Plasma pentraxin 3 in idiopathic inflammatory myopathies: a possible new biomarker of disease activity

Pentraxin-3 (PTX3) is a component of humoral innate immunity with essential functions both in promotion and resolution of inflammation. We aimed to study the PTX3 in the plasma and in the muscle of patients with idiopathic inflammatory myopathies (IIM) and whether PTX3 may correlate with disease activity. Plasma PTX3 levels were assessed in 20 patients with IIMs, 10 dermatomyositis (DM), and 10 polymyositis (PM), compared to 10 patients with rheumatoid arthritis (RA) and 10 healthy donors (HDs) aged, sex, and body mass index matched. Disease activity in IIMs was assessed by Myositis Disease Activity Assessment Visual Analog Scale (MYOACT), while disease activity score on 28 joints (DAS28) was used for RA patients. Muscle histopathology and immunohistochemical (IHC) analyses were also performed. Mean plasma PTX3 levels were significantly higher in IIM patients than HDs (518 ± 260 pg/ml vs. 275 ± 114 pg/ml, P = 0.009). Linear regression analysis adjusted for age, sex, and disease duration showed a direct correlation between PTX3 and CPK levels (β: 0.590), MYOACT (β: 0.759), and physician global assessment of disease activity (β: 0.832) in IIMs. No association between PTX3 levels and DAS28 was found in RA. Global PTX3 pixel fraction was higher in IIM than HDs muscle, but a lower PTX3 expression was found in perifascicular areas of DM and in myofibers with sarcolemmal staining for membrane attack complement. PTX3 plasma levels were increased in IIMs and correlated with disease activity suggesting a possible role as biomarker of disease activity. PTX3 showed a different distribution in DM or PM muscle.

AB0134 IN-VITRO STUDY ON THE EFFECT OF SELECTIVE Jak-INHIBITORS ON PBMCs STAT3 PHOSPHORYLATION FROM SYSTEMIC SCLEROSIS PATIENTS

Background

Systemic sclerosis (SSc) is a rare autoimmune connective tissue disease characterized by autoimmunity-driven damage and vasculopathy leading to fibrosis of the skin and internal organs (1). The Janus kinase (Jak) - signal transducer and activator of transcription (STAT) pathway has been evidenced markedly activated in SSc patients (2, 3), and its inhibition has been proved in preclinical and clinical trials (4), but no data on Jak selective inhibition are available.

Objectives

To explore the effect of selective inhibition of Jak/STAT pathway in peripheral blood mononuclear cells (PBMC) from SSc patients.

Methods

In vitro Jak inhibition of the subunit 3 of phosphorylated (p) than activated STAT was measured by flow cytometry in peripheral blood mononuclear cells (PBMC) from SSc patients naïve to any immunosuppressive and/or corticosteroids (n.5). pSTAT3 activity was also assessed after stimulation with recombinant human 0.1 ng/ml IL-6 (Peprotech – NJ, USA). The PBMC were overnight incubated with IC50 concentrations of selective Jak1-, Jak2-, Jak3- and Tyk2-inhibitors (Biovision Inc. – CA, USA). Percentages of pSTAT3 positive cells were compared in presence of different compounds stimulation.

Results

After overnight incubation, percentage of pSTAT3 positive cells was significantly higher in CD14pos compared to CD4pos (16.3%; 95CI 10-22 vs 10.7%; 95CI 4--18, – p=0.02). pSTAT3posCD14pos cells were halved only by selective Jak3-inhibitor, while pSTAT3posCD4pos cells were reduced by 36% by selective Jak1-inhibitor. Selective Jak2- or Tyk2-inhibitors did not interfere with STAT3 phosphorylation in PBMC from SSc patients. After IL-6 stimulation, we observed a 2- and a 1.5-fold increase in percentage of pSTAT3posCD4pos and pSTAT3posCD14pos cells, respectively. pSTAT3posCD14pos cells were reduced in the PBMC co-culture with IL-6 and Jak-selective inhibitors, in contrast no effects were found in CD4pos cells. Specifically, selective Jak1- and Jak3-inhibitors reduced pSTAT3posCD14pos cells by an average of 37% and 25%, respectively. No effects were observed after co-culture with IL-6 and selective Jak2- or Tyk2-inhibitors.

Conclusion

Jak/STAT3 pathway of PBMC from SSc patients with active disease may be differently modulated by specific inhibitors. Selectivity of Jak1- and Jak3-inhibitors seems more relevant, especially in CD14pos monocytes after IL-6 stimulation. These preliminary findings highlight some evidence for effectiveness of selective Jak-inhibitors in SSc treatment.

