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

Background

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

Objectives

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

Methods

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

Results

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

Table 1.

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

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

Conclusion

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

References

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

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

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

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

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

Disclosure of Interests

None declared

AB0660 Long-term effect of combination therapy with rituximab and mycophenolic acid on cardiac manifestations, pulmonary function and skin fibrosis in systemic sclerosis

Background

Cardiac manifestations in systemic sclerosis (SSc) can be either due to the fibrotic and vascular process or secondary to pulmonary arterial hypertension (PAH), cardiac inflammation, or renal crisis. Despite being one of the leading causes of death in SSc, cardiac involvement and its therapeutic options have been poorly studied. According to the ACR/EULAR recommendations, therapy with cyclophosphamide (CP) is applied to patients with cardiac manifestations. However, in case of inadequate response to CP, there are no other therapeutics evaluated.

Objectives

The aim of this retrospective analysis was to explore the efficacy of a therapy with rituximab and mycophenolic acid (MPA), especially in cases of CP failure or therapy induced cardiac toxicity

Methods

14 Patients with SSc and cardiac involvement (defined as troponin T elevation plus right- or left ventricular systolic or diastolic dysfunction, myocarditis, pericarditis, right heart failure secondary to PAH, or arrhythmias) were analysed. Two patients each showed concomitant myositis and rheumatoid arthritis, respectively. Twelve patients were initially treated with CP and two patients with methotrexate (MTX). Due to a disease progress (either cardiac involvement, skin fibrosis or lung function) a therapy with rituximab and MPA was initiated [1] These patients were followed for up to five years.

Results

Before initiation of CP or MTX electrocardiogram showed arrhythmias (atrial fibrillation, conduction blocks, multifocal ventricular extrasystoles (VES)) in 9 patients. Echocardiography revealed abnormalities in 10 patients including reduced left-ventricular ejection fraction (LV-EF), diastolic dysfunction, mitral regurgitation, or aortic aneurysm. 3 patients had PAH, 2 patients were diagnosed with post capillary pulmonary hypertension. Cardiac MRI revealed signs of myocarditis in 4 patients. 4 patients required cardiac resynchronization therapy or pacemaker implantation. Moreover, body plethysmography showed a reduction in forced vital capacity (FVC) in 12 patients, suggestive of restrictive lung disease. Under therapy with CP 11 patients had suffered from disease progress, 1 patient developed relapsing pneumonias and the 2 patients with overlap rheumatoid arthritis developed cardiac disease manifestations on MTX monotherapy. Consequently, rituximab 1000 mg q12weeks and MPA 1000 mg bid were initiated. Under this combination troponin T decreased in all patients (p=0.0002), LV-EF improved in 5, remained normal in 7 and deteriorated in 2 patients. The rate of VES improved in 8 patients. In one patient, myocarditis resolved completely (MRI). Moreover, pulmonary artery systolic pressure, measured by echocardiography, improved in all patients diagnosed with PAH under stable therapy. The modified Rodnan skin score improved in all patients, FVC improved in 7 patients, remained stable in 6 and decreased in the patient with overlap myositis. Rituximab infusions could be extended (1000 mg q24weeks) after 24-36 months of treatment in 11 patients. All patients showed peripheral blood depletion of B cells without noticed severe IgG deficiency. While 11 patients did not develop severe complications 2 patients died during follow-up of pneumonia and cardiogenic shock (overlap myositis), respectively and one patient developed a relapse of lung cancer with cerebral metastasis.

Conclusion

Therapy with rituximab and MPA is a promising alternative. However, its use requires risk stratification of patients with respect to adverse side effects which needs to be explored in future studies.

References

[1]Rimar D, Rosner I, Slobodin G. Upfront Combination Therapy With Rituximab and Mycophenolate Mofetil for Progressive Systemic Sclerosis. J Rheumatol 2021;48:304–5. https://doi.org/10.3899/jrheum.200484.

Disclosure of Interests

None declared

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

Background

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

Objectives

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

Methods

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

Results

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

Table 1.

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

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

Conclusion

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

References

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

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

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

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

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

Acknowledgements

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

Disclosure of Interests

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

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

Background

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

Objectives

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

Methods

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

Results

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

Conclusion

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

References

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

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

Acknowledgements

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

Disclosure of Interests

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

OP0054 NEW ROLE FOR PROTEINASE 3 IN IL-16 BIOACTIVITY CONTROL IN GRANULOMATOSIS WITH POLYANGIITIS

Background:

The immunomodulatory cytokine IL-16 is increased in several inflammatory and autoimmune diseases1. IL-16 recruits and activates CD4+ immune cells such as T cells, dendritic cells, or monocytes. IL-16 is produced by various immune and non-immune cells, but synthesis and storage of IL-16 is regulated differentially depending on the cell type and stimulation. For its biological activity, IL-16 cleavage by caspase-3 is required1. Necrotizing granulomatous inflammation is a hallmark of granulomatosis with polyangiitis (GPA) with neutrophil dysregulation as a central driver of chronic inflammation and autoimmunity2. Earlier studies showed a correlation between increased serum IL-16 and disease parameters in AAV, including GPA3, but functional evidence for a direct link between IL-16 and neutrophils in granulomatous inflammation is missing so far.

Objectives:

In this study we aim to identify a functional link between increased IL-16, neutrophils, and the autoantigen proteinase 3 (PR3) with regard to chronic inflammation and autoimmunity in GPA.

Methods:

IL-16 was measured in sera of GPA patients (n = 40) and healthy controls (HC, n = 50) by ELISA and correlated with clinical features, such as disease activity (BVAS), creatinine, GFR, VDI and PR3-ANCA status. IL-16 protein expression was analyzed in peripheral blood mononuclear cells (PBMC) and polymorphonuclear cells (PMN) from GPA patients and HC (n = 5, each) by SDS-PAGE and western blot. Binding affinity of recombinant pro-IL-16 to native human PR3 was assessed by microscale thermophoresis. Cleavage of pro-IL-16 by active human PR3 was performed at various time points at 37°C. Cleavage products were analyzed by SDS-PAGE and western blot.

