JAK/STAT signaling in rheumatoid arthritis leukocytes is uncoupled from serum cytokines in a subset of patients

OBJECTIVE

Rheumatoid Arthritis (RA) is a systemic autoimmune disease involving pro-inflammatory cytokines that can be therapeutically targeted by antibodies or kinase inhibitors. Nevertheless, these drugs fail in a subset of patients independent of the abundance of the targeted cytokines. We aim to explore the cellular basis of this phenomenon by analyzing the relation of cytokine abundance and activation of downstream signaling pathways in RA.

METHODS

The study included 62 RA patients and 9 healthy controls (HC). Phosphorylation of STAT 1-6 in various immune cell subsets was determined ex vivo using a novel robust flow cytometry-based protocol. Serum concentrations of IL-6, IL-10, IL-12p70, IL-17 A, interferon gamma, and TNF-alpha in the same samples were measured using highly sensitive single molecule array (SIMOA).

RESULTS

We found an increase in circulating cytokines in RA patients, while STAT activity was lower in RA patients compared to HC. Based on STAT activity we determined three endotypes in active RA patients (cDAI>10, n = 28): 1) those with active STAT5a/b signaling in T cells (n = 7/28), 2) those with a low STAT activity in all assessed cell types (n = 14/28), and 3) those with active STAT1 and STAT3 signaling mainly in myeloid cells (n = 7/28). Integrating intracellular STAT activation and cytokine analysis revealed diminished JAK/STAT signaling in a subset of patients (n = 8/20) despite elevated serum cytokine concentrations.

CONCLUSION

Diminished JAK/STAT signaling in active RA may partly explain unresponsiveness to therapy targeting cytokine signaling. Analysis of JAK/STAT phosphorylation may identify patients at risk for non-response to these therapies.

Soluble Urokinase Plasminogen Activator Receptor (SuPAR) Analysis for Diagnosis of Periprosthetic Joint Infection

Soluble urokinase plasminogen activator receptors (suPARs) are a biomarker for inflammatory diseases. This study aims to investigate its diagnostic properties regarding periprosthetic joint infections (PJI). This retrospective cohort study included adult patients who underwent joint puncture for suspected PJI. The presence of PJI was determined according to the criteria of the European Bone and Joint Infection Society (EBJIS). Laboratory study analyses included the determination of white blood cells (WBC) in whole blood, C-reactive protein (CRP) in blood plasma, and suPAR in both blood plasma and synovial fluid. Appropriate diagnostic cut-off values were identified utilizing Youden's J, and their diagnostic performance was determined by calculating the positive (PPV) and negative predictive value (NPV) for each marker. Sixty-seven cases were included in the final analysis. Forty-three samples (64%) were identified as periprosthetic joint infection (PJI) and twenty-four specimen (36%) were PJI negative cases. The PPV and NPV were 0.80 and 0.70 for synovial suPAR, 0.86 and 0.55 for CRP, 0.84 and 0.31 for WBC and 1.00 and 0.31 for plasma suPAR. Synovial suPAR showed a solid diagnostic performance in this study and has the potential to be an alternative or complementary biomarker for PJI. Further investigations in larger patient collectives are indicated.

Ruxolitinib, IV Immunoglobulin, and High-Dose Glucocorticoids for Critically Ill Adults With Secondary Hemophagocytic Lymphohistiocytosis: A Single-Center Observational Pilot Study

OBJECTIVES

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a cytokine-driven inflammatory syndrome that is associated with substantial morbidity and mortality and frequently leads to ICU admission. Overall survival in adults with sHLH remains poor, especially in those requiring intensive care. Classical chemotherapeutic treatment exhibits myelosuppression and toxicity. Recently, inhibition of Janus kinase signaling by ruxolitinib has shown efficacy in pediatric HLH. We therefore aimed to determine the activity and safety of a ruxolitinib-based regimen, in critically ill adults with sHLH.

DESIGN

Observational pilot study.

SETTING

Single-center tertiary academic ICU.

PATIENTS

Nine adults (≥ 18 yr) who fulfilled at least five of the eight HLH-2004 criteria.

INTERVENTION

Triplet regimen combining: 1) ruxolitinib, 2) polyvalent human IV immunoglobulins (IVIG) at a dose of 1 g/kg bodyweight for 5 days, and 3) high-dose corticosteroids (CSs, dexamethasone 10 mg/m² body surface area, or methylprednisolone equivalent) with subsequent tapering according to the HLH-2004 protocol.

MEASUREMENT AND MAIN RESULTS

Nine patients (median age: 42 yr [25th-75th percentile: 32-54]; male: n = 6 males, median H-score: 299 [255-304]) were treated with the triplet regimen. The median Sequential Organ Failure Assessment score at HLH diagnosis was 9 (median; 25th-75th percentile: 7-12), indicating multiple-organ dysfunction in all patients. Within 10 days a significant decrease of the inflammatory parameters soluble interleukin-2 receptor and ferritin as well as a stabilization of the blood count could be shown. All patients were alive at ICU discharge (100% ICU survival), 1 patient died after ICU discharge because of traumatic intracerebral hemorrhage that might be related to HLH or treatment, corresponding to an overall survival of 86% in a 6 months follow-up period.