References

[1]Benfaremo D, et al. Systemic Sclerosis: From Pathophysiology to Novel Therapeutic Approaches. Biomedicines. 2022;10(1):163.

[2]Talotta R. The rationale for targeting the JAK/STAT pathway in scleroderma-associated interstitial lung disease. Immunotherapy. 2021;13(3):241-256.

[3]Cacciapaglia F, et al. Phosphorylated signal transducer and activator of transcription 3 (pSTAT3) is highly expressed in CD14+ circulating cells of scleroderma patients. Rheumatology (Oxford). 2020;59(6):1442-1444.

[4]Karalilova RV, et al. Tofacitinib in the treatment of skin and musculoskeletal involvement in patients with systemic sclerosis, evaluated by ultrasound. Rheumatol Int. 2021;41(10):1743-1753.

Disclosure of Interests

None declared

POS0928 THE IDENTIFICATION OF PENTRAXIN 3 AS BIOMARKER OF DISEASE ACTIVITY IN IDIOPATHIC INFLAMMATORY MYOPATHIES

Background

Muscle involvement is only one feature of idiopathic inflammatory myopathies (IIM). Muscle enzymes do not always represent the best marker of disease activity and other inflammation markers such as ESR and CRP may be normal even with an active disease. Pentraxin-3 (PTX3) is an inflammatory marker produced in many inflammatory and non-inflammatory cells and serum level has been related to higher risk of major cardiovascular events and atherosclerosis1. PTX3 levels have been examined in various rheumatic and autoimmune diseases2, but data of PTX3 levels in patients affected with IIM have not been reported.

Objectives

The aim of the current study was to identify whether serum PTX3 level could be a marker of disease activity in patients affected with IIM.

Methods

Twenty patients affected with IIM (13 Dermatomyositis and 7 Polymyositis), 10 rheumatoid arthritis patients and 10 healthy controls (HC) aged, sex and BMI matched were evaluated. PTX3 levels was assessed using a commercially available enzyme-linked immunosorbent assay (Human Pentraxin3 ELISA Kit, Abcam) kit. Three different cardiovascular risk scores were used to estimate the 10-years CV risk. Carotid intima media thickness (cIMT) was measured with a My Lab XPro80 (Esaote SpA, Genova, Italy) using a linear array ultrasound probe small parts broadband transducer (5–15 MHz) both in right and left carotid. Myositis disease activity was evaluated by using myositis disease activity assessment visual analog scales (MYOACT) [19] established by the International Myositis Assessment and Clinical Studies (IMACS) group. Manual muscle test (MMT8) was used to assess muscle impairment. Exclusion criteria were a diagnosis of diabetes or a history of previous major CV events.

Results

Demographic and disease characteristics of our cohort are showed in Table 1. IIM patients showed higher levels of PTX3 compared to HCs (518±260 pg/ml vs 275±114 pg/ml, p<0.05), while no difference was observed compared to RA patients (383±260 pg/ml). PTX3 levels do not correlate with lipid levels, QIMT and cardiovascular risk scores both in IIM, RA and HC. No correlation was found between DAS28-ESR and PTX3 levels in RA patients. Of note, a direct correlation was found between PTX3 levels and MYOACT-GLOBAL DISEASE ACTIVITY (r=0.675, p=0.002), PTX3 levels and MYOACT- GLOBAL-EXTRA-SKELETAL MUSCLE DISEASE ACTIVITY (r=0.542, p=0.013), while an inverse correlation was found between PTX3 levels and MMT8 (r=-0.510, p=0.02).

