transition of pre-BII large to pre-BII small cells due to increased Aiolos’ degradation, conse-quently impairing the development of immature B cells. Our data can instruct immunologi-cal monitoring of patients treated with iberdomide, and provide insights in the mechanisms of therapeutic efficacy.

References

[1]Rivellese, F., et al., Effects of targeting the transcription factors Ikaros and Aiolos on B cell activation and differentiation in systemic lupus erythematosus. Lupus Sci Med, 2021. 8(1).

[2]Thakurta, A., et al., Developing next generation immunomodulatory drugs and their combinations in multiple myeloma. Oncotarget, 2021. 12(15): p. 1555-1563.

[3]Kraus, H., et al., A Feeder-Free Differentiation System Identifies Autonomously Proliferating B Cell Precursors in Human Bone Marrow. The Journal of Immunology, 2014. 192(3): p. 1044-1054.

[4]Troilo, A., et al., Nonpermissive bone marrow environment impairs early B-cell development in common variable immunodeficiency. Blood, 2020. 135(17): p. 1452-1457.

Disclosure of Interests

Iga Janowska: None declared, Jakov Korzhenevich: None declared, Julian Staniek: None declared, Raquel Lorenzetti: None declared, Lukas Konstantinidis: None declared, Miriam Erlacher: None declared, Peter Schafer Employee of: BMS, Reinhard Voll: None declared, Jens Thiel Grant/research support from: BMS (former Cellgene), Nils Venhoff: None declared, Marta Rizzi Grant/research support from: BMS (former Cellgene)

POS0408 TRANSFER OF HUMAN RHEUMATOID ARTHRITIS MONONUCLEAR CELLS INDUCES ARTHRITIS IN IMMUNODEFICIENT HLA-DR4 TRANSGENIC MICE

Background

Rheumatoid arthritis (RA) is a systemic autoimmune disease leading to erosive joint destruction. Although the exact pathogenesis is still elusive, the strong association of certain HLA class II molecules, such as HLA-DRB1*0401 (HLA-DR4), suggest involvement of CD4+ T cells (1,2). Mouse models of RA mimic specific aspects of the disease but are limited by the differences between human and murine immune systems.

Objectives

We aimed to establish a humanized mouse model (humice) carrying DR4+ RA PBMCs to study its role in the pathogenesis of RA without putting patients at risk.

Methods

Peripheral blood mononuclear cells (PBMC) of HLA-DR4 positive RA patients or controls were isolated and injected into NSG-Ab0 DR4 mice (NOD-scid IL2Rgammanull mice lacking MHC class II while expressing the human HLA-DR4) to create humice. Human immune cell composition within humice was profiled using flow cytometry. Development of RA was monitored by examination of the joints and micro computed tomography analysis. Joints were analysed by histology regarding pannus formation, bone erosions, cartilage damage, and human cell infiltration.

Results

Transfer of RA PBMCs induced arthritis in humice recapitulating hallmarks of RA including immune cell infiltration, pannus formation, increased osteoclastogenesis, cartilage damage, and bone erosions. Arthritis was dependent on the implanted human cells as NSG-Ab0 DR4 mice without transfer of human PBMCs did not develop arthritis. T-helper 1 (Th1) cells, dominated the human immune cell composition in humice, while regulatory T cells (Tregs) were diminished compared to donor PBMC composition. Mice humanized with cells from RA patients were more likely to develop inflammatory joint disease, compared to healthy HLA-DR4 positive controls (RA donor 70% vs. healthy control 20%, p=0.00196). CTLA-4 Ig treatment prevented arthritis development in this model (p=0.0055).

Conclusion

Humice carrying DR4+ RA PBMCs developed an RA-like erosive joint disease driven by the implanted human immune system. The data implies that the disease can be transferred by arthritogenic cells found in the peripheral blood of RA patients. This model will allow new insights into the pathogenesis of RA.

References

[1]Goulielmos GN, Zervou MI, Myrthianou E, Burska A, Niewold TB, Ponchel F. Genetic data: The new challenge of personalized medicine, insights for rheumatoid arthritis patients. Gene Available from: http://www.ncbi.nlm.nih.gov/pubmed/26869316

[2]Holoshitz J. The rheumatoid arthritis HLA–DRB1 shared epitope. Curr Opin Rheumatol Available from: http://www.ncbi.nlm.nih.gov/pubmed/20061955

Disclosure of Interests

None declared.

AB0472 DEFINING AN ACCEPTABLE STATE OF QUALITY OF LIFE IN PRIMARY SJÖGREN’S SYNDROME

Background

The PSS-QoL (the Primary Sjögren’s Syndrome Quality of Life Questionnaire) is a disease-specific health-related quality of life (HRQL) questionnaire in primary Sjögren Syndrome (PSS). The psychometric testing showed a valid and reliable assessment, which allows a comprehensive evaluation of the patients’ perspective and the extent of the disease in PSS.

Objectives

To define the threshold of an acceptable QoL state (AQLS) and the minimal detectable change (MDC) of the PSS-QoL.

Methods

Data of patients from the PSS registry of the Medical University of Graz fulfilling the 2016 ACR/EULAR classification criteria for PSS were analysed. Patients completed the PSS-Qol and ESSPRI (EULAR Sjögren’s syndrome patient-reported index), disease activity was assessed by the ESSDAI (EULAR Sjögren’s syndrome disease activity index) and an evaluator’s global assessment (EGA, scale from 0 to 10). Receiver operating characteristic curve analyses were used to estimate the AQLS based on patients’ assessment on the extent of HRQL. We selected the optimal cut-off of PSS-QoL by the maximal Youden index. At the follow – up visits after 12 months, patients assessed, whether their HRQL had changed. An anchoring method based on this evaluation was used to estimate the MDC of PSS-QoL. Furthermore, clinical data were compared in AQLS and non-AQLS groups.

Results

Data from 152 PSS patients were analysed which of 91.4% (n=139) were female. The mean age was 59.65±12.3 years (± standard deviation) and the mean disease duration was 5.6±5.3 years.

The AQLS estimate was defined as PSS-QoL≤29.5. 40.1% (n=61) were categorized to be in AQLS. Although AQLS patients were significantly younger (56.9±13.1years vs 61.5±11.4 years, p<0.01) they had a longer disease duration (6.9±5.8 years vs. 4.7±4.7 years, p<0.05) compared to non-AQLS patients. AQLS patients had a lower EGA (2 [0-5] vs 3 [0-7], p<0.01 (median [range]), higher IgG (15.7[7.7-33.8, range] vs 13.1 [6.5-38.1], p<0.05) and higher rheumatoid-factor IgA (84 [0-500] vs 20 [0-500], p<0.01).

AQLS patients showed significantly lower burden of sicca (measured by ESSPRI and sicca VAS scores).

The MDC for PSS-QoL was defined as 12.2 points. After one year, patients’ HRQL did not change in 83.3% and got worse 7.1%.

Conclusion

This study determined the AQLS and the minimal detectable change for HRQL. These results will help evaluating the HRQL of patients in clinical practice, as well as possible assistance designing future clinical trials. Patients in AQLS show lower dryness scores but higher immunological activity compared to non-AQLS patients. Longitudinal studies are needed to determine factors affecting patients’ HRQL in PSS.

Disclosure of Interests

None declared

AB0019 RITUXIMAB TREATMENT DOES NOT ALTER EXPRESSION OF CO-STIMULATION MARKER CD19 ON B CELLS IN SYSTEMIC SCLEROSIS PATIENTS

Background

CD19 is a membrane glycoprotein interacting with different surface molecules like the B cell receptor (BCR) and is crucial for antigen-independent development as well as immunoglobulin-induced activation of B cells.[1] Alterations in this signalling pathway can incline autoantibody production and systemic autoimmunity in humans. Rituximab (RTX), a CD20 antagonist appears to be an effective candidate in the treatment of different autoimmune diseases that are partly driven by autoreactive B cells, such as systemic sclerosis (SSc).[2] It has been speculated that RTX might work not only by depleting B cells but also to down regulate activation markers, such as CD19.

Objectives

In-depth analysis of CD19 abundancy and activation on B cells in SSc patients with and without RTX treatment

Methods

Peripheral blood samples from 41 patients suffering from SSc (median ± standard deviation SD, age: 54.3 ± 10.6 years, female ratio: 0.8) and 45 age- and sex-matched healthy controls (HC) (age: 51.0 ± 13.9 years, female ratio: 0.8) were drawn and PBMCs were isolated on-site. We performed flow cytometry analysis on a standardized BD LSRFortessa platform to identify B cell (CD19+CD20+) subpopulations. The geometric mean fluorescence intensity (gMFI) for CD19 in all B cell subtypes was extracted from the data set and used for further statistical analysis. Additionally, a quantitative flow cytometric bead-based assay (QuantiBRITE PE kit from Becton Dickinson) was used for the estimation of CD19 antibodies bound per cell.

Results

3 out of 41 SSc patients were in high disease activity at the time of blood drawal. 23 SSc patients were under RTX therapy of whom 5 patients still displayed measurable B cells frequencies. Naïve B cells made up the most abundant B cell population in SSc patients. Thus, the frequency of IgM+/IgD+/CD27- B cells was 67.9% ±13.2 (mean ±SD), followed by class-switched memory B cells (IgM-/IgD-/CD27+, 10.5 ± 4.9), non-switched memory B cells (IgM+/IgD+/CD27+, 4.0 ± 3.6) and plasmablasts (0.3 ± 4.4). Pairwise Wilcoxon Tests (Bonferroni-corrected for multiple testing) showed significant differences (p < 0.001) between frequencies of naïve B cells and all other cell types. In contrast, naïve B cells displayed the second lowest CD19 gMFI levels (7601.0 ± 1912.0) in the dataset. Non-switched memory B cells in SSc patients showed the highest CD19 gMFI (10620.0 ± 15689.8), followed by class-switched (9388 ± 3048.6). As expected, Plasmablasts displayed the lowest CD19 gMFI levels (4799.0 ± 4185.7). The decrease in CD19 gMFI was again highly significant. This trajectory in decreasing CD19 gMFI was found in both HCs and SSc patients. We saw a significant reduction in percentages of non-switch B cells and class-switched B cells in SSc patients compared to HCs (4.0 ± 3.6 vs 6.5 ± 4.2, p = 0.029, 10.5 ± 4.9 vs 13.2 ± 7.2 p = 0.04) but an increase in CD19 gMFI in non-switched B cells (HC: 9204.5 ± 2116.8, p = 0.05). Interestingly, SSc patients under RTX treatment had significantly lower class-switched memory B cell frequencies compared to HCs (6.4 ± 4.2 vs. 13.2 ± 7.2, p = 0.015). However, RTX did not affect CD19 gMFI or bound CD19 in SSc.

Conclusion

RTX treatment in SSc is not associated with downregulation of the co-stimulation marker CD19. Thus, the main effect of this drug is the reduction of B cells, especially class-swtched memory B cells that might have a high capacity to activate other cells involved in the pathogenesis of SSc.

