Dynamic Changes in the Nasal Microbiome Associated With Disease Activity in Patients With Granulomatosis With Polyangiitis.

OBJECTIVE: Little is known about temporal changes in nasal bacteria in granulomatosis with polyangiitis (GPA). This study was undertaken to examine longitudinal changes in the nasal microbiome in association with relapse in GPA patients. METHODS: Bacterial 16S ribosomal RNA gene sequencing was performed on nasal swabs from 19 patients with GPA who were followed up longitudinally for a total of 78 visits, including 9 patients who experienced a relapse and 10 patients who remained in remission. Relative abundance of bacteria and ratios between bacteria were examined. Generalized estimating equation models were used to evaluate the association between bacterial composition and 1) disease activity and 2) levels of antineutrophil cytoplasmic antibody (ANCA) with specificity for proteinase 3 (PR3), adjusted for medication. RESULTS: Corynebacterium and Staphylococcus were the most abundant bacterial genera across all nasal samples. Patients with quiescent disease maintained a stable ratio of Corynebacterium to Staphylococcus across visits. In contrast, in patients who experienced a relapse, a significantly lower ratio was observed at the visit prior to relapse, followed by a higher ratio at the time of relapse (adjusted P < 0.01). Species-level analysis identified an association between a higher abundance of nasal Corynebacterium tuberculostearicum and 1) relapse (adjusted P = 0.04) and 2) higher PR3-ANCA levels (adjusted P = 0.02). CONCLUSION: In GPA, significant changes occur in the nasal microbiome over time and are associated with disease activity. The occurrence of these changes months prior to the onset of relapse supports a pathogenic role of nasal bacteria in GPA. Our results uphold existing hypotheses implicating Staphylococcus as an instigator of disease and have generated a novel finding involving Corynebacterium as a potential mediator of disease in GPA.

Characterizing infection in anti-neutrophil cytoplasmic antibody-associated vasculitis: results from a longitudinal, matched-cohort data linkage study.

OBJECTIVES: Infection exerts a major burden in ANCA-associated vasculitis (AAV), however, its precise extent and nature remains unclear. In this national study we aimed to longitudinally quantify, characterize and contextualize infection risk in AAV. METHODS: We conducted a multicentre matched cohort study of AAV. Complementary data on infections were retrieved via data linkage with the population-based Scottish microbiological laboratory, hospitalization and primary care prescribing registries. RESULTS: A total of 379 AAV patients and 1859 controls were followed up for a median of 3.5 years (interquartile range 1.9-5.7). During follow-up, the proportions of AAV patients with at least one laboratory-confirmed infection, severe infection and primary care antibiotic prescription were 55.4%, 35.6% and 74.6%, respectively. The risk of infection was higher in AAV than in matched controls {laboratory-confirmed infections: incidence rate ratio [IRR] 7.3 [95% confidence interval (CI) 5.6, 9.6]; severe infections: IRR 4.4 [95% CI 3.3, 5.7]; antibiotic prescriptions: IRR 2.2 [95% CI 1.9, 2.6]}. Temporal trend analysis showed that AAV patients remained at a higher risk of infections throughout the follow-up period, especially year 1. Although the Escherichia genus was the most commonly identified pathogen (16.6% of AAV, 5.5% of controls; P < 0.0001), AAV patients had the highest risk for Herpes [IRR 12.5 (95% CI 3.7, 42.6)] and Candida [IRR 11.4 (95% CI 2.4, 55.4)]. CONCLUSION: AAV patients have up to seven times higher risk of infection than the general population and the overall risk remains significant after 8 years of follow-up. The testing of enhanced short- to medium-term prophylactic antibiotic regimes should be considered.

No evident association of nasal carriage of Staphylococcus aureus or its small-colony variants with cotrimoxazole use or ANCA-associated vasculitis relapses.