Results:

Circulating IL-16 was significantly increased in GPA patients compared to HC. Elevated IL-16 positively correlated with BVAS, creatinine, VDI and PR3-ANCA status and negatively correlated with GFR. In PMBC and PMN from GPA and HC we identified different expression patters of precursor and active forms of IL-16. In healthy PBMC we found high amounts of precursor (80kD), pro-IL-16 (55kD) and active IL-16 (17kD). In contrast, PBMC from GPA patients had lower amounts of pro-IL-16 and no active IL-16, indicating activation and secretion of IL-16 due to inflammatory stimulation, as shown earlier5. In GPA PMN we detected no precursor IL-16, but pro-IL-16 and its active form, in contrast to very low amounts of all IL-16 forms in healthy PMN. Processing and release of IL-16 in neutrophils has been linked to apoptosis and secondary necrosis5. By interaction studies we demonstrated direct binding of pro-IL-16 to PR3 with a Kd of 10 nM. In a subsequent cleavage assay we confirmed IL-16 processing by PR3 in a time-dependent manner.

Conclusion:

Correlation of serum IL-16 with clinical features of GPA suggests that IL-16 is associated with markers of disease activity, tissue damage and autoreactivity. We showed that PBMC and PMN represent a source of IL-16 in GPA. By the identification of PR3 as an additional IL-16-activating enzyme we could demonstrate a potential link between excessive PR3 expression, cell death and IL-16-dependent mechanisms, contributing to chronic granulomatous inflammation and autoimmunity in GPA.

References:

[1]Glass, W. G. et al. Not-so-sweet sixteen: The role of IL-16 in infectious and immune-mediated inflammatory diseases. J. Interf. Cytokine Res. 26, 511–520 (2006).

[2]Millet, A. et al. Proteinase 3 on apoptotic cells disrupts immune silencing in autoimmune vasculitis. J. Clin. Invest. 125, 4107–4121 (2015).

[3]Yoon, T. et al. Serum interleukin-16 significantly correlates with the Vasculitis Damage Index in antineutrophil cytoplasmic antibody-associated vasculitis. Arthritis Res. Ther. 22, 1–6 (2020).

[4]Elssner, A. et al. IL-16 Is Constitutively Present in Peripheral Blood Monocytes and Spontaneously Released During Apoptosis. J. Immunol. 172, 7721–7725 (2004).

[5]Roth, S. et al. Secondary necrotic neutrophils release interleukin-16C and macrophage migration inhibitory factor from stores in the cytosol. Cell Death Discov. 1, 15056 (2015).

Disclosure of Interests:

None declared

[Pathogenesis of large vessel vasculitides]

Large vessel vasculitides comprise two distinct entities, giant cell arteritis (GCA) and Takayasu arteritis (TAK). GCA is the most common vasculitis in central Europe, becoming manifested at an age over 50 years. In contrast, the much rarer TAK affects almost exclusively young adults and mostly women. Both vasculitides are granulomatous arteritides affecting mainly the aorta and its major arterial branches. GCA and TAK are associated with different major histocompatibility complex genes. Infections possibly play a role in the initiation of large vessel vasculitides. Activation of dendritic cells in the adventitia induces chemokine and cytokine-mediated recruitment and maturation of T‑helper (Th)1 and Th17 cells and macrophages producing cytokines, growth factors and matrix metalloproteinases. In GCA, CD4+ T‑helper cells and macrophages are predominantly found in the inflammatory infiltrate. In TAK, the infiltrate also contains cytotoxic CD8+ T‑cells and γδ T‑cells. This could indicate different antigenic triggers in GCA and TAK. Inflammatory infiltration with T‑cells and macrophages and activation of myofibroblasts and smooth muscular cells induce vascular remodeling with intimal hyperplasia and destruction of the media. Remodeling is histologically characterized by progressive arterial wall fibrosis, vascular stenosis and obstruction. In summary, GCA and TAK represent two different entities with a distinct human leukocyte antigen (HLA) and potentially etiopathogenetic background. Clinically, inflammation-related general symptoms and signs of ischemia are encountered, accompanied by increased levels of serological markers of inflammation.

FRI0001 NEUTROPHILS IN GRANULOMATOSIS WITH POLYANGIITIS DISPLAY FEATURES OF PYROPTOSIS

Background:

Granulomatosis with polyangiitis (GPA) is characterized by extravascular necrotizing granulomatous inflammation and systemic ANCA – associated (AAV) vasculitis with neutrophils as a key player in the pathogenesis (1). We and others have shown that neutrophil-related cell death mechanisms contribute to chronic inflammatory processes in AAV (2, 3). Recently, another form of inflammatory cell death primarily described in monocytes called pyroptosis was also discovered in neutrophils (4). A cardinal feature of pyroptosis is the activation of the NLRP3 inflammasome, a sensor of different pathogen- and damage-associated molecular patterns (PAMP, DAMP), following caspase-1-mediated processing and secretion of IL-1beta (5).

Objectives:

The aim of this study was to investigate, if neutrophils from GPA patients express pyroptosis-related components NLRP3, active caspase 1 and cleaved IL-1beta.

Methods:

Polymorphonuclear leukocytes (PMN) were isolated from peripheral blood of GPA patients and healthy controls (HC) (n = 10 each). Expression of NLRP3, inactive/active caspase 1 and active IL-1beta was determined by western blot. In addition, peripheral blood mononuclear cells (PBMC) were isolated from GPA and HC. mRNA expression ofnlrp3andil1bwas determined by qPCR. To exclude false-positive results by contamination with monocytes we performed flow cytometry analysis of whole blood samples with markers CD3, CD14, CD15, CD66b and NLRP3.