References

[1]M. Wang et al., “Identification and Validation of Predictive Biomarkers to CD19- and BCMA-Specific CAR T-Cell Responses in CAR T-Cell Precursors,” Blood, vol. 134, no. Supplement_1, pp. 622–622, Nov. 2019, doi: 10.1182/blood-2019-122513.

[2]S. Ebata et al., “Safety and efficacy of rituximab in systemic sclerosis (DESIRES): a double-blind, investigator-initiated, randomised, placebo-controlled trial,” Lancet Rheumatol., 2021.

Acknowledgements

This work was funded by a grant from JDRF, LRA and NMSS (grant key: 2-SRA-2021-1043-S-B) and the Austrian Federal Government within the COMET K1 Centre Program, Land Steiermark and Land Wien.

Disclosure of Interests

Barbara Dreo: None declared, Barbara Prietl: None declared, Selina Kofler: None declared, Verena Pfeifer: None declared, Harald Sourij: None declared, Florentine Moazedi-Fürst: None declared, Sonja Kielhauser: None declared, Monica D’Orazio: None declared, Sabine Zenz: None declared, Jens Thiel Speakers bureau: Novartis, GSK, Vifor, BMS, Consultant of: Novartis, GSK, Vifor, Grant/research support from: BMS, Martin Stradner: None declared, Hans-Peter Brezinsek: None declared

POS0250 PLASMA MITOCHONDRIAL DNA AS A BIOMARKER IN THE DIAGNOSIS AND FOLLOW-UP OF ANCA-ASSOCIATED VASCULITIDES

Background

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) include granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) (1, 2). ANCA recognize the antimicrobial proteins proteinase 3 (PR3) or myeloperoxidase (MPO) (1,2) and trigger the formation of neutrophil extracellular traps (NETs), which release DNA into the extracellular space and systemic circulation. This cell-free (cf)DNA induces endothelial damage, vascular inflammation and necrosis (3).

Objectives

The nature, diagnostic and prognostic value of cfDNA in AAV is still unknown. The aim of the present study was to examine the clinical utility of cfDNA quantification as a biomarker in AAV.

Methods

Total DNA was isolated from platelet-free plasma samples of healthy controls (HC) and consecutive AAV patients. Plasma and clinical data were collected at baseline and follow-up. Copy numbers were quantified by qPCR for mtDNA (ATP-6 gene) and nuclear (n) DNA (GAPDH gene) (4). Patients with eosinophilic GPA (EGPA) were excluded.

Results

Ninety-two HC (median age 51 ± 9, 48.2% female) and 104 AAV patients (median age 64 ± 10, 48% female, mean BVAS: 0; range: 0-40) were available for analysis. Eighty-four (80.8%) of these patients were diagnosed with GPA, and 20 with MPA (19.2%).

mtDNA levels were significantly elevated in AAV plasma (8.7x107 copies/ml plasma, 95% CI: 5.3x107 to 1.3 x108)), compared to HC plasma (6.7x106 copies/ml plasma, 95% CI: 5.4x106 to 9.1x107, p<0.0001). nDNA levels in contrast did not differ between AAV (4.0x106 copies/ml plasma, 95%CI: 2.7x106 to 5.0x106) and HC (3.3x106 copies/ml plasma, 95%CI: 2.4x106 to 4.7x106, p=0.30). ROC analysis showed that a cut-off value of 1.3x107 mtDNA copy numbers differentiated between AAV and HC with 89.4% sensitivity, 82.6% specificity and an AUC of 0.94. For AAV patients with active AAV, a cut-off value of 2.9x107 mtDNA copy numbers differentiated between AAV and HC with 96.1% sensitivity, 98.9% specificity and an AUC of 0.99 (Figure 1a).

Figure 1.

(a.) ROC curve for mtDNA plasma concentrations to discriminate between HC and active AAV patients (BVAS>0). AUC: area under the curve. (b.) Plasma mtDNA levels distinguish between AAV patients with active disease versus patients in a state of remission. Whiskers represent 95% CI. (c.) Plasma mtDNA levels in AAV patients correlate with the evolution of disease activity at follow-up.

With the exception of the peripheral nervous system involvement, there was no association of mtDNA elevation with any particular type of active organ involvement at the time of blood sampling. A positive correlation between all cell-free DNA species and anti-MPO antibody titres was observed, as expected (for cfDNA, nDNA and mtDNA - r=0.25, p=0.01; r=0.21, p=0.02; r=0.22, p=0.02, respectively).

AAV patients with active disease (BVAS>0) had a mean of 2.0x108 copies/ml of mtDNA in plasma which was higher compared to HC (p<0.0001) and AAV patients in remission (BVAS=0) (6.2x107copies/ml, p=0.03). For nDNA on the other hand, there were similar levels in active disease as in remission (5.3x106 and 4.8x106 copies/ml, respectively; p=0.64) (Figure 1b).

Follow-up data were available for 27 AAV patients (median follow-up: 6 ± 6 months, IQR: 12). Longitudinal changes in mtDNA levels robustly correlated with changes in BVAS (r=0.56, p=0.002, Figure 1c).

Conclusion

The quantification of cell free mtDNA - but not nDNA - copy numbers allows a sensitive and specific distinction between healthy individuals and patients with active AAV. mtDNA levels correlate cross sectionally with disease activity in AAV patients. Plasma mtDNA quantification may therefore aid in the diagnosis of AAV and in monitoring AAV activity.

References

[1]Kitching, A.R., et al. Nat Rev Dis Primers6, 71 (2020).

[2]Kallenberg, C. Nat Rev Rheumatol10, 484–493 (2014).

[3]Kessenbrock, K., et al. Nat Med15, 623–625 (2009).

[4]Giaglis S, et al. RMD Open 2021;7:e002010.(2021)

Disclosure of Interests

None declared

POS1063 STAT PHOSPHORYLATION AS A MARKER FOR DISEASE ACTIVITY IN PATIENTS WITH PSORIATIC ARTHRITIS: AN EXPLORATIVE ANALYSIS

Background

Numerous cytokines that influence disease activity in psoriatic arthritis (PsA) are modulators of the Janus Kinases/Signal Transducers and Activators of Transcription (JAK/STAT) pathway. The JAK1/STAT1/STAT3/STAT5 network can drive the expansion of Th17 and regulatory T cells via proinflammatory cytokines in PsA joints,[1], [2] while hyperphosphorylation of STAT3 in immune cells has previously been shown to promote PsA pathogenesis through the Interleukin (IL)-23/IL-17/IL-22 axis.[3] Therefore, the phosphorylation status of STAT molecules in leucocytes of PsA patients may indicate active disease and could potentially guide treatment with JAK inhibitors.

Objectives

To analyse phosphorylated STAT (pSTAT) levels of circulating leucocyte subsets in PsA patients with active and inactive disease

Methods

Whole blood was drawn on consecutive PsA patients fulfilling the CASPAR criteria[4] to perform flow cytometry analysis using the BD FACSLyric platform. Disease activity was assessed using the Disease activity for psoriasis arthritis (DAPSA) score.[5] All steps from storage of drawn blood to cell fixation were performed at 4°C to prevent auto-activation of leucocytes. The geometric mean fluorescence intensities (gMFI) of pSTATs in granulocytes, monocytes, B cells and CD4+/- naïve/memory T cells were compared between patients with moderate to high (MoDA/HDA) and remission to low disease activity (REM/LDA). Correlation analysis between gMFIs and DAPSA scores were performed.

Results

Forty-two patients (female ratio: 0.48) with established PsA (median ± standard deviation, age: 56 ± 12.54 years, disease duration: 8.50 ± 7.10 years) were included in this study. Twenty-one percent of patients were in MoDA/HDA, while the remaining 79% were in REM/LDA. Patients in MoDA/HDA showed significantly higher pSTAT3 levels in CD4+ naïve (gMFI median ± standard deviation: 284.5 ± 79.9 vs 238 ± 92.9, p = 0.011), CD4- naïve (297 ± 107.5 vs 238 ± 98.4, p = 0.04), CD4+ memory (227 ± 62.9 vs 190.5 ± 72.2, p = 0.009) and CD4- memory T cells (209 ± 66.8 vs 167.0 ± 64.9, p = 0.036). On the other hand, PsA patients in remission or low disease activity displayed higher pSTAT1 levels in granulocytes (2509 ± 1887 vs 1330.5 ± 784.1, p = 0.040) and monocytes (255 ± 230 vs 144 ± 62.5, p = 0.049). Positive correlations were found between DAPSA scores and pSTAT3 in CD4+ naïve and memory T cells (Spearman’s correlation coefficient rho (ρ) = 0.5, p = 0.0012 and ρ = 0.47, p = 0.0025 resp.) whereas pSTAT1 in granulocytes and monocytes were negatively correlated with the DAPSA scores (ρ = -0.45, p = 0.0074 and ρ = -0.34, p = 0.05).

Conclusion

Differential phosphorylation of STAT3 and STAT1 molecules in circulating leucocyte subsets indicates PsA disease activity. Further studies to examine the value of STAT phosphorylation patterns guiding JAK inhibitor therapy are underway.

References

[1]U. Fiocco et al., “Ex vivo signaling protein mapping in T lymphocytes in the psoriatic arthritis joints,” J. Rheumatol., vol. 93, pp. 48–52, 2015, doi: 10.3899/jrheum.150636.

[2]S. K. Raychaudhuri, C. Abria, and S. P. Raychaudhuri, “Regulatory role of the JAK STAT kinase signalling system on the IL-23/IL-17 cytokine axis in psoriatic arthritis,” Ann. Rheum. Dis., vol. 76, no. 10, pp. e36–e36, 2017.

[3]E. Calautti, L. Avalle, and V. Poli, “Psoriasis: A STAT3-centric view,” International Journal of Molecular Sciences, vol. 19, no. 1. MDPI AG, Jan. 06, 2018, doi: 10.3390/ijms19010171.

[4]W. Taylor, D. Gladman, P. Helliwell, A. Marchesoni, P. Mease, and H. Mielants, “Classification criteria for psoriatic arthritis: Development of new criteria from a large international study,” Arthritis Rheum., vol. 54, no. 8, pp. 2665–2673, 2006, doi: 10.1002/art.21972.

[5]M. M. Schoels, D. Aletaha, F. Alasti, and J. S. Smolen, “Disease activity in psoriatic arthritis (PsA): Defining remission and treatment success using the DAPSA score,” Ann. Rheum. Dis., vol. 75, no. 5, pp. 811–818, 2016, doi: 10.1136/annrheumdis-2015-207507.

Disclosure of Interests

Barbara Dreo: None declared, Daniel Ruben Pietsch: None declared, Rusmir Husic Speakers bureau: MSD, Lilly und Abbvie, Angelika Lackner: None declared, Johannes Fessler: None declared, Janine Rupp: None declared, Anirudh Subramanian Muralikrishnan: None declared, Jens Thiel Speakers bureau: GSK, BMS, AbbVie, Novartis, Consultant of: GSK, Novartis, Grant/research support from: BMS, Martin Stradner Speakers bureau: Eli Lilly, Pfizer, MSD, BMS, AbbVie, Janssen, Consultant of: Eli Lilly, AbbVie, Janssen, Philipp Bosch Grant/research support from: Pfizer

POS0917 TRANSTHORACIC LUNG SONOGRAPHY (LUS) – USEFUL SURVEILLANCE TOOL IN SYSTEMIC SCLEROSIS ASSOCIATED INTERSTITIAL LUNG DISEASE?