OBJECTIVE: To identify the role of Staphylococcus aureus (SA) or its intracellular small-colony variant phenotype (SCV) with co-trimoxazole (CTX) or ANCA-associated vasculitis (AAV) activity. METHODS: All consecutive AAV patients with granulomatosis with polyangiitis (GPA), eosinophilic GPA or microscopic polyangiitis, followed at the French National Vasculitis Referral Center (09/2012-05/2013), and hospitalized non-AAV controls, exclusively for SA/SCV carriage comparisons, were enrolled. All had bilateral anterior nasal swab cultures. Nasal SA or SCV carriage was determined and associations with relapse(s), BVAS, ANCA-positivity, anti-staphylococcal and immunosuppressant use, were analysed ⩾4 years post-inclusion. RESULTS: Nasal SA carriage rates did not differ among AAVs (P = 0.53): GPA (24/80; 30%), EGPA (7/28; 25%) and microscopic polyangiitis (3/11; 27.3%); and the rate was less frequent in controls than in GPA patients not taking CTX (P = 0.04). AAV patients taking CTX prophylaxis had less nasal SA carriage (8.7% vs 36.2%; P = 0.02). Nasal SA carriage or CTX use did not modify relapse rates, BVAS or ANCA-positivity at inclusion or during follow-up. Nasal SCV carriage, found in 15/207 (7.2%) patients, was similar for GPA (10/24; 41.7%), microscopic polyangiitis (2/7; 28.6%) and eosinophilic GPA (2/3; 66.7%), but higher (P = 0.02) than controls (1/14; 7.1%). SCV carriage by AAV groups did not modify relapse rates or ANCA positivity at inclusion or during follow-up; a trend towards higher BVAS was observed only for anti-PR3 ANCA patients. CONCLUSION: Nasal SA or SCV carriage was comparable among AAVs but more frequent than in controls. Nasal SA or SCV carriage and CTX use did not modify AAV relapse rates.

The composition and functional protein subsystems of the human nasal microbiome in granulomatosis with polyangiitis: a pilot study.

BACKGROUND: Ear, nose and throat involvement in granulomatosis with polyangiitis (GPA) is frequently the initial disease manifestation. Previous investigations have observed a higher prevalence of Staphylococcus aureus in patients with GPA, and chronic nasal carriage has been linked with an increased risk of disease relapse. In this cross-sectional study, we investigated changes in the nasal microbiota including a detailed analysis of Staphylococcus spp. by shotgun metagenomics in patients with active and inactive granulomatosis with polyangiitis (GPA). Shotgun metagenomic sequence data were also used to identify protein-encoding genes within the SEED database, and the abundance of proteins then correlated with the presence of bacterial species on an annotated heatmap. RESULTS: The presence of S. aureus in the nose as assessed by culture was more frequently detected in patients with active GPA (66.7%) compared with inactive GPA (34.1%). Beta diversity analysis of nasal microbiota by bacterial 16S rRNA profiling revealed a different composition between GPA patients and healthy controls (P = 0.039). Beta diversity analysis of shotgun metagenomic sequence data for Staphylococcus spp. revealed a different composition between active GPA patients and healthy controls and disease controls (P = 0.0007 and P = 0.0023, respectively), and between healthy controls and inactive GPA patients and household controls (P = 0.0168 and P = 0.0168, respectively). Patients with active GPA had a higher abundance of S. aureus, mirroring the culture data, while healthy controls had a higher abundance of S. epidermidis. Staphylococcus pseudintermedius, generally assumed to be a pathogen of cats and dogs, showed an abundance of 13% among the Staphylococcus spp. in our cohort. During long-term follow-up of patients with inactive GPA at baseline, a higher S. aureus abundance was not associated with an increased relapse risk. Functional analyses identified ten SEED protein subsystems that differed between the groups. Most significant associations were related to chorismate synthesis and involved in the vitamin B12 pathway. CONCLUSION: Our data revealed a distinct dysbiosis of the nasal microbiota in GPA patients compared with disease and healthy controls. Metagenomic sequencing demonstrated that this dysbiosis in active GPA patients is manifested by increased abundance of S. aureus and a depletion of S. epidermidis, further demonstrating the antagonist relationships between these species. SEED functional protein subsystem analysis identified an association between the unique bacterial nasal microbiota clusters seen mainly in GPA patients and an elevated abundance of genes associated with chorismate synthesis and vitamin B12 pathways. Further studies are required to further elucidate the relationship between the biosynthesis genes and the associated bacterial species.

Characterisation of the nasal microbiota in granulomatosis with polyangiitis.