Table 1.IIM 20pz (13 DM, 7 PM)RA 10pzHealthy Control 10pzFemale, n. (%)18 (90%)9 (90%)9 (90%)Age55,3 (7,8)58,3 (5,9)54,6 (6,5)BMI25,5 (4,1)23,9 (3,1)24,6 (3,5)Duration of disease, median (IQR)7,3 (4 – 12,8)13,5 (10,5 – 18,5)*Physician Global Assessment2,1 (2,1)2 (2,2)Patient Global Assessment4 (3,6)2,7 (2,3)Health Assessment Questionnaire0,7 (0,8)0,9 (0,9)Manual Muscle Testing 876,2 (6,6)DAS282,6 (1,1)Skin involvement, n. (%)13 (65)Lung involvement, n. (%)7 (35)Dysphagia, n. (%)11 (55)Arthritis, n. (%)4 (20)Malignancies, n. (%)0 (0)0 (0)0 (0)Arterial hypertension, n. (%)6 (30)2 (20)1 (10)Current steroid therapy2,5 (0 – 5)0 (0 – 3,8)Smoking, n. (%)6 (30)2 (20)3 (30)Total cholesterol, mg/dl203,3 (28,6)215,0 (29,5)216,2 (27,3)HDL cholesterol, mg/dl62,7 (14,7)62,6 (14,2)65,1 (18,2)ESR, mm/h16,7 (12,2)19 (11,7)PCR, mg/l2,9 (2,1)4,1 (5)SCORE median (IQR)0,5 (0 – 2)1 (0 – 3)1 (0,8 – 1,3)CUORE median (IQR)1,9 (0,6 – 3,5)1,6 (1 – 4)1,7 (1,2 – 2,8)QRISK3 median (IQR)4,7 (2,1 – 11,3)7,5 (3,2 – 13,6)4,2 (3,1 – 5,5)QIMT Max, median (IQR)742,5 (636,8 – 804)833 (685,3 – 961) *756 (711 – 820)Mean QIMT, median (IQR)679 (613,1 – 736,3)764,3 (664,5 – 854,1) *703,3 (697,3 – 742,8)Pentraxin 3, pg/ml518 (260)383 (146)275 (114)*

Data are expressed as “mean (SD)” where not otherwise specified.

*p<0.05, **p<0.01, ***p<0.001 vs IIM

Conclusion

In IIM patients, PTX3 levels are higher than HC and correlate with disease activity, both for muscular and extra-muscular manifestations, being a possible biomarkers of disease activity.

References

[1]Front Immunol. 2019; 10: 823

[2]Arch Med Sci. 2020; 16(1): 81–86

Disclosure of Interests

None declared

AB0070 INHIBITION OF STAT3 IN PBMCs FROM RHEUMATOID ARTHRITIS PATIENTS: CLUES TO UNDERSTAND SELECTIVITY OF JANUS KINASE INHIBITORS

Background

The Janus kinase (Jak) - signal transducer and activator of transcription (STAT) pathway has 4 Jak proteins and 7 STAT factors that mediate intracellular downstream of cytokine receptors. Targeted small-molecule therapies with different bond affinity to Jak proteins have been demonstrated effective in rheumatoid arthritis (RA) treatment, but the clinical significance of selective inhibition remains unclear.

Objectives

To explore the effect of selective inhibition of Jak-STAT pathway in peripheral blood mononuclear cells (PBMC) from RA patients compared to healthy donors (HD).

Methods

In vitro Jak inhibition of the subunit 3 of phosphorylated (p) than activated STAT was measured by flow cytometry in peripheral blood mononuclear cells (PBMC) from RA patients with active disease (DAS28>5.1) naïve to any DMARDs (n.5) and HD (n.5), following recombinant human 0.1 ng/ml IL-6 (Peprotech – NJ, USA) stimulation. After blood separation, PBMC were overnight incubated with IC50 concentrations of selective Jak1-, Jak2-, Jak3- and Tyk2-inhibitors (Biovision Inc. – CA, USA) with or without IL-6 stimulation. Mean fold-increase of pSTAT3 was then compared in presence of different compounds stimulation.

Results

Mean pSTAT3 activity after overnight incubation was significantly higher in RA patients compared to HD (37%; 95CI 8.2-56.7 vs 17.9%; 95CI 4.6-21 – p=0.01). After IL-6 stimulation, a 2-fold and a 1.4-fold increase in pSTAT3 levels was observed in PBMC from RA patients and HD, respectively. In unstimulated PBMC from HD Jak-inhibitors didn’t significantly reduced pSTAT3 activity. In CD14+ cells from RA patients, pSTAT3 activity was reduced with no differences between all four selective Jak-inhibitors, while in CD4+ cells only Jak1-inhibition was able to reduce by 40% pSTAT3 activity. After IL-6 stimulation, the co-culture with Jak1- or JaK3- selective inhibitors was able to significantly reduce pSTAT3 levels in CD4+ lymphocytes, by an average of 20%. While in CD14+ monocytes Jak1-, Jak2- and Jak3- selective inhibitors were able to reduce pSTAT3 activity by a mean of 30%. Tyk-2 selective inhibitor did not interfere with STAT3 activation by IL-6 stimulation of PBMC from RA patients and HD.

Conclusion

Jak/STAT3 activity of PBMC from RA patients with active disease may be differently modulated by specific inhibitors. Selectivity of Jak-inhibitors seems more relevant in lymphocytes after IL-6 stimulation. These preliminary findings may explain discrepancies in effectiveness of selective Jak-inhibitors and pave the way for different choices in clinical practice.