CONCLUSION

In this small case series, a triplet regimen of ruxolitinib in combination with IVIG and CS was highly effective and save for treating critically ill adults with sHLH.

POS1390 ULTRASOUND BASED WITHDRAWAL OF BIOLOGICS IN RHEUMATOID ARTHRITIS (RA-BioStop)

Background

Discontinuation of biological (b)DMARDs may be considered in rheumatoid arthritis (RA) patients in persistent clinical remission [1]. Some earlier studies reported that baseline ultrasound may predict successful tapering or withdrawal of bDMARDs, while others found that ultrasound had little additional value over clinical parameters alone [2-4]. The majority of these studies, however, were limited by small sample size, inadequate remission criteria and variable tapering regimens.

Objectives

To test the hypothesis whether ultrasound-verified subclinical inflammation might predict a relapse in RA patients in stringent clinical remission who discontinue bDMARDs.

Methods

Prospective, phase IV clinical trial including RA patients in persistent clinical remission according to the ACR/EULAR criteria treated with a combination of conventional synthetic (cs)DMARD plus bDMARDs. Upon stopping the bDMARD, 9 study visits were conducted within 52 weeks. At each visit, patients underwent clinical examination and ultrasound of 14 joints. The primary hypothesis was that a Power Doppler (PD) score >0 predicted a relapse until week 16 after bDMARD cessation. Relapse was defined as change from remission to moderate/high disease activity according to the simplified disease activity index.

Results

Although 110 patients were required by the protocol, inclusion had to be stopped after reaching 38 (34.5%) due to insufficient recruitment. There were 9, 10 and 13 relapses between baseline and weeks 16, 24 and 52, respectively. Relapses till week 16 tended to be more common in patients with PD score >0 at baseline than in those without [9/30 (30.0%) vs. 0/7 (0%), p=0.160)]. Similar observations were made for weeks 24 [9/30 (30.0%) vs. 1/7 (14.3%), p=0.647)] and 52 [12/30 (40.0%) vs. 1/7 (14.3%), p=0.383)]. Kaplan-Meier plot indicates the relapse-free survival in patients with and without PD+ synovitis at baseline (Figure 1).

Figure 1.

Kaplan-Meier analysis of relapses according to presence or absence of Power Doppler (PD) synovitis at baseline.

PD scores were higher at the time of relapse as compared to the preceding visits [mean difference in the PD score 3.2 (±4.5) points, p=0.034]. PD scores were also higher at visits preceding a relapse [mean 5.6 (±3.9), n=13] as compared to the mean PD score across all visits of patients without a relapse [mean 2.0 (±1.5), n=24, p=0.003, respectively]. There were trends towards a higher mean baseline PD score in patients who had a relapse between baseline and week 16 as compared to those who remained in remission (5.2 ± 5.8 vs. 2.3 ± 3.0, p=0.079). Similar observations were made for relapses until weeks 24 and 52. No difference was observed comparing mean residual swollen or tender joint counts at baseline between patients with and without a relapse. There were 9 adverse events. All of them were mild to moderate.

Conclusion

In RA patients in strict clinical remission, PD assessment at baseline but not clinical joint count could help identify patients who will relapse after the cessation of a bDMARD. Due to insufficient recruitment and limited power of the present trial, however, no definitive conclusion can be made.

References

[1]Smolen JS, Landewé RBM, Bijlsma JWJ, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2019 update. Ann Rheum Dis 2020;79:685-99.

[2]Naredo E, Valor L, De la Torre I, et al. Predictive value of Doppler ultrasound-detected synovitis in relation to failed tapering of biologic therapy in patients with rheumatoid arthritis. Rheumatology (Oxford) 2015;54:1408–14.

[3]Lamers-Karnebeek FB, Luime JJ, Cate DFT, et al. Limited value for ultrasonography in predicting flare in rheumatoid arthritis patients with low disease activity stopping TNF inhibitors. Rheumatology (Oxford) 2017;56:1560–5.

[4]Terslev L, Brahe CH, Hetland ML, et al. Doppler ultrasound predicts successful discontinuation of biological DMARDs in rheumatoid arthritis patients in clinical remission. Rheumatology (Oxford) 2021;60:5549–59.