Results:

PMN from GPA patients showed markedly increased expression of NLRP3, active caspase 1 and active IL-1beta compared to HC. In contrast, there was no difference between GPA and HC on the mRNA level of neithernlrp3noril1bin PBMC. In addition, we confirmed by flow cytometry increased expression of NLRP3 in PMN from GPA, but not in monocytes.

Conclusion:

Here we provide evidence, that neutrophils from GPA undergo pyroptosis, demonstrated by increased NLRP3, active caspase 1 expression as well as IL-1beta processing. Neutrophils are present in high numbers at the site of granulomatous lesions of inflamed tissue in GPA and IL-1beta is increased in GPA sera (2). Therefore, neutrophils represent a potential source of IL-1beta in GPA. Given the fact that GPA-associated features such as massive release of necrosis-related DAMP or microbial agents such asStaphylococcus aureus(6) can activate the NLRP3-inflammasome, we identified here a potential relevant mechanism of neutrophils contributing to chronic inflammation of GPA.

References:

[1]Jennette, J.C., and Falk, R.J. (2014). Pathogenesis of antineutrophil cytoplasmic autoantibody-mediated disease. Nat. Rev. Rheumatol.10, 463–473.

[2]Millet, A., Martin, K.R., Bonnefoy, F., Saas, P., Mocek, J., Alkan, M., Terrier, B.,Kerstein,A., Tamassia, N., Satyanarayanan, S.K., et al. (2015). Proteinase 3 on apoptotic cells disrupts immune silencing in autoimmune vasculitis. J. Clin. Invest. 125, 4107–4121.

[3]Schreiber, A., Rousselle, A., Becker, J.U., von Mässenhausen, A., Linkermann, A., and Kettritz, R. (2017). Necroptosis controls NET generation and mediates complement activation, endothelial damage, and autoimmune vasculitis. Proc. Natl. Acad. Sci. 201708247.

[4]Tourneur, L., and Witko-Sarsat, V. (2019). Inflammasome activation: Neutrophils go their own way. J. Leukoc. Biol.105, 433–436.

[5]Bergsbaken, T., Fink, S.L., and Cookson, B.T. (2009). Pyroptosis: Host cell death and inflammation. Nat. Rev. Microbiol.7, 99–109.

[6]Lamprecht, P.,Kerstein, A., Klapa, S., Schinke, S., Karsten, C.M., Yu, X., Ehlers, M., Epplen, J.T., Holl-Ulrich, K., Wiech, T., et al. (2018). Pathogenetic and Clinical Aspects of Anti-Neutrophil Cytoplasmic Autoantibody-Associated Vasculitides. Front. Immunol.9, 1–10.

Disclosure of Interests:

Anja Kerstein-Staehle: None declared, Nadja Leinung: None declared, Jannik Meyer: None declared, Silke Pitann: None declared, Antje Müller: None declared, Gabriela Riemekasten Consultant of: Cell Trend GmbH, Janssen, Actelion, Boehringer Ingelheim, Speakers bureau: Actelion, Novartis, Janssen, Roche, GlaxoSmithKline, Boehringer Ingelheim, Pfizer, Peter Lamprecht: None declared

AB0496 AUTOANTIBODIES TARGETING COMPLEMENT RECEPTORS 3A AND 5A1 ARE DECREASED IN ANCA-ASSOCIATED VASCULITIS AND CORRELATE WITH HIGHER RELAPSE RATE

Background:

Activation of the alternative and final common pathways have been shown in ANCA-associated vasculitis (AAV) (1). Circulating titers of C5a are elevated and correlate with disease activity in AAV. Binding to the corresponding G protein-coupled receptor (GPCR) C5aR1 enhances the influx of neutrophils, leading to ROS generation and severe necrotizing of vascular walls (2). Moreover, subsequent interaction of C5a with C5aR1 may represent a proinflammatory amplification loop (3). Blocking of the receptor is protective in a murine model in AAV (4). In humans, avacopan, a C5aR1-inhibitor showed promising results as glucocorticoid-sparing agent in two randomized phase II and one ongoing phase III clinicals trials in AAV (NCT02994927). Notably, disease-specific anti-GPCR autoantibody (aab) signatures have been found in different autoimmune diseases (5).

Objectives:

The aim of the present study was to examine whether (patho)physiological anti-C3aR and anti-C5aR1 aabs correlate with clinical findings in AAV, and whether this is linked to the clinical outcome.

Methods:

Sera and plasma of AAV patients [granulomatosis with polyangiitis (GPA), n=64; microscopic polyangiitis (MPA), n=26; eosinophilic granulomatosis with polyangiitis (EGPA), n=11] were measured by Elisa for circulating autoantibodies against complement receptors C3a (anti-C3aR aab) and C5a (anti-C5aR1 aab) and plasma levels of C3a and C5a. Expression of C3aR and C5aR1 on T-cells was determined using flow cytometry. Clinical data were assessed at the time of serum sampling and during follow-up for 48 months

Results:

GPA displayed low titers of anti-C3aR aab (GPA:5.33±2.54vs. HD:6.47±2.61, P=0.0031). Anti-C5aR1 aab were decreased in AAV, especially in GPA (GPA:1.02±1.07vs. HD:6.63±2.91, P=<0.0001). Plasma levels of C5a and anti-C5aR aab yielded an inverse correlation in AAV (r=-0.6813, P=0.0127). C5aR1 expression was increased on T-cells in GPA (CD4+C5aR1+T-cells: GPA:10.76±2.55%vs. HD:3.44±0.68%, P=0.0021; CD8+C5aR1+T-cells GPA:9.74±2.10%vs.HD:4.11±0.92%, P=0.0198). Reduced titers of anti-C5aR1 aab <0.45U/ml displayed an increased relapse risk for major organ involvement in GPA (HR 12.85, P=0.0014).