References

[1]Tanaka Y, et al. Nat Rev Rheumatol. 2022 Jan 5:1–13.

[2]Traves PG, et al. Ann Rheum Dis. 2021 Jul;80(7):865-875.

[3]Choy EH. Rheumatology (Oxford). 2019 Jun 1;58(6):953-962.

Disclosure of Interests

None declared

AB0844 SERUM sCD40L LEVEL CAN PREDICT SHORT-TERM CLINICAL OUTCOMES IN PATIENTS WITH PSORIATIC ARTHRITIS ON TREATMENT WITH APREMILAST

Background:

The pathogenesis of Psoriatic Arthritis (PsA) involves several pathways simultaneously, including the CD40/CD40L interaction. In vitro evidence suggests that the cleavage of soluble CD40L (sCD40L) may happen as a Phosphodiesterase 4- (PDE4) dependent reaction [1-3].

Objectives:

Here we investigate whether apremilast, a PDE4 inhibitor, could modify circulating level of soluble CD40L (sCD40L) in PsA patients, and the possible associations of these changes with clinical response.

Methods:

Consecutive patients with PsA starting apremilast in routine clinical practice between October 2018 and September 2019 in a single center were longitudinally observed. Sera were collected at baseline and at the 6-month follow up visit. Demographics and clinical characterstics at different observation times were recorded. Samples were ran in a Bio-Plex ProTM plate for sCD40L level. To investigate the association of sCD40L level with DAPSA minor response and DAPSA Low Disease Activity (LDA) and/or Remission (ie DAPSA ≤14) at 6 months of treatment, multivariate logistic regression models with backward selection (p <0.05) were built.

Results:

We studied n.27 patients (16/27 women, 59.6%) with PsA with mean age (± SD) of 58.4 ± 10.4 years. A significant reduction of the mean values of DAPSA, LEI and PASI was evidenced at 6 months. Mean serum level of sCD40L decreased from 5364.02 ± 2025.70 to 4412.14 ± 2629.81 pg/ml after 6 months of apremilast treatment (p=0.01, Figure 1). Baseline sCD40L was an independent predictor of DAPSA minor response (OR 1.0006, 95% CI 1.0001-1.0012; AUC 0.76 (95% CI 0.55-0.97)). Moreover baseline DAPSA (OR 0.80, 95% CI 0.65-0.98) and baseline sCD40L (OR 1.001, 95%CI 1.0001-1.0028; AUC 0.85 95% CI 0.69-0.98, Figure 2) were independently associated with DAPSA LDA/Remission.

Conclusion:

Apremilast may decrease sCD40L level in PsA patients. Higher baseline serum sCD40L level may predict short-term clinical response to apremilast.

References:

[1]Davidson DC, Jackson JW, Maggirwar SB. Targeting platelet-derived soluble CD40 ligand: a new treatment strategy for HIV-associated neuroinflammation? J Neuroinflammation 2013;10:144.

[2]Vanichakarn P, Blair P, Wu C, Freedman JE, Chakrabarti S. Neutrophil CD40 enhances platelet-mediated inflammation. Thromb Res 2008;122(3):346-58.

[3]Totani L, Amore C, Di Santo A, et al. Roflumilast inhibits leukocyte-platelet interactions and prevents the prothrombotic functions of polymorphonuclear leukocytes and monocytes. J Thromb Haemost 2016;14(1):191-204.

Disclosure of Interests:

Vincenzo Venerito: None declared, Dorotea Natuzzi: None declared, Rita Bizzoca: None declared, Nunzia Lacarpia: None declared, Marco Fornaro: None declared, maria giannotta: None declared, giulia righetti: None declared, Giuseppe Lopalco: None declared, Florenzo Iannone Consultant of: Speaker and consulting fees from AbbVie, Eli Lilly, Novartis, Pfizer, Roche, Sanofi, UCB, MSD, Speakers bureau: Speaker and consulting fees from AbbVie, Eli Lilly, Novartis, Pfizer, Roche, Sanofi, UCB, MSD

Serum sCD40L levels are increased in patients with psoriatic arthritis and are associated with clinical response to apremilast