Background

The Interstitial lung disease (ILD) represent a major cause of mortality in Systemic sclerosis (SSc). Validated methods for screening and therapy monitoring of SSc-ILD are needed. In the recent literatur, the transthoracic lung sonography (LUS) emerges as a reliable tool for the early detection of lung alterations. It was recently reported that SSc-ILD-patients have thicker artefacts reflecting the pleuraline compared with SSc-patients without ILD, but it still remains unknown if the thickness of the pleuraline changes with a proper therapy response.

Objectives

The aim of the study was to compare the thickness of the pleuraline of SSc-ILD-patients without biological Disease Modifying Anti-Rheumatic Drugs (bDMARDS) with those successfully treated with bDMARDs in order to establish if LUS can be a reliable surveillance tool in SSc-ILD. Additionally, since our Grazer-Schema (Mycofenolat mofetil (MMF)+ rituximab (RTX) 500 mg i.v. in week 0 and 2 every 3 months) is succesfully used in our clinic since more than 10 years in patients nonresponding to methotrexate (MTX) or cyclophosphamide, we report 10 years follow-up data of 5 Patients before and after receiving that schema.

Methods

29 prospectively enrolled SSc-patients were assessed according to the European League Against Rheumatism Scleroderma Trial and Research standards. Written informed consent was obtained from all patients and the study was approved by the Ethics Committee of Graz. Validated clinical scores, such as the scleroderma disease activity (SScAS) and the scleroderma disease severity scale (SScSS) were assessed. The thickness of the pleuraline was detected with LUS. The presence of ILD was assessed by high-resolution computed tomography. Twenty-five SSc-patients enrolled between 2008 and 2009, who underwent LUS with the same technical instruments and some of the same operators, were taken as a control group since they were untreated yet or were not assuming bDMARDs(1).

Results

Of the 29 SSc-patients (27 females/2 males) enrolled between 2019 and 2020, seventeen patients had radiographic signs of ILD (SSc-ILD+/2019-20, n=17). Until the LUS was performed, all SSc-ILD+/2019-20 showed a good clinical response to the therapy with RTX in combination with MMF. Of the 25 SSc-patients enrolled in our previous study, (n=25; 23 females/ 2 males), twelve of these patients had radiographic signs of ILD (SScILD+/2009-10, n=12); 7 were under MTX or Cyclosporin and 5 were untreated. Additionally, data collected from 5 SSc-ILD+/2009-2010 at baseline were analysed in a 10- years- follow up. As expected, SSc-ILD+ patients had a thicker pleuraline than SSc-ILD- patients. The pleura was significantly thinner in patients under MMF und RTX compared to the pleuraline of patients without bDMARDs (1,8 mm ± 0,7 Vs 0,95 ± 0,31; p < 0,00). Interestingly those patients reported less frequently dry cough or dyspnoea, showing that the lower pleura thickness could be associated with a better clinical outcome. In a 10 Year follow-up after continued treatment with MMF and RTX, a significant reduction of the thickness of the pleura could be found (Mean 0,68 ± 0,2 VS 1,5 ± 0,4; p < 0,00). Interestingly, such significant improvement could be found in all of these 5 patients receiving our Grazer Schema. Remarkably, the pleuraline-thickness was comparable to the thickness of the pleura of SSc-ILD-patients. This finding shows that the increase in thickness of the pleuraline can be totally reversible under treatment.

Conclusion

Due to the encouraging validity, reliability and simplicity of LUS, it has been increasingly considered as an excellent screening tool for SSc-ILD. Its sensitivity to reveal parenchyma and pleura changes over time in treated patients, make it also a helpful and safe methodology to follow up SSc-ILD patients.

References

[1]Moazedi-Fuerst, F. C. et al. Pulmonary echography in systemic sclerosis. Clinical Rheumatology (2012) doi:10.1007/s10067-012-2055-8.

Disclosure of Interests

None declared

POS0786 IDENTIFYING INDIVIDUALS AT RISK FOR SJÖGREN’S SYNDROME – THE PRE-SJÖGREN SYNDROME TARGETED IMMUNOLOGY EVALUATION (PRESTIGE) STUDY

Background

Primary Sjögren’s Syndrome (pSS) is a chronic autoimmune disease. Symptoms range from sicca to systemic, potentially life-threatening organ damage. Little is known about the onset of the disease. Anti-Ro antibodies are described to develop years before the first symptoms. In addition, first degree relatives of pSS patients have an 11- to 19- fold increased risk of developing pSS themselves.

Objectives

To identify and follow-up individuals at risk for pSS in order to study symptoms and immune pathology before and at development of pSS.

Methods

In this ongoing long-term study individuals at risk for developing pSS but not fulfilling the ACR-EULAR classification criteria of pSS were included, defined as: 1.) Anti-SSA positive individuals (Anti-SSA+) without any sicca symptoms or diagnosis of an underlying systemic autoimmune disease; 2.) First degree relatives of patients (relatives) with an established diagnosis of pSS and typical autoantibodies (ANA ≥ 1:160 and/or anti-SSA+ and/or rheumatoid factor+); 3.) Individuals with at least one feature of the ACR-EULAR classification criteria for pSS, but not fulfilling the criteria (incomplete).

At baseline and at annual visits, demographic data, blood, saliva and urine samples were collected and stored. Salivary and lacrimal flow, salivary gland ultrasonography (SGUS), and patient-related outcome measures were analysed. A lip salivary gland biopsy was performed at baseline and upon development of symptoms suggestive of pSS. The primary endpoint was the development of definite pSS according to the ACR-EULAR classification criteria.

Results

After the first year of recruitment, 50 individuals (Anti-SSA+ n=27, relatives n=21, incomplete n=2) were screened at baseline, of whom 28 were identified as individuals at risk for pSS and were included in the study. Twenty-two individuals were excluded from the study, most of whom were “relatives” with negative autoantibodies. Of these 28 individuals at risk, 89% were female (n=25), they had a median age of 53 years (IQR: 19) and 57% (n=16) had positive antinuclear antibodies. 86 percent were positive for anti-SSA and 14% were positive for anti-SSB. Decreased complement C3 and C4 were found in 18% and 4%, respectively. Serum IgG concentration was elevated in 29% of individuals. A reduction of lacrimal flow was found in 29% and stimulated whole salivary flow was reduced in 29%. The median of the ESSPRI was 1.6 (3.0). Eight-teen percent of the investigated individuals had a pathological ultrasound [Hocevar score median 4,5 (9,0)] and in 9% a focus score ≥ 1 [median 0.15 (0.57)] was found in the lip salivary gland biopsies. Four patients (14%) met the primary endpoint and were diagnosed with pSS within the first year.

Conclusion

The design of the PRESTIGE study allows us to follow individuals at risk for pSS and will help to unveil symptoms and immune pathology as pSS develops. We suggest to establish a larger international pre-pSS cohort to increase statistical power.

Disclosure of Interests

None declared

AB0471 FIRST SYMPTOMS AT THE ONSET OF PRIMARY SJÖGREN’S SYNDROME – THE PATIENTS’ PERSPECTIVE OF A SNEAKY DISEASE

Background

Primary Sjögren Syndrome (PSS) is an autoimmune disorder with a diverse spectrum of clinical manifestations ranging from sicca symptoms to severe systemic organ involvement. Little is known about the symptoms at the onset of PSS, as these are often ignored by both, patients and physicians leading to a substantial delay of diagnosis.

Objectives

The aim of this study was to investigate patients’ recollection of the first symptoms before diagnosis of PSS in qualitative interviews. The second aim was to verify and quantify these aspects in a representative cohort.

Methods

All PSS patients fulfilled the EULAR/ACR 2016 classification criteria. In the first part of the study, consecutive PSS patients were recruited for individual, semi-structured interviews. A discussion guide with five open-ended questions was developed to explore patients’ experiences on the onset of PSS. All interviews were audio-recorded and transcribed verbatim, and an inductive thematic data analysis was performed using MAXQDA software (VERBI, Berlin, Germany).

In the second part, the identified aspects of the qualitative analysis were grouped to a checklist with ten items. Patients were asked to complete the checklist before their routine clinical assessment.

Results

One-hundred and thirty-four patients participated in the study. The qualitative part was completed by 31 PSS patients; 90.3% (n=28) were female and patients had a mean disease duration of 6.9 years (±5.7(SD)) and a mean age of 58.1 years (±12.6).

Four different major aspects emerged of how patients experienced the beginning and first symptoms of PSS: (1) sicca symptoms started after initial swelling of parotis and/or lymph nodes (2) “Classic” PSS symptoms (fatigue, pain, dryness): patients reported wandering joint pain before diagnosis with a long time apart from first symptoms until diagnosis. Patients described joint pain, chronic malaise, and fatigue over months. (3) Hormonal changes (e.g. after birth, hysterectomy) or infections before the onset of PSS symptoms. (4) Slowly progressing discomfort due to sicca: patients reported a slow progression of symptoms with no initial recognition of sicca discomfort. In these patients recurrent dental problems and loss of teeth in the years prior to diagnosis was common.

In the second part of the study, the four themes were verified in an independent cohort of 103 PSS patients. Patients were 59.9 (±13.7) years old and six patients were male. The main symptom before diagnosis was dryness (n=77, 74.8%) with wandering joint pain (n=51, 49.5%) and fatigue (n=47, 45.6%). In 38.8% (n=40), patients reported a swelling/inflammation of the parotid gland at the onset of disease.

Conclusion

We identified four themes describing the initial symptoms of PSS. Raising awareness of these symptoms among physicians and among the general public may allow earlier diagnosis of PSS.

Disclosure of Interests

None declared

AB0815 SLEEP DISORDERS ARE FREQUENT IN SPONDYLOARTHRITIS, ASSOCIATED WITH REDUCED QUALITY OF LIFE AND DEPRESSION AND MORE PREVALENT IN FEMALE PATIENTS

Background

Axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA) may have a profound impact on health-related quality of life (HRQoL) and sleep despite effective treatment.

Objectives

To assess sleep and HRQoL in SpA and determine associated factors.

Methods

Monocentric questionnaire-based assessment of HRQoL, function, sleep and depression in 314 SpA patients (n=168 PsA, n=146 axSpA).