Acknowledgements

This study was funded by a grant of the Austrian Research Fund (KLI514-B30)

Disclosure of Interests

Christian Dejaco Speakers bureau: Pfizer, AbbVie, MSD, Roche, BMS, UCB, Consultant of: Pfizer, AbbVie, MSD, Roche, BMS, UCB, Grant/research support from: Pfizer, Irina Gessl: None declared, Rusmir Husic Speakers bureau: MSD, Lilly und Abbvie, Thomas Deimel: None declared, Angelika Lackner: None declared, Gabriela Supp: None declared, Josef Hermann Speakers bureau: Novartis, Lilly, AbbVie, Janssen, Consultant of: GlaxoSmithKline, Otsuka Pharmaceutical Europe Ltd, Josef S. Smolen Speakers bureau: AbbVie, Amgen, AstraZeneca, Astro, Bristol-Myers Squibb, Celgene, Celltrion, Chugai, Gilead, ILTOO, Janssen, Lilly, Merck Sharp & Dohme, Novartis- Sandoz, Pfizer, Roche, Samsung, Sanofi, and UCB, Consultant of: AbbVie, Amgen, AstraZeneca, Astro, Bristol-Myers Squibb, Celgene, Celltrion, Chugai, Gilead, ILTOO, Janssen, Lilly, Merck Sharp & Dohme, Novartis- Sandoz, Pfizer, Roche, Samsung, Sanofi, and UCB, Grant/research support from: Abbvie, AstraZeneca, Lilly and Roche, Martin Stradner Speakers bureau: Eli Lilly, Pfizer, MSD, BMS, AbbVie, Janssen, Consultant of: Eli Lilly, AbbVie, Janssen, Daniel Aletaha Speakers bureau: Abbvie, Amgen, Lilly, Janssen, Merck, Novartis, Pfizer, Roche, Sandoz, Consultant of: Abbvie, Amgen, Lilly, Janssen, Merck, Novartis, Pfizer, Roche, Sandoz, Grant/research support from: Abbvie, Amgen, Lilly, Novartis, Roche, SoBi, Sanofi, Gerold Schwantzer: None declared, Peter Mandl Speakers bureau: AbbVie, Janssen and Novartis, Grant/research support from: AbbVie, BMS, Novartis, Janssen, MSD and UCB

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

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

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

AB0031 DEEP IMMUNE PHENOTYPING OF SLE AND RA BY MACHINE LEARNING

Background

Breakdown of self-tolerance is an important common mechanism in autoimmunity. Despite considerable clinical heterogeneity, many autoimmune diseases exhibit common immunological mechanisms leading to a breakdown of self-tolerance. Identification of unique and similar patterns across different autoimmune disease may help to understand their pathophysiology behind.

Objectives

Establishing workflows for the multi-parameter deep immune phenotyping of T- and B-cells by unsupervised machine learning (ML) methods for feature extraction, cluster analysis and anomaly detection.

Methods

We use machine learning to identify common patterns and dissimilarities between type 1 diabetes (T1D, n=69), rheumatoid arthritis (RA, n=63), systemic lupus erythematosus (SLE, n=38) and healthy controls (n=69) samples based on multi-plex immune phenotyping. PBMCs were isolated from patients with T1D, RA, SLE, and controls. A flow cytometry-based approach was applied, and a traditional analysis was compared to a ML method implemented in R [1] and based on self-organizing maps (Figure 1). Our pipeline includes unsupervised pre-gating, normalization, FlowSOM clustering [2], and a statistical model (GLMM), to check for significant differential abundances of cell populations among the autoimmune conditions.

Figure 1.

Results

After applying our automated workflow to one T cell panel we could identify 14 cell clusters present in all the samples. The GLMM test revealed a cluster with a significant difference (p=0.035) and a trending one (p=0.059) on the abundance across the different diseases. In particular, CD4pos T cells expressing high IL-7 receptor (CD127) levels and median amounts of CD15s but low CD25, CD161 and FoxP3 are increased in T1D whereas CD4+CD25++CD15s+FoxP3lowCD161lowCD45RA- cells are increased in SLE.

Conclusion

This unbiased, unsupervised ML workflow was able to identify canonical and novel clusters of T cells that are similar in RA, SLE and T1D. Additionally, a novel memory T cell population expressing CD15s was shown. This unsupervised analysis approach for large datasets enables the discovery of new immune cell populations complementing traditional workflows.

References

[1]Ellis B, Haaland P, Hahne F, Le Meur N, Gopalakrishnan N, Spidlen J, Jiang M, Finak G (2021). flowCore: flowCore: Basic structures for flow cytometry data. R package version 2.6.0.

[2]Van Gassen S, Callebaut B, Van Helden MJ, Lambrecht BN, Demeester P, Dhaene T, Saeys Y. FlowSOM: Using self-organizing maps for visualization and interpretation of cytometry data. Cytometry Part A. 2015 Jul;87(7):636-45.

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

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

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

Humoral immune response to COVID-19 vaccination in diabetes is age-dependent but independent of type of diabetes and glycaemic control: The prospective COVAC-DM cohort study

AIMS

To investigate the seroconversion following first and second COVID-19 vaccination in people with type 1 and type 2 diabetes in relation to glycaemic control prior to vaccination and to analyse the response in comparison to individuals without diabetes.

