Aberrant cytokine pattern of the nasal mucosa in granulomatosis with polyangiitis

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.

Translational implications of humoral and cellular immune dysfunction in granulomatosis with polyangiitis

Granulomatosis with polyangiitis (GPA) is a rare systemic ANCA (Anti-neutrophil cytoplasmic antibodies) associated vasculitis (AAV). In the last couple of decades, GPA has emerged as a disease of concern due to rapid increase in the prevalence and incidence especially in developing countries. Unknown aetiology and rapid progression have made GPA a critical disease. Thus, establishing specific tools to facilitate early and faster disease diagnosis and efficient disease management has immense importance. GPA may develop in genetically predisposed individuals on receiving the external stimulus (i.e. microbial pathogen, pollutant etc.) that triggers the immune response. B-cell activating factor (BAFF) produced by the neutrophils, promotes the B-cell maturation and survival which leads to increased ANCA production. Abnormal B-cell and T-cell proliferation and their cytokine response plays a major role in disease pathogenesis and granuloma formation. ANCA interacts with neutrophils and induces the neutrophil extracellular traps (NETs) formation and reactive oxygen species (ROS) production which leads to the endothelial cell injury. This review article summarizes the critical pathological events and how cytokines and immune cells shape the GPA pathogenesis. Decoding this complex network would facilitate in developing tools for diagnosis, prognosis and disease management. Recently developed specific monoclonal antibodies (MAbs) targeting cytokines and immune cells are being used for safer treatment and achieving longer remission.

The role of trimethoprim/sulfametoxazole in reducing relapses and risk of infections in ANCA-associated vasculitis: a meta-analysis

OBJECTIVES

To assess available evidence from randomized controlled trials (RCTs) and observational studies including a control group regarding the role of trimethoprim/sulfametoxazole (TMP/SMX) in reducing the relapse rate in patients with granulomatosis with polyangiitis (GPA) and the risk of infections in patients with ANCA-associated vasculitis (AAV).

METHODS

MEDLINE, EMBASE, The Cochrane Library databases, Scopus, Web of Science and ClinicalTrials.gov were searched from inception until 15 January 2020 to identify controlled studies assessing the role of TMP/SMX in reducing the rate of relapse in patients with GPA (primary outcome) and the number and/or severity of infections in patients with AAV (secondary outcome). Two reviewers independently selected eligible studies and extracted data. Cumulative risk ratios (RRs) with 95% CI were calculated using a random effect meta-analysis.

RESULTS

Eight studies were selected out of 2907 records. Seven studies (520 patients) (of which two were RCTs) assessed the role of TMP/SMX in the relapse rate in patients with GPA. TMP/SMX was not associated with a reduced risk of relapse (RR = 1.15, 95% CI: 0.51, 2.55; I2 = 78.5%; P < 0.001). Sensitivity analysis according to the dose of TMP/SMX (960 mg twice daily vs three times/week) confirmed the results. One retrospective cohort study (192 patients) was identified demonstrating a significant reduction of severe infections in patients with AAV receiving prophylaxis with TMP/SMX in association with rituximab.

CONCLUSION

TMP/SMX was not associated with a reduced risk of relapse in patients with GPA. TMP/SMX might be useful in the reduction of infectious complications.

PROSPERO DATABASE REGISTRATION CODE

CRD42019118983.

Wegener's granulomatosis and differential diagnosis of mucosal leishmaniasis

Granulomatosis with polyangiitis with nasal septal perforation can be confused with infectious diseases such as mucosal leishmaniasis, so these cases warrant an in-depth study in order to provide the correct treatment. Among the main characteristics to consider to define a Wegener's granulomatosis as opposed to an infectious disease are vasculitis, lymphadenopathy, and sinusopathy.

Genetic diversity of Staphylococcus aureus influences disease phenotype of systemic lupus erythematosus

OBJECTIVE

We investigated the genetic diversity, molecular epidemiology and evolutionary dynamics of Staphylococcus aureus (SA) isolated from SLE patients by means of phylogenetic analysis.

METHODS

Consecutive SLE patients (ACR 1997 criteria) were enrolled: clinical/laboratory data were collected and nasal swab for SA identification was performed. On the basis of the translation elongation factor (tuf) gene, a phylogenetic analysis was performed to investigate relationships and to assess significant clades. Selective pressure analysis was used to investigate the evolution of the SA tuf gene. The gene sequences from non-SLE individuals, downloaded from the GenBank database, were compared through phylogenetic analysis with the tuf gene from SLE patients.

RESULTS

We enrolled 118 patients [M/F 10/108; median (interquartile range (IQR)) age 45.5 (13.2) years; median (IQR) disease duration 120 (144) months]. Twenty-four patients (20.3%) were SA carriers (SA+), three of them MRSA. SA+ SLE showed significantly higher SLEDAI-2k values [SA+: median (IQR) 2 (3.75); SA-: 0 (2); P = 0.04]. The phylogenetic analysis, restricted to 21 non-MRSA SA+, revealed a statistically supported larger clade (A, n = 17) and a smaller one (B, n = 4). Patients located in clade A showed a significantly higher prevalence of joint involvement (88.2%) in comparison with clade B (50.0%, P < 0.0001) and SA- (62.7%, P < 0.0001). Haematological manifestations were significantly more frequent in clade A (64.7%) compared with B (50.0%, P = 0.004).

