Severe impaired respiratory ciliary function in Wegener granulomatosis

Upper Respiratory Microbiome in Vasculitis

The pathogenesis of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), such as granulomatosis with polyangiitis, is not well understood. These diseases cause significant inflammation in the upper airway. The nares and upper airway are host to many commensal microbes as well as a frequent site of exposure to pathogenic microbes. This review explores the association between upper airway microbial dysregulation and AAV. The role of Staphylococcus aureus colonization as a possible driver of disease is discussed, as well as recent work exploring how fluctuations in the abundance and diversity of commensal microbes are related to vasculitis and risk of flare.

Patient-Reported Sinonasal Symptoms and Risk of Relapse in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

OBJECTIVE

Relapses are frequent and difficult to predict in antineutrophil cytoplasmic antibody-associated vasculitis (AAV), resulting in long-term use of immunosuppression. Although sinonasal disease is associated with relapse of AAV, detailed characterization of sinonasal symptoms is lacking. Using a patient-reported outcome, the 22-item SinoNasal Outcome Test (SNOT-22), we investigated the relationship between sinonasal symptoms and disease activity in AAV.

METHODS

This was a prospective, longitudinal study of individual with AAV and healthy individuals. Relapse was defined as a Birmingham Vasculitis Activity Score for Wegner's Granulomatosis score >0. Higher SNOT-22 scores indicate worse symptoms. Generalized estimating equation and Cox proportional hazard models evaluated the association between SNOT-22 and relapse.

RESULTS

There were 773 visits (106 active disease visits) from 168 patients with AAV and 51 controls. Median SNOT-22 at remission was higher in AAV versus controls (20 vs 5; P < 0.001) and higher during active disease versus remission (P < 0.001). In all AAV, and particularly within granulomatosis with polyangiitis, higher SNOT-22 scores were observed months to years before relapse and were associated with increased risk of relapse (hazard ratio 2.7, 95% confidence interval 1.2-6.2; P = 0.02). Similar findings were seen when examining patients with versus without sinonasal disease and after removing relapses limited to the ear, nose, and throat.

CONCLUSION

A patient-reported outcome measure of sinonasal disease, the SNOT-22, not only changes with disease activity in AAV, but also is associated with a higher risk of relapse within two years. These findings support the possibility that the SNOT-22 score may enhance prediction of relapse and that persistent sinonasal disease may be important in the pathophysiology of relapse.

The Nasal Microbiome in ANCA-Associated Vasculitis: Picking the Nose for Clues on Disease Pathogenesis

PURPOSE OF REVIEW

The onset and progression of small vessel vasculitis associated with anti-neutrophil cytoplasmic antibodies has been linked to microbial infections. Here, we provide a brief overview of the association of nasal colonization of Staphylococcus aureus with ANCA-associated vasculitis (AAV) and discuss several recent studies mapping the nasal microbiome in AAV patients in particular.

RECENT FINDINGS

Nasal microbiome studies revealed dysbiosis as a common trait in active AAV which tends to normalize upon immunosuppressive treatment and quiescent disease. However, due to differences in study design, patient selection, and methodology, the reported microbiome profiles differ considerably precluding conclusions on causal relationships. The microbiome is an emerging area of research in AAV warranting further investigation. Ideally, such studies should be combined with mechanistic studies to unravel key elements related to host-microbe interactions and their relevance for AAV pathogenesis.

BXSB/MpJ-Yaa mouse model of systemic autoimmune disease shows increased apoptotic germ cells in stage XII of the seminiferous epithelial cycle

In mammals, the reproductive system and autoimmunity regulate mutual functions. Importantly, systemic autoimmune diseases are thought to cause male infertility but the underlying pathological mechanism remains unclear. In this study, the morpho-function of the testes in BXSB/MpJ-Yaa mice was analyzed as a representative mouse model for systemic autoimmune diseases to investigate the effect of excessive autoimmunity on spermatogenesis. At 12 and 24 weeks of age, BXSB/MpJ-Yaa mice showed splenomegaly and increased levels of serum autoantibodies, whereas no controls showed a similar autoimmune condition. In histological analysis, the enlarged lumen of the seminiferous tubules accompanied with scarce spermatozoa in the epididymal ducts were observed in some of the BXSB/MpJ-Yaa and BXSB/MpJ mice but not in C57BL/6N mice. Histoplanimetrical analysis revealed significantly increased residual bodies and apoptotic germ cells in the seminiferous tubules in BXSB/MpJ-Yaa testes without apparent inflammation. Notably, in stage XII of the seminiferous epithelial cycles, the apoptotic germ cell number was remarkably increased, showing a significant correlation with the indices of systemic autoimmune disease in BXSB/MpJ-Yaa mice. Furthermore, the Sertoli cell number was reduced at the early disease stage, which likely caused subsequent morphological changes in BXSB/MpJ-Yaa testes. Thus, our histological study revealed the altered morphologies of BXSB/MpJ-Yaa testes, which were not observed in controls and statistical analysis suggested the effects of an autoimmune condition on this phenotype, particularly the apoptosis of meiotic germ cells. BXSB/MpJ-Yaa mice were shown to be an efficient model to study the relationship between systemic autoimmune disease and the local reproductive system.

