POS0246 SEQUENTIAL RITUXIMAB AND MEPOLIZUMAB IN EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS

Background

Rituximab (RTX) is an effective remission-induction treatment in ANCA-associated vasculitides (AAVs). Some reports have suggested that it might be effective also in Eosinophilic Granulomatosis with Polyangiitis (EGPA), to induce and maintain remission of vasculitic manifestations [1,2]. However, its effects for preventing respiratory relapses seem to be poor. Mepolizumab (Mepo) (both 100 and 300mg/month) is effective in improving respiratory manifestations and lung function, while partially controlling also systemic activity [3,4]. Isolated case reports further indicate that the sequential therapy with RTX and Mepo might be effective [5-7].

Objectives

The study aimed to investigate the efficacy and safety of a therapeutic regimen based on sequential RTX and Mepo for the control of EGPA.

Methods

A multicenter, retrospective, cohort study was conducted on adult patients diagnosed with EGPA according to the ACR classification criteria [8] or MIRRA trial criteria [3]. Only patients who received induction therapy with RTX (any dosage), and subsequent treatment with Mepo (100-300 mg/4 weeks) within 12 months from last RTX administration were included. Patients receiving other induction therapies between RTX and Mepo were excluded. The effectiveness of sequential RTX and Mepo was assessed in terms of disease activity (by the Birmingham Vasculitis Activity Score, BVAS) and daily corticosteroid dosage. Safety data were also collected.

Results

Thirty-four EGPA patients treated with sequential RTX and Mepo were included (59% females, median age of 51 years (IQR 40-58); 41% ANCA positive).

In most cases (26/34; 76%), RTX was started at the dosage of 1g q2w, and all except two patients had active disease at time of RTX beginning [median BVAS of 9 (IQR 6-14)]. Specifically, most patients started RTX for the control of systemic manifestations (19/34; 56%), or of both systemic and respiratory symptoms (11/34; 32%). All except one patient were receiving oral corticosteroids, at a median dosage of 25 mg/day (10-38).

Mepo was started after a median of 14 months (6-23) from RTX initiation and after a median of 5 months (IQR 3-11) from the last RTX administration. Mepo was used at the dosage of 100mg/4 weeks in 32/34 (94%), mostly for the control of respiratory manifestations (25/34, 74%). At the time of starting Mepo, the median BVAS was 4 (2-8), and median prednisolone dose 10 mg/day (7-15). After a median follow-up of 28 months (IQR 23-33) from starting Mepo, the median BVAS decreased to 1.5 (IQR 0-4) and the median corticosteroid dosage to 5 mg/day (2.5-5), with 7/34 (21%) patients being off steroids. At last follow-up, most patients were off-RTX (28/34), typically due to stable disease remission (20/34; 59%).

Both RTX and Mepo were well-tolerated; 5 patients had adverse events on RTX (none serious), and 5 on Mepo (including one serious infection).

Conclusion

Sequential use of RTX and Mepo seems to be effective for remission induction and maintenance in EGPA.

References

[1]Emmi, Ann Rheum Dis, 2018

[2]Teixeira, RMD Open, 2019 3. Wechsler, NEJM, 2017

[4]Bettiol, Arthritis Rheumatol, 2021

[5]Shiroshita, Respir Med Case Rep, 2018

[6]Higashitani, Mod Rheumatol Case Rep, 2021

[7]Afiari, Cureus 2020

[8]Masi, Arthritis Rheum, 1990

Table 1.

Effectiveness of sequential RTX and Mepo in the 34 patients included in the study

RTX beginningMepo beginningLast follow-upMedian time elapsed (IQR)-14 months (6-23) from RTX beginning28 months (23-33) from Mepo beginningDosage1g q2w (26/34);100mg/4 weeks (32/34)6 patients off Mepo; 28 patients off RTX375mg/m2 for 4 weeks (8/34)300mg/4 weeks (2/34)Reason for treatment beginning (manifestations)Systemic (19/34);Respiratory (25/34);-Systemic + respiratory (11/34);Systemic (4/34);Only respiratory (3/34);Remission maintenance (5/34)Other (1/34)BVAS (median, IQR)9 (6-14)4 (2-8)1.5 (0-4)Prednisolone dosage (median, IQR), mg/day25 (10-38)10 (7-15)5 (2.5-5)