Results

Under effective treatment 138 SpA patients (46.5%) demonstrated abnormal sleep behaviour. 49.3% reported not being able to sleep through the night, with 6.1 % needing sleeping pills. 11.9% indicated feeling unrefreshed most mornings. Abnormal sleep behaviour was associated with female sex (p=0.005), HLAB27 (p=0.034), functional impairment (p=0.001) and depression (p<0.001). Patients reporting unrestful sleep had significantly more depressive symptoms (p<0.001) and highly reduced physical and mental HRQoL (p<0.001). Satisfaction with health was rated significantly lower (p<0.001). Patients with axial involvement (axSpA/axPsA) reported worse sleep quality (p=0.002) and waking too early (p=0.038) despite 73.7% receiving biologics. Sleep quality and early awakening correlated with BASDAI (p<0.001). Smokers had a reduced HRQoL (p=0.018) despite younger age (p=0.008). Female patients had worse sleep quality (p<0.001), needing more time to fall asleep (p=0.022), not being able to sleep through the night (p=0.026) and feeling unrefreshed in the morning (p<0.001). They had a reduced physical (p=0.019) and mental HRQoL (p=0.003), more depressive symptoms (p=0.040) and lower functional capacity (p=0.002). Functional capacity was associated with younger age (p<0.001), sex (p=0.042), smoking (p=0.008), sleep quality (p<0.001) and depression (p<0.001). 66.2% of patients have been assessed longitudinally, before and 3y later during COVID19 pandemic. Physical and mental HRQoL were stable over time. Functional capacity had decreased slightly. Subjective QoL during the COVID19 pandemic was not reduced compared to before. Regarding depressive symptoms, there was a mild but significant improvement over time (p=0.019). Furthermore, we observed an improvement of environmental QoL (p=0.034) during COVID pandemic. Overall subjective QoL as well as satisfaction with health did not change significantly. Patients who had changed therapy (37% of the cohort) still had a reduced physical HRQoL (p=0.022) as well as significantly more depressive symptoms (p=0.010) and perceived their overall QoL as being worse (p=0.016).

Conclusion

Despite treatment many SpA patients have a reduced HRQoL and impaired sleep quality with significant differences between male and female patients. Impact of COVID19 pandemic was low.

Table 1.

Disclosure of Interests

Natalie Frede Grant/research support from: Novartis study grant, Eva Rieger: None declared, Raquel Lorenzetti Grant/research support from: Novartis study grant, Ana Venhoff: None declared, Carolin Hentze: None declared, Ilona Jandova: None declared, Cornelia Glaser: None declared, Jens Thiel Speakers bureau: Novartis, AbbVie, Pfizer, BMS, UCB, Consultant of: Novartis, AbbVie, Pfizer, BMS, UCB, Grant/research support from: BMS, Novartis study grants, Reinhard Voll Speakers bureau: Novartis, AbbVie, Pfizer, BMS, UCB, Consultant of: Novartis, AbbVie, Pfizer, BMS, UCB, Lilly, Grant/research support from: Novartis study grant, Nils Venhoff Speakers bureau: Novartis, AbbVie, Pfizer, BMS, UCB, Consultant of: Novartis, AbbVie, Grant/research support from: Novartis study grant

AB0732 Abatacept as therapy option in systemic sclerosis (SSc) patients after years of Grazer- protocol treatment- Our Experience

Background

Previous studies have provided evidence that T cells may play a significant role in the pathogenesis of systemic sclerosis (SSc) and observational studies reported that Abatacept, which interferes with T cells activation, appeared to be safe and effective in SSc-patients with skin and muscle involvement. So far, there was no significant effective treatment for SSC-ILD. We have recently demonstrated the effectiveness of intensified –RTX- long term treatment (“Grazerprotocol” with 500 mg RTX in week 0 and 2, every 3 months +/- MMF) in SSc patients with severe organ involvement and/or progressive form non responding to methotrexate or cyclophosphamide. However, no data are available concerning how long Patients with a stable disease need to be treated. B-cell-depletion therapy over years for SSC in remission might represent a risk factor for infections. Additionally, the parenteral administration is associated with an increase in health care and patients are bound to regular hospital visits, which is a limiting factor for life quality.

Objectives

We aimed to investigate if subcutaneous Abatacept could be used as a maintenance treatment in SSc-patients reaching a stable disease activity after a treatment with RTX administered according to our Grazer protocol over several years.

Methods

In this retrospective analysis, we retrieved data from 20 patients who fulfilled the diagnosis criteria for systemic sclerosis (SSc) according to the European League Against Rheumatism Scleroderma Trial and Research standards, who started a treatment with abatacept (ABA) after years of 500 mg RTX therapy every three months +/- MMF (Grazer protocol). The following clinical parameter were evaluated: modified Rodnan Skin Score (mRSS), Systemic Sclerosis Activity Score (SScAS), Systemic Sclerosis Severity Score (SScSS) and lung diffusing capacity for carbon monoxide (DLCO). Lab parameters like IgG, ANA, ENA and inflammation parameters were routinely assessed. Clinical data from baseline visit (BSL) (before ABA treatment start) and follow-up visit (FU) (after 6 months of treatment) were collected.

Results

We included 20 SSc patients in this retrospective analysis who changed from RTX to Abatacept. The majority were female (n=16; 94.1%), with a mean age ±SD of 54.8 years ±11 and an average disease duration of 7.7 years ±4.5. In 17.9% (n=4) treatment needed to be stopped due to disease flare after three months (lung n=2, skin and tendons n=2).

However, interestingly, Abatacept further decreased significantly mRSS between baseline visit and follow-up visit regarding the affected skin of the fingers. Thus, the mRSS went from 3.9±3.4 to 2.5±1.8 (p<0.05). As expected, no significant difference in the EUSTAR-SScAS, or ScSS or DLCO was found. No infections were observed during the abatacept follow-up period and Immunoglobulins remained within the normal range.

Conclusion

Abatacept might be a feasible option as a maintenance therapy after intensive immunomodulation with RTX and may give our patients the possibility to further improve their quality of life.

The fact that 4 patients experienced a relapse after switching to Abatacept warrants further studies to find prognostic factors.

Disclosure of Interests

None declared

POS1265 DISTURBED CELLULAR IMMUNITY FOLLOWING mRNA VACCINATION AGAINST COVID-19 IN PATIENTS WITH B-CELL DEPLETING THERAPY

Background

Immunocompromised patients are considered high-risk and prioritized for vaccination against COVID-19 (1). Furthermore, vaccination-induced CD4 and CD8 T-cell responses have been suggested to have a protective role in COVID-19 (2). If T-cell responses are diminished after vaccination in immunocompromised individuals is not known to date.

Objectives

To investigate cellular immunity following mRNA vaccination against COVID-19 in healthy individuals and patients undergoing B-cell depletion therapy.

Methods

In this interim analysis of the CoVVac study (NCT04858607), we analyzed T-cell responses in autoimmune patients treated with B-cell depleting therapy (BD, n=41) and age-matched healthy controls (HCs, n=50) 3-4 weeks after the second dose of mRNA vaccination against COVID-19. Therefore, we isolated PBMCs and stimulated them with a peptide pool covering the spike protein in vitro. Reactive CD4 and CD8 T-cells were determined by staining for IFNg, TNFa, IL-2 and GzmB by flow cytometry. Anti-SARS-CoV-2 antibody assays targeting the receptor-binding domain (RBD) or trimeric S protein (TSP) were performed to elucidate concomitant B-cell responses.

Results

We observed significant alterations in anti-SARS-CoV-2 antibody responses in our cohort, the frequency of IFNg+ and IL-2+ CD4 and CD8 T-cells was similar in BD patients and controls. On the other hand, TNFa+ CD4 T-cells were significantly enriched in healthy controls versus BD patients (p=0.017) and correlated significantly with antibody titres (p=0.003). Similarly, GzmB+ CD8 T-cells were significantly diminished in our patient cohort (p<0.001) and also showed a significant correlation with antibody titres (p<0.001). Overall, the frequency of GzmB+ CD8 T-cells correlated very well with reactivity of T-cell subsets for other cytokines. This effect, however, is lost in the BD cohort. No difference was observed in the frequency of TNFa+ CD8 T-cells between the groups.

Only 21 (42%) healthy individuals and 14 (34%) patients showed reactive T-cells for all the cytokines tested. This observation is mainly explained by a lack of cytokine production of CD8 T-cells in 26 (52%) HCs and 27 (66%) BD patients. In turn, 22 (44%) HCs and 17 (42%) patients didn’t show any IL-2 producing CD8 cells. Of note, only 2 (4%) of HCs showed no GzmB+ CD8 T-cells whereas the number increased to 15 (37%) of BD individuals (p<0.001). In contrast, 42 (84%) HCs as well as 32 (78%) of patients showed production of all IFNg, TNFa and IL-2 in CD4 T-cells.

Conclusion

Our data suggest that most patients with B-cell depleting therapy are able to mount T-cell responses similar to those of healthy individuals while a minority of these patients did not show complete immunity against SARS CoV-2. Further analyses are needed to better understand a possible link of B-cell depletion therapy and CD8 T-cell responses.

References

[1]Shields AM, Burns SO, Savic S, Richter AG; UK PIN COVID-19 Consortium. COVID-19 in patients with primary and secondary immunodeficiency: The United Kingdom experience. J Allergy Clin Immunol. 2021 Mar;147(3):870-875.e1.

[2]Angyal, A., Longet, S., Chalk, J., 2022. T-cell and antibody responses to first BNT162b2 vaccine dose in previously infected and SARS-CoV-2-naive UK health-care workers: a multicentre prospective cohort study. The Lancet Microbe 3

Disclosure of Interests

None declared

AB0622 The Joint Vasculitis Registry in German-speaking countries (GeVas) – subgroup analysis of 113 GPA-patients

Background

Granulomatosis with polyangiitis (GPA) is the second most frequent vasculitis in Germany with an annual incidence of 34 per million and a prevalence of 210 per million [1]. GPA is characterized by its chronic course, frequent relapses, significant overall morbidity and mortality, and substantial socio-economic impact. Multiorgan involvement affecting the respiratory tract, kidney, and other organs is common. Limited variants also occur [2]. So far, prospective long-term observational data on the disease course of GPA are missing in Germany. Therefore, the Joint Vasculitis Registry in German-speaking countries (GeVas) has been established to follow the course of patients recently diagnosed with vasculitis or a change of their treatment due to a relapse (inception cohort). The GeVas registry allows long-term follow-up of a substantial cohort of vasculitis patients in a multicenter setting.

Objectives

To present the first data on the follow-up of newly diagnosed and relapsing GPA enrolled in the GeVas registry.

Methods

GeVas is a prospective, web-based, multicenter, clinician-driven registry for the documentation of organ manifestations, damage, long-term outcomes, and therapy regimens in various types of vasculitis. Recruitment started in June 2019. By January 2022, 17 centers in Germany were initiated and started enrolling patients. Meanwhile, more than 350 patients have been documented in the registry. Sites in Austria and the German-speaking cantons of Switzerland will be integrated soon [3].

Results

By mid-October 2021, the participating centers included 113 patients with GPA. The majority of patients were PR3-ANCA positive and affected by general symptoms, ENT, lung, renal, and neurological involvement. Patients commonly received cyclophosphamide or rituximab in combination with glucocorticoids for the induction of remission. Fewer patients received methotrexate or other immunosuppressants. Patient characteristics and therapy are summarized in Table 1.

Table 1.

Patient characteristics (n = 113). *Unless otherwise specified.