Changes in the composition of the upper respiratory tract microbial community in granulomatosis with polyangiitis

Dysbiosis¸ i.e. changes in microbial composition at a mucosal interface, is implicated in the pathogenesis of many chronic inflammatory and autoimmune diseases. To assess the composition of the microbial upper respiratory tract (URT) community in patients with granulomatosis with polyangiitis (GPA), we used culture-independent high-throughput methods. In this prospective clinical study, nasal swabs were collected from patients with GPA, patients with rheumatoid arthritis (RA, disease control), and healthy controls. Nasal bacterial taxa were assessed using V3-V4 region 16S rRNA amplicon sequencing. Staphylococcus aureus, Haemophilus influenza, and entero- and rhinoviruses were detected using qPCR. Unbiased metagenomic RNA sequencing (UMERS) was performed in a subset of samples to determine the relative abundance of bacterial, fungal, and viral species. A trend toward reduced microbiome diversity was detected in GPA samples compared with healthy controls. The abundance of bacterial taxa and microbial richness were significantly decreased in GPA samples compared with RA samples. The relative abundance of bacterial families shifted, with increased Planococcaceae and decreased Moraxellaceae, Tissierellaceae, Staphylococcaceae, and Propionibacteriaceae in GPA and RA. Further, decreased abundance of Corynebacteriaceae, and Aerococcaceae was observed in GPA samples. Significantly more colonization of S. aureus was seen in the nasal microbiome of GPA compared with RA and healthy control samples. H. influenzae colonization was also observed in GPA samples. UMERS detected the presence of rhinoviral sequences in some GPA samples. Thus, our study uncovered changes in the URT microbial composition in patients with GPA and RA, suggesting that both immunosuppression and disease background affect the URT microbiome. Complex alterations of host-microbiome interactions in the URT could influence chronic endonasal inflammation in GPA.

Pathogenetic and Clinical Aspects of Anti-Neutrophil Cytoplasmic Autoantibody-Associated Vasculitides

Anti-neutrophil cytoplasmic autoantibodies (ANCA) targeting proteinase 3 (PR3) and myeloperoxidase expressed by innate immune cells (neutrophils and monocytes) are salient diagnostic and pathogenic features of small vessel vasculitis, comprising granulomatosis with polyangiitis (GPA), microscopic polyangiitis, and eosinophilic GPA. Genetic studies suggest that ANCA-associated vasculitides (AAV) constitute separate diseases, which share common immunological and pathological features, but are otherwise heterogeneous. The successful therapeutic use of anti-CD20 antibodies emphasizes the prominent role of ANCA and possibly other autoantibodies in the pathogenesis of AAV. However, to elucidate causal effects in AAV, a better understanding of the complex interplay leading to the emergence of B lymphocytes that produce pathogenic ANCA remains a challenge. Different scenarios seem possible; e.g., the break of tolerance induced by a shift from non-pathogenic toward pathogenic autoantigen epitopes in inflamed tissue. This review gives a brief overview on current knowledge about genetic and epigenetic factors, barrier dysfunction and chronic non-resolving inflammation, necro-inflammatory auto-amplification of cellular death and inflammation, altered autoantigen presentation, alternative complement pathway activation, alterations within peripheral and inflamed tissue-residing T- and B-cell populations, ectopic lymphoid tissue neoformation, the characterization of PR3-specific T-cells, properties of ANCA, links between autoimmune disease and infection-triggered pathology, and animal models in AAV.

Bronchiectasis is highly prevalent in anti-MPO ANCA-associated vasculitis and is associated with a distinct disease presentation

OBJECTIVES

To assess the prevalence of bronchiectasis in a Western cohort with ANCA-positive granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) and its correlations with disease presentation and outcome.