Disclosure of Interests

Alessandra Bettiol: None declared, Maria Letizia Urban: None declared, Federica Bello: None declared, Davide Fiori: None declared, Irene Mattioli: None declared, Giuseppe Lopalco: None declared, Florenzo Iannone: None declared, Allyson Egan: None declared, Luca Moroni: None declared, Lorenzo Dagna Consultant of: Consultation honoraria from GSK outside the current work, Marco Caminati: None declared, Simone Negrini: None declared, Paolo Cameli: None declared, Marco Folci: None declared, Paola Toniati: None declared, Roberto Padoan: None declared, Oliver Flossmann: None declared, Roser Solans-Laqué: None declared, Laura Losappio: None declared, Jan Schroeder Consultant of: Advisory Board fees from AstraZeneca and GSK, Marc André: None declared, Laura Moi: None declared, paola parronchi Consultant of: Consultation honoraria from GSK and Novartis, Fabrizio Conti: None declared, Savino Sciascia: None declared, David Jayne Consultant of: Consultant for Astra-Zeneca, Aurinia, BMS, Boehringer-Ingelheim, Chemocentryx, Chugai, CSL, GSK, Infla-RX, Janssen, Novartis, Roche/Genentech, Takeda and Vifor, Augusto Vaglio Consultant of: Consultation honoraria from GSK outside the current work, Giacomo Emmi Consultant of: Consultation honoraria from GSK outside the current work

POS1212 SARS-CoV-2 INFECTION AMONG PATIENTS WITH BEHÇET’S SYNDROME

Background:

Studies on SARS-Cov-2 in Behçet’s syndrome (BS) patients are limited to two small case series from European centres.[1,2]

Objectives:

We aimed to assess the prevalence of SARS-CoV-2 infection among Italian BS patients referring to Careggi University Hospital (Florence, Italy) and to evaluate the possible association between BS disease activity and treatment and the risk of Sars-CoV-2 infection among patients with BS.

Methods:

A survey was conducted among 335 subjects diagnosed with BS and followed at Careggi University Hospital. Moreover, we conducted a case-control study. Cases were described in term of SARS-CoV-2 manifestation and prognosis, changes in disease activity, and in pharmacological therapies. Sars-CoV-2 negative controls matched 1:3 by sex, age and disease duration ± 5 years were randomly selected.

Results:

Out of 335 BS patients, 12 declared to have/have had SARS-CoV-2 infection (3.6%). Eight were females (median age of 40 years), with a median duration of BS disease of 6 years; five had active disease. Nine patients reported fever, 9 myalgia/arthralgia, 5 gastrointestinal symptoms, 5 anosmia/ageusia, 5 cough, 3 headache, 3 fatigue, 2 breathlessness, panic attacks and dizziness (one each). Before infection, patients were treated with corticosteroids, colchicine, hydroxychloroquine (HCQ), traditional DMARDs [azathioprine (n patients = 4), methotrexate (n=1)], and biologics DMARDs [adalimumab (n=6), infliximab (n=2), secukinumab (n=1), and canakinumab (n=1)]. Therapy was suspended for a median time of 33 days in 9patients and resumed after a median time of 5 days from negativation. Regarding SARS-CoV-2 treatment, most patients started or increased corticosteroids, whereas heparin and antipyretic drugs were used in 4 and 5 patients, respectively. Cases were comparable to controls in terms of disease manifestations, activity, and immunomodulating therapy, with the only exception of corticosteroids, whose daily dose was significantly higher in cases (Table 1).

Conclusion:

Prevalence of SARS-CoV-2 infection among Italian BS patients is 3.6%, similarly to the Italian general population (4.2%). Disease activity at time of infection was not associated with an increased risk of SARS-CoV-2 infection. Most patients interrupted biologic DMARDs. However, use of DMARDs, seemed not to be associated with an increased risk of SARS-CoV-2 infection, while higher doses of corticosteroids resulted to be more common among patients with SARS-CoV-2 infection as compared to controls. No patient required hospitalization or died. Our experience shows encouraging data about BS patients who do not appear be at greater risk of SARS-CoV-2 infection or complications than the general population.

References:

[1]Espinosa et al. COVID-19 and Behçet’s disease: clinical case series. Ann Rheum Dis. 2020

[2]Yurttaş et al. Characteristics and outcomes of Behçet’s syndrome patients with Coronavirus Disease 2019: a case series of 10 patients. IEM. 2020

[3]http://www.salute.gov.it

Table 1.

Features of SARS-CoV-2+ cases and matched controls

12 SARS-CoV-2+ CASESPRE-INFECTION12 SARS-CoV-2+ CASESPOST-INFECTION36 CONTROLSp-value*Female sex8 (66.7%)24 (66.7%)Matching variableMedian age40 (IQR 31-45)40 (IQR 32-44)Matching variableMedian disease duration6 (IQR 5-9)6 (IQR 3-8)Matching variableActive disease (BDCAF≥1)5 (41.7%)4 had disease relapse24 (66.7%)0.176Immunomodulating therapyCorticosteroids –8 (66.7%)8 (66.7%)12 (33.3%)0.088Median dosage (IQR)5 (IQR 0-12.5)6 (IQR 0-15)0 (IQR 0-2.5)0.010Colchicine2 (16.7%)Continued11 (30.6%)0.469HCQ1 (8.3%)Continued1 (2.8%)0.441Traditional DMARDs5 (41.7%)1 interrupted8 (22.2%)0.263Biologic DMARDs10 (83.3%)8 interrupted27 (75%)0.705Disease involvementMucocutaneous5 (41.7%)12 (33.3%)0.731Articular5 (41.7%)4 worsened17 (47.2%)1.000Ocular02 (5.6%)n.a.Vascular00n.a.Neurological3 (25%)8 (22.2%)1.000Gastrointestinal2 (16.7%)1 worsened6 (16.7%)1.000