OBJECTIVES: Prior studies have suggested a potential link between nasal microbes and granulomatosis with polyangiitis (GPA; Wegener's), but these studies relied on culture-dependent methods. This study comprehensively examined the entire community of nasal microbiota (bacteria and fungi) in participants with GPA compared with healthy controls using deep sequencing methods. METHODS: 16S rRNA and internal transcribed spacer gene sequencing were performed on nasal microbial DNA isolated from nasal swabs of 60 participants with GPA and 41 healthy controls. Alpha and beta diversity were assessed as well as the relative abundance of the most abundant bacterial and fungal taxa. The effects of covariates including disease activity and immunosuppressive therapies on microbial composition were evaluated. RESULTS: Compared with controls, participants with GPA had a significantly different microbial composition (weighted UniFrac p=0.04) and lower relative abundance of Propionibacterium acnes and Staphylococcus epidermidis (for both, false discovery rate-corrected p=0.02). Disease activity in GPA was associated with a lower abundance of fungal order Malasseziales compared with participants with GPA in remission (p=0.04) and controls (p=0.01). Use of non-glucocorticoid immunosuppressive therapy was associated with 'healthy' nasal microbiota while participants with GPA who were off immunosuppressive therapy had more dysbiosis (weighted UniFrac p=0.01). No difference in the relative abundance of Staphylococcus aureus was observed between GPA and controls. CONCLUSIONS: GPA is associated with an altered nasal microbial composition, at both the bacterial and fungal levels. Use of immunosuppressive therapies and disease remission are associated with healthy microbial communities.

The presence of staphylococcal superantigens in nasal swabs and correlation with activity of granulomatosis with polyangiitis in own material.

OBJECTIVES: Nasal carriage of Staphylococcus aureus and its superantigens (SAg) seem to be a risk factor disease exacerbation in granulomatosis with polyangiitis (GPA). We investigated the association between the presence of SAg in nasal swabs and activity of disease in GPA patients also taking into account correlation with an antimicrobial treatment. METHODS: In a prospective study of a total of 150 GPA patients hospitalised in the period 2009-2016, nasal swabs were examined for the presence of Staphylococcus aureus and SAg. Subsequently, the association with disease activity was assessed. RESULTS: Of 362 Staphylococcus aureus-positive nasal swab cultures from 115 of the 150 patients, the presence of at least one SAg in 126 samples (34.8%) from 56 patients (48.7%) was found. Among the 17 patients with limited to subglottic stenosis (SGS) disease, SAg were detected in 6 cases (35.3%). We did not find a significant correlation between the presence of SAg and disease activity (p=0.986), although when individual SAg were analysed separatively, SED and TSST-1 were more frequently present in active disease. Additionally, the results of the analysis demonstrated a protective effect of trimethoprim/sulfamethoxazole (T/S) treatment (0R 0.52, p<0.0092) in GPA patients. Interestingly, GPA limited to SGS appeared as an unfavourable factor associated with disease activity (0R 1.84, p=0.05). CONCLUSIONS: The association between staphylococcal SAg in nasal swabs and GPA activity is not evident. Multiple mechanisms that may lead to disease activation still need to be investigated.

Linked help from bacterial proteins drives autoantibody production in small vessel vasculitis.

The small vessel vasculitides granulomatosis with polyangiitis (GPA) and microscopic polyangiitis are associated with autoantibodies to neutrophil cytoplasm antigens (ANCA), principally proteinase-3 (PR3) and myeloperoxidase (MPO). There is an association between GPA and nasal carriage of Staphylococcus aureus. The recent finding that S. aureus produces proteins that bind tightly to and block the function of both PR3 and MPO suggests a mechanism for ANCA formation. The bacterial protein-autoantigen conjugate is recognised by B cells with ANCA specificity, internalised, and the bacterial protein processed and presented to T cells with specificity for bacterial peptides. The T cell can then provide help to the B cell, allowing class switching, affinity maturation and the production of pathogenic ANCA. This mechanism predicts that T cells with this specificity will be found in patients, and that the bacterial protein-autoantigen conjugate will be particularly efficient at eliciting ANCA production.

Genetic loci of Staphylococcus aureus associated with anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides.