METHODS

Retrospective study of ANCA-associated vasculitis (AAV) patients followed at Nantes University Hospital (2005-2015). Clinical, biological, and follow-up data were collected through chart review. Two experienced radiologists blinded to the clinical data interpreted chest high-resolution CTs according to the Feischner Society criteria.

RESULTS

Fifty-eight patients were included: 30 had MPA (51.7%) and 28 had GPA (48.3%). The median age at AAV diagnosis was 65.5 years. Anti-MPO-ANCA and anti-PR3-ANCA were present in 39 (67.2%) and 19 (32.8%) patients, respectively. Overall, bronchiectasis was found in 22 patients (37.9%), all of whom had anti-MPO ANCA. In multivariate analysis, bronchiectasis was independently associated with anti-MPO-ANCA, female gender and age at AAV diagnosis. Furthermore, anti-MPO ANCA patients with bronchiectasis had more frequent peripheral nerve involvement (54.5 vs. 17.6%, p = 0.019) and less frequent renal involvement than those without bronchiectasis (40.9% vs. 82.3%, p = 0.009). Disease course, survival and risk of severe pulmonary infection were similar in patients with and without bronchiectasis on chest CT.

CONCLUSIONS

This study shows that bronchiectasis is a highly prevalent pre-existing respiratory condition in Caucasian patients with anti-MPO AAV. This subset of patients exhibits a distinct presentation. Further studies are needed to confirm these findings and clarify the clinical implications of this association. Whether the respiratory tract could be the site of initiation of anti-MPO auto-immunity remains to be investigated.

Motile cilia defects in diseases other than primary ciliary dyskinesia: The contemporary diagnostic and research role for transmission electron microscopy

Ultrastructural studies have underpinned the cell biological and clinical investigations of the varied roles of motile cilia in health and disease, with a long history since the 1950s. Recent developments from transmission electron microscopy (TEM; cryo-electron microscopy, electron tomography) have yielded higher resolution and fresh insights into the structure and function of these complex organelles. Microscopy in ciliated organisms, disease models, and in patients with ciliopathy diseases has dramatically expanded our understanding of the ubiquity, multisystem involvement, and importance of cilia in normal human development. Here, we review the importance of motile cilia ultrastructural studies in understanding the basis of diseases other than primary ciliary dyskinesia.

Orphan diseases of the nose and paranasal sinuses: Pathogenesis - clinic - therapy

Rare rhinological diseases are a diagnostic challenge. Sometimes it takes months or even years from the primary manifestation of the disease until the definitive diagnosis is establibshed. During these times the disease proceeds in an uncontrolled or insufficiently treated way. (Irreversible) damage results and sometimes life-threatening situations occur. The unexpected course of a (misdiagnosed) disease should lead to further diagnostic reflections and steps in order to detect also rare diseases as early as possible. The present paper discusses granulomatous diseases of the nose and paranasal sinuses caused by mycobacteria, treponema, Klebsiella, fungi, and protozoa as well as vasculitis, sarcoidosis, rosacea, cocaine-induced midline destruction, nasal extranodal NK/T cell lymphoma, and cholesterol granuloma. Furthermore, diseases with disorders of the mucociliary clearance such as primary ciliary dyskinesia and cystic fibrosis are presented, taking into consideration the current literature.

Vδ2 T cell deficiency in granulomatosis with polyangiitis (Wegener's granulomatosis)

Previous studies have characterized phenotypic and functional alterations within T-cell receptor αβ-expressing T cells in patients with granulomatosis with polyangiitis (GPA). We analyzed the frequency, subset composition and in vitro activation of blood γδ T cells in GPA patients. We observed a significant reduction of γδ T cell numbers, due to the selective depletion of the Vδ2 subset which remained consistent over time upon repeated analysis. The loss of Vδ2 T cells was not due to migration into the inflamed lesions as very few γδ T cells were detected in inflammatory infiltrates. The memory subset distribution did not differ among Vδ2 T cells from healthy donors and GPA patients. Importantly, the remaining Vδ2 T cells were capable of responding to phosphoantigen stimulation in vitro. The marked depletion of blood Vδ2 T cells in GPA suggests cellular exhaustion, possibly due to chronic exposure to and continuous overstimulation by microbial phosphoantigens.

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.