*p-value from Fisher exact test for unpaired data between first columns vs third columns

Disclosure of Interests:

None declared.

Inducible phosphorylation of NF-kappa B p65 at serine 468 by T cell costimulation is mediated by IKK epsilon

Here we identify IKKepsilon as a novel NF-kappaB p65 kinase that mediates inducible phosphorylation of Ser468 and Ser536 in response to T cell costimulation. In addition, the kinase activity of IKKepsilon contributes to the control of p65 nuclear uptake. Serines 468 and 536 are evolutionarily conserved, and the surrounding amino acids display sequence homology. Down-regulation of IKKepsilon levels by small interfering RNA does not affect inducible phosphorylation of Ser536 but largely prevents Ser468 phosphorylation induced by T cell costimulation. Ser536-phosphorylated p65 is found predominantly in the cytosol. In contrast, the Ser468 phosphorylated form of this transcription factor occurs mainly in the nucleus, suggesting a function for transactivation. Reconstitution of p65-/- cells with either wild type p65 or point-mutated p65 variants showed that inducible phosphorylation of Ser468 serves to enhance p65-dependent transactivation. These results also provide a mechanistic link that helps to explain the relevance of IKKepsilon for the expression of a subset of NF-kappaB target genes without affecting cytosolic IkappaBalpha degradation.

NF-kappaB: a multifaceted transcription factor regulated at several levels

NF-kappaB is a generic name for an evolutionarily conserved transcription-factor system that contributes to the mounting of an effective immune response but is also involved in the regulation of cell proliferation, development, and apoptosis. The implication of NF-kappaB in central biological processes and its extraordinary connectivity to other signaling pathways raise a need for highly controlled regulation of NF-kappaB activity at several levels. While all NF-kappaB activation pathways share a central and critical proteasome-mediated step that leads to the degradation of inhibitory proteins and the release of DNA-binding subunits, there is evidence for a downstream level of NF-kappaB regulation that employs several mechanisms. These include promoter-specific exchange of dimers and modification of the transactivating p65 subunit by phosphorylation, acetylation, ubiquitination, or prolyl isomerization. The signaling pathways and enzymes controlling this second level of regulation and their potential use as therapeutic targets for the treatment of NF-kappaB-associated pathologies are discussed here.

T cell receptor-induced lipid raft recruitment of the I kappa B kinase complex is necessary and sufficient for NF-kappa B activation occurring in the cytosol

TCR-induced NF-kappa B activation is necessary for the innate immune response and involves induced lipid raft recruitment of the I kappa B kinase (IKK) complex. In this study, we systematically investigated lipid raft recruitment of members of the NF-kappa B activation pathway in human T cells. All upstream components leading to IKK activation were found constitutively or inducibly in lipid rafts, while the NF-kappa B/I kappa B complex and phosphorylated forms of IKK alpha/beta, I kappa B alpha and p65 are exclusively found in the cytosolic fraction. Disruption of raft organization precluded NF-kappaB activation induced by T cell costimulation, but IL-1-triggered NF-kappa B activation remained unaffected. Targeting of the IKK complex to lipid rafts caused constitutive IKK activation and NF-kappa B DNA binding, which was further triggered upon T cell costimulation. Various experimental approaches revealed that costimulation-induced IKK alpha/beta activation loop phosphorylation is independent from IKK beta-mediated transautophosphorylation, but rather involves phosphorylation by the IKK-interacting protein NIK and its upstream activator COT.

Comparative analysis of T-cell costimulation and CD43 activation reveals novel signaling pathways and target genes

The CD43 lymphocyte surface receptor is involved in the regulation of lymphocyte adhesion and activation. Many CD43 functions remain controversial or unclear, and it is not known to which extent CD43 signaling pathways are shared with or distinct from those used by the T-cell receptor (TCR). Here, we systematically compared signaling events and target gene expression induced by CD43 or T-cell costimulation in primary human peripheral T cells. These studies identify nuclear factor-κB (NF-κB) p65 serine 468 as a novel inducible phosphorylation site strongly induced by T-cell costimulation and only weakly triggered by CD43 ligation. We also identified CD43 as a novel Jun N-terminal kinase (JNK) activator and a comprehensive analysis of further signaling events suggests that both stimuli use overlapping but also distinct signaling pathways. Microarray analysis of inflammatory genes shows 1 group of genes coregulated by both stimuli and 2 further groups of target genes affected solely by costimulation or primarily by CD43. (Blood. 2004;104:3302-3304)