CONCLUSION

We suggest a possible role of SA nasal carriage status in SLE disease activity. Moreover, our findings support the hypothesis that bacterial genetic variants may be associated with specific disease features.

Nasal microbiome research in ANCA-associated vasculitis: Strengths, limitations, and future directions

The human nasal microbiome is characterized by biodiversity and undergoes changes during the span of life. In granulomatosis with polyangiitis (GPA), the persistent nasal colonization by Staphylococcus aureus (S. aureus) assessed by culture-based detection methods has been associated with increased relapse frequency. Different research groups have characterized the nasal microbiome in patients with GPA and found that patients have a distinct nasal microbiome compared to controls, but the reported results between studies differed. In order to increase comparability, there is a need to standardize patient selection, sample preparation, and analytical methodology; particularly as low biomass samples like those obtained by nasal swabbing are impacted by reagent contamination. Optimization in obtaining a sample and processing with the inclusion of critical controls is needed for consistent comparative studies. Ongoing studies will analyze the nasal microbiome in GPA in a longitudinal way and the results will inform whether or not targeted antimicrobial management in a clinical trial should be pursued or not. This review focuses on the proposed role of S. aureus in GPA, the (healthy) nasal microbiome, findings in the first pilot studies in GPA, and will discuss future strategies.

The microbiome in autoimmune rheumatic disease

Microbial contributions to the immunopathogenesis of autoimmune rheumatic diseases have been studied since the advent of germ theory in the 19th century. With the exception of Group A Streptococcus in rheumatic fever, early studies failed to establish causal relationships between specific pathobionts and rheumatic disease. Today, systemic autoimmune diseases are thought to result from a complex interplay of environmental factors, individual genetic risk, and stochastic events. Interactions of microbiota and the immune system have been shown to promote and sustain chronic inflammation and autoimmunity. In mechanistic studies, microbe-immune cell interactions have been implicated in the initiation of autoimmune rheumatic diseases, e.g., through the posttranslational modification of autoantigens in rheumatoid arthritis or through neutrophil cell death and cross-reactivity with commensal orthologs in systemic lupus erythematosus. In parallel, modern molecular techniques have catalyzed the study of the microbiome in systemic autoimmune diseases. Here, I review current insights gained into the skin, oral, gut, lung, and vascular microbiome in connective tissue diseases and vasculitis. Mechanism relevant to the development and propagation of autoimmunity will be discussed whenever explored. While studies on autoimmune rheumatic disease have almost invariably shown abnormal microbiome structure (dysbiosis), substantial variability in microbial composition between studies makes generalization difficult. Moreover, an etiopathogenic role of specific pathobionts cannot be inferred by association alone. Integrating descriptive studies of microbial communities with hypothesis-driven research informed by immunopathogenesis will be important in elucidating targetable mechanisms in preclinical and established rheumatic disease.

Staphylococcus aureus Nasal Carriage and Autoimmune Diseases: From Pathogenic Mechanisms to Disease Susceptibility and Phenotype

The role of infective agents in autoimmune diseases (ADs) development has been historically investigated, but in the last years has been strongly reconsidered due to the interest in the link between the microbiome and ADs. Together with the gut, the skin microbiome is characterized by the presence of several microorganisms, potentially influencing innate and adaptive immune response. S. aureus is one of the most important components of the skin microbiome that can colonize anterior nares without clinical manifestations. Data from the literature demonstrates a significantly higher prevalence of nasal colonization in ADs patients in comparison with healthy subjects, suggesting a possible role in terms of disease development and phenotypes. Thus, in the present narrative review we focused on the mechanisms by which S. aureus could influence the immune response and on its relationship with ADs, in particular granulomatosis with polyangiitis, rheumatoid arthritis, and systemic lupus erythematosus.

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.

An immunological perspective on rheumatic heart disease pathogenesis: more questions than answers

Acute rheumatic fever (ARF) and the related rheumatic heart disease (RHD) are autoimmune diseases thought to be triggered by group A streptococcal (GAS) pharyngitis. RHD is a leading cause of mortality in the developing world. The strong epidemiological association between GAS throat infection and ARF is highly suggestive of causation, but does not exclude other infections as contributory. There is good evidence of both humoral and cellular autoreactivity and GAS/self cross-reactivity in established RHD. RHD pathogenesis could feasibly be triggered and driven by humoral and/or cellular molecular cross-reactivity between GAS and host cardiac tissues (molecular mimicry). However, good evidence of humoral pathogenicity is lacking and the specific triggering event for RHD remains unknown. It is likely that the critical immunological events leading to ARF/RHD occur at the point of contact between GAS and the immune system in the throat, strongly implicating the mucosal immune system in RHD pathogenesis. Additionally, there is circumstantial evidence that continued live GAS may play a role in ARF/RHD pathogenesis. We suggest that future avenues for study should include the exclusion of GAS components directly contributing to RHD pathogenesis; large genome-wide association studies of patients with RHD looking for candidate genes involved in RHD pathogenesis; genome-wide association studies of GAS from patients with ARF taken at diagnosis to look for characteristics of rheumatogenic strains; and performing case/control studies of GAS pharyngitis/ARF/patients with RHD, and controls to identify microbiological, immunological and environmental differences to elucidate RHD pathogenesis.