CategoryFeaturen (%)*AgeAge (years); median [range]60 [51 - 70]GenderMale61 (54.0)Female52 (46.0)Reason for inclusion in the registryNewly diagnosed vasculitis57 (51.4)Relapse56 (49.6)ANCA statusPR3-ANCA99 (87.6)MPO-ANCA4 (3.6)ANCA negative9 (7.9)Organ manifestationGeneral symptoms86 (76.1)ENT69 (61.1)Lung/chest66 (58.4)Renal35 (31.0)Cardiovascular7 (6.2)GI3 (2.7)Neurological27 (23.9)TherapyGlucocorticoid102 (90.3)Rituximab56 (49.6)Cyclophosphamide37 (32.7)Methotrexate and other immunosuppressants, respectively26 (23.0) and 19 (16.8), respectively

Conclusion

Here, we present the first interim analysis of the GeVas registry. Clinical manifestations of GPA reported herein show less frequent renal involvement in comparison with a recent report from another European registry (POLVAS) and an UK study [4, 5]. This is potentially related to the predominance of recruiting rheumatology centers thus far. By contrast, respiratory tract involvement is more frequent and PR3-ANCA less common in Japan [5]. Further data are prospectively documented and a follow up analysis is in progress.

References

[1]Hellmich B, et al. New insights into the epidemiology of ANCA-associated vasculitides in Germany: results from a claims data study. Rheumatology 2021;60:4868-73.

[2]Kitching AR, et al. ANCA-associated vasculitis. Nat Rev Dis Primers 2020;6:71.

[3]Iking-Konert C, et al. The Joint Vasculitis Registry in German-speaking countries (GeVas) – a prospective, multicenter registry for the follow-up of long-term outcomes in vasculitis. BMC Rheumatol 2021;5:40.

[4]Wójcik K, et al. Clinical characteristics of Polish patients with ANCA-asscoiated vasculitides – retrospective analysis of POLVAS registry. Clin Rheumatol 2019;38:2553-63.

[5]Furuta S, et al. Comparison of the phenotype and outcome of granulomatosis with polyangiitis between UK and Japanese cohorts. J Rheumatol 2017;44:216-22.

Acknowledgements

GeVas was supported by unrestricted grants by: DGRh, John Grube Foundation, Vifor and Roche Pharma

Disclosure of Interests

Sabrina Arnold: None declared, Pia Wallmeier: None declared, Fabian Schubach: None declared, Gabriele Ihorst: None declared, Peer Aries: None declared, Raoul Bergner Consultant of: VIFOR, Jan Philip Bremer: None declared, Norman Görl: None declared, Bernhard Hellmich: None declared, Jörg Henes: None declared, Bimba Hoyer: None declared, Antje Kangowski: None declared, Ina Kötter: None declared, Claudia Metzler: None declared, Ulf Müller-Ladner: None declared, Matthias Schaier: None declared, Ulf Schönermark: None declared, Jens Thiel: None declared, Leonore Unger: None declared, Nils Venhoff Speakers bureau: Roche and Vifor: speaker honoraries, Consultant of: Roche and Vifor: advisory boards, Grant/research support from: John-Grube Research Award 2021, Julia Weinmann-Menke: None declared, Jana Petersen: None declared, Christof Iking-Konert Speakers bureau: Lecture fees from: Chugai, GSK, Roche, and Vifor, Consultant of: Consulting fees from: Chugai, GSK, Roche, and Vifor, Grant/research support from: Research grants for GeVas: Roche, Vifor, DGRh, John Grube Foundation, Peter Lamprecht Speakers bureau: Chugai, GSK, Roche, and Vifor, Consultant of: Chugai, GSK, Roche, and Vifor, Grant/research support from: DGRh, John Grube Foundation, Roche, and Vifor

POS0800 THE JOINT VASCULITIS REGISTRY IN GERMAN-SPEAKING COUNTRIES (GeVas) – SUBGROUP ANALYSIS OF 131 GCA-PATIENTS REFERENCES:

Background

The most frequent form of vasculitis in elderly people is giant cell arteritis (GCA) with an annual incidence rate less than 10 per 100,000 persons over the age of 50. Like most vasculitides, GCA is characterized by chronicity and relapses, leading to significant overall morbidity and higher mortality in a subset of patients with aortic involvement and dissection. Most studies carried out so far have been retrospective, used monocentric study designs and small patient cohorts. Therefore, the Joint Vasculitis Registry in German-speaking countries (GeVas) has been established to record patients, who have been recently diagnosed with vasculitis or who have changed their treatment due to a relapse (inception cohort). The GeVas-Registry allows a long-term follow-up of a substantial cohort of vasculitis patients in a prospective and multicenter manner.

Objectives

To describe the subgroup of GCA and its characteristics within the GeVas registry.

Methods

GeVas is a prospective, web-based, multicenter, clinician-driven registry for the documentation of organ manifestations, damage, long-term outcomes, and therapy regimens in various types of vasculitis. Recruitment started in June 2019. By January 2022, 17 centers in Germany were initiated and have begun enrolling patients. Meanwhile, more than 350 patients have been documented in the registry. Sites in Austria and the German-speaking cantons of Switzerland will be integrated soon (1).

Results

By mid-October 2021, the participating centers recruited 131 GCA patients into the registry. 21.7% of patients (n=28) were enrolled in the registry due to relapse, and 78.3% (n=101) due to a first-time diagnosis. In accordance with long-standing epidemiology data, the majority of patients (67,2%), were female (n=88), and 32.8% (n=43) were male. Mean age was 74 years (max. 92y, min. 52y). The most frequently recorded organ manifestations in GCA patients addressed cranial and ophthalmic symptoms, and the cardiovascular system. However, vascular lung/chest involvement was also observed in 3% of cases (n=4). Out of the 131 patients, 97.7% (n=128) received immunosuppressive therapy, three refused to take any medication. An equal number of patients were treated with glucocorticoid (GC) therapy. While about two equal parts were treated by stable long term oral GC therapy (47,7%, n=62) or by i.v. pulse therapy followed by tapering (49,2%, n=64), only about 2.3% (n=3) were treated by oral GC therapy with intermittent i.v. pulses. 48.5% (n=63) of patients received tocilizumab as additional immunosuppressive therapy, 19.2% (n=25) methotrexate, and 18.5% (n=24) cyclophosphamide i.v. pulses.

Conclusion

In June 2019, we successfully established the prospective multicenter vasculitis registry GeVAS. It describes the first systematically recorded prospective GCA cohort in German-speaking countries. Its characteristics correspond to those that can be expected from the literature, with some unexpected finding e.g. the high proportion of patients treated with cyclosphosphamid, probably reflecting a sicker patient population with e.g. aortic or central nervous involvement. After 2.5 years of follow-up documentation, the first long-term results will be systematically evaluated and interpreted. The newly acquired data on disease manifestation, diagnostics and therapy regimens will provide important insights into the treatment of GCA patients in Germany and may generate further research goals.

References

Trial registration: German Clinical Trials Register (Deutsches Register Klinischer Studien): DRKS00011866. Registered 10 May 2019. 3

[1]C Iking-Konert; P Wallmeier; S Arnold; S Adler; K de Groot; B Hellmich; B Hoyer; K Holl-Ulrich; Ihorst; M Kaufmann; I Kötter; U Müller-Ladner; T Magnus; J. Rech; H. Schulze-Koops; N. Venhoff; T. Wiech; P. Villiger; F. Schubach; P. Lamprecht. The Joint Vasculitis Registry in German-speaking countries (GeVas) – a prospective, multicenter registry for the follow-up of long-term outcomes in vasculitis. BMC Rheumatol. 2021 Jul 31;5(1):40. doi: 10.1186/s41927-021-00206-2.

Acknowledgements

GeVas was supported by unrestricted grants by: DGRh, John Grube Foundation, Vifor and Roche Pharma

Disclosure of Interests

Pia Wallmeier: None declared, Sabrina Arnold: None declared, Fabian Schubach: None declared, Gabriele Ihorst: None declared, Peer Aries: None declared, Raoul Bergner Consultant of: Advisory Board VIFOR, Grant/research support from: John-Grube Research Award 2021, Jan Philip Bremer: None declared, Norman Görl: None declared, Bernhard Hellmich: None declared, Jörg Henes: None declared, Bimba Hoyer: None declared, Antje Kangowski: None declared, Ina Kötter: None declared, Tim Magnus: None declared, Claudia Metzler: None declared, Ulf Müller-Ladner: None declared, Matthias Schaier: None declared, Ulf Schönermark: None declared, Jens Thiel: None declared, Leonore Unger: None declared, Nils Venhoff Speakers bureau: Roche and Vifor, Consultant of: Roche and Vifor, Grant/research support from: John-Grube Research Award 2021, Julia Weinmann-Menke: None declared, Jana Petersen: None declared, Peter Lamprecht Speakers bureau: Lecture fees from: Chugai, GSK, Roche, Consultant of: Consulting & lecture fees from: Chugai, GSK, Roche, and Vifor., Grant/research support from: Research grants for GeVas: DGRh, John Grube Foundation, Roche, and Vifor, Christof Iking-Konert Speakers bureau: lecture fees from: Chugai, GSK, Roche, and Vifor., Consultant of: Consulting fees from: Chugai, GSK, Roche, and Vifor., Grant/research support from: Research grants for GeVas: DGRh, John Grube Foundation, Roche, and Vifor;

OP0182 SECUKINUMAB IN GIANT CELL ARTERITIS: THE RANDOMISED, PARALLEL-GROUP, DOUBLE-BLIND, PLACEBO-CONTROLLED, MULTICENTRE PHASE 2 TitAIN TRIAL

Background

Little is known about glucocorticoid-sparing agents in giant cell arteritis (GCA) except for IL-6 inhibition. Secukinumab (SEC) has shown significant improvements in the signs and symptoms of IL-17A driven medical conditions such as plaque psoriasis, psoriatic arthritis, and axial spondyloarthritis.1,2 It has a favourable long-term safety profile.1,2

Objectives

TitAIN is the first randomised controlled trial investigating the potential efficacy, safety, and tolerability of SEC in GCA patients (pts).

Methods

This phase 2, randomised, double-blind, placebo (PBO) controlled, multicentre, proof-of-concept trial enrolled pts (aged ≥50 years) with new onset (diagnosed within 6 weeks (wks) of baseline) or relapsing (diagnosed >6 wks from baseline) GCA, naïve to biological therapy. Pts were randomised (1:1) to SEC 300 mg or PBO initially administered wkly (5 doses) and every 4 wks thereafter through Wk 48 (last dose), in combination with a 26-wk prednisolone taper regimen starting from baseline. Proportion of GCA pts in sustained remission until Wk 28 was the primary endpoint assessed by a Bayesian analysis of the posterior distribution with non-responder imputation. Other key endpoints included proportion of GCA pts in sustained remission until Wk 52 (based on study data with non-responder imputation) and time to first GCA flare after baseline.