Conclusion:

As potential diagnostic marker, anti-C5aR1 aab titer may additionally be useful to monitor disease activity in AAV.

References:

[1]Chen M et al.Complement deposition in renal histopathology of patients with ANCA-associated pauci-immune glomerulonephritis.Nephrol Dial Transpl. 2009;24:1247-1252

[2]Schreiber A et al.C5a receptor mediates neutrophil activation an ANCA-induced glomerulonephritis.J Am Soc Nephrol. 2009; 20:289-298

[3]Lamprecht P et al.: Pathogenetic and clinical aspects of Anti-Neutrophil Cytoplasmic Autoantibody-associated vasculitides.Front Immunol.2018 Apr 9;9-680

[4]Xiao H et al.C5a receptor (CD88) blockade protects against MPO-ANCA GN.J Am Soc Nephrol. 2014;25(2):225-31

[5]Klapa S et al. Decreased endothelin receptor A autoantibody levels are associated with early ischaemic events in patients with giant-cell arteritis.Ann Rheum Dis2019 Oct;78(19):1443-1444

Disclosure of Interests:

Sebastian Klapa Grant/research support from: Actelion, Consultant of: Pfizer, Abbvie, Antje Müller: None declared, Andreas Koch: None declared, Anja Kerstein-Staehle: None declared, Wataru Kaehler: None declared, Harald Heidecke Shareholder of: Cell Trend GmbH, Employee of: Cell Trend GmbH, Speakers bureau: Cell Trend GmbH, Susanne Schinke Speakers bureau: Pfizer, Markus Huber-Lang: None declared, Martin Nitschke: None declared, Silke Pitann: None declared, Christian Karsten: None declared, Gabriela Riemekasten Consultant of: Cell Trend GmbH, Janssen, Actelion, Boehringer Ingelheim, Speakers bureau: Actelion, Novartis, Janssen, Roche, GlaxoSmithKline, Boehringer Ingelheim, Pfizer, Peter Lamprecht: None declared

THU0025 MICRO-RNA DIFFERENTIALLY REGULATE THE ALTERNATIVE PRTN3-MRNA IN GRANULOMATOSIS WITH POLYANGIITIS

Background:

Micro-RNAs (miRNA) are short non-coding RNAs that regulate inflammation mostly by translational repression. Previously, we screened 847 miRNAs in nasal tissue from GPA patients and found a disease associated alteration of miRNA expression compared to healthy controls and chronic rhinosinusitis. MiR-184 was most over expressed in nasal tissue from GPA (13.4x). The dual-luciferase reporter assay confirmed a significant reduction of Proteinase-3 (PRTN3) expression by miR-184 (1).

PRTN3 transcripts with an alternative 3’ untranslated region (UTR) have been described in GPA (2). The pathophysiological relevance of this alternative transcript remains unclarified.

Objectives:

To identify new miRNA targets of potential pathophysiological relevance in GPA, we validated the effect of the 21 most dysregulated miRNAs on the mRNA of PRTN3. Further, we included the alternative PRTN3 mRNA in our screen to look for new regulatory differences.

Methods:

The inhibitory capacity of miRNAs on Proteinase-3 mRNA was estimated by a dual-luciferase reporter system. The sequences of the alternative (132bp longer) and the regular 3’UTR-PRTN3 were cloned and inserted into the pmirGLO vector and co-transfected with 21 miRNA mimics into HeLa cells. Co-transfection withCaenorhabditis elegansmiRNA 67 mimic (cel-miR-67) was used as negative control. Statistical significance was evaluated by students t-test adjusted for multiple comparisons (Holm-Sidak).

Results:

For 18 of 21 investigated miRNAs no effects could be observed on the alternative and the regular 3’UTR-PRTN3. But there were remarkable differential effects of let-7f, miR-184 and miR-708. Let-7f (-29,2%) and miR-708 (-23,6%) both showed a suppression of the alternative 3’UTR-PRTN3 but no effect on the regular 3’UTR-PRTN3 while miR-184 only suppressed the regular 3’UTR (-17,5 %) and not the alternative variant (fig. 1-2).

Fig. 1.

Dual-luciferase reporter assay with the regular 3’UTR of PRTN3 cloned into the pmirGLO vector compared to empty vector (NTC). Significant effect for miR-184 (17,5 %), miR-708 no effect and let-7f small but not significant reduction in luciferase activity (12,3 %). Data represent 3 independent experiments with triplicate measurements. miR-184 was tested 6 times. *P<0.05; ns = not significant; error bars display standard deviation.

Fig. 2.

Dual-luciferase reporter assay with the alternative 3’UTR of PRTN3. Significant effects of let-7f (29,2 %) and miR-708 mimic (23,6 %) but no significant effects of miR-184 of luciferase activity. 3 independent experiments with triplicate measurements. *P<0.05

Conclusion:

Disease specific miRNA signatures together with an increased PRTN3 level and in alternative PRTN3 mRNA in GPA suggest a dysregulation of PRTN3 expression in GPA. To our knowledge this is the first analysis in GPA showing that miRNAs can differentially regulate the expected and the alternative 3’UTR variants of PRTN3-mRNA. As miR-184 is markedly upregulated in GPA, a repression of PRTN3 is to be anticipated, possibly as a reaction to previous neutrophil activation with PRTN3 overexpression. Our findings also strengthen the potential pathophysiological role of the alternative PRTN3 mRNA.

