Myeloperoxidase-specific antineutrophil cytoplasmic antibody-associated vasculitis

Myeloperoxidase (MPO)-specific antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (MPO-ANCA-associated vasculitis) is one of two major ANCA-associated vasculitis variants characterised by systemic necrotising vasculitis with few or no immune deposits. MPO-ANCA-associated vasculitis predominantly affects small blood vessels and, in contrast to its counterpart proteinase 3-ANCA-associated vasculitis, is generally not associated with granulomatous inflammation. The kidneys and lungs are the most commonly affected organs. The pathogenesis of MPO-ANCA-associated vasculitis is characterised by loss of tolerance to the neutrophil enzyme MPO. This loss of tolerance leads to a chronic immunopathological response where neutrophils become both the target and effector of autoimmunity. MPO-ANCA drives neutrophil activation, leading in turn to tissue and organ damage. Clinical trials have improved the therapeutic approach to MPO-ANCA-associated vasculitis. However, there remains substantial unmet need regarding relapse frequency, toxicity of current treatment, and long-term morbidity. In this Series paper, we present the current state of research regarding pathogenesis, diagnosis, and treatment of MPO-ANCA-associated vasculitis.

Proteinase 3-specific antineutrophil cytoplasmic antibody-associated vasculitis

Proteinase 3 (PR3)-specific antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is one of two major ANCA-associated vasculitis variants and is pathogenically linked to granulomatosis with polyangiitis (GPA). GPA is characterised by necrotising granulomatous inflammation that preferentially affects the respiratory tract. The small vessel vasculitis features of GPA are shared with microscopic polyangiitis. Necrotising granulomatous inflammation of GPA can lead to PR3-ANCA and small vessel vasculitis via activation of neutrophils and monocytes. B cells are central to the pathogenesis of PR3-ANCA-associated vasculitis. They are targeted successfully by remission induction and maintenance therapy with rituximab. Relapses of PR3-ANCA-associated vasculitis and toxicities associated with current standard therapy contribute substantially to remaining mortality and damage-associated morbidity. More effective and less toxic treatments are sought to address this unmet need. Advances with cellular and novel antigen-specific immunotherapies hold promise for application in autoimmune disease, including PR3-ANCA-associated vasculitis. This Series paper describes the inter-related histopathological and clinical features, pathophysiology, as well as current and future targeted treatments for PR3-ANCA-associated vasculitis.

The Joint Vasculitis Registry in German-speaking countries (GeVas): subgroup analysis of 266 AAV-patients

OBJECTIVES

Prospective long-term observational data on the disease course of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) were missing in Germany to date. Therefore, the Joint Vasculitis Registry in German-speaking countries (GeVas) has been established to follow the course of patients with AAV. The aim of this study is to present baseline data of patients with newly diagnosed and relapsing AAV enrolled in the GeVas registry.

METHODS

GeVas is a prospective, web-based, multicentre, 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.

RESULTS

Between June 2019 and October 2022, 266 patients with AAV were included in the GeVas registry, hereof 173 (65%) with new-onset and 93 (35%) with relapsing AAV. One hundred and sixty-two (61%) patients were classified as granulomatosis with polyangiitis (GPA), 66 (25%) as microscopic polyangiitis (MPA), 36 (13%) as eosinophilic granulomatosis with polyangiitis (EGPA), and 2 (1%) as renal limited AAV. The median age was 59 years (51-70 years, IQR), 130 (51%) patients were female. Most patients were ANCA positive (177; 67%) and affected by general symptoms, pulmonary, ear nose throat (ENT), renal and neurological involvement. For induction of remission, the majority of patients received glucocorticoids (247, 93%) in combination with either rituximab (118, 45%) or cyclophosphamide (112, 42%).

CONCLUSIONS

Demographic characteristics are comparable to those in other European countries. Differences were found regarding ANCA status, frequencies of organ manifestations, and therapeutic regimens. The GeVas registry will allow longitudinal observations and prospective outcome measures in AAV.

Characteristics and outcome of ANCA-associated vasculitides induced by anti-thyroid drugs: a multicentre retrospective case-control study

OBJECTIVE

Data on ANCA-associated vasculitis (AAV) induced by anti-thyroid drugs (ATD) are scarce. We aimed to describe the characteristics and outcome of these patients in comparison to primary AAV.

METHODS

We performed a retrospective multicentre study including patients with ATD-induced AAV. We focused on ATD-induced microscopic polyangiitis (MPA) and compared them with primary MPA by matching each case with four controls by gender and year of diagnosis.

RESULTS

Forty-five patients with ATD-induced AAV of whom 24 MPA were included. ANCA were positive in 44 patients (98%), including myeloperoxidase (MPO)-ANCA in 21 (47%), proteinase 3 (PR3)-ANCA in six (13%), and double positive MPO- and PR3-ANCA in 15 (33%). Main clinical manifestations were skin involvement (64%), arthralgia (51%) and glomerulonephritis (20%). ATD was discontinued in 98% of cases, allowing vasculitis remission in seven (16%). All the remaining patients achieved remission after glucocorticoids, in combination with rituximab in 11 (30%) or cyclophosphamide in four (11%). ATD were reintroduced in seven cases (16%) without any subsequent relapse. Compared with 96 matched primary MPA, ATD-induced MPA were younger at diagnosis (48 vs 65 years, P < 0.001), had more frequent cutaneous involvement (54 vs 25%, P = 0.007), but less frequent kidney (38 vs 73%, P = 0.02), and a lower risk of relapse (adjusted HR 0.07; 95% CI 0.01, 0.65, P = 0.019).