Results

Out of 52 randomised pts (SEC, n=27; PBO, n=25), 71.2% (n=37) completed study treatment (SEC, 81.5%; PBO, 60.0%). Overall, 42 (80.8%) pts had new onset GCA and 10 (19.2%) pts had relapsing GCA at baseline. Proportion (posterior median with 95% credibility interval) of GCA pts in sustained remission until Wk 28 was higher with SEC, 70.1% (51.6%-84.9%), than with PBO, 20.3% (12.4%-30.0%); odds ratio (posterior median with 95% credibility interval), 9.31 (3.54-26.29) (Table 1). Until Wk 52, proportion (95% confidence interval) of GCA pts in sustained remission were 59.3% (38.8%-77.6%) in SEC group and 8.0% (1.0%-26.0%) in PBO group (Table 1). Median (95% confidence interval) time to first GCA flare after baseline was not reached for GCA pts treated with SEC and was 197.0 (101.0-280.0) days for PBO (Figure 1). Overall, treatment-emergent adverse events (AEs) occurred in 98.1% (SEC vs PBO, 100.0% vs 96.0%) and serious AEs in 32.7% (SEC vs PBO, 22.2% vs 44.0%) pts. Two pts in each SEC and PBO groups had AEs that led to study drug discontinuation and 1 pt in each group had AEs that led to death (not treatment-related). There were no new or unexpected safety signals identified with SEC treatment.

Table 1.

Proportion of GCA patients with sustained remission (Full analysis set) until Week 28 and 52

Proportion of ptsSecukinumab (N=27)Placebo (N=25)Median percentage (95% credibility interval), Wk 2870.1% (51.6%, 84.9%)20.3% (12.4%, 30.0%)Percentage (95% confidence interval), Wk 5259.3% (38.8%, 77.6%)8.0% (1.0%, 26.0%)

The full analysis set comprises all pts to whom study treatment has been assigned by randomisation and who received at least one dose of randomised study treatment (secukinumab or placebo).

GCA, giant cell arteritis; N, number of pts in each treatment group in the full analysis set, pts, patients; Wk, Week

Figure 1.

Kaplan-Meier plot of time to first GCA flare from baseline up to Week 52 (Full analysis set)

Conclusion

SEC demonstrated a higher sustained remission rate and longer time to first GCA flare vs PBO through 52 wks in pts with GCA. This proof-of-concept phase 2 study supports further development of SEC as a potential treatment in combination with 26 wk glucocorticoid taper for pts with GCA.

References

[1]Mease PJ, et al. ACR Open Rheumatol. 2020;2(1):18-25

[2]Baraliakos X, et al. RMD Open. 2019;5:e001005

Disclosure of Interests

Nils Venhoff Speakers bureau: AbbVie, Novartis, Bristol-Myers-Squibb, Chugai, Roche, Vifor, Consultant of: AbbVie, Chugai, Novartis, Vifor, Grant/research support from: Bristol-Myers-Squibb, Novartis, Wolfgang A. Schmidt Speakers bureau: Abbvie, Chugai, Medac, Novartis, Roche, Sanofi, Consultant of: Advisory board member: Abbvie, Chugai, GlaxoSmithKline, Novartis, Roche, Sanofi, Grant/research support from: principle investigator in GCA trials: Abbvie, GlaxoSmithKline, Novartis, Sanofi, Raoul Bergner Speakers bureau: Abbvie, Bristol Myers Squibb, Chugai, Novartis, Roche, Consultant of: Advisory board member: Gilead, GlaxoSmithKline, Vifor, Jürgen Rech Speakers bureau: Abbvie, Biogen, BMS, Chugai, GSK, Janssen, Lilly, MSD; Novartis, Roche, Sanofi, Sobi, UCB, Consultant of: Abbvie, Biogen, BMS, Chugai, GSK, Janssen, Lilly, MSD, Novartis, Roche, Sanofi, Sobi, UCB, Leonore Unger Paid instructor for: Novartis, Hans-Peter Tony Consultant of: Abbvie, BMS, Chugai, Gilead, Lilly, Novartis, Roche, Sanofi, Meryl Mendelson Shareholder of: Novartis Pharmaceuticals Corporation, Employee of: Novartis Pharmaceuticals Corporation, Christian Sieder Employee of: Novartis Pharma GmbH, Meron Maricos Employee of: Novartis Pharma GmbH, Jens Thiel Speakers bureau: Novartis, GSK, Bristol-Myers-Squibb, Roche, AstraZeneca, Vifor, Consultant of: Novartis, Janssen, GSK; research grants: Bristol-Myers-Squibb, Novartis

AB0701 ANTIBODY RAPID TEST POSITIVE HEALTH CARE WORKERS AT A GERMAN UNIVERSITY HOSPITAL: FIRST WAVE CHARACTERISTICS

Background:

Freiburg was among the most heavily affected German cities during the first wave of Sars-Cov-2 infections in spring 2020. Consequently, the University Medical Center Freiburg was one of the first hospitals in Germany to treat Covid19 patients.

Objectives:

To assess the proportion and characteristics of health care workers (HCW) that have been infected during that first wave SARS-CoV-2 serum IgG and IgM antibodies were measured.

Methods:

HCW (n=902, mean age: 40.7 years) participated in this study, and filled out an epidemiological questionnaire. Serum samples were analysed for SARS-Cov-2 IgG/IgM antibodies via rapid diagnostic test (RT) and via ELISA. Statistical analyses were performed using STATA 14.2. An exposure prevention score was developed to quantify the adherence to preventive measures in everyday life.

Results:

902 HCW were tested by RT, and 499 by ELISA. In total, 11.5% of recruited HCW were antibody-positive in the RT, 12.2% in the ELISA. 87.5% of RT positives, 98% of ELISA-positives reported symptoms, compared to 74.6% and 78% of negatives, respectively. Symptoms such as cough (57%/46%), loss of smell and taste (34%/5.2%), fatigue (68%/45%), fever (48%/24%), body aches (45%/22%), and headaches (58%/46%) were reported by significantly more RT positives compared to negatives. The respective differences were even more pronounced (p<0.001) among ELISA-positives compared to negatives with >50% of those positive reported impaired smell or taste compared to less than 7% among the group of ELISA-negatives (p<0.00001).

In logistic regression models, shift work and belonging to the lowest quartile of the exposure prevention score were significantly associated with seropositivity in both tests. Exposure towards children was inversely associated with seropositivity, however, in the finally adjusted model only significant for those that were RT-positive, but not ELISA-positive, reflecting the lower specificity of the former.

Conclusion:

The endemic infection rate in HCW was high. HCW adhering to preventive measures in everyday life had lower infection rates.

Disclosure of Interests:

Manuel Beck: None declared, Alexandra Nieters: None declared, Marta Rizzi: None declared, Ulrich Salzer: None declared, Jens Thiel Speakers bureau: BMS, Nils Venhoff Speakers bureau: Novartis, Nicole Peter: None declared, Hermann Eibel: None declared, Reinhard Voll Speakers bureau: Novartis, Grant/research support from: BMS, Pfizer, Novartis, Stephanie Finzel Speakers bureau: Novartis

Transcriptional landscapes of floral meristems in barley

Organ development in plants predominantly occurs postembryonically through combinatorial activity of meristems; therefore, meristem and organ fate are intimately connected. Inflorescence morphogenesis in grasses (Poaceae) is complex and relies on a specialized floral meristem, called spikelet meristem, that gives rise to all other floral organs and ultimately the grain. The fate of the spikelet determines reproductive success and contributes toward yield-related traits in cereal crops. Here, we examined the transcriptional landscapes of floral meristems in the temperate crop barley (Hordeum vulgare L.) using RNA-seq of laser capture microdissected tissues from immature, developing floral structures. Our unbiased, high-resolution approach revealed fundamental regulatory networks, previously unknown pathways, and key regulators of barley floral fate and will equally be indispensable for comparative transcriptional studies of grass meristems.

Tissue-Specific Transcriptome Analysis Reveals Candidate Transcripts Associated with the Process of Programmed B Chromosome Elimination in Aegilops speltoides

Some eukaryotes exhibit dramatic genome size differences between cells of different organs, resulting from programmed elimination of chromosomes. Here, we present the first transcriptome analysis of programmed chromosome elimination using laser capture microdissection (LCM)-based isolation of the central meristematic region of Aegilops speltoides embryos where B chromosome (B) elimination occurs. The comparative RNA-seq analysis of meristematic cells of embryos with (Bplus) and without Bs (B0) allowed the identification of 14,578 transcript isoforms (35% out of 41,615 analyzed transcript isoforms) that are differentially expressed during the elimination of Bs. A total of 2908 annotated unigenes were found to be up-regulated in Bplus condition. These genes are either associated with the process of B chromosome elimination or with the presence of B chromosomes themselves. GO enrichment analysis categorized up-regulated transcript isoforms into 27 overrepresented terms related to the biological process, nine terms of the molecular function aspect and three terms of the cellular component category. A total of 2726 annotated unigenes were down-regulated in Bplus condition. Based on strict filtering criteria, 341 B-unique transcript isoforms could be identified in central meristematic cells, of which 70 were functionally annotated. Beside others, genes associated with chromosome segregation, kinetochore function and spindle checkpoint activity were retrieved as promising candidates involved in the process of B chromosome elimination.

Barley HISTIDINE KINASE 1 (HvHK1) coordinates transfer cell specification in the young endosperm

Cereal endosperm represents the most important source of the world's food; nevertheless, the molecular mechanisms underlying cell and tissue differentiation in cereal grains remain poorly understood. Endosperm cellularization commences at the maternal-filial intersection of grains and generates endosperm transfer cells (ETCs), a cell type with a prominent anatomy optimized for efficient nutrient transport. Barley HISTIDINE KINASE1 (HvHK1) was identified as a receptor component with spatially restricted expression in the syncytial endosperm where ETCs emerge. Here, we demonstrate its function in ETC fate acquisition using RNA interference-mediated downregulation of HvHK1. Repression of HvHK1 impairs cell specification in the central ETC region and the development of transfer cell morphology, and consecutively defects differentiation of adjacent endosperm tissues. Coinciding with reduced expression of HvHK1, disturbed cell plate formation and fusion were observed at the initiation of endosperm cellularization, revealing that HvHK1 triggers initial cytokinesis of ETCs. Cell-type-specific RNA sequencing confirmed loss of transfer cell identity, compromised cell wall biogenesis and reduced transport capacities in aberrant cells and elucidated two-component signaling and hormone pathways that are mediated by HvHK1. Gene regulatory network modeling was used to specify the direct targets of HvHK1; this predicted non-canonical auxin signaling elements as the main regulatory links governing cellularization of ETCs, potentially through interaction with type-B response regulators. This work provides clues to previously unknown molecular mechanisms directing ETC specification, a process with fundamental impact on grain yield in cereals.

AB0682 FUNCTIONAL IMPAIRMENT IN PATIENTS WITH AXIAL SPONDYLOARTHROPATHY IN A GERMAN COHORT: WORSE OUTCOMES AND WORSE QUALITY OF LIFE FOR FEMALE PATIENTS

Background:

Axial spondyloarthritis (AxSpA) may lead to significant structural damage resulting in marked impairment and disability. Historically, AxSpA has been thought to have a distinct male predominance regarding both, occurrence but also disease severity. However, it has recently been shown in international cohorts that women with AxSpA may have in fact an increased disease burden and worse outcome than their male counterparts.