MATERIALS AND METHODS

This prospective, multicentre cohort study analysed people with type 1 and type 2 diabetes and a glycated haemoglobin level ≤58 mmol/mol (7.5%) or >58 mmol/mol (7.5%), respectively, and healthy controls. Roche's Elecsys anti-SARS-CoV-2 S immunoassay targeting the receptor-binding domain was used to quantify anti-spike protein antibodies 7 to 14 days after the first and 14 to 21 days after the second vaccination.

RESULTS

A total of 86 healthy controls were enrolled in the study, as well as 161 participants with diabetes, of whom 150 (75 with type 1 diabetes and 75 with type 2 diabetes) were eligible for the analysis. After the first vaccination, only 52.7% of participants in the type 1 diabetes group and 48.0% of those in the type 2 diabetes group showed antibody levels above the cut-off for positivity. Antibody levels after the second vaccination were similar in participants with type 1 diabetes, participants with type 2 diabetes and healthy controls after adjusting for age, sex and multiple testing (P > 0.05). Age (r = -0.45, P < 0.001) and glomerular filtration rate (r = 0.28, P = 0.001) were significantly associated with antibody response.

CONCLUSIONS

Anti-SARS-CoV-2 S receptor-binding domain antibody levels after the second vaccination were comparable in healthy controls and in participants with type 1 and type 2 diabetes, irrespective of glycaemic control. Age and renal function correlated significantly with the extent of antibody levels.

Evaluation of autoantibodies as predictors of treatment response and immune-related adverse events during the treatment with immune checkpoint inhibitors: A prospective longitudinal pan-cancer study

Background

The presence of autoantibodies in the serum of cancer patients has been associated with immune‐checkpoint inhibitor (ICI) therapy response and immune‐related adverse events (irAEs). A prospective evaluation of different autoantibodies in different cancer entities is missing.

Materials and Methods

In this prospective cohort study, we included a pan‐cancer cohort of patients undergoing ICI treatment and measured a comprehensive panel of autoantibodies at treatment start and at the time point of first response evaluation. The presence and induction of autoantibodies (ANA, ENA, myositis, hepatopathy, rheumatoid arthritis) in different cancer entities were assessed and the association between autoantibodies and disease control rate (DCR), objective response rate (ORR), and progression‐free survival (PFS), as well as the development of grade 3 or higher irAEs were evaluated by logistic regression models, cox proportional hazard models, and Kaplan–Meier estimators.

Results

Of 44 patients with various cancer entities, neither the presence of any positive autoantibody measurement nor the presence of positive antinuclear antibodies (ANA) [≥1:80] at baseline was associated with the examined clinical endpoints (DCR, ORR, PFS) in univariable and multivariable analyses. After 8–12 weeks of ICI treatment, DCR, ORR, and PFS did not significantly differ between patients with and without any positive autoantibody measurement or positive ANA titers. The frequency of irAEs did not differ depending on autoantibody status of the patients.

Conclusion

Autoantibodies at treatment initiation or induction after 8–12 weeks of ICI treatment are not associated with treatment efficacy as indicated by DCR, ORR, and PFS or higher grade irAEs.

Antifungal prophylaxis for prevention of COVID-19-associated pulmonary aspergillosis in critically ill patients: an observational study

BACKGROUND

Coronavirus disease 19 (COVID-19)-associated pulmonary aspergillosis (CAPA) emerged as important fungal complications in patients with COVID-19-associated severe acute respiratory failure (ARF). Whether mould active antifungal prophylaxis (MAFP) can prevent CAPA remains elusive so far.

METHODS

In this observational study, we included all consecutive patients admitted to intensive care units with COVID-19-associated ARF between September 1, 2020, and May 1, 2021. We compared patients with versus without antifungal prophylaxis with respect to CAPA incidence (primary outcome) and mortality (secondary outcome). Propensity score adjustment was performed to account for any imbalances in baseline characteristics. CAPA cases were classified according to European Confederation of Medical Mycology (ECMM)/International Society of Human and Animal Mycoses (ISHAM) consensus criteria.

RESULTS

We included 132 patients, of whom 75 (57%) received antifungal prophylaxis (98% posaconazole). Ten CAPA cases were diagnosed, after a median of 6 days following ICU admission. Of those, 9 CAPA cases were recorded in the non-prophylaxis group and one in the prophylaxis group, respectively. However, no difference in 30-day ICU mortality could be observed. Thirty-day CAPA incidence estimates were 1.4% (95% CI 0.2-9.7) in the MAFP group and 17.5% (95% CI 9.6-31.4) in the group without MAFP (p = 0.002). The respective subdistributional hazard ratio (sHR) for CAPA incidence comparing the MAFP versus no MAFP group was of 0.08 (95% CI 0.01-0.63; p = 0.017).

CONCLUSION

In ICU patients with COVID-19 ARF, antifungal prophylaxis was associated with significantly reduced CAPA incidence, but this did not translate into improved survival. Randomized controlled trials are warranted to evaluate the efficacy and safety of MAFP with respect to CAPA incidence and clinical outcomes.