Transient and selective NF-kappa B p65 serine 536 phosphorylation induced by T cell costimulation is mediated by I kappa B kinase beta and controls the kinetics of p65 nuclear import

Full transcriptional activity of the nuclear, DNA-bound form of NF-kappaB requires additional posttranslational modifications. In this study, we systematically mapped the T cell costimulation-induced phosphorylation sites within the C-terminal half of the strongly trans-activating NF-kappaB p65 subunit and identified serine 536 as the main phosphorylation site. The transient kinetics of serine 536 phosphorylation paralleled the kinetics of IkappaBalpha and IkappaB kinase (IKK) phosphorylation and also mirrored the principle of T cell costimulation. The TCR-induced pathway leading to serine 536 phosphorylation is regulated by the kinases Cot (Tpl2), receptor interacting protein, protein kinase Ctheta, and NF-kappaB-inducing kinase, but is independent from the phosphatidylinositol 3-kinase/Akt signaling pathway. Loss-of-function and gain-of-function experiments showed phosphorylation of p65 serine 536 by IKKbeta, but not by IKKalpha. Phosphorylation occurs within the cytoplasmic and intact NF-kappaB/IkappaBalpha complex and requires prior phosphorylation of IkappaBalpha at serines 32 and 36. Reconstitution of p65(-/-) cells either with wild-type p65 or a p65 mutant containing a serine to alanine mutation revealed the importance of this phosphorylation site for cytosolic IkappaBalpha localization and the kinetics of p65 nuclear import.

Structure-function relationship between the human chemokine receptor CXCR3 and its ligands

I-TAC, IP10, and Mig are interferon-gamma inducible CXC chemokines that share the same G-protein-coupled receptor CXCR3, which is preferentially expressed on Th1 lymphocytes. We have explored the structure-function relationship of the CXCR3 ligands, in particular of I-TAC, which has highest affinity for CXCR3 and is the most potent agonist. A potent antagonist for CXCR3 was obtained by NH(2)-terminal truncation of I-TAC. I-TAC (4-73), which lacks the first three residues, has no agonistic activity but competes for the binding of I-TAC to CXCR3-bearing cells and inhibits migration and Ca(2+) changes in such cells in response to stimulation with I-TAC, IP10, and Mig. It does also not induce internalization of CXCR3, which is in support of the lack of agonistic effects. Hybrid chemokines between I-TAC and IP10 were used to identify regions responsible for the higher activity of I-TAC. I-TAC-like IP10 analogs are obtained by substituting the NH(2) terminus (residues 1-8) or N-loop region (residues 12-17) of IP10 with those of I-TAC, suggesting that the differences in function of the CXCR3 ligands can be assigned to distinct regions and that these regions are interchangeable. Structure-activity studies with Mig showed that the extended basic COOH-terminal region, which is not present in I-TAC and IP10, is important for binding and activity.

The ligands of CXC chemokine receptor 3, I-TAC, Mig, and IP10, are natural antagonists for CCR3

Th1 and Th2 lymphocytes express a different repertoire of chemokine receptors (CCRs). CXCR3, the receptor for I-TAC (interferon-inducible T cell alpha-chemoattractant), Mig (monokine induced by gamma-interferon), and IP10 (interferon-inducible protein 10), is expressed preferentially on Th1 cells, whereas CCR3, the receptor for eotaxin and several other CC chemokines, is characteristic of Th2 cells. While studying responses that are mediated by these two receptors, we found that the agonists for CXCR3 act as antagonists for CCR3. I-TAC, Mig, and IP10 compete for the binding of eotaxin to CCR3-bearing cells and inhibit migration and Ca(2+) changes induced in such cells by stimulation with eotaxin, eotaxin-2, MCP-2 (monocyte chemottractant protein-2), MCP-3, MCP-4, and RANTES (regulated on activation normal T cell expressed and secreted). A hybrid chemokine generated by substituting the first eight NH(2)-terminal residues of eotaxin with those of I-TAC bound CCR3 with higher affinity than eotaxin or I-TAC (3- and 10-fold, respectively). The hybrid was 5-fold more potent than I-TAC as an inhibitor of eotaxin activity and was effective at concentrations as low as 5 nm. None of the antagonists described induced the internalization of CCR3, indicating that they lack agonistic effects and thus qualify as pure antagonists. These results suggest that chemokines that attract Th1 cells via CXCR3 can concomitantly block the migration of Th2 cells in response to CCR3 ligands, thus enhancing the polarization of T cell recruitment.