CONCLUSION

ATD-induced AAV were mainly MPA with MPO-ANCA, but double MPO- and PR3-ANCA positivity was frequent. The most common manifestations were skin and musculoskeletal manifestations. ATD-induced MPA were less severe and showed a lower risk of relapse than primary MPA.

[Granulomatosis with polyangiitis and microscopic polyangiitis]

Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are two entities of ANCA-associated vasculitis (AAV). Both diseases are characterised by systemic necrotising small-vessel vasculitis, which can affect any organ. In GPA, extravascular necrotising granulomatous inflammation, usually affecting the respiratory tract, is found in addition. In the majority of cases, the clinical presentation is dominated by a pulmonary-renal syndrome with alveolar haemorrhage and rapidly progressive glomerulonephritis. Other organ involvement is found as well. In GPA, the upper respiratory tract is commonly affected. GPA is associated with anti-neutrophil cytoplasmic autoantibodies (ANCA) with specificity for proteinase 3 (PR3-ANCA) and MPA with specificity for myeloperoxidase (MPO-ANCA). Immunosuppressive therapy depends on disease activity and the severity of organ involvement.

Data quality and patient characteristics in European ANCA-associated vasculitis registries: data retrieval by federated querying

OBJECTIVES

This study aims to describe the data structure and harmonisation process, explore data quality and define characteristics, treatment, and outcomes of patients across six federated antineutrophil cytoplasmic antibody-associated vasculitis (AAV) registries.

METHODS

Through creation of the vasculitis-specific Findable, Accessible, Interoperable, Reusable, VASCulitis ontology, we harmonised the registries and enabled semantic interoperability. We assessed data quality across the domains of uniqueness, consistency, completeness and correctness. Aggregated data were retrieved using the semantic query language SPARQL Protocol and Resource Description Framework Query Language (SPARQL) and outcome rates were assessed through random effects meta-analysis.

RESULTS

A total of 5282 cases of AAV were identified. Uniqueness and data-type consistency were 100% across all assessed variables. Completeness and correctness varied from 49%-100% to 60%-100%, respectively. There were 2754 (52.1%) cases classified as granulomatosis with polyangiitis (GPA), 1580 (29.9%) as microscopic polyangiitis and 937 (17.7%) as eosinophilic GPA. The pattern of organ involvement included: lung in 3281 (65.1%), ear-nose-throat in 2860 (56.7%) and kidney in 2534 (50.2%). Intravenous cyclophosphamide was used as remission induction therapy in 982 (50.7%), rituximab in 505 (17.7%) and pulsed intravenous glucocorticoid use was highly variable (11%-91%). Overall mortality and incidence rates of end-stage kidney disease were 28.8 (95% CI 19.7 to 42.2) and 24.8 (95% CI 19.7 to 31.1) per 1000 patient-years, respectively.

CONCLUSIONS

In the largest reported AAV cohort-study, we federated patient registries using semantic web technologies and highlighted concerns about data quality. The comparison of patient characteristics, treatment and outcomes was hampered by heterogeneous recruitment settings.

Safety and efficacy of secukinumab in patients with giant cell arteritis (TitAIN): a randomised, double-blind, placebo-controlled, phase 2 trial

BACKGROUND

The treatment of giant cell arteritis with glucocorticoid-sparing agents is an unmet medical need. We evaluated the efficacy and safety of secukinumab, an anti-interleukin-17A monoclonal antibody, in patients with giant cell arteritis.

METHODS

We conducted a Bayesian randomised, parallel-group, double-blind, placebo-controlled, multicentre, phase 2 study at 11 clinics or hospitals in Germany. Patients aged 50 years or older with new-onset or relapsing giant cell arteritis who were naive to biological therapy and already receiving glucocorticoids with a prednisolone equivalent dose of 25-60 mg/day were eligible for inclusion. Participants were assigned (1:1) to receive 300 mg secukinumab or placebo subcutaneously once a week up to week 4 and every 4 weeks thereafter. In both treatment groups, prednisolone dose was tapered down to 0 mg over a 26-week period. Patients, investigator staff, and clinical trial team were masked to the treatment assignment. The primary endpoint was the median proportion (Bayesian analysis) of patients with sustained remission until week 28 in the full analysis set (ie, all patients who received at least one dose of assigned treatment, analysed according to treatment assigned at randomisation). Sustained remission rate of the placebo group from a previous trial of tocilizumab in patients with giant cell arteritis was used to derive the prior distribution of placebo sustained remission rate for the primary endpoint. The safety of secukinumab was assessed in the safety set (ie, all patients who received at least one dose of study treatment, analysed according to study treatment received). This trial is completed and is registered with ClinicalTrials.gov, NCT03765788.

FINDINGS

Of the 65 patients who were assessed for eligibility, 52 patients (median age 75 years [IQR 69-79]; 35 [67%] female and 17 [33%] male, 52 [100%] White) were enrolled between Jan 30, 2019 and March 30, 2020 and were randomly assigned to receive secukinumab (n=27) or placebo (n=25). Four of 27 patients in the secukinumab group and eight of 25 patients in the placebo group discontinued treatment by week 28 of the study. On the basis of the Bayesian analysis, the median proportion of patients in sustained remission until week 28 was 70% (95% credibility interval 52-85) in the secukinumab group versus 20% (12-30) in the placebo group. The incidence of adverse events was similar in the secukinumab (27 [100%] of 27 patients had any adverse event) and placebo groups (24 [96%] of 25 patients had any adverse event); the most common adverse events were hypertension (six [22%] of 27 patients in the secukinumab group and eight [32%] of 25 patients in the placebo group) and nasopharyngitis (five [19%] of 27 patients in the secukinumab group and five [20%] of 25 patients in the placebo group). Two patients (one in each group) died during the study, neither of which was considered to be related to study treatment.