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.

Infectious triggers for vasculitis

PURPOSE OF REVIEW

Infections have been suggested to contribute to disease induction and reactivation in many of the idiopathic vasculitides. This review describes and evaluates the evidence that microbes are involved in the etiopathogenesis of these diseases.

RECENT FINDINGS

Large-vessel vasculitis has recently been associated with two specific bacteria. Mycobacterium tuberculosis is thought to have an inducing role in Takayasu arteritis and a Burkholderia bacterium might be involved in giant cell arteritis. Hepatitis B and C viruses have been linked to polyarteritis nodosa. In antineutrophil cytoplasmic autoantibody-associated vasculitis, and more specifically granulomatosis with polyangiitis (GPA), Staphylococcus aureus has been the focus of many studies. Chronic nasal carriage of S. aureus is related to endonasal activity and disease relapses in GPA patients. Moreover, antibacterial treatment is known to reduce the risk for disease relapses. If and how pathogens trigger vasculitis is still unclear, but several potential mechanisms have been suggested and are briefly reviewed here.

SUMMARY

Although many observations suggest a link between infections and the development of vasculitis, no direct proof exists. Transcriptomic and proteomic studies of the pathogens involved could aid in identifying specific or common traits of pathogens that are relevant for the development and reactivation of vasculitis.

Staphylococcus Aureus carriage and long-term Rituximab treatment for Granulomatosis with polyangiitis

Objective. Chronic nasal carriage of Staphylococcus aureus (SA) increases the risk of relapse while Rituximab (RTX) is an effective agent for inducing and maintaining remission in patients with Granulomatosis with polyangiitis (GPA). We investigated whether B cell depletion and hypogammaglobulinemia that occur during RTX treatment increase the risk of chronic SA nasal carriage and subsequent disease flares, in GPA patients on long-term RTX maintenance therapy.

Methods. Retrospective cohort study from a disease registry involving 29 GPA patients receiving RTX maintenance (median RTX dose of 9 g) during a median period of 49 months. Nasal swabs were collected prior and during RTX for a median of 3 and 9 swabs respectively. Persistent SA nasal carriage was defined with the presence of SA in more than 75% of nasal swabs.

Results. SA nasal carriage did not change during RTX (p = 0.297). However, the rate of positive nasal swabs in GPA patients with transient SA nasal carriage during RTX maintenance increased from 0 prior RTX to 0.42 during RTX (p = 0.017). Persistent SA nasal carriage did not increase the risk of relapses (p = 0.844), of hypogammaglobulinemia (p = 0.122) and of severe infections (p = 0.144), but reduced the risk of chronic infections (p = 0.044). Change in SA carriage status during RTX did not influence the risk of relapses (p = 0.756), hypogammaglobulinamia (p = 0.474) and infections, either severe (p = 0.913) or chronic (p = 0.121).

Conclusion. Long-term RTX maintenance therapy in GPA patients did not significantly influence SA nasal carriage status. Persistent SA carriage during long-term RTX treatment did not seem to increase the risk of relapses, but seemed to decrease the risk of hypogammaglobulinemia associated chronic infections.

Staphylococcus aureus Colonization: Modulation of Host Immune Response and Impact on Human Vaccine Design

In apparent contrast to its invasive potential Staphylococcus aureus colonizes the anterior nares of 20–80% of the human population. The relationship between host and microbe appears particularly individualized and colonization status seems somehow predetermined. After decolonization, persistent carriers often become re-colonized with their prior S. aureus strain, whereas non-carriers resist experimental colonization. Efforts to identify factors facilitating colonization have thus far largely focused on the microorganism rather than on the human host. The host responds to S. aureus nasal colonization via local expression of anti-microbial peptides, lipids, and cytokines. Interplay with the co-existing microbiota also influences colonization and immune regulation. Transient or persistent S. aureus colonization induces specific systemic immune responses. Humoral responses are the most studied of these and little is known of cellular responses induced by colonization. Intriguingly, colonized patients who develop bacteremia may have a lower S. aureus-attributable mortality than their non-colonized counterparts. This could imply a staphylococcal-specific immune “priming” or immunomodulation occurring as a consequence of colonization and impacting on the outcome of infection. This has yet to be fully explored. An effective vaccine remains elusive. Anti-S. aureus vaccine strategies may need to drive both humoral and cellular immune responses to confer efficient protection. Understanding the influence of colonization on adaptive response is essential to intelligent vaccine design, and may determine the efficacy of vaccine-mediated immunity. Clinical trials should consider colonization status and the resulting impact of this on individual patient responses. We urgently need an increased appreciation of colonization and its modulation of host immunity.