The proteinase 3 (PR3)-positive anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) granulomatosis with polyangiitis (GPA) has been associated with chronic nasal S. aureus carriage, which is a risk factor for disease relapse. The present study was aimed at comparing the genetic make-up of S. aureus isolates from PR3-ANCA-positive GPA patients with that of isolates from patients suffering from myeloperoxidase (MPO)-ANCA-positive AAV, and isolates from healthy controls. Based on a DNA microarray-based approach, we show that not only PR3-ANCA-positive GPA patients, but also MPO-ANCA-positive AAV patients mainly carried S. aureus types that are prevalent in the general population. Nonetheless, our data suggests that MPO-ANCA-associated S. aureus isolates may be distinct from healthy control- and PR3-ANCA-associated isolates. Furthermore, several genetic loci of S. aureus are associated with either PR3-ANCA- or MPO-ANCA-positive AAV, indicating a possible role for pore-forming toxins, such as leukocidins, in PR3-ANCA-positive GPA. Contrary to previous studies, no association between AAV and superantigens was detected. Our findings also show that a lowered humoral immune response to S. aureus is common for PR3-ANCA- and MPO-ANCA-positive AAV. Altogether, our observations imply that the presence or absence of particular virulence genes of S. aureus isolates from AAV patients contributes to disease progression and/or relapse.

Chronic nasal Staphylococcus aureus carriage identifies a subset of newly diagnosed granulomatosis with polyangiitis patients with high relapse rate.

Objective: The aim of this study was to evaluate whether chronic nasal carriage of Staphylococcus aureus (SA) is related to relapses in patients with newly diagnosed ANCA-associated vasculitis (AAV). Methods: In two clinical trials (n = 200), for early systemic (n = 83) and generalized (n = 117) AAV, nasal swabs were obtained monthly and at the time of a relapse. Chronic nasal SA carriage (CNSAC) was defined as ⩾ 75% of cultures being SA positive, with non-carriers being SA negative in all cultures and remaining patients being intermittent carriers. Fifty-five of 200 (27.5%) patients received prophylactic trimethoprim/sulfamethoxazole (T/S) against Pneumocystis jirovecii . Results: Of the total AAV patients, 24/200 (12%) were chronic, 102/200 (51%) intermittent and 74/200 (37%) non-carriers. Of 65 relapsing patients, 10/24 (41.7%) were chronic, 32/102 (31.4%) intermittent and 23/74 (31.1%) non-carriers (P = 0.59). For all AAV patients, CNSAC was not associated with an increased relapse risk [odds ratio (OR) = 1.57, 95% CI: 0.66, 3.76; P = 0.31]. However, 23/24 chronic carriers had granulomatosis with polyangiitis (GPA). In the 73 patients with generalized GPA (hazard ratio = 4.10, 95% CI: 1.37, 12.25; P = 0.01) and the 78 patients with early systemic GPA during immunosuppression (hazard ratio = 2.73, 95% CI: 0.95, 7.87; P = 0.06), relapse rates were higher for chronic SA carriers. Prophylactic T/S was not associated with a reduced relapse risk (OR = 0.71, 95% CI: 0.36, 1.41; P = 0.33). Nevertheless, prophylactic T/S reduced CNSAC (OR = 0.19, 95% CI: 0.04, 0.91; P = 0.04). Conclusion: The frequency of CNSAC in newly diagnosed GPA paralleled that in the general population. This subset of GPA patients (23/151, 15.2%) has a high relapse rate despite immunosuppression and prophylactic T/S treatment, requiring further investigations on pathogenesis and therapy.

[Intraocular Inflammation: Autoimmune or Infectious?]. / Intraokulare Entzündung: autoimmun oder infektiös?

Presentation of 3 cases of intraocular inflammation: 1. 47-year old female patient with severe necrotising scleritis and uveitis with underlying granulomatous polyangiitis (formerly known as Wegener granulomatosis, in honour of the German pathologist Friedrich Wegener), known for 10 years. 2. 48-year old male patient with longstanding bilateral uveitis and granulomatous polyangiitis for 2 years. In the histopathological examination of the enucleation specimen, a retrolental tumour turned out to be a granuloma. 3. 57-year old male patient in status post renal transplantation with intraocular cellular infiltration suspicious for lymphoma, which surprisingly proved to be Toxoplasma gondii-associated uveitis. The clinical course and characteristic histological signs and therapeutic options are discussed.