INTERPRETATION

Patients with active giant cell arteritis had a higher sustained remission rate in the secukinumab group than in the placebo group at week 28, in combination with glucocorticoid taper regimen. Secukinumab was tolerated well with no new safety concerns. This proof-of-concept phase 2 study further supports the development of secukinumab as a treatment option for people with giant cell arteritis.

FUNDING

Novartis Pharma.

Spectrum of ANCA-specificities in eosinophilic granulomatosis with polyangiitis. A retrospective multicentre study

OBJECTIVES

To determine the spectrum of anti-neutrophil cytoplasmic antibody (ANCA) antigen-specificities in eosinophilic granulomatosis with polyangiitis (EGPA), an ANCA-associated vasculitis (AAV) entity.

METHODS

We conducted a retrospective analysis of 73 EGPA patients from three German tertiary referral centres for vasculitis. In addition to in-house ANCA testing, pentraxin 3 (PTX3)- and olfactomedin 4 (OLM4)-ANCA were determined using a prototype cell-based assay for research (EUROIMMUN, Lübeck, Germany). Patient characteristics and clinical manifestations were evaluated and compared based on ANCA status.

RESULTS

Myeloperoxidase (MPO)-ANCA positive patients (n=8; 11%) significantly more frequently displayed peripheral nervous system (PNS) and pulmonary involvement and less frequently heart involvement compared to MPO-ANCA negative patients. PTX3-ANCA positive patients (n=5; 6.8%) had a significantly higher prevalence of ear, nose and throat, pulmonary, gastrointestinal and PNS involvement, and a lower prevalence of renal and central nervous system involvement compared to PTX3-ANCA negative patients. Proteinase 3 (PR3)-ANCA and OLM4-ANCA were detected in 2 patients (2.7%) each with multiorgan involvement. One PR3-ANCA positive patient was also positive for bactericidal permeability increasing protein (BPI)-ANCA.

CONCLUSIONS

In addition to MPO, the spectrum of ANCA antigen specificities includes various other target antigens such as PR3, BPI, PTX3, and OLM4, potentially segregating further EGPA subgroups. A lower prevalence of MPO-ANCA was detected in this study compared with other studies. OLM4 is reported as novel ANCA antigen-specificity in EGPA, and thus AAV.

Case report: Schnitzler-like syndrome without monoclonal gammopathy

Schnitzler syndrome is a rare autoinflammatory disorder characterized by urticarial rash, joint pain, recurrent fever, leucocytosis, elevated C-reactive protein (CRP) and serum amyloid A (SAA), and monoclonal IgM or IgG gammopathy. According to the Strasbourg criteria, both urticarial rash and gammopathy are mandatorily required for the diagnosis of Schnitzler’s syndrome. However, incomplete variants lacking either skin symptoms or monoclonal gammopathy have also been described. Here, we report a case in which the diagnosis of Schnitzler-like syndrome was made despite the absence of gammopathy, based on neutrophilic dermal inflammation, episodic and excessive increase in inflammatory parameters, and prompt response to anakinra, a soluble IL1 receptor antagonist (sIL-1RA). In addition, we detected neutrophil epitheliotropism, which is highly suggestive of autoinflammatory disease. Using whole-exome sequencing, we were unable to find a causative pathogenic mutation but did find several mutations possibly related to the inflammatory processes in this patient. This and other cases highlight that the existing Strasbourg criteria are too strict to capture Schnitzler-like syndromes that may respond well and rapidly to IL1 inhibition. Recurrent episodes of disease with normalization of inflammatory symptoms in the interval, rapid response to anakinra, and neutrophilic epitheliotropism in a lesional skin biopsy may help confirm the diagnosis of Schnitzler-like syndrome.

Autoimmune pre-disease

Approximately 5% of the world-wide population is affected by autoimmune diseases. Overall, autoimmune diseases are still difficult to treat, impose a high burden on patients, and have a significant economic impact. Like other complex diseases, e.g., cancer, autoimmune diseases develop over several years. Decisive steps in the development of autoimmune diseases are (i) the development of autoantigen-specific lymphocytes and (often) autoantibodies and (ii) potentially clinical disease manifestation at a later stage. However, not all healthy individuals with autoantibodies develop disease manifestations. Identifying autoantibody-positive healthy individuals and monitoring and inhibiting their switch to inflammatory autoimmune disease conditions are currently in their infancy. The switch from harmless to inflammatory autoantigen-specific T and B-cell and autoantibody responses seems to be the hallmark for the decisive factor in inflammatory autoimmune disease conditions. Accordingly, biomarkers allowing us to predict this progression would have a significant impact. Several factors, such as genetics and the environment, especially diet, smoking, exposure to pollutants, infections, stress, and shift work, might influence the progression from harmless to inflammatory autoimmune conditions. To inspire research directed at defining and ultimately targeting autoimmune predisease, here, we review published evidence underlying the progression from health to autoimmune predisease and ultimately to clinically manifest inflammatory autoimmune disease, addressing the following 3 questions: (i) what is the current status, (ii) what is missing, (iii) and what are the future perspectives for defining and modulating autoimmune predisease.

COVID-19 pandemic impairs medical care of vasculitis patients in Germany: Results of a national patient survey

Objective

To analyze the impact of the COVID-19 pandemic on medical care and vaccination acceptance of vasculitis patients in Germany.