References:

[1]Schinke S et alPROTEINASE-3 REGULATING MICRO-RNA IN GRANULOMATOSIS WITH POLYANGIITIS. Ann Rheum Dis 2019 (78 Suppl 2):437

[2]McInnes E et alDysregulation of Autoantigen Genes in ANCA-Associated Vasculitis Involves Alternative Transcripts and New Protein Synthesis J Am Soc Nephrol. 2015 26(2): 390–399

Acknowledgments:

Vasculitis foundation for funding

Disclosure of Interests:

Nick Reichard: None declared, Anja Kerstein-Staehle: None declared, Antje Müller: None declared, Gabriela Riemekasten Consultant of: Cell Trend GmbH, Janssen, Actelion, Boehringer Ingelheim, Speakers bureau: Actelion, Novartis, Janssen, Roche, GlaxoSmithKline, Boehringer Ingelheim, Pfizer, Peter Lamprecht: None declared, Susanne Schinke Speakers bureau: Pfizer

[De-escalation of therapy in ANCA-associated vasculitides]

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) require a differentiated therapeutic approach depending on the degree of organ dysfunction and disease activity. In organ dysfunction and life-threatening AAV cyclophosphamide and rituximab are recommended for the induction of remission. For remission induction with a lack of organ dysfunction and non-life-threatening AAV, methotrexate or mycophenolate mofetil are recommended. For remission maintenance therapy azathioprine or methotrexate are used. In the case of contraindications, intolerance or previous failure of azathioprine and methotrexate treatment, rituximab, leflunomide or mycophenolate mofetil may be used as alternatives. Maintenance therapy is usually continued for at least 2 years. De-escalation of therapy requires continuous clinical monitoring while the glucocorticoid medication and immunosuppressive therapy is tapered; however, every de-escalation of therapy carries a risk of relapse.

[Effector memory T‑cells in the pathogenesis of ANCA-associated vasculitides. German version]

Patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides (AAV) have an expansion of effector memory T‑cells in peripheral blood. The enlarged effector memory cell population contains distinct cell subsets, including T‑helper type 1 (Th1) CD4+ T‑cells lacking co-stimulatory CD28 expression and Th17 cells in granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) and Th2 type and Th17 cells in eosinophilic granulomatosis with polyangiitis (EGPA). The cytokine response of autoreactive proteinase 3 (PR3)-specific effector memory T‑cells is skewed towards an increase of Th2 type, Th17 and Th22 cell fractions in GPA. Anomalous effector memory CD4+ T‑cell co-stimulation is suggested by the aberrant expression of P‑selectin glycoprotein ligand‑1, beta‑2 integrin, chemokine receptors, natural-killer group 2 member D (NKG2D) and other activating receptors. The increased expression of these receptors is accompanied by T‑cell activation and migration to inflamed tissues. The T‑cells are abundant and secrete proinflammatory cytokines in inflammatory lesions in AAV. The T‑cell mediated tissue damage correlates with renal outcome, whereas B-cell infiltration does not. Activation of lesional CD4+NKG2D+ effector memory T‑cells is independent of the antigen; moreover, CD4+NKG2D+ effector memory T‑cells display NK-cell-like cytotoxicity towards microvascular endothelial cells in vitro. Thus, effector memory T‑cells play an important role in tissue damage and disease progression in AAV. Sequentially administered or combined with B-cell depleting therapy, T‑cell-directed therapies, especially those directed against effector memory CD4+ T‑cells, may further improve the outcome and help to achieve long-term remission in AAV.

[Clinical spectrum of IgG4-related diseases and the connection to rheumatology]

Rheumatologist should be familiar with the concept of IgG4-related disease (IgG4-RD). Due to the clinical spectrum IgG4-RD can fall directly within the scope of rheumatology and are often diagnosed primarily by rheumatologists. Furthermore, IgG4RD are relevant differential diagnoses for many other rheumatic conditions. Finally, there are an increasing amount of data suggesting an important role of immunological processes observed in IgG4-RD for other rheumatic diseases.

Preliminary classification criteria for the cryoglobulinaemic vasculitis

Background

To develop preliminary classification criteria for the cryoglobulinaemic syndrome or cryoglobulinaemic vasculitis (CV).

Methods

Study part I developed a questionnaire for CV to be included in the formal, second part (study part II). Positivity of serum cryoglobulins was defined by experts as an essential condition for CV classification. In study part II, a core set of classification items (questionnaire, clinical and laboratory items, as agreed) was tested in three groups of patients and controls—that is, group A (new patients with the CV), group B (controls with serum cryoglobulins but lacking CV) and group C (controls without serum cryoglobulins but with features which can be observed in CV).

Results

In study part I (188 cases, 284 controls), a positive response to at least two of three selected questions showed a sensitivity of 81.9% and a specificity of 83.5% for CV. This questionnaire was employed and validated in study part II, which included 272 patients in group A and 228 controls in group B. The final classification criteria for CV, by pooling data from group A and group B, required the positivity of questionnaire plus clinical, questionnaire plus laboratory, or clinical plus laboratory items, or all the three, providing a sensitivity of 88.5% and a specificity of 93.6% for CV. By comparing data in group A versus group C (425 controls), the same classification criteria showed a sensitivity 88.5% and a specificity 97.0% for CV.

Conclusion

Classification criteria for CV were developed, and now need validation.

[Adult-onset Still's disease, Schnitzler syndrome, and autoinflammatory syndromes in adulthood]

Adult-onset Still's disease (AoSD), Schnitzler syndrome, and cases of adult-onset autoinflammatory syndromes [10-15% of cases of familial Mediterranean fever (FMF) and tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS)] are characterized by a genetic predisposition, with increased interleukin (IL)-1beta and IL-18 production and TNF-alpha signaling, respectively. As a result, periodic fever and inflammation at barrier tissues (synovial tissues, serous membranes, and the skin) are encountered in such patients. Pathophysiological insights into these diseases have renewed interest in research on IL-1beta in rheumatic diseases and have opened new therapeutic avenues. Recently published studies have shown that patients with Schnitzler syndrome, methotrexate-refractory AoSD, and colchicine-refractory FMF or contraindications to colchicines in FMF respond well to treatment with the soluble IL-1 receptor antagonist anakinra. For TRAPS patients, the p75 TNF-alpha receptor/Fc-IgG1 fusion protein etanercept is the treatment of first choice.