Objectives:

The aim of this project was to analyse functional capacity in a German cohort of AxSpA patients and identify associated factors by comparing demographic data, clinical characteristics, disease activity and treatments.

Methods:

Analysis of a German University Hospital outpatient clinic cohort of 150 AxSpA patients. Questionnaire-based screening tools were used to assess disease activity, functional impairment and quality of life (BASDAI, FFbH, WHOQOL-BREF). Female and male patients were compared by independent samples two-tailed T tests for continuous variables as well as chi-squared test for categorical variables.

Results:

A German cohort of 150 AxSpA patients with 89 male and 61 female patients (mean age 49.3 years for males, 48.5 for females, p=0.77) was analyzed for functional capacity. Female patients had a significantly higher functional impairment in everyday life compared to males (p=0.013). After adjusting for age, linear regression showed female sex still to be significantly associated with functional impairment. Female patients rated their satisfaction with health as well as their physical and mental health-related quality of life significantly lower than male patients (p=0.015, respectively p=0.003 and p=0.002).

There were no significant differences in disease duration, diagnostic delay or family history between male and female patients (p=0.731, p=0.971 and p=0.776). Women had a slightly higher disease activity (BASDAI 4.08 vs. 3.36), although just not statistically significant in our cohort (p=0.056). Female patients had more peripheral joint involvement (52.5% vs. 34.8%, p=0.032), as well as more enthesitis (31.1% vs. 16.9%, p=0.04), whereas there were no differences concerning eye involvement (p=0.51). Female patients were less likely to be HLA B27 positive (65.6 vs. 80.7%, p=0.04). and were less likely to be on anti-TNF treatment (p=0.032, respectively p=0.042).

Conclusion:

Also in our cohort female patients had a higher burden of disease as well as a worse patient reported outcome with worse quality of life and more self-reported functional impairment in everyday life. These data underline the importance of raising awareness for sex differences in disease presentation and suggest that female patients might require different treatment to achieve improved outcomes.

Disclosure of Interests:

None declared

THU0030 DISTINCT EFFECTS OF FIVE JAK INHIBITORS IN THE MODULATION OF HUMAN B CELL ACTIVATION

Background:

JAK inhibitors have been successfully introduced in the treatment of rheumatoid arthritis (RA) and psoriatic arthritis and are in clinical trials for numerous other autoimmune diseases. JAK inhibition effectively reduces cytokine-mediated activation and survival of pathology-driving immune cells by targeting signaling downstream of cytokine receptors. The outcome of such immunomodulation hence will largely depend on the intrinsic expression of the four different JAKs, the cytokine environment and the targeted cell type. Comparative studies investigating the effect on B cells are lacking. In light of the use of JAK inhibitor treatment in autoantibody mediated diseases, the study of the B cell compartment represents a milestone to assess their potential.

Objectives:

We thus aimed to study the B cell compartment as well as B cell function under JAK inhibition in RA patients and to compare the specific effect the JAK inhibitors tofacitinib (pan-JAK), baricitinib (JAK1/2), ruxolitinib (JAK1/2), upadacitinib and filgotinib (selective JAK1) on in vitro B cell activation, differentiation, proliferation, and class switch.

Methods:

B cell subpopulations in RA patients treated with baricitinib or tofacitinib was assessed by flow cytometric analysis of peripheral blood mononuclear cells. For in vitro studies, magnetically isolated total B cells from healthy donors were stimulated T-cell -independently with CpG and treated with scalar doses of the JAK inhibitors tofacitinib, baricitinib, ruxolitinib, upadacitinib and filgotinib. Flow cytometric analysis was performed on days 0, 3 and 6. Cytokine secretion was measured by Cytokine Multiplex Assay.

Results:

B cell phenotyping of RA patients treated with JAK inhibitors baricitinib or tofacitinib showed an increase in marginal zone (MZ) B cells. To investigate this further, we turned to an in vitro model of T-cell-independent B cell activation with CpG via TLR9, known to support MZ B cell expansion. Here, JAK1/2 and selective JAK1 inhibitor treatment led to a dose-dependent decrease of total B cell numbers. When assessing B cell-subpopulations, we observed an altered B cell differentiation with a significant increase in MZ-like B cells under JAK inhibition, which led to a subsequent increase in plasmablast differentiation in the first days. This effect was more pronounced upon pan-JAK inhibitor treatment than JAK1 or JAK1/2 inhibition, indicating that broader JAK inhibition is associated with a stronger effect (tofa > ruxo > bari > upa > filgo).

Notably, we further detected a significant dose-dependent reduction of switched memory formation, strongest with JAK1/2 inhibition (upa > ruxo > bari > tofa > filgo). Consistent with this finding, we observed decreased AID expression under JAK inhibition. Concomitantly, induction of STAT3 expression and STAT3 phosphorylation were reduced under JAK inhibition, suggesting that downstream signalling was abrogated.

To assess the role of autocrine signaling in this system, we measured cytokine secretion upon JAK inhibition and found that JAK2 inhibition led to reduced IL10 secretion. This in turn resulted in an increase of inflammatory cytokines such as IL6, TNF, highlighting the importance of B cell as cytokine-secreting cell type.

Conclusion:

In a T-independent in vitro B cell model JAK inhibition led to a reduced total B cell number as well as reduced switched memory development, whereas MZ-like B cells were increased. Especially JAK2 inhibition strongly impaired switched memory formation. JAK inhibition does not only impact cytokine signalling but also leads to changes in cytokine secretion dynamics and amounts, potentially impacting other cell types.

In conclusion, JAK inhibition has a major effect on B cell activation and maturation, with differential outcomes between JAK inhibitors hinting towards distinct and unique effects on B cell homeostasis.

Disclosure of Interests:

None declared

THU0053 CONTRIBUTION OF DEFECTIVE NON-APOPTOTIC FAS SIGNALING TO IMMUNE DYSREGULATION IN AUTOIMMUNE LYMPHOPROLIFERATIVE SYNDROME (ALPS)

Background:

ALPS patients show impaired generation of humoral memory for T independent antigens whereas they generate memory for self-antigens due to impaired FAS-dependent removal of autoreactive germinal center B cells. It is known that FAS signaling via caspase activation results in cell apoptosis. However, FAS ligation may also initiate or modulate non-apoptotic signaling as shown for example by its ability to activate NF-κB. Recent data implicate a regulatory role of FAS in the modulation of mTOR signaling in ALPS double-negative T cells. Moreover, a recently described C194V FAS mutation disturbs its post-translational modification leading to impaired apoptosis induction while non-apoptotic signalling is still intact. Consequently, C194V FAS protects from the autoimmune phenotype in the murine ALPS system. This supports the view that FAS may prevent autoimmunity with other mechanisms than inducing apoptosis.

Objectives:

We hypothesize that FAS mutations impair this modulatory signaling, leading to hyper-activation of B cells. Therefore we aim to investigate non apoptotic FAS signaling in B cells derived from healthy individuals and ALPS patients.

Methods:

We studied resting and activated B cells in ALPS patients in presence or absence of FAS ligand by flow cytometry analysing relevant molecules to the CD40 signaling pathway. We used mass cytometry to perform functional phenotyping of B cells isolated from secondary lymphoid organs. Proteomic studies were performed to identify potential signaling circuits and RNA sequencing to study the consequences of FAS signaling on B cell fate.

Results:

In CD40L activated B cells, FAS signaling results in specific modulation of the mTOR signaling pathway. This modulation is absent in ALPS derived B cells. In line with these data germinal center B cells and plasmablast from secondary lymphoid organs of ALPS patients show hyperactive mTOR signaling pathway. Proteomic studies identify a circuit that links FAS to the phosphatase PTEN via DAXX and the deubiquitinase USP7.

Conclusion:

We describe a new role of FAS in the regulation of B cell activation. Defects in FAS signaling in ALPS contribute to dysregulation of the mTOR signaling pathway and disturbed B cell development.

Disclosure of Interests:

None declared

AB0033 CHARACTERIZATION OF THE PERIPHERAL B CELL COMPARTMENT IN PATIENTS WITH EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS

Background:

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare form of systemic vasculitis, which is characterized by bronchial asthma, hypereosinophilia, and systemic vasculitis. B-lymphocytes play a key role in EGPA as producers of IgE and anti-neutrophil cytoplasmic antibodies (ANCAs). Indeed, the neutrophils that are targeted by these antibodies are widely described as the mechanism of endothelial damage in this disease. On the other side, the therapeutic response to rituximab in EGPA patients provides evidence for a role of B-cells in the pathogenesis of EGPA. Therefore characterizing B cell subpopulations may help in understanding the disease and the treatment.

Objectives:

To characterize the peripheral B cell compartment in patients with EGPA and to analyze the in vivo potential of B lymphocytes to class-switch to IgE and to assess in vitro the differentiation potential of naïve B cells of EGPA patients into IgE-secreting plasmablasts.

Methods:

Clinical characteristics of the patients, including organ involvement and treatment regimen were evaluated. Laboratory work-up included ANCA-status, eosinophils, IgE, IgG, IgA, IgM, and peripheral CD19+B-cell count. For immunophenotyping isolated PBMCs were stained with monoclonal or polyclonal antibodies and B cells were classified into: naïve, marginal zone, class-switched memory B cells, unconventional memory B cells, transitional and plasmablasts. Furthermore, the expression of IgG+ and subclasses IgG1-4, IgA+, IgE+B cells, BAFFR and TACI was quantified. For in vitro differentiation assays magnetically isolated B lymphocytes from EGPA patients and age-matched healthy controls were stimulated with CD40L, IL-21 and IL-4. Starting the culture with equal number of B cells, the absolute number of plasmablasts, and IgE class switched cells after 9 days was determined by counting the events in the CD27highCD38high gate or the IgG/A/D-IgE+gate by flow cytometry. IgE secretion in the supernatant was measured by ELISA. JAK-STAT signalling pathway was analyzed in response to IL-4 and IL-21 stimulation and phosphorylation of STAT5 and 6 measured by flow cytometry.

Results:

34 patients with EGPA diagnosed according to ACR and CHC-criteria were included into the study. Ten of these patients were analysed separately because they received rituximab therapy. Peripheral B cell numbers in EGPA patients were markedly diminished. B cell subpopulation phenotyping showed in average 57.9% naïve B cells, 12.5 % marginal zone like B cells and 19.2% switched memory B cells. Plasmablasts constituted in average 1.15% of the peripheral B cell compartment, transitional B cells 2.0%. Interestingly, the expression of BAFF receptor and TACI in the memory B cell subset was significantly decreased in EGPA patients when compared with healthy donors. In vitro assays of isolated B cells from EGPA patients demonstrated an increased proportion of IgE-class-switched B cells after 9 days of culture under IL4 stimulation compared with controls. However, no differences were observed in the phosphorylation of STAT5 and STAT6 after stimulation with IL-4 or IL-21.