Methods

A web-based national survey was developed by rheumatology centers and vasculitis patient advocacy groups. The survey was distributed nationwide by mail and flyers and could be accessed via a QR-code or weblink from December 2021 to April 2022. Descriptive statistics [mean, median, standard derivation (SD), 25%, 75% quantile] were calculated. 95% confidence intervals were presented for responses that were directly related to the impact of COVID-19 on parameters associated with vasculitis patient care.

Results

The online survey was completed by 117 patients with small and large vessel vasculitis [granulomatosis with polyangiitis (n = 69), eosinophilic granulomatosis with polyangiitis (n = 16), microscopic polyangiitis (n = 12), giant cell arteritis (n = 17) and Takayasu's arteritis (n = 3)]. Prescheduled rheumatological appointments had been canceled due to the COVID-19 pandemic in 12.6% of the respondents [95% confidence interval (CI), 7.3-20.0%); in 9% (95% CI, 4.5-15.6%)] appointments had been replaced by digital services. Therapeutic regimens were changed (shifted, reduced, or discontinued) due to the pandemic in 15.5% (95% CI 9.5-22.2%). Vaccination coverages were generally high compared to patients with other rheumatic diseases and the general population. Highest vaccination coverage was observed against COVID-19 (98.1% 95% CI 93.9-99.6%).

Conclusion

Vasculitis patients experienced changes in medical care during COVID-19 pandemic such as cancelation of prescheduled rheumatology appointments and modifications in therapeutic regimens. The overall acceptance rate for vaccination was comparatively high, particularly for vaccination against COVID-19.

2022 American College of Rheumatology/EULAR Classification Criteria for Takayasu Arteritis

OBJECTIVE

To develop and validate new classification criteria for Takayasu arteritis (TAK).

METHODS

Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in 6 phases: 1) identification of candidate criteria items, 2) collection of candidate items present at diagnosis, 3) expert panel review of cases, 4) data-driven reduction of candidate items, 5) derivation of a points-based classification score in a development data set, and 6) validation in an independent data set.

RESULTS

The development data set consisted of 316 cases of TAK and 323 comparators. The validation data set consisted of an additional 146 cases of TAK and 127 comparators. Age ≤60 years at diagnosis and imaging evidence of large-vessel vasculitis were absolute requirements to classify a patient as having TAK. The final criteria items and weights were as follows: female sex (+1), angina (+2), limb claudication (+2), arterial bruit (+2), reduced upper extremity pulse (+2), reduced pulse or tenderness of a carotid artery (+2), blood pressure difference between arms of ≥20 mm Hg (+1), number of affected arterial territories (+1 to +3), paired artery involvement (+1), and abdominal aorta plus renal or mesenteric involvement (+3). A patient could be classified as having TAK with a cumulative score of ≥5 points. When these criteria were tested in the validation data set, the model area under the curve was 0.97 (95% confidence interval [95% CI] 0.94-0.99) with a sensitivity of 93.8% (95% CI 88.6-97.1%) and specificity of 99.2% (95% CI 96.7-100.0%).

CONCLUSION

The 2022 American College of Rheumatology/EULAR classification criteria for TAK are now validated for use in research.

Low Concentrations of C5a Complement Receptor Antibodies Are Linked to Disease Activity and Relapse in Antineutrophil Cytoplasmic Autoantibody-Associated Vasculitis

OBJECTIVE

To examine concentrations of circulating antibodies targeting C3a and C5a complement receptors in antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) and analyze their association with disease activity.

METHODS

Concentrations of antibodies against C3a and C5a complement receptors (anti-C3aR and anti-C5aR) and plasma complement fragments C3a and C5a were determined in patients with AAV (n = 110; granulomatosis with polyangiitis [GPA; n = 82] or microscopic polyangiitis [MPA; n = 28]), systemic lupus erythematosus (SLE) patients as disease controls (n = 36), and healthy donors (n = 220). C3aR and C5aR expression by circulating neutrophils, monocytes, and T cells was analyzed using flow cytometry. Clinical data were assessed at time of serum sampling and during follow-up for 60 months.

RESULTS

In AAV, anti-C3aR and anti-C5aR antibodies were decreased (P = 0.0026 and P ≤ 0.0001, respectively). In remission, anti-C3aR antibody concentrations rose to values comparable to healthy donors, whereas anti-C5aR antibody concentrations did not. In GPA, anti-C5a and anti-C5aR antibody concentrations inversely correlated with each other (r = -0.6831, P = 0.0127). In newly diagnosed GPA, decreased concentrations of anti-C5aR antibodies but not anti-C3aR antibodies were associated with disease activity (P = 0.0009). Moreover, low anti-C5aR antibodies were associated with relapse in GPA (hazard ratio 3.54, P = 0.0009) and MPA (hazard ratio 4.41, P = 0.0041). The frequency of C5aR-expressing cells within T cell populations was increased in GPA (P = 0.0021 for CD4+ T cells; P = 0.0118 for CD8+ T cells), but not in MPA.

CONCLUSION

Low concentrations of anti-C5aR antibodies reflect disease activity and are associated with an increased risk for relapse in AAV.