Olfactory dysfunction in Wegener's granulomatosis

Necrotizing granulomatous inflammation of the upper respiratory tract is one of the hallmarks of Wegener's granulomatosis (WG), which may explain the reason for olfactory dysfunction in WG. However, a systematic analysis using modem olfactory testing tools has not been performed and potential causes of dysfunction at different levels of olfactory information processing remain obscure so far. In this study a group of 76 WG-patients was examined with sniffin'sticks screening 12, odour threshold (T)/discrimination (D)/identification (I) TDI-score, active anterior rhinomanometry and a standardized questionnaire for olfactory function. WG-patients were aware of their olfactory dysfunction, as proven by psychophysiological test results. An altered olfactory function was significantly correlated to local administration of mupirocin and to the time interval between first diagnosis and study entry. None of the other variables had a statistical significant effect on the olfactory dysfunction.

[Autoinflammatory syndromes]

In its strict sense, the term "autoinflammatory syndromes" comprises the hereditary periodic fever syndromes (HPF), which are caused by mutations of pattern-recognition receptors (PRR) and perturbations of the cytokine balance. These include the crypyrinopathies, familial Mediterranean fever, TNF-receptor associated periodic fever syndrome (TRAPS), hyper-IgD and periodic syndrome (HIDS), pyogenic sterile arthritis, pyoderma gangrenosum and acne (PAPA) syndrome, NALP12-HPF, and the Blau syndrome. The diseases are characterized by spontaneous activation of cells of the innate immunity in the absence of ligands. Autoantibodies are usually not found. HPF clinically present with recurrent fever episodes and inflammation, especially of serosal and synovial interfaces and the skin. Intriguingly, PRR-mediated autoinflammtory mechanisms also play a role in a number of chronic inflammatory and autoimmune diseases.

[Diagnosis, therapy and current research aspects of selected chronic inflammatory diseases with head and neck involvement]

Wegener's granulomatosis, Churg-Strauss syndrome and analgesics intolerance syndrome with polyps demonstrate non-specific manifestations in the head and neck region. These symptoms can often lead to early diagnosis and initiation of the correct therapy. However, symptoms are often ambiguous and many rare differential diagnoses must be borne in mind. This clinical picture presents a challenge for the otorhinolaryngologist, who is commonly the first contacted physician. Diagnostics and therapy have to be carried out in an interdisciplinary approach between rheumatologist, pulmonologist, pathologist, radiologist, ophthalmologist, infection specialist and nephrologist. Despite significant scientific and therapeutic advances, these diseases remain incurable. In recent decades they have lost their life-threatening character (Wegener's granulomatosis) and are now chronically relapsing diseases. Their aetiology, however, is still unclear and treatment leads to a wide spectrum of undesirable effects. Research work is needed to advance diagnostics and therapy in this field. Recent research aspects are presented in this article.

Severe impaired respiratory ciliary function in Wegener granulomatosis

OBJECTIVE

The pathogenesis of granulomatous inflammation in the respiratory tract and autoimmunity in Wegener granulomatosis (WG) are poorly understood. Since mucociliar clearance represents the first major line of defence in the respiratory tract and its breakdown facilitates chronic inflammation, we investigated ciliary beat frequency (CBF) in WG.

METHODS

Nasal epithelial cells were obtained from 30 patients with WG with involvement of the upper respiratory tract, 12 patients with other inflammatory rheumatic disease and 10 healthy controls. CBF was measured at 5 and 24 h after collection.

RESULTS

were correlated with clinical data. Results: CBF was significantly reduced in WG compared to disease and healthy controls after 5 and 24 h. In WG, CBF almost stagnated after 24 h. Reduction of CBF correlated with the cumulative number of immunosuppressive agents in WG, but not in disease controls. No correlation was found between CBF impairment and cyclophosphamide levels, disease extent, disease activity, disease duration, serological and microbiological findings, or inflammation markers.

CONCLUSION

CBF is severely impaired in WG, potentially influenced by immunosuppressive treatment. To what extent CBF impairment and subsequent barrier dysfunction are caused by other factors still has to be elucidated. Supportive measures to improve mucociliary clearance should be discussed in patients with WG.

[Interleukin-17 in chronic inflammatory and autoimmune diseases: rheumatoid arthritis, Crohn's disease and Wegener's granulomatosis]

Data from recent animal experiments and clinical studies show that interleukin-17 (IL-17A, B, C, D, E, and F) plays an important role as proinflammatory cytokine in the host response to extracellular bacteria and in chronic inflammatory and autoimmune diseases. These findings have led to a revision of the well-known T(H)1/T(H)2 hypothesis. In rheumatoid arthritis elevated IL-17 serum levels, Th-17 cells in synovial fluid and in T-cell-rich areas of inflamed synovia are found. In Wegener's granulomatosis, IL-17D is expressed in nasal granulomas. In Crohn's disease IL-17 as well as IL-17 plus IFN-gamma producing CD4(+) T-cells are detected in peripheral blood and inflamed intestinal mucosa. So far, CD4(+)IL-17(+)IFN-gamma(+) T-cells have been described only in humans. These and other findings indicate a number of differences in the cytokine response between murine models and human beings.

Unclassified vasculitis with acral ischemic lesions: "forme fruste" or idiopathic vasculitis?

BACKGROUND AND OBJECTIVES

While acral ischemia and necrosis represent a common problem in connective tissue diseases and other disorders, acral ischemic lesions are also occasionally encountered in primary and secondary systemic vasculitides. Here we report on the course of 4 patients with acral ischemic lesions as a hallmark of unclassified vasculitis. We compare these cases with 4 additional cases of acral ischemia complicating classified vasculitis.