Conclusion:

In the EGPA-patients we observed markedly diminished B-cells despite of normal lymphocyte counts. B cells showed a reduced expression of BAFF-R and TACI. Class switch to IgE is enhanced in EGPA patients.

Disclosure of Interests:

None declared

[IL-1-blockade with Anakinra during pregnancy : Retrospective analysis of efficacy and safety in female patients with familial Mediterranean fever]

OBJECTIVE

To retrospectively assess and analyze the clinical efficacy and safety of off-label interleukin-1 (IL-1) blockade with anakinra during pregnancy of patients with familial Mediterranean fever (FMF).

METHODS

Retrospective analysis of clinical and laboratory parameters making use of an electronic database system. Detailed descriptions of the genotype and phenotype of FMF are given and the course of the pregnancy and fetal development are reported.

RESULTS

The data of three patients and a total of four pregnancies under treatedment with anakinra were analyzed. All patients were of Mediterranean origin, fulfilled the Tel Hashomer criteria for diagnosis of FMF and had a confirmed mutation in the MEFV gene. In all patients, treatment with anakinra was initiated due to an insufficient treatment response to colchicine. Anakinra led to a rapid response in all patients. In three pregnancies anakinra treatment was continued during the whole pregnancy, while in one pregnancy anakinra was started in the second trimester because of uncontrolled FMF activity. Fetal development was normal in all pregnancies. In two patients the fetuses were carried to term, while in one patient a primary cesarean section was carried out in week 33 because of an increased risk for complications. All children showed an unremarkable early childhood development without any signs of an existing disease.

CONCLUSION

The data of our retrospective analysis suggest that IL-1-blockade by anakinra is an effective and safe treatment in pregnant women suffering from FMF, which can reliably prevent disease flares. In the four pregnancies presented the use of anakinra did not result in impaired fetal and (early) childhood development.

An in vivo demonstration of efficacy and acute safety of burst wave lithotripsy using a porcine model

Burst wave lithotripsy (BWL) is a new non-invasive method for stone comminution using bursts of sub-megahertz ultrasound. A porcine model of urolithiasis and techniques to implement BWL treatment has been developed to evaluate its effectiveness and acute safety. Six human calcium oxalate monohydrate stones (6-7 mm) were hydrated, weighed, and surgically implanted into the kidneys of three pigs. Transcutaneous stone treatments were performed with a BWL transducer coupled to the skin via an external water bath. Stone targeting and treatment monitoring were performed with a co-aligned ultrasound imaging probe. Treatment exposures were applied in three 10-minute intervals for each stone. If sustained cavitation in the parenchyma was observed by ultrasound imaging feedback, treatment was paused and the pressure amplitude was decreased for the remaining time. Peak negative focal pressures between 6.5 and 7 MPa were applied for all treatments. After treatment, stone fragments were removed from the kidneys. At least 50% of each stone was reduced to <2 mm fragments. 100% of four stones were reduced to <4 mm fragments. Magnetic resonance imaging showed minimal injury to the functional renal volume. This study demonstrated that BWL could be used to effectively fragment kidney stones with minimal injury.

Laser Capture Microdissection-Based RNA-Seq of Barley Grain Tissues

Spatiotemporal patterning throughout the plant body depends to a large degree on cell- and tissue-specific expression of genes. Subsequently, for a better understanding of cell and tissue differentiation processes during plant development it is important to conduct transcript analyses in individual cells or tissue types rather than in bulk tissues. Laser capture microdissection (LCM) provides a useful method for isolating specific cell types from complex tissue structures for downstream applications. Contrasting to mammalian cells, the texture of plant cells is more critical due to hard, cellulose-rich cell walls, large vacuoles, and air spaces which complicates tissue preparation and extraction of macromolecules, like DNA and RNA. In particular, developing barley seeds (i.e. grains) depict cell types with differences in osmomolarity (meristematic, differentiating and degenerating tissues) and contain high amounts of the main storage product starch. In this study, we report about methods allowing tissue-specific transcriptome profiling by RNA-seq of developing barley grain tissues from low-input RNA amounts. Details on tissue preparation, laser capture microdissection, RNA isolation, and linear mRNA amplification to produce high-quality samples for Illumina sequencing are provided. Particular emphasis was placed on the influence of the mRNA amplification step on the transcriptome data and the fidelity of deduced expression levels obtained by the developed methods. Analysis of RNA-seq data confirmed sample processing as a highly reliable and reproducible procedure that was also used for transcriptome analyses of different tissue types from barley plants.

Spatiotemporal Dynamics of Oligofructan Metabolism and Suggested Functions in Developing Cereal Grains

Oligofructans represent one of the most important groups of sucrose-derived water-soluble carbohydrates in the plant kingdom. In cereals, oligofructans accumulate in above ground parts of the plants (stems, leaves, seeds) and their biosynthesis leads to the formation of both types of glycosidic linkages [β(2,1); β(2,6)-fructans] or mixed patterns. In recent studies, tissue- and development- specific distribution patterns of the various oligofructan types in cereal grains have been shown, which are possibly related to the different phases of grain development, such as cellular differentiation of grain tissues and storage product accumulation. Here, we summarize the current knowledge about oligofructan biosynthesis and accumulation kinetics in cereal grains. We focus on the spatiotemporal dynamics and regulation of oligofructan biosynthesis and accumulation in developing barley grains (deduced from a combination of metabolite, transcript and proteome analyses). Finally, putative physiological functions of oligofructans in developing grains are discussed.

Caspase-like activities accompany programmed cell death events in developing barley grains

Programmed cell death is essential part of development and cell homeostasis of any multicellular organism. We have analyzed programmed cell death in developing barley caryopsis at histological, biochemical and molecular level. Caspase-1, -3, -4, -6 and -8-like activities increased with aging of pericarp coinciding with abundance of TUNEL positive nuclei and expression of HvVPE4 and HvPhS2 genes in the tissue. TUNEL-positive nuclei were also detected in nucellus and nucellar projection as well as in embryo surrounding region during early caryopsis development. Quantitative RT-PCR analysis of micro-dissected grain tissues revealed the expression of HvVPE2a, HvVPE2b, HvVPE2d, HvPhS2 and HvPhS3 genes exclusively in the nucellus/nucellar projection. The first increase in cascade of caspase-1, -3, -4, -6 and -8-like activities in the endosperm fraction may be related to programmed cell death in the nucellus and nucellar projection. The second increase of all above caspase-like activities including of caspase-9-like was detected in the maturating endosperm and coincided with expression of HvVPE1 and HvPhS1 genes as well as with degeneration of nuclei in starchy endosperm and transfer cells. The distribution of the TUNEL-positive nuclei, tissues-specific expression of genes encoding proteases with potential caspase activities and cascades of caspase-like activities suggest that each seed tissue follows individual pattern of development and disintegration, which however harmonizes with growth of the other tissues in order to achieve proper caryopsis development.

Gibberellin-to-abscisic acid balances govern development and differentiation of the nucellar projection of barley grains

In cereal grains, the maternal nucellar projection (NP) constitutes the link to the filial organs, forming a transfer path for assimilates and signals towards the endosperm. At transition to the storage phase, the NP of barley (Hordeum vulgare) undergoes dynamic and regulated differentiation forming a characteristic pattern of proliferating, elongating, and disintegrating cells. Immunolocalization revealed that abscisic acid (ABA) is abundant in early non-elongated but not in differentiated NP cells. In the maternally affected shrunken-endosperm mutant seg8, NP cells did not elongate and ABA remained abundant. The amounts of the bioactive forms of gibberellins (GAs) as well as their biosynthetic precursors were strongly and transiently increased in wild-type caryopses during the transition and early storage phases. In seg8, this increase was delayed and less pronounced together with deregulated gene expression of specific ABA and GA biosynthetic genes. We concluded that differentiation of the barley NP is driven by a distinct and specific shift from lower to higher GA:ABA ratios and that the spatial-temporal change of GA:ABA balances is required to form the differentiation gradient, which is a prerequisite for ordered transfer processes through the NP. Deregulated ABA:GA balances in seg8 impair the differentiation of the NP and potentially compromise transfer of signals and assimilates, resulting in aberrant endosperm growth. These results highlight the impact of hormonal balances on the proper release of assimilates from maternal to filial organs and provide new insights into maternal effects on endosperm differentiation and growth of barley grains.

Spatio-temporal dynamics of fructan metabolism in developing barley grains

Barley (Hordeum vulgare) grain development follows a series of defined morphological and physiological stages and depends on the supply of assimilates (mainly sucrose) from the mother plant. Here, spatio-temporal patterns of sugar distributions were investigated by mass spectrometric imaging, targeted metabolite analyses, and transcript profiling of microdissected grain tissues. Distinct spatio-temporal sugar balances were observed, which may relate to differentiation and grain filling processes. Notably, various types of oligofructans showed specific distribution patterns. Levan- and graminan-type oligofructans were synthesized in the cellularized endosperm prior to the commencement of starch biosynthesis, while during the storage phase, inulin-type oligofructans accumulated to a high concentration in and around the nascent endosperm cavity. In the shrunken endosperm mutant seg8, with a decreased sucrose flux toward the endosperm, fructan accumulation was impaired. The tight partitioning of oligofructan biosynthesis hints at distinct functions of the various fructan types in the young endosperm prior to starch accumulation and in the endosperm transfer cells that accomplish the assimilate supply toward the endosperm at the storage phase.

Development of endosperm transfer cells in barley

Endosperm transfer cells (ETCs) are positioned at the intersection of maternal and filial tissues in seeds of cereals and represent a bottleneck for apoplasmic transport of assimilates into the endosperm. Endosperm cellularization starts at the maternal-filial boundary and generates the highly specialized ETCs. During differentiation barley ETCs develop characteristic flange-like wall ingrowths to facilitate effective nutrient transfer. A comprehensive morphological analysis depicted distinct developmental time points in establishment of transfer cell (TC) morphology and revealed intracellular changes possibly associated with cell wall metabolism. Embedded inside the grain, ETCs are barely accessible by manual preparation. To get tissue-specific information about ETC specification and differentiation, laser microdissection (LM)-based methods were used for transcript and metabolite profiling. Transcriptome analysis of ETCs at different developmental stages by microarrays indicated activated gene expression programs related to control of cell proliferation and cell shape, cell wall and carbohydrate metabolism reflecting the morphological changes during early ETC development. Transporter genes reveal distinct expression patterns suggesting a switch from active to passive modes of nutrient uptake with the onset of grain filling. Tissue-specific RNA-seq of the differentiating ETC region from the syncytial stage until functionality in nutrient transfer identified a high number of novel transcripts putatively involved in ETC differentiation. An essential role for two-component signaling (TCS) pathways in ETC development of barley emerged from this analysis. Correlative data provide evidence for abscisic acid and ethylene influences on ETC differentiation and hint at a crosstalk between hormone signal transduction and TCS phosphorelays. Collectively, the data expose a comprehensive view on ETC development, associated pathways and identified candidate genes for ETC specification.