POS0102 GO ASK YOUR PATIENTS! PSS-QoL REPORTED PERCEPTION OF DRYNESS CORRELATES WITH LACRIMAL AND SALIVARY FLOW IN PRIMARY SJÖGREN’S SYNDROME

Background:

The patient perspective is an essential outcome parameter in the quest for effective therapy in primary Sjögren’s Syndrome (PSS). The EULAR Sjögren’s Syndrome Patient Reported Index (ESSPRI) is recommended by EULAR to quantify patient’s symptom burden and has been used in several clinical trials. Surprisingly, the patient’s perception of dryness quantified with ESSPRI does not correlate with objective measures of salivary or lacrimal flow.

Objectives:

Thus, we evaluated a newly developed assessment tool-the Primary Sjögren’s Syndrome Quality of Life Questionnaire (PSS-QoL) - for quantifying symptoms of dryness in comparison with the ESSPRI and objective measurements of salivary and lacrimal flow.

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. The patient perspective was analyzed by PSS-QoL, ESSPRI, Xerostomia Inventory (XI) and Ocular Surface Disease Index (OSDI). Sicca signs were measured with Schirmer’s test, unstimulated salivary flow test (USF) and stimulated salivary flow test (SSF). Patients were categorized into groups based on the presence of subjective and/or objective dryness: 1) objective dryness only, 2) subjective dryness only, and 3) both, subjective and objective dryness. ESSDAI (EULAR Sjögren’s Syndrome Disease Activity Index) and EGA (Evaluator Global Assessment, numeric rating scale from 0 to 10) were obtained. In addition, free light chains (FLC) ĸ and λ, rheumatoid factor (RF) IgM and IgA were determined.

Results:

Data from 123 PSS patients were analyzed; 91.9% (n=113) were female, with a mean disease duration of 6.2 (±5.3) years and mean age of 60.1 (±12.4) years. PSS-QoL-dryness revealed significant negative correlations with Schirmer’s test (r=-0.31, p<0.05) and SSF-test (r=-0.39, p<0.01). In contrast, we found no significant correlation between ESSPRI-dryness and any objective dryness test. Lower perceived dryness was associated with higher immunological activity determined by increased levels of IgG, FLC and RF-IgA. Patients with objective signs and subjective symptoms of dryness had higher clinical and immunological disease activity compared to patients with subjective symptoms only (table 1).

Table 1.

Comparison of perceived dryness-groups with clinical parameters

PSS-QoL MouthpPSS-QoL Eyespsubjobj/subjsubjobj/subjEGA1.0 [0-5]2.0 [0-7]<0.051.0 [0-3]2.0 [0-7]<0.05ESSDAI1.0 [0-144.0 [0-15<0.053.0 [0-74.0 [0-15nsESSPRI-pain3.0 [0-9]3.0 [0-10]ns4.0 [1-8]3.0 [0-10]<0.05RF-IgM19.0 [5-524]31.0 [7-417]ns10.0[5-33]26.0[7-524]<0.01FLC-λ15.1 [7.0-68.3]20.1 [2.6-124.0]<0.0113.4 [7.0-54.5]18.7[2.6-124.0]<0.01IgG11.9 [6.5-37.2]16.1 [7.4-33.8]ns12.8 [6.5-20.6]14.8[7.4-37.2]nsC40.2 [0.01-0.41]0.17 [0.00-0.43]<0.010.2 [0.09-0.41]0.18 [0.00-0.43]nsRF-IgA11.0 [1-500]103 [0-500]<0.014.5 [1-465]63 [0-500]<0.01

C4=Complementfactor 4; EGA=Evaluators Global Assessment; ESSDAI=EULAR Sjögren Syndrome Disease Activity Index; ESSPRI=EULAR Sjögren Syndrome Patient Reported Index; FLC-λ=Free light chain Lambda; IgG=Immunoglobulin G; obj/subj=objective and subjective dryness-group; PSS-QoL=Primary Sjögren Syndrome Quality of Life Questionnaire; RF-IgA=rheumatoid factor Immunoglobulin A; RF-IgM=rheumatoid factor Immunoglobulin M; subj=subjective dryness-group.

Conclusion:

Patients’ perception of dryness assessed by PSS-QoL correlates with objective measurements of salivary gland function while ESSPRI-dryness did not. Based on the PSS-QoL and objective measures of dryness two distinct groups of PSS patients could be distinguished, which may have implications in daily practice and future clinical studies.

Disclosure of Interests:

None declared

Convalescent plasma therapy and mortality in COVID-19 patients admitted to the ICU: a prospective observational study

Background

This study aimed to quantify the potential survival benefit of convalescent plasma therapy (CVP) in critically ill patients with acute respiratory failure related to coronavirus disease-2019 (COVID-19).

Methods

This is a single-center prospective observational cohort study in COVID-19 patients with acute respiratory failure. Immediately after intensive care unit (ICU) admission patients were allocated to CVP treatment following pre-specified criteria to rapidly identify those patients potentially susceptible for this treatment. A propensity score adjustment [inverse probability of treatment weighted (IPTW) analysis] was implemented to account rigorously for imbalances in prognostic variables between the treatment groups.