The pathogenesis of psoriatic arthritis (PsA) involves several pathways, including the CD40/CD40L signaling which promotes the release of multiple cytokines. Transmembrane CD40L is also released in soluble form (sCD40L) and phosphodiesterase 4 (PDE4) seems to be involved in its cleavage. We aimed to investigate whether apremilast, a PDE4 inhibitor, could modify circulating levels of sCD40L in PsA patients, and the possible associations of these changes with clinical response. Consecutive PsA patients starting apremilast in routine clinical practice were prospectively observed. Disease Activity of Psoriatic Arthritis (DAPSA), Psoriasis Area Severity Index (PASI), Leeds Enthesitis Score (LEI) and serum samples were collected at baseline and at 6 months. Samples were run in a Bio-Plex ProTM plate for sCD40L. To investigate the association of sCD40L level with DAPSA based minor response, low disease activity (LDA) and/or remission at 6 months of treatment, multivariate logistic regression models with backward selection (P < 0·05) were built. We studied 27 patients (16 of 27 women, 59·6%) with PsA and mean age [± standard deviation (s.d.)] of 58·4 ± 10 years. A significant reduction of the mean values of DAPSA, LEI and PASI was detected at 6 months. Mean serum levels of sCD40L decreased from baseline 5364 ± 2025 pg/ml to 4412 ± 2629 at 6 months (P = 0·01). Baseline DAPSA [odds ratio (OR) = 0·80, 95% confidence interval (CI) = 0·65-0·98] and sCD40L (OR = 1·001, 95% CI = 1·0001-1·0027) were independently associated with DAPSA LDA/remission at 6 months. In PsA patients, sCD40L levels decrease upon apremilast treatment and might predict short-term clinical response to apremilast.

Seed dormancy and control of germination in Sisymbrella dentata (L.) O.E. Schulz (Brassicaceae)

Seed germination responsiveness to environmental cues is crucial for plant species living in changeable habitats and can vary among populations within the same species as a result of adaptation or modulation to local climates. Here, we investigate the germination response to environmental cues of Sisymbrella dentata (L.) O.E. Schulz, an annual endemic to Sicily living in Mediterranean Temporary Ponds (MTP), a vulnerable ecosystem. Germination of the only two known populations, Gurrida and Pantano, was assessed over a broad range of conditions to understand the role of temperatures, nitrate, hormones (abscisic acid - ABA and gibberellins - GA) and after-ripening in dormancy release in this species. Seed germination responsiveness varied between the two populations, with seeds from Gurrida germinating under a narrower range of conditions. Overall, this process in S. dentata consisted of testa and endosperm rupture as two sequential events, influenced by ABA and GA biosynthesis. Nitrate addition caused an earlier testa rupture, after-ripening broadened the thermal conditions that allow germination, and alternating temperatures significantly promoted germination of non-after-ripened seeds. Primary dormancy in S. dentata seeds likely allows this plant to form a persistent seed bank that is responsive to specific environmental cues characteristic of MTP habitats.

Bosentan regulates the expression of adhesion molecules on circulating T cells and serum soluble adhesion molecules in systemic sclerosis-associated pulmonary arterial hypertension

Objectives:

To study the expression of adhesion molecules in patients with systemic sclerosis (SSc) with and without pulmonary arterial hypertension (PAH) and the effects of therapy with the endothelin-1 (ET-1) receptor antagonist, bosentan.

Methods:

In all, 35 patients with SSc and 25 healthy donors (HD) were selected for this study. Of 35 patients, 10 had isolated PAH assessed by Doppler echocardiography and treated with bosentan. Peripheral blood (PB) lymphocytes were isolated by density gradient centrifugation, and the expression of lymphocyte function-associated antigen-1 (LFA-1), very late antigen-4 (VLA-4) and L-selectin on CD3 T cells was assessed by double immunofluorescence and flow-cytometry. As endothelial activation markers, serum soluble P-selectin, platelet/endothelial cell adhesion molecule (PECAM)-1, vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule (ICAM)-1 and von Willebrand factor (vWF) antigen were assessed by ELISA. In patients with SSc-PAH, T cell subsets and soluble endothelial markers were assessed at baseline and after 6 and 12 months of bosentan therapy.

Results:

In patients with SSc-PAH, serum soluble ICAM-1, VCAM-1, P-selectin and PECAM-1 levels were higher than in HD at baseline and fell to normal values after 12 months of bosentan therapy. CD3–LFA1 T cells were significantly higher in PAH-SSc at baseline than in HD or SSc and significantly decreased after therapy. CD3–L-selectin T cells were significantly lower in SSc-PAH at baseline than in HD or SSc and rose to normal levels after bosentan therapy.

Conclusions:

This study confirms that endothelial activation occurs in SSc, and suggests that changes in the T cell/endothelium interplay take place in SSc-associated PAH. Bosentan seems to be able to hamper these changes and restore T cell functions in these patients.