OBJECTIVES

To report on our experience with cases of unclassified vasculitis and acral ischemic lesions during the past 5 years and review the literature on vasculitis and acral ischemic lesions.

METHODS

The case history of one of the patients with unclassified vasculitis and acral ischemic lesions is reported in detail. The Medical history of another 3 patients presenting with vasculitic acral ischemic lesions and unclassified vasculitis during the past 5 years in our department (Lübeck/Bad Bramstedt) is summarized and compared to the course of patients with acral ischemic lesions complicating classified vasculitides. A PubMed database review of reports on acral ischemic lesions and vasculitis from 1985 to August 2006 was performed using the following combination of keywords: "Vasculitis" [MeSH] AND ("Necrosis" [MeSH] OR "Ischemia" [MeSH] OR "Infarction" [MeSH]) AND ("Extremities" [MeSH] OR "Fingers [MeSH] OR "Toes" [MeSH] OR "limb"), yielding 1328 entries. This search was subsequently limited to "Humans, All Adult (19+ years)", yielding 904 entries. Only three (0.7%) of these entries described one (one paper) or more (n=28) patients (two papers) with idiopathic vasculitis characterized by digit necrosis in the absence of systemic manifestations (except in some cases for arthralgia) or laboratory parameters pointing to a diagnosis of an established type of vasculitis.

RESULTS

A 37-year-old female presented with acral ischemic lesions of the left forefoot, fingers and toes, and Raynaud's phenomenon. Angiography showed multiple stenoses of ulnar and digital arteries, anterior and posterior tibialis arteries, and occlusions of radial artery and occlusion of the plantar artery in the absence of large vessel abnormalities. Histological analysis of an amputation disclosed giant cell arteritis of small vessels. The patient achieved remission with immunosuppressive treatment (cyclophosphamide and prednisolone). Three other patients with acral ischemic lesions and unclassified vasculitis also lacking other manifestations and defining laboratory and technical features during initial presentation and follow-up of 4 month to 5 years are presented. Necrotizing and leukocytoclastic vasculitis were present in two other patients, respectively. In contrast, acral ischemic lesions could be attributed to rheumatoid vasculitis and essential cryoglobulinemic vasculitis in two other cases each based on the patient's history and laboratory findings at the time of presentation of acral ischemic lesions.

CONCLUSIONS

While acral ischemic lesions could represent initial or isolated (forme fruste) manifestations of a defined vasculitis, acral ischemic lesions may rarely be encountered as the predominant manifestation of an as yet unclassified vasculitis. the histological findings seem to differ. Our report includes a peculiar case of giant cell arteritis of small arteries not classifiable as giant cell arteritis of large arteries or Takayasu disease.

[B lymphocyte differentiation in granulomatous tissues of the lung and the nasal mucosa in Wegener's granulomatosis: origin of anti-neutrophil cytoplasmic antibody formation?]

Wegener's granulomatosis (WG) starts with granulomatous inflammation of the respiratory tract before it converts into a potentially organ and life threatening systemic vasculitis associated with anti-neutrophil cytoplasmic antibodies (ANCA). The site of formation of the highly specific ANCA directed against "Wegener's autoantigen" proteinase 3 (PR3) is still unknown. Previously, we have shown that follicle-like B lymphocytic infiltrates in the vicinity to PR3 expressing cells in WG-granulomata. We characterized the immunoglobulin-VH repertoire in lung and nasal granulomata (paraffin embedded) from four WG patients. A total of 115 individual VH genes were characterized and compared to 84 VH genes from the peripheral blood of a healthy donor. We found an increased frequency of mutations with a bias to amino acid exchanges within the antigen binding sites (CDR) 1 and 2 in WG tissue. A large number of mutations led to negatively charged amino acids and may increase affinity to the positively charged PR3. Furthermore, the occurrence of differently mutated members of one B cell clone indicates clonal expansion and intraclonal diversification by an antigen, e.g. PR3. Several WG tissue derived genes displayed similarities to published sequences from peripheral PR3 ANCA producing B cells. Thus, granulomata of the lower and upper respiratory tract contain follicle-like B cell clusters with a selected VH repertoire infiltrate in WG. WG granulomata could be the place of autoantigen presentation and formation of high-affinity ANCA within neoformed ectopic or tertiary lymphoid-like tissue areas.

Current knowledge on cellular interactions in the WG-granuloma

Wegener's granulomatosis (WG) usually starts as granulomatous disease of the respiratory tract (so-called localized WG) before it converts to systemic disease (generalized WG) with the emergence of proteinase 3-specific antineutrophil cytoplasmic autoantibodies (PR3-ANCA) and PR3-ANCA associated autoimmune vasculitis. So far, it remains unresolved how tolerance to "Wegener's autoantigen" PR3 is broken and the immune response to PR3 sustained. Further, the relationship between granulomatous lesions and systemic vasculitis is poorly understood. None of the ANCA-animal-models has reproduced granulomata typical of WG so far. A number of endogenous and exogenous factors (HLA-DPB1*0401/PTPN22*620W, respiratory epithelial barrier dysfunction? S. aureus, cPR3?) could favour initial formation of granulomata in the respiratory tract and break of tolerance. PR3 induces dendritic cell maturation via the protease activated receptor (PAR)-2 and evokes a strong Th1-type T-cell res-ponse in WG. Clusters of PR3+ cells (neutrophils/monocytes) surrounded by antigen-presenting cells, Th1-type CD4+CD28- effector memory T-cells, maturing B- and plasmacells are found in WG-granulomata of the upper respiratory tract. Thus, WG-granulomata might provide the necessary "proinflammatory environment" for the break of tolerance and display features of lymphoid-like tissue neoformation, in which autoimmunity to PR3 could be sustained. Subsequent PR3-ANCA associated systemic vasculitis gives rise to new inflammatory lesions in many other organs, thereby promoting a self-perpetuating pathology characterized by inflammation and autoimmunity to PR3.