Results

We included 120 patients of whom 48 received CVP. Thirty percent were female with a median age of 66 years [25th–75th percentile 54–75]. Eighty-eight percent of patients presented with severe acute respiratory failure as displayed by a median paO₂/FiO₂ ratio (Horowitz Index) of 92 [77–150]. All patients required any kind of ventilatory support with more than half of them (52%) receiving invasive ventilation. Thirty-day ICU overall survival (OS) was 69% in the CVP group and 54% in the non-CVP group (log-rank p = 0.049), respectively. After weighing the time-to-event data for the IPTW, the favorable association between CVP and OS became even stronger (log-rank p = 0.035). Moreover, an exploratory analysis showed an overall survival benefit of CVP therapy for patients with non-invasive ventilation (Hazard ratio 0.12 95% CI 0.03–0.57, p = 0.007)

Conclusion

Administration of CVP in patients with acute respiratory failure related to COVID-19 is associated with improved ICU survival rates.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00867-9.

AB0146 DRUG DEPENDENT ALTERATIONS IN B-CELL REPERTOIRE IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS WITH LOW DISEASE ACTIVITY

Background:

B-cells play a major role in the pathogenesis and perpetuation of the immune response in systemic lupus erythematosus (SLE). So far, B-cell subtypes have been studied well, but the precise mechanisms of the B-cell alterations during disease activity and during remission, depending on different medication, are still unclear.

Objectives:

The aim of our study was to investigate the drug dependent alterations in the B-cell repertoire of SLE patients with low disease activity (SLEDAI – 2K ≤4).

Methods:

Peripheral blood samples from 39 patients suffering from SLE (mean±SD; age 43±13 years, 87.2% females, disease duration 11.1±7 years) were drawn over 2 years. All SLE patients were in remission or low disease activity (median±SE, SLEDAI of 2.0±1.5). B-cells were characterized using CD19, CD20, CD5, CD27 antibodies and were grouped in naïve (IgD+27-), non-switched memory (IgD+, CD27+), memory (IgD-,CD27+), B1 (CD5+27-) and MBL-like (CD5++) B-cells. A quantitative flow cytometric bead-based assay (QuantiBRITE PE kit from Becton Dickinson) was used for the estimation of CD19 antibodies bound per cell. Further, CD38 and CD86 antibodies were used to characterize the B-cell subsets. All cytometric measurements were performed using a standardized BD LSR Fortessa platform. After 3 years of follow-up, patients’ data about disease activity and current medication were obtained.

Results:

22 SLE patients were treated with hydroxychloroquine (85.8%) and 19 patients received mycophenolate mofetil (MMF; n=14; 54.6%) or azathioprine (AZA; n= 5; 19.5 %). 5 patients were treated with other DMARDs. Independently of hydroxychloroquine and/or MMF, no significant differences were seen in naïve, non-switched memory, post-switched memory, plasma blasts, B1- or MBL-like B-cells. Patients treated with AZA had significantly lower naïve B-cells (mean±SD, 39.3±6.7vs. 73.1±19.3 %; p = 0.028), but had significantly higher IgD-post switched B-cells (31.2±9.1 vs.12.5 ±9.2 %; p = 0.028, respectively) compared with no AZA-treatment. Interestingly, activated B-cells (5.5±1.5 vs. 1.8±1.1%; p = 0.009) were significantly higher in AZA-treated. After 3 years of follow-up, almost all patients were in remission (median±SE, SLEDAI of 2.0±2.0), except of 3 patients with a SLEDAI of ≥ 6. Interestingly, those patients had at baseline, statistically higher naïve B-cells (p = 0.041) and lower B1-like B-cells (p =0.020) compared with patients with low disease activity.

Conclusion:

Our results suggest that independently of hydroxychloroquine and/or MMF treatment, all patients with low disease activity had similar normal B-cell subsets. Interestingly, in the small group of patients who were treated with AZA, a reduced regeneration of B-cells was shown. Patients with higher disease and high naïve B-cells showed an increased disease activity after three years.

Acknowledgments:

The research was performed in “CBmed” and funded by the Austrian Federal Government within the COMET K1 Centre Program, Land Steiermark and Land Wien.

Disclosure of Interests:

None declared

THU0031 ABATACEPT ALTERS THE FREQUENCY OF IMMUNOREGULATORY AND EFFECTOR T CELL SUBPOPULATIONS IN RHEUMATOID ARTHRITIS

Background:

Under physiological conditions, T regulatory cells (Tregs) are responsible for the downregulation of the immune response. In autoimmune diseases, such as rheumatoid arthritis (RA), auto-inflammation is driven by an imbalance of activation and downregulation of immunological pathways. Thus, treatment plans for autoimmune diseases often involve the enhancement of immunoregulatory pathways by administering inhibitors of costimulation, i.e. CTLA-4-Ig (abatacept, ABA). ABA binds specifically to CD80 and CD86 on antigen presenting cells (APC). Consequently, T cell activation via the CD28 receptor is blocked. Previous studies have demonstrated surprising effects of abatacept on Tregs, specifically decreased frequency of these cells but enhancement in their function1. Whether these alterations can only be found in patients with ABA treatment, or whether they are also present in patients receiving other anti-inflammatory drugs is currently unknown.