Aberrant cytokine pattern of the nasal mucosa in granulomatosis with polyangiitis.

INTRODUCTION: In granulomatosis with polyangiitis (GPA), a complex autoimmune small-vessel vasculitis frequently associated with chronic necrotizing inflammation of the nasal mucosa, elevated nasal Staphylococcus (S.) aureus carrier rates are a risk factor for relapse. As cytokines are primarily involved in the regulation of defense against potentially pathogenic microorganisms, the aim of this study was to compare healthy individuals and GPA patients with respect to their baseline cytokine expression of nasal epithelial cells (NEC), which form the first barrier against such triggers. The ability of S. aureus to influence the nasal microenvironment's cytokine secretion was assessed by exemplary stimulation experiments. METHODS: Baseline expression of 19 cytokines of primary NEC of GPA patients and normal controls (NC) was quantified by a multiplex cytokine assay. Stimulation experiments were performed with supernatants of S. aureus and expression of interleukin-8 was determined by ELISA. RESULTS: In GPA, an altered pattern of baseline cytokine expression with significantly up-regulated G-CSF and reduced interleukin (IL)-8 concentrations was observed. Both NEC of GPA patients and NC responded to stimulation with S. aureus, but GPA patients displayed a significantly lower IL-8 secretion and a diminished dynamic range of response towards the stimulus. CONCLUSIONS: The data presented underline the hypothesis of a disturbed epithelial nasal barrier function in GPA. The dysregulated baseline expression of G-CSF and IL-8 and the reduced response to microbial stimulation may facilitate changes in the composition of the nasal flora and favour an imbalanced inflammatory response, which might be relevant for the disease course.

Antimicrobial peptides in nasal secretion and mucosa with respect to S. aureus colonisation in Wegener´s granulomatosis.

OBJECTIVES: Nasal S. aureus carrier rates are significantly higher in patients with Wegener's granulomatosis (WG) compared to healthy controls (HC), and nasal colonisation is a risk-factor for relapse. Antimicrobial peptides (AMP) are important defence molecules maintaining an intact barrier function. It is the aim of this study to see if there is a possible link between the nasal AMP pattern and S. aureus colonisation, a link which has not been investigated so far. METHODS: ELISA was applied to quantify LL-37 and hBD-3 concentrations in nasal secretions (14 WG patients, 13 HC) with and without nasal S. aureus colonisation. Immunohistochemistry was used to detect the cellular sources of AMP in the nasal mucosa. Functional analyses of primary nasal epithelial cell cultures (NEC) of these groups stimulated with S. aureus were performed. RESULTS: LL-37 was found in significantly higher concentrations in colonised individuals (WG: p=0.001; HC: p=0.014).Using immunohistochemistry, local cellular sources for AMP could be demonstrated. After stimulation with S. aureus, significantly higher concentrations of LL-37 and hBD-3 could be detected in the supernatant of NEC of WG patients (LL-37: p=0.001; hBD-3: p=0.001) and HC (LL-37: p=0.019; hBD-3: p=0.001). HBD-3 concentrations were significantly lower in the supernatant of stimulated NEC of WG patients compared to the NEC of HC (p=0.032), and the dynamic range of the hBD-3 answer was significantly smaller in WG compared to HC (p=0.016). CONCLUSIONS: The dynamic response towards challenges with microbes is dysregulated in WG, and this might be one reason for higher S. aureus colonisation rates in WG.

Bacterial infections in Wegener's granulomatosis: mechanisms potentially involved in autoimmune pathogenesis.