Cartilage destruction in granulomatosis with polyangiitis (Wegener's granulomatosis) is mediated by human fibroblasts after transplantation into immunodeficient mice

A key feature of granulomatosis with polyangiitis (GPA; or Wegener's granulomatosis) is the granulomatous inflammation of the upper respiratory tract, which leads to the subsequent destruction of adjacent tissues. The aim of our work was to study the histopathological and cellular components of tissue destruction of human GPA tissue transplanted into immunodeficient mice. Biopsy specimens from patients with active GPA (n = 10) or sinusitis (controls, n = 6) were s.c. co-implanted with healthy allogeneic human nasal cartilage into immunodeficient pfp/rag2(-/-) mice. Transplants were examined for their destructive capability of the allografted human cartilage. In addition, nasal fibroblasts from patients with GPA (n = 8) and control healthy nasal fibroblasts (n = 5) were cultured, and cell proliferation and apoptosis were quantified. mRNA and protein levels of matrix metalloproteinases and cytokines were evaluated at baseline and after proinflammatory stimulation. GPA implants showed massive destruction of the co-implanted human cartilage, whereas cartilage destruction was only marginal in control samples. Destruction was mediated by human fibroblasts and could be inhibited by corticoid treatment. The up-regulated production of matrix metalloproteinases 1, 3, and 13 and cytokines IL-6 and IL-8 was found in vivo and in vitro. Although proliferation of isolated fibroblasts was comparable between GPA and controls, GPA samples showed a significant delay of apoptosis. The destruction of nasal cartilage in GPA is mainly mediated by fibroblasts that can be blocked by corticosteroids, and this tissue destruction is not dependent on the influx of leukocytes.

Molecular signatures of a disturbed nasal barrier function in the primary tissue of Wegener's granulomatosis

Wegener's granulomatosis (WG) is a complex autoimmune disease of unknown etiology, frequently involving localized inflammation of the nasal mucosa as an early manifestation. The current hypothesis suggests that the disease is triggered by a disturbed interaction between genetic and environmental effects, such as an altered microflora at mucosal layers. In this study, a systematic assessment of 49 transcripts with potential pathophysiological relevance was performed using quantitative real-time PCR in nasal mucosa samples of more than 80 individuals, including normal control (NC) individuals and disease controls. In addition, colonization with Staphylococcus aureus was quantified in the same individuals to assess its impact on transcriptomic signatures. Transcription profiles show an increased heterogeneity in diseased individuals. In all, 10 transcripts were identified to be differentially expressed (P≤0.05, false discovery rate ≤0.05) between patients with WG and NC individuals. These transcripts include antimicrobial peptides (human β-defensin (DEFB)1: fold-change WG vs. controls: +4.45, lysozyme: -3.4, DEFB4 and S100A7 (S100 calcium-binding protein A7): both "switched on" in WG), innate immune receptors (Toll-like receptor 4: -2.1, NOD-like receptor C3: -2.1, scavenger receptor CD36: +2.9), and cytokines (interferon-γ: -14, transforming growth factor-β 1: -1.4, interleukin-17D: -2.7). These transcriptional profiles are independent of S. aureus colonization. This study for the first time describes that, on the basis of data obtained from the primary nasal tissue, WG exhibits molecular features that allow its differentiation from other inflammatory disorders with involvement of the nasal mucosa. Further studies based on these findings may enable the identification of subphenotypes, which are currently discussed as an important target for a personalized medicine approach, aiming to reduce side effects and the number of therapy non-responders.

Clinical and immunological features of drug-induced and infection-induced proteinase 3-antineutrophil cytoplasmic antibodies and myeloperoxidase-antineutrophil cytoplasmic antibodies and vasculitis

PURPOSE OF REVIEW

Drugs and infections may induce antineutrophil cytoplasmic antibodies (ANCA) and vasculitic manifestations mimicking ANCA-associated vasculitides (AAV) and mechanisms relevant in their pathogenesis. This review summarizes the most recent findings in this field.

RECENT FINDINGS

Drug-induced and infection-induced proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA may be associated with a vasculitis clinically resembling AAV. Mechanisms relevant for the break of tolerance and induction of ANCA (e.g. danger signals, superantigens, neutrophil extracellular traps, protease-activated receptor-2, IL-17 cells) may be shared to some extent between drug-induced and infection-induced ANCA-positive vasculitis and AAV, especially with regard to the potential role of infection in Wegener's granulomatosis. Differences in immunopathology, clinical presentation, and functional aspects of ANCA help to distinguish drug-induced and infection-induced ANCA-positive vasculitis from AAV, and present new avenues for future research in this field.