Objectives:

The aim of our research was to delineate the impact of ABA on the different subsets of effector and regulatory T cells in RA and compare these findings with patients receiving tocilizumab (TCZ) or rituximab (RTX).

Methods:

Peripheral blood samples from 56 RA patients (median ± SE; age: 60.5 ± 1.3 years, female ratio: 0.7, disease duration: 17.9 ± 2.1 years; respectively) were drawn over a sampling period of 2 years. Freshly isolated PBMCs of RA patients were stained with fluorochrome-labelled antibodies and T cell subsets were identified by flow cytometric means. CD3+CD4+T cells were further classified using different T cell markers (CD25, CD127, CD39, CD95). All cytometric measurements were performed using a standardized BD LSR-Fortessa platform. RA patients were compared according to their treatment with ABA, TCZ or RTX.

Results:

Eighteen out of 56 RA patients (32%) received ABA, 25 patients (45%) received TCZ and 13 patients (23%) were under CD20+ cell depletion therapy with RTX. RA patients receiving ABA displayed a significant decrease in CD3+CD4+CD25+CD127dimTregs (3.7% ± 0.4) compared to patients with TCZ (5.4% ± 0.4, p = 0.041) and patients under RTX treatment (7.52% ± 0.93, p = 0.026). CD39+Tregs were significantly higher in RA patients treated with TCZ (49.5% + 3.2, p = 0.000) or RTX (50.5% ± 5.3, p = 0.026) compared to patients receiving ABA (24.5% ± 3.1). In addition, the frequency of CD95+Tregs was significantly reduced in ABA patients compared to RTX patients (59.6% ± 3.1 vs.76.7% ± 3.6, p = 0.014; respectively). Interestingly, T cells displaying an effector T cell phenotype (CD3+CD4+CD25+/-CD127+) were increased in ABA treated patients compared to RTX treated patients (59.6% ± 3.1 and 76.7% ± 3.6, p = 0.002). Since none of our patients were a non-responder or had high disease activity, we could not analyse whether these changes are associated with treatment outcome.

Conclusion:

Our data demonstrate that blockage of T cell stimulation via ABA leads to characteristic alterations in different regulatory and effector T cells not seen in patients treated with TCZ or RTX. Further studies must clarify whether the analysis of regulatory and effector T cell subpopulations before treatment initiation can be used as biomarker for treatment response.

References:

[1]Álvarez-Quiroga C, Abud-Mendoza C, Doníz-Padilla L, et al. CTLA-4-Ig therapy diminishes the frequency but enhances the function of treg cells in patients with rheumatoid arthritis.J Clin Immunol. 2011;31(4):588-595.doi:10.1007/s10875-011-9527-5

Acknowledgments:

Work done in “CBmed” was funded by the Austrian Federal Government within the COMET K1 Centre Program, Land Steiermark and Land Wien.

Disclosure of Interests:

None declared

Therapeutic Potential of Targeting the Th17/Treg Axis in Autoimmune Disorders

A disruption of the crucial balance between regulatory T-cells (Tregs) and Th17-cells was recently implicated in various autoimmune disorders. Tregs are responsible for the maintenance of self-tolerance, thus inhibiting autoimmunity, whereas pro-inflammatory Th17-cells contribute to the induction and propagation of inflammation. Distortion of the Th17/Treg balance favoring the  pro-inflammatory Th17 side is hence suspected to contribute to exacerbation of autoimmune disorders. This review aims to summarize recent data and advances in targeted therapeutic modification of the Th17/Treg-balance, as well as information on the efficacy of candidate therapeutics with respect to the treatment of autoimmune diseases.

An effective approach to prevent immune rejection of human ESC-derived allografts

Human embryonic stem cells (hESCs) hold great promise for cell therapy as a source of diverse differentiated cell types. One key bottleneck to realizing such potential is allogenic immune rejection of hESC-derived cells by recipients. Here, we optimized humanized mice (Hu-mice) reconstituted with a functional human immune system that mounts a vigorous rejection of hESCs and their derivatives. We established knockin hESCs that constitutively express CTLA4-Ig and PD-L1 before and after differentiation, denoted CP hESCs. We then demonstrated that allogenic CP hESC-derived teratomas, fibroblasts, and cardiomyocytes are immune protected in Hu-mice, while cells derived from parental hESCs are effectively rejected. Expression of both CTLA4-Ig, which disrupts T cell costimulatory pathways, and PD-L1, which activates T cell inhibitory pathway, is required to confer immune protection, as neither was sufficient on their own. These findings are instrumental for developing a strategy to protect hESC-derived cells from allogenic immune responses without requiring systemic immune suppression.