[Report on the 34th meeting of the German Clinical Immunology Workgroup, Frankfurt, 03.-04.11.2006]

The annual meeting of the Clinical Immunology Workgroup focused on autoimmune vasculitides. The role of innate immunity, T- and B-cells, and innovative therapies for autoimmune vasculitides was discussed. Further topics of the meeting were the role of endothelial microparticles, ghrelin and leptin, regulatory and effector-memory T-cells in ANCA-associated vasculitides, as well as the lethal midline granuloma, intracytoplasmic cytokine-profile in Behcet's disease, autoantibodies in rheumatoid arthritis, polyarteritis nodosa with cranial manifestation, ILT6 as genetic marker in multiple sclerosis and Sjögren's syndrome, alpha-fodrin autoantibodies in multiple sclerosis, interferon-g autoantibodies in a patient with atypical mycobacteriosis, and autoreactive T-cells in murine lupus.

Is PR3-ANCA formation initiated in Wegener's granulomatosis lesions? Granulomas as potential lymphoid tissue maintaining autoantibody production

In Wegener's granulomatosis (WG), antiproteinase 3 (PR3) autoantibodies (PR3-ANCA) are crucial in the development of generalized vasculitis. Wegener's pathognomonic lesion, a granulomatous inflammation of the upper and lower respiratory tract, contains abundant lymphocytes and macrophages. Lymphocyte clusters in germinal center-like formation within the granulomatous lesion are frequently observed, which suggests antigen-driven B cell maturation. Wegener's autoantigen PR3, the target for autoreactive B and T cells, is expressed in granulomatous lesions. Disease progression in WG is accompanied by a profound generalized alteration of T cell differentiation with an increase of effector memory T cells (CD4(+)CD28(-)). The cytokine profile suggests an aberrant Th1-type response either to an environmental trigger and/or the autoantigen PR3 itself. Staphylococcus aureus, a risk factor for disease exacerbation, is widely present in the upper airways in WG. The Ig gene repertoire from WG lesions indicates a predominance of VH3+ B cells with affinity to PR3 as well as to the S. aureus B cell superantigen SPA. Hence, within the WG lesion, S. aureus might support the maturation of PR3-affinity B cells that enter a germinal center reaction in contact with PR3 and T cells and expand, leading to PR3-ANCA production. Thus, granulomatous lesions could represent a potential lymphoid tissue-maintaining autoantibody production rather than a simple, random leukocyte accumulation in WG.

B lymphocyte maturation in Wegener's granulomatosis: a comparative analysis of VH genes from endonasal lesions

BACKGROUND

Anti-neutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 (PR3) are highly specific for Wegener's granulomatosis (WG). Evidence for a pivotal role of PR3-ANCA in the induction of vasculitis has been demonstrated. B cell clusters have been observed within endonasal biopsy specimens.

OBJECTIVES

To determine whether B cell selection and maturation take place in granulomatous lesions of WG.

METHODS

Granulomatous lesions and the immunoglobulin (VH) gene repertoire from nasal tissue of six WG patients-two active and two smouldering localised WG (ANCA negative, restricted to respiratory tract), plus one active and one smouldering PR3-ANCA positive generalised WG-were characterised by immunohistochemistry, polymerase chain reaction, cloning, DNA sequencing and database comparison.

RESULTS

B lymphocyte-rich, follicle-like areas were observed proximal to PR3 positive cells and plasma cells in granulomatous lesions; 184 VH genes from these granulomatous lesions were compared with 84 VH genes from peripheral blood of a healthy donor. The mutational pattern of VH genes from active WG resembled memory B cells. Structural homologies of VH genes from granulomatous lesions to PR3-ANCA encoding genes were detected. Significantly more genes (55%, 45%, and 53%, respectively) from active WG compared with the healthy repertoire carried mutations to negatively charged amino acids within the binding site coding regions, favouring affinity to the positively charged PR3.

CONCLUSIONS

Selection and affinity maturation of potentially PR3-ANCA producing autoreactive B cells may start in granulomatous lesions, thereby contributing to disease progression from ANCA negative localised to PR3-ANCA positive generalised WG.

Lack of efficacy of rituximab in Wegener's granulomatosis with refractory granulomatous manifestations

OBJECTIVE

To investigate the safety and efficacy of rituximab (RTX) in patients with refractory Wegener's granulomatosis (WG).

PATIENTS AND METHODS

Eight consecutive patients with active refractory WG were included. In all patients disease activity had persisted despite standard treatment with cyclophosphamide and prednisolone, as well as tumour necrosis factor alpha blockade 3 months before inclusion in the study. Patients had particular granulomatous manifestations like retro-orbital granulomata (n=5), nodules of the lungs (n=1), and subglottic stenosis (n=2). RTX was given intravenously every 4th week in combination with the standard treatment in five patients and with methotrexate in two others. Disease extent and activity were monitored clinically by interdisciplinary care, immunodiagnostics (ANCA serology, B cells by flow cytometry), and magnetic resonance imaging.

RESULTS

Beneficial response and a reduction in disease activity were seen in three patients, two of whom went into complete remission. In three other patients, disease activity remained unchanged while the disease progressed in the remaining two patients. In all patients peripheral blood B cells fell to zero during treatment with RTX. cANCA titres remained unchanged in all except one patient.

CONCLUSION

In this pilot study, B lymphocyte depletion was not associated with a change of the ANCA titres or obvious clinical improvement of refractory granulomatous disease in patients with WG. Further studies are needed to evaluate the role of RTX in WG.