The neutrophil: A key resourceful agent in immune‐mediated vasculitis

The term "vasculitis" refers to a group of rare immune-mediated diseases characterized by the dysregulated immune system attacking blood vessels located in any organ of the body, including the skin, lungs, and kidneys. Vasculitides are classified according to the size of the vessel that is affected. Although this observation is not specific to small-, medium-, or large-vessel vasculitides, patients show a high circulating neutrophil-to-lymphocyte ratio, suggesting the direct or indirect involvement of neutrophils in these diseases. As first responders to infection or inflammation, neutrophils release cytotoxic mediators, including reactive oxygen species, proteases, and neutrophil extracellular traps. If not controlled, this dangerous arsenal can injure the vascular system, which acts as the main transport route for neutrophils, thereby amplifying the initial inflammatory stimulus and the recruitment of immune cells. This review highlights the ability of neutrophils to "set the tone" for immune cells and other cells in the vessel wall. Considering both their long-established and newly described roles, we extend their functions far beyond their direct host-damaging potential. We also review the roles of neutrophils in various types of primary vasculitis, including immune complex vasculitis, anti-neutrophil cytoplasmic antibody-associated vasculitis, polyarteritis nodosa, Kawasaki disease, giant cell arteritis, Takayasu arteritis, and Behçet's disease.

Granulomatose mit Polyangiitis und mikroskopische Polyangiitis

Die Granulomatose mit Polyangiitis (GPA) und mikroskopische Polyangiitis (MPA) sind zwei zur ANCA-assoziierten Vaskulitis (AAV) zählende Entitäten. Beiden Erkrankungen liegt eine systemische nekrotisierende Kleingefäßvaskulitis zugrunde, die jedes Organ betreffen kann. Bei der GPA ist zusätzlich eine in der Regel den Respirationstrakt betreffende extravaskuläre nekrotisierende granulomatöse Entzündung vorzufinden. Das klinische Bild wird in der Mehrzahl der Fälle durch ein pulmo-renales Syndrom mit alveolärer Hämorrhagie und rapid-progressiver Glomerulonephritis sowie weitere Organmanifestationen bestimmt. Bei der GPA imponiert zudem die fast regelhafte Mitbeteiligung des oberen Respirationstrakts. Die GPA ist mit Anti-Neutrophilen zytoplasmatischen Autoantikörpern (ANCA) mit einer Spezifität für die Proteinase 3 (PR3-ANCA) und die MPA für Myeloperoxidase (MPO-ANCA) assoziiert. Die immunsuppressive Therapie richtet sich nach der Krankheitsaktivität und Schwere der Organbeteiligung.

Immunogenic cell death as driver of autoimmunity in granulomatosis with polyangiitis

Cell death and dysregulated clearance of dead cells play essential roles in the induction of chronic inflammatory processes and autoimmune diseases. Granulomatosis with polyangiitis (GPA), a neutrophil-driven autoimmune disorder, is characterized by necrotizing inflammation predominantly of the respiratory tract and an anti-neutrophil cytoplasmic autoantibody (ANCA)-associated systemic necrotizing vasculitis. Defective regulation of neutrophil homeostasis and cell death mechanisms have been demonstrated in GPA. Disturbed efferocytosis (i.e., phagocytosis of apoptotic neutrophils by macrophages) as well as cell death-related release of damage-associated molecular patterns (DAMP) such as high mobility group box 1 (HMGB1) contribute to chronic non-resolving inflammation in GPA. DAMP have been shown to induce innate as well as adaptive cellular responses thereby creating a prerequisite for the development of pathogenic autoimmunity. In this review, we discuss factors contributing to as well as the impact of regulated cell death (RCD) accompanied by DAMP-release as early drivers of the granulomatous tissue inflammation and autoimmune responses in GPA.

Both T and B cells are indispensable for the development of a PBMC transfer-induced humanized mouse model for SSc

BACKGROUND

Recently, a novel humanized mouse model for systemic sclerosis (SSc) was established by transferring peripheral blood mononuclear cells (PBMC) from patients with SSc to Rag2^-/-Il2rg^-/- immunodeficient mice. Here, we aimed to investigate the role of T and B cells in this humanized mouse model.

METHODS

T and B cells were depleted in vitro from freshly isolated PBMC using anti-CD3 and anti-CD19 magnetic microbeads, respectively. Subsequently, PBMC and T or B cell-depleted PBMC were transferred into Rag2^-/-/Il2rg^-/- mice via intraperitoneal injection. Twelve weeks after the transfer, mice were sacrificed and evaluated.

RESULTS

Mice transferred with whole PBMC from SSc patients developed systemic inflammation in the lungs, kidneys, and liver, and 6 out of 11 mice died or had to be sacrificed during the experiment. By contrast, such inflammation and death were not observed in mice transferred with corresponding T or B cell-depleted PBMC. In line with this finding, transfer with whole PBMC restored the splenic white pulp composing of human T, B, and plasma cells and led to the production of a considerable amount of human autoantibodies in recipient mice, while those immunological features were rarely observed in mice that received T or B cell-depleted PBMC. In contrast to our previous findings demonstrating a transfer of the protective effect of a B cell therapy into the mouse, treatment of SSc patients with chemical immunosuppressive drugs did not affect the pathogenicity of PBMC.

CONCLUSIONS

This study demonstrates that both T and B cells are indispensable for the pathogenesis of the PBMC transfer-induced mouse model for SSc.

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;

[Update on etiopathogenesis of small vessel vasculitis]

Small vessel vasculitis is characterized by a necrotizing inflammation of the vessel wall predominantly with involvement of small intraparenchymal arteries, arterioles, capillaries and venules. Medium-sized and occasionally large vessels can also be involved. Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (granulomatosis with polyangiitis, microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis) are differentiated from immune complex vasculitides based on immunopathological and serological aspects. Immune complex vasculitides include IgA vasculitis, cryoglobulinemic vasculitis, hypocomplementemic urticarial vasculitis (anti-C1q vasculitis) and anti-glomerular basement membrane disease. Epidemiological and next-generation sequencing-based studies have significantly contributed to the identification of predisposing environmental factors and genetic risk factors in recent years. Under specific conditions ANCA and immune complexes can induce premature intravascular activation of neutrophilic granulocytes with degranulation and release of enzymes and reactive oxygen species, which leads to vascular damage. In granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis various factors, such as barrier dysfunction and dysbiosis of the microbiome contribute to extravascular granuloma formation predominantly affecting the respiratory tract.