Ultrasound for diagnosis of carpal tunnel syndrome: comparison of different methods to determine median nerve volume and value of power Doppler sonography

OBJECTIVE

To compare ultrasound measurement of median nerve cross-sectional area (CSA) at different anatomical landmarks and to assess the value of power Doppler signals within the median nerve for diagnosis of carpal tunnel syndrome (CTS).

METHODS

A prospective study of 135 consecutive patients with suspected CTS undergoing two visits within 3 months. A final diagnosis of CTS was established by clinical and electrophysiological findings. CSA was sonographically measured at five different levels at forearm and wrist; and CSA wrist to forearm ratios or differences were calculated. Intraneural power Doppler signals were semiquantitatively graded. Diagnostic values of different ultrasound methods were compared by receiver operating characteristic curves using SPSS.

RESULTS

CTS was diagnosed in 111 (45.5%) wrists; 84 (34.4%) had no CTS and 49 (20.1%) were possible CTS cases. Diagnostic values were comparable for all sonographic methods to determine median nerve swelling, with area under the curves ranging from 0.75 to 0.85. Thresholds of 9.8 and 13.8 mm(2) for the largest CSA of the median nerve yielded a sensitivity of 92% and a specificity of 92%. A power Doppler score of 2 or greater had a specificity of 90% for the diagnosis of CTS. Sonographic median nerve volumetry revealed a good reliability with an intraclass correlation coefficient of 0.90 (95% CI 0.79 to 0.95).

CONCLUSIONS

Sonographic assessment of median nerve swelling and vascularity allows for a reliable diagnosis of CTS. Determination of CSA at its maximal shape offers an easily reproducible tool for CTS classification in daily clinical practice.

Proliferation analysis of the growth plate after diaphyseal midshaft fracture by 5'-bromo-2'-deoxy-uridine

Both stimulative and inhibitory growth disturbances may occur after a fracture during the growth period. The exact mechanism responsible for stimulative growth disturbances in the immature skeleton is unexplained. It's possible that chondrocyte proliferation leads to overgrowth. This study investigates the effect of a fracture on the proliferation of chondrocytes at the nearby growth plate and its effect on the contra-lateral leg. Fifty-six 1-month-old Sprague-Dawley rats (weight, 100-120 g) were randomised to either an experimental or a control group. A closed mid-diaphyseal tibial fracture was produced in all animals of the experimental group using a standardised technique. On day 3, 10, 14 and 29 of the experiment, the rats were euthanised and their tibial growth plates were subjected to histological analysis. 5'-Bromo-2'-deoxy-uridine labelling was used for the quantitative analysis of chondrocyte proliferation. Safranin O staining provided the histological overview for the subsequent analysis of BrdU-labelling. Immunohistochemical analysis showed increased proliferation of chondrocytes in the growth plates of broken bones during fracture healing. This proliferation peaked on day 3 post-fracture and then reduced gradually until day 29. No increase in the rate of proliferation was observed on the contra-lateral limbs of the animals in the experimental group. Following a diaphyseal fracture of the tibia, the growth plates located next to the fracture react with increased cell proliferation. This proliferation was not observed in the contra-lateral uninjured tibia. This investigation shows that the post-traumatic length discrepancy is a local biological process at the growth plate brought about by the fracture.

Characterization of HULC, a novel gene with striking up-regulation in hepatocellular carcinoma, as noncoding RNA

BACKGROUND & AIMS

Recent studies have highlighted the role of noncoding RNAs (ncRNAs) in carcinogenesis, and suggested that this class of genes might be used as biomarkers in cancer. We searched the human genome for novel genes including ncRNAs related to hepatocellular carcinoma (HCC).

METHODS

An HCC-specific gene library was generated and screened for deregulated genes with 46 HCCs, 4 focal nodular hyperplasias, and 7 cirrhoses utilizing cDNA arrays. Sequencing of library clones identified a novel ncRNA as the most up-regulated gene in HCC. This gene was also cloned from different monkeys and characterized by quantitative RT-PCR, Northern blot analysis and in situ hybridization. Structural and functional studies included comparative sequence and protein expression analyses, quantitative RT-PCR of polysomal preparations, and siRNA-mediated knockdown experiments.

RESULTS

The most up-regulated gene in HCC named highly up-regulated in liver cancer (HULC) was characterized as a novel mRNA-like ncRNA. HULC RNA is spliced and polyadenlyated, and resembles the mammalian LTR transposon 1A. It does not contain substantial open reading frames, and no native translation product was detected. HULC is present in the cytoplasm, where it copurifies with ribosomes. siRNA-mediated knockdown of HULC RNA in 2 HCC cell lines altered the expression of several genes, 5 of which were known to be affected in HCC, suggesting a role for HULC in post-transcriptional modulation of gene expression.

CONCLUSIONS

HULC is the first ncRNA with highly specific up-regulation in HCC. Because HULC was detected in blood of HCC patients, a potential use as novel biomarker can be envisaged.