PURPOSE OF REVIEW: Wegener's granulomatosis is associated with bacterial infection, in particular nasal carriage of Staphylococcus aureus. Infection may play a role in the induction of autoimmunity as well as in the effector phase of the disease. Here, the current hypotheses aiming to explain the link between infections and Wegener's granulomatosis immunopathogenesis are reviewed and discussed. RECENT FINDINGS: In recent years, studies suggested that molecular mimicry could play a role in antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV), either via direct mimicry between human lysosome-associated membrane protein-2 and bacterial FimH or indirectly via the development of antibodies against a peptide complementary to proteinase 3 (cPr3). More recent work has focused on Toll-like receptors (TLRs), a family of receptors specialized in the recognition of pathogen-associated molecular patterns. In animal models, it has been shown that TLR ligands can aggravate anti-MPO antibody-mediated disease. Furthermore, it was shown that a TLR9 ligand can trigger the production of ANCA in vitro by peripheral blood-derived B lymphocytes from AAV patients. The newly described process of ANCA-mediated neutrophil extracellular trap formation may provide an endogenous TLR9 ligand. Finally, TLR2 signaling is involved in the development of a Th17-driven immune response, consistent with skewing towards a Th17 T cell phenotype that has been observed in Wegener's granulomatosis. SUMMARY: Although Wegener's granulomatosis pathophysiology is becoming better understood, the specific events leading to autoimmunity are not clear. Recent studies show that several mechanisms may be involved in linking infection to autoimmunity. Molecular mimicry may be involved, and a role for TLR signaling is suggested.

What is the evidence for prophylactic antibiotic treatment in patients with systemic vasculitides?

PURPOSE OF REVIEW: Microbial factors are supposed to play an inducing and/or reactivating role in many of the idiopathic systemic vasculitides. This review evaluates the evidence that microbes are involved in the etiopathogenesis of the disease focusing on possibilities for antimicrobial intervention. RECENT FINDINGS: The clinical presentation of hepatitis B virus (HBV)-associated polyarteritis nodosa (PAN) is different from that of non-HBV-PAN and requires antiviral treatment. In hepatitic C virus (HCV)-associated autoimmune diseases, type 2 cryoglobulinemia is present in 52% of cases. Chronic nasal carriage of Staphylococcus aureus is related to endonasal activity of Wegener's granulomatosis and recurrent relapses, and prophylactic treatment with co-trimoxazole is effective in reducing relapse rate. SUMMARY: Patients with PAN should be tested for HBV, and patients with type 2 cryoglobulinemia for HCV. When tested positive, antiviral treatment should be considered. Patients with Wegener's granulomatosis should be tested for nasal carriage of S. aureus, and prophylactic treatment with co-trimoxazole should be considered in case of persistent endonasal activity of Wegener's granulomatosis together with S. aureus carriage. The efficacy of S. aureus elimination for preventing relapses of Wegener's granulomatosis should be evaluated.

Nasal carriage of Staphylococcus aureus and endonasal activity in Wegener s granulomatosis as compared to rheumatoid arthritis and chronic Rhinosinusitis with nasal polyps.

OBJECTIVES: Nasal colonisation with Staphylococcus aureus (S. aureus) has been implicated in Wegener's granulomatosis (WG) disease activity. In this study, the frequency of nasal colonisation with S. aureus in WG was compared to healthy and disease control groups for the first time. Moreover, endonasal activity was correlated to colonisation. PATIENTS AND METHODS: Nasal carriage of S. aureus of a well-defined group of 89 patients with WG was compared to 40 patients with chronic rhinosinusitis with nasal polyps (CRS), 35 patients with rheumatoid arthritis (RA), 50 hospital staff members and 25 subjects without regular hospital contact and correlation analysis of nasal carriage and endonasal activity of WG was performed. RESULTS: WG patients showed significantly higher rates (72%) of nasal colonisation with S. aureus compared to CRS patients (28%) and healthy subjects without regular hospital contact (25%, 95%-CI), but not to RA patients (46%) and hospital staff members (58%). WG patients with nasal carriage of S. aureus had significantly higher endoscopically proven endonasal activity (p=0.01), significantly more often first manifestation of WG in the upper respiratory tract (p=0.02) and higher relapse-rates (p=0.052) than WG patients without such carriage. CONCLUSIONS: Endonasal activity in WG is associated with higher nasal S. aureus colonisation rates and subsequent higher relapse rates. The higher frequency of S. aureus colonisation could be a consequence of a recently shown mucosal barrier defect in WG and facilitate chronic inflammation and granuloma formation in the upper respiratory tract.