New insights into the epidemiology of ANCA-associated vasculitides in Germany: results from a claims data study

OBJECTIVE

ANCA-associated vasculitides (AAV) are rare, potentially life-threatening autoimmune diseases characterized by systemic inflammation and organ damage. AAV prevalence rates reported in Europe vary considerably and robust data sources are often lacking. This study aimed to examine the feasibility of claims data analysis as a complementary method to registry-based studies to assess the epidemiology of AAV.

METHODS

In this retrospective observational study, anonymized longitudinal claims data from years 2013-2016 from German statutory health insurance companies (data source: InGef, Institute for Applied Health Research) have been analysed on an age- and gender-stratified cohort of ∼3 million persons representative of the German population. In this cohort, granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) patients were identified.

RESULTS

The study cohort revealed a prevalence for GPA and MPA of 210 and 46 cases per million people, respectively. The annual incidence comprised 34 GPA cases and 13 MPA cases per million people per year. Hence, 17 500 AAV patients (GPA and MPA) are estimated to live in Germany, with an annual increase of 3200 patients. According to their demographic and disease-specific characteristics, AAV patients identified in this claims data approach are representative.

CONCLUSION

This is the first study using claims data to assess the epidemiology of AAV. In Germany, AAV was diagnosed more frequently than it was estimated by previous self-reporting registry-based studies. The findings indicate that epidemiological data of AAV may have been underestimated but may also reflect improved diagnostic methods and disease recognition.

Efficacy and safety of secukinumab in patients with giant cell arteritis: study protocol for a randomized, parallel group, double-blind, placebo-controlled phase II trial

Background

One key pathological finding in giant cell arteritis (GCA) is the presence of interferon-gamma and interleukin (IL)-17 producing T helper (Th) 1 and Th17 cells in affected arteries. There is anecdotal evidence of successful induction and maintenance of remission with the monoclonal anti-IL-17A antibody secukinumab. Inhibition of IL-17A could therefore represent a potential new therapeutic option for the treatment of GCA.

Methods

This is a randomized, parallel-group, double-blind, placebo-controlled, multi-center, phase II study in which patients, treating physicians, and the associated clinical staff as well as the sponsor clinical team are blinded. It is designed to evaluate efficacy and safety of secukinumab compared to placebo in combination with an open-label prednisolone taper regimen. Patients included are naïve to biological therapy and have newly diagnosed or relapsing GCA. Fifty patients are randomly assigned in a 1:1 ratio to receive either 300 mg secukinumab or placebo subcutaneously at baseline, weeks 1, 2 and 3, and every 4 weeks from week 4. Patients in both treatment arms receive a 26-week prednisolone taper regimen. The study consists of a maximum 6-week screening period, a 52-week treatment period (including the 26-week tapering), and an 8-week safety follow-up, with primary and secondary endpoint assessments at week 28. Patients who do not achieve remission by week 12 experience a flare after remission or cannot adhere to the prednisolone tapering will enter the escape arm and receive prednisolone at a dose determined by the investigator’s clinical judgment. The blinded treatment is continued. Two optional imaging sub-studies are included (ultrasound and contrast-media enhanced magnetic resonance angiography [MRA]) to assess vessel wall inflammation and occlusion before and after treatment. The primary endpoint is the proportion of patients in sustained remission until week 28 in the secukinumab group compared to the proportion of patients in the placebo group. A Bayesian approach is applied.

Discussion

The trial design allows the first placebo-controlled data collection on the efficacy and safety of secukinumab in patients with GCA.

Trial registration

ClinicalTrials.gov NCT03765788. Registration on 5 December 2018, prospective registration, EudraCT number 2018-002610-12; clinical trial protocol number CAIN457ADE11C.

The Joint Vasculitis Registry in German-speaking countries (GeVas) - a prospective, multicenter registry for the follow-up of long-term outcomes in vasculitis

Background

Vasculitides comprise a group of rare diseases which affect less than 5 in 10.000 individuals. Most types of vasculitis can become organ- and life-threatening and are characterized by chronicity, high morbidity and relapses, altogether resulting in significant morbidity and mortality. Previous studies have been either monocentric or mainly retrospective – studies with a prospective design mostly consisted of rather small cohorts of 100 to 200 patients.

The aim of the Joint Vasculitis Registry in German-speaking countries (GeVas) is to record all patients who have been recently diagnosed with vasculitis or who have changed their treatment due to a relapse (inception cohort). In GeVas, data are collected prospectively in a multicenter design in Germany, Austria and Switzerland. By this approach, courses of vasculitis and their outcomes can be monitored over an extended period.

Methods

GeVas is a prospective, web-based, multicenter, clinician-driven registry for the documentation of organ manifestations, damage, long-term progress and other outcomes of various types of vasculitis. The registry started recruiting in June 2019. As of October 2020, 14 centers have been initiated and started recruiting patients in Germany. Involvement of sites in Austria and the German-speaking counties of Switzerland is scheduled in the near future.

Discussion

In June 2019, we successfully established a prospective multicenter vasculitis registry being the first of its kind in German-speaking countries. The participating centers are currently recruiting, and systematic analysis of long-term vasculitis outcomes is expected in the ensuing period.