SUMMARY

Medications and infections, which induce PR3-ANCA and MPO-ANCA, have to be considered in the differential diagnosis of primary AAV. Moreover, there is clinical and experimental evidence for an association between certain drugs and infections with ANCA-production. Analysis of ANCA-induction in such conditions also sheds new light on our understanding of immune mechanisms relevant in the break of tolerance and ANCA-production in AAV.

Value of anti-infective chemoprophylaxis in primary systemic vasculitis: what is the evidence?

Although infections are a major concern in patients with primary systemic vasculitis, actual knowledge about risk factors and evidence concerning the use of anti-infective prophylaxis from clinical trials are scarce. The use of high dose glucocorticoids and cyclophosphamide pose a definite risk for infections. Bacterial infections are among the most frequent causes of death, with Staphylococcus aureus being the most common isolate. Concerning viral infections, cytomegalovirus and varicella-zoster virus reactivation represent the most frequent complications. The only prophylactic measure that is widely accepted is trimethoprim/sulfamethoxazole to avoid Pneumocystis jiroveci pneumonia in small vessel vasculitis patients with generalised disease receiving therapy for induction of remission.

Granuloma formation in ANCA-associated vasculitides

Granuloma formation is a key pathologic finding in two of the anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides: Wegener's granulomatosis (WG) and Churg-Strauss syndrome (CSS). So far, no animal models have been established convincingly reproducing both vasculitic and granulomatous features typical of WG and CSS. In biopsies, granulomatous lesions are found both at distant extravascular sites and in the vicinity of inflamed vessels, e.g. in the lung. Intriguingly, WG-granulomata appear to display features of tertiary lymphoid tissue. Cartilaginous and osseous destruction is caused by granulomatous inflammation invading adjacent tissues. Rhinosinusitis is regularly encountered in WG and CSS. Septal perforation, saddle nose deformity, middle and inner ear symptoms, and granulomatous invasion of the palate, orbita, meninges, or the pituitary gland may complicate WG. Both common (e.g. FCGR3B copy number) and distinct (e.g. HLA-DP, IL-10.2) genetic factors have been identified in AAV potentially favouring inflammation and autoimmunity. The HLA-DPB1/RING1/RXRB region constitutes a quantitative trait locus for ANCA-positive WG with the strongest association to be reported up to now. A profound alteration of the T-cell response including Th1 and Th17 responses, anomalously NK-receptor-expressing 'NK-like' T cells, and dysfunctional regulatory T cells could facilitate and sustain granuloma formation and autoimmunity.

[Infectious pulmonary complications of rheumatic diseases]

Infectious complications are a central problem in the treatment of patients with rheumatic diseases. The increased infection rate is mainly caused by immunosuppressive medication, particularly glucocorticoids. A more aggressive diagnostic approach, often including bronchoscopic procedures, is often necessary to obtain samples for microbiological examinations. In immuno-compromised patients the failure of a calculated empiric antibiotic therapy is associated with a higher risk of fatal outcome. Among possible opportunistic infections Pneumocystis jirovecii pneumonia (PCP), invasive aspergillosis and CMV reactivations are most relevant. Furthermore, particularly with the use of TNF-blocking agents, reactivation of latent tuberculosis (TB) might be observed. There are only a few situations in which anti-infective chemo-prophylaxis is established: In the case of latent TB INH-prophylaxis should be given when anti-TNF-therapy is considered. There is evidence in favour of PCP prophylaxis with trimethoprim/cotrimoxazole in patients receiving intense immunosuppression with high dose glucocorticoids and cyclophosphamide.

[New pathogenetic aspects in primary systemic vasculitides]

Primary systemic vasculitides are defined according immunopathological features and the size of the involved vessels. Three anti-neutrophil cytoplasmic autoantibody (ANCA) associated small vessel vasculitides (Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis) can be distinguished from the so-called Non-ANCA-associated vasculitides, i.e. granulomatous vasculitides of large vessels (giant cell arteritis, Takayasu arteritis) and immune complex-mediated vasculitides of medium-sized and small vessels (Polyarteriitis nodosa, Kawasaki disease and Henoch-Schönlein purpura, cryoglobulinemic vasculitis, cutaneous leukocytoklastische angiitis). Predisposing genetic and other endogenous and exogenous factors facilitate the activation of innate immunity and induce persisting inflammatory reactions resulting in different forms of (auto)-immune vasculitides.