Trial registration

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

Transfer of PBMC From SSc Patients Induces Autoantibodies and Systemic Inflammation in Rag2-/-/IL2rg-/- Mice

Objective

The contribution of sustained autologous autoantibody production by B cells to the pathogenesis of systemic sclerosis (SSc) and granulomatosis with polyangiitis (GPA) is not fully understood. To investigate this, a humanized mouse model was generated by transferring patient-derived peripheral blood mononuclear cells (PBMC) into immunocompromised mice.

Methods

PBMC derived from patients with SSc and GPA as well as healthy controls (HD) were isolated, characterized by flow cytometry, and infused into Rag2^-/-/IL2rg^-/- mice. In addition, PBMC from SSc patients treated with rituximab were transferred into mice. Twelve weeks later, human autoantibodies were determined in blood of the recipient mice and affected tissues were analyzed for pathological changes by histology and immunohistochemistry.

Results

Mice engrafted with PBMC derived from SSc patients developed autoantibodies such as antinuclear antibodies (ANA) mimicking the pattern of the respective donors. Moreover, cellular infiltrates dominated by B cells were observed in lung, kidney and muscles of the recipient mice. By contrast, PBMC derived from HD or GPA patients survived in recipient mice after transfer, but neither human autoantibodies nor inflammatory infiltrates in tissues were detected. Furthermore, these pathological changes were absent in mice transferred with PBMC from rituximab-treated SSc patients.

Conclusion

This humanized mouse model is indicative for cross-reactivity of human lymphocytes to murine autoantigens and argues for a pivotal role of B cells as well as of sustained autoimmunity in the pathogenesis of SSc. It provides a powerful tool to study interstitial lung disease and so far, under-recognized disease manifestations such as myositis and interstitial nephritis.

Granulomatous Inflammation in ANCA-Associated Vasculitis

ANCA-associated vasculitis (AAV) comprises granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). While systemic vasculitis is a hallmark of all AAV, GPA is characterized by extravascular granulomatous inflammation, preferentially affecting the respiratory tract. The mechanisms underlying the emergence of neutrophilic microabscesses; the appearance of multinucleated giant cells; and subsequent granuloma formation, finally leading to scarred or destroyed tissue in GPA, are still incompletely understood. This review summarizes findings describing the presence and function of molecules and cells contributing to granulomatous inflammation in the respiratory tract and to renal inflammation observed in GPA. In addition, factors affecting or promoting the development of granulomatous inflammation such as microbial infections, the nasal microbiome, and the release of damage-associated molecular patterns (DAMP) are discussed. Further, on the basis of numerous results, we argue that, in situ, various ways of exposure linked with a high number of infiltrating proteinase 3 (PR3)- and myeloperoxidase (MPO)-expressing leukocytes lower the threshold for the presentation of an altered PR3 and possibly also of MPO, provoking the local development of ANCA autoimmune responses, aided by the formation of ectopic lymphoid structures. Although extravascular granulomatous inflammation is unique to GPA, similar molecular and cellular patterns can be found in both the respiratory tract and kidney tissue of GPA and MPA patients; for example, the antimicrobial peptide LL37, CD163⁺ macrophages, or regulatory T cells. Therefore, we postulate that granulomatous inflammation in GPA or PR3-AAV is intertwined with autoimmune and destructive mechanisms also seen at other sites.

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

FC 039RENAL OUTCOME AFTER RITUXIMAB IN ADULT-ONSET IGA VASCULITIS AND CRESCENTIC IGA NEPHROPATHY: A MULTICENTRE STUDY

Background and Aims

Glucocorticoids (GC) and/or immunosuppressive agents are the mainstay of therapy for adult-onset IgA Vasculitis (IgAV), but their efficacy is often partial while their toxicity is relevant. Recently, rituximab (RTX) has been reported as a safe and effective option but only few data on renal outcome are available.1 RTX has also been used in a few cases of crescentic IgA Nephropathy (cIgAN), an IgAN subset with vasculitic lesions and poor response to conventional immunosuppressive regimens.2 We present the results of a multicentre cohort of patients with IgAV and cIgAN treated with RTX.

Method

The databases of 16 consorted European centres were investigated to screen for patients with adult-onset, biopsy-proven IgAV and cIgAN (crescents in ≥25% glomeruli and rapid eGFR worsening at presentation), who received RTX as induction therapy. We selected patients with active renal manifestations at the time of RTX. Remission was defined as a Birmingham Vasculitis Activity Score (BVAS)=0 or &lt;5 if it was due to persistent proteinuria and relapse as an increase in BVAS requiring change in immunosuppressive therapy.

Results

We identified 38 patients with IgAV and 12 patients with cIgAN who received RTX and had active renal involvement at the time of treatment. The median age at onset was 40 years (interquartile range, IQR, 25-53) and more than two-thirds of patients were male (Table 1). The median follow-up after RTX was 41 months (IQR 18-60).

Renal outcomes are reported in Table 2. At the time of treatment, 24 patients (48%) had eGFR ≥60 mL/min/1.73 m2. All had IgAV and their median BVAS was 17 (IQR 10-22). Furthermore, all had microhaematuria and proteinuria. Renal histology showed mesangial or focal endocapillary proliferation in 12/17 (71%) patients who underwent biopsy (class II-IIIA according to Pillebout3). Twenty patients (83%) achieved remission; after a median of 12 months (range 9-14), four experienced a minor relapse and one had a major relapse with significant renal disease progression. Renal function remained stable in all but two patients who developed end-stage renal disease (ESRD). Micro-haematuria subsided in 14/24 (58%) and median 24h proteinuria decreased from 1750 mg (IQR 865-3275) to 175 mg (IQR 100-800) at last follow-up (p=0.029).

Of the 26 patients with eGFR &lt;60 mL/min/1.73 m2, 14 had IgAV and 12 had cIgAN. All were biopsied and 20 (77%) had diffuse endo/extra-capillary proliferation (classes IIIB-IV). Five patients required dialysis but recovered soon after treatment start. Remission was achieved by 16/26 (61%); eight (50%) subsequently relapsed and two (12%) reached ESRD. At last follow-up, eGFR was ≥60 mL/min/1.73 m2 in 8/26 (31%), 10/26 (48%) had stable renal function as compared to the time of RTX, while 8/26 (31%) had developed ESRD. Median 24h proteinuria decreased from 3400 mg (IQR 2150-6500) to 770 mg (177-1315) (p=0.016).

Remission rate and ESRD-free survival were respectively 86% and 92% in patients with IgAV, while they were respectively 42% and 42% in cIgAN patients. Furthermore, 21/24 (87%) patients who received RTX alone or combined to glucocorticoids but not to immunosuppressive agents achieved remission and 22/24 (92%) were ESRD-free at last follow-up. Of the 26 patients receiving immunosuppressive agents, 17 (65%) obtained remission and 18 (69%) were ESRD-free at last assessment. Over the whole follow-up, only one patient reported a severe adverse effect related to RTX (pneumonia).

Conclusion

Renal involvement in adult-onset IgAV and cIgAN is frequently severe. RTX, combined or not with other immunosuppressive agents, may improve renal manifestations and is well tolerated. IgAV patients show higher remission rates and a longer ESRD-free survival as compared to cIgAN patients.

Low-Dose IL-2 Therapy in Autoimmune and Rheumatic Diseases

Regulatory T cells (Treg) are crucial for the maintenance of peripheral tolerance and for the control of ongoing inflammation and autoimmunity. The cytokine interleukin-2 (IL-2) is essentially required for the growth and survival of Treg in the peripheral lymphatic tissues and thus plays a vital role in the biology of Treg. Most autoimmune and rheumatic diseases exhibit disturbances in Treg biology either at a numerical or functional level resulting in an imbalance between protective and pathogenic immune cells. In addition, in some autoimmune diseases, a relative deficiency of IL-2 develops during disease pathogenesis leading to a disturbance of Treg homeostasis, which further amplifies the vicious cycle of tolerance breach and chronic inflammation. Low-dose IL-2 therapy aims either to compensate for this IL-2 deficiency to restore a physiological state or to strengthen the Treg population in order to be more effective in counter-regulating inflammation while avoiding global immunosuppression. Here we highlight key findings and summarize recent advances in the clinical translation of low-dose IL-2 therapy for the treatment of autoimmune and rheumatic diseases.

GPA-Induced Granulomatous Endocarditis Mimicking a Thrombotic Mitral Valve Stenosis

We present the case of a patient with granulomatous endocarditis of the mitral valve leading to severe valve stenosis caused by granulomatosis with polyangiitis. Endocarditis is a rare complication of granulomatosis with polyangiitis that may be misdiagnosed as infectious endocarditis or, as in our case, thrombotic lesions. (Level of Difficulty: Intermediate.)

[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

[Anti B-cell-antibody treatment for maintenance of remission in granulomatosis with polyangiitis and microscopic polyangiitis]

Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are the most frequent primary necrotizing small vessel vasculitides. In these formerly fatal diseases remission can be induced by stage- and activity-adapted immunosuppressive regimens in the majority of patients. This does not lead to drug-free long-term remission or even cure. Consequently, maintenance of remission medication is needed. Recent randomized controlled trials demonstrated that maintenance treatment with the anti-B-cell antibody Rituximab, administered 6-monthly as opposed to azathioprine leads to a significantly lower relapse rate but a similar profile of adverse events. These data enabled the extension of the approval of Rituximab for maintenance of remission treatment of GPA and MPA in Germany in 2018. Guidelines and expert recommendations concerning measures of infection prevention and vaccination of immunosuppressed patients as well as the management of hypogammaglobulinemia and cytopenia on Rituximab are presented in this review.

Genome-wide association study of eosinophilic granulomatosis with polyangiitis reveals genomic loci stratified by ANCA status

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare inflammatory disease of unknown cause. 30% of patients have anti-neutrophil cytoplasmic antibodies (ANCA) specific for myeloperoxidase (MPO). Here, we describe a genome-wide association study in 676 EGPA cases and 6809 controls, that identifies 4 EGPA-associated loci through conventional case-control analysis, and 4 additional associations through a conditional false discovery rate approach. Many variants are also associated with asthma and six are associated with eosinophil count in the general population. Through Mendelian randomisation, we show that a primary tendency to eosinophilia contributes to EGPA susceptibility. Stratification by ANCA reveals that EGPA comprises two genetically and clinically distinct syndromes. MPO+ ANCA EGPA is an eosinophilic autoimmune disease sharing certain clinical features and an HLA-DQ association with MPO+ ANCA-associated vasculitis, while ANCA-negative EGPA may instead have a mucosal/barrier dysfunction origin. Four candidate genes are targets of therapies in development, supporting their exploration in EGPA.

[Actual Treatment Options for Giant Cell Arteritis]

To prevent serious complications such as permanent loss of vision and structural vascular damage, treatment must be initiated quickly in patients with giant-cell arteritis (GCA). So far, usually long-term corticosteroids in cumulative high dosages have been the standard therapy option. However, steroids are often insufficient to achieve adequate disease control and are associated with serious adverse events. Therefore, steroid-sparing therapy options are the focus of interest.