[Faecal microbiota study reveals specific dysbiosis in spondyloarthritis according to subtype, disease activity and treatment]. / Estudio de microbiota fecal revela disbiosis específica en espondiloartritis, según subtipo, actividad de la enfermedad y tratamiento.

OBJECTIVE: To compare the diversity and composition of the gastrointestinal microbiome of patients with SpA. METHODS: MiSeq sequencing of the V3-V4 region of the 16S ribosomal RNA gene was performed on DNA isolated from stool. Patients with concurrent SpA and IBD were excluded. Differences were assessed for richness and diversity indices by QIIME 2™. Differences between means >0,2% with a p-value<0,05 were assumed significant. Institutional Ethics Committee endorsement. RESULTS: 69 individuals included, 49 with SpA (ankylosing spondylitis-AS 72,9%, psoriatic arthritis-PsA 18,8%, reactive arthritis-ReA 8,3%) 5 positive controls-dysbiosis and 15 controls-eubiosis. Conventional treatment in 42,9%, anti-IL-17 16,3% and anti-TNF 40,8%. By subtype, statistically significant differences in favour of AS were found for the diversity indices. AS vs PsA there was a difference in favour of AS for Clostridium clostridioforme (p=0,002), Gemmiger formicilis (p=0,009), Roseburia inulivorans (p=0,008) and Lachnospira pectinoschiza. AS vs ReA there was a difference in favour of AS for L. pectinoschiza (p=0,009), Ruminococcus callidus (p=0.006), Clostridium ruminantium (p=0.031); G. formicilis (p=0,034). Diversity and richness showed differences in patients with high activity for Simpson's and Pielou's indices. In high activity, lower enrichment of Bacteroides eggerthii (p= 0,0003), C. ruminantium (p= 0,026) and Alistipes putredinis (p=0,035) was found. The number of ASV was higher in the anti-IL-17 vs conventional group (p=0.025) and a trend between anti-IL-17 vs anti-TNF (p=0.09). In anti-TNF there was a lower proportion for C. clostridioforme (p=0.023), G. formicilis (p=0.030) and R. callidus (p= 0.003). In anti IL-17, Alistipes indistinctus (p= 0.012) was decreased. CONCLUSIONS: There are differences in microbial diversity for SpA subtypes. The level of disease activity is plausible to influence the composition of the faecal microbiota. Anti-TNFα treatment may influence the microbiome environment favouring restoration of the gut microbiota, while anti-IL-17 may maintain an inflammatory environment.

OBJETIVO: Comparar la diversidad y composición del microbioma gastrointestinal de pacientes con EspA. MÉTODOS: La secuenciación MiSeq de la región V3-V4 del gen ARN ribosomal 16, se realizó en ADN aislado de heces. Se excluyeron pacientes con EspA y EII simultánea. Se evaluaron diferencias para los índices de riqueza y diversidad por medio de QIIME 2™. Las diferencias entre medias> 0,2%, con un valor de p< 0,05, se asumieron significativas. Aval del Comité de Ética Institucional. RESULTADOS: 69 individuos incluidos, 49 con EspA (espondilitis anquilosante-EA 72,9%, artritis psoriásica-APs 18,8%, artritis reactiva-ARe 8,3%), cinco controles positivos-disbiosis y 15 controles-eubiosis. El tratamiento convencional en 42,9%, anti-IL-17 16,3%, y anti-TNF 40,8%. Por subtipo-EasP, se encontraron diferencias estadísticamente significativas a favor de EA para los índices de diversidad. Entre EA vs APs, hubo diferencia a favor de EA para Clostridium clostridioforme (p=0,002), Gemmiger formicilis (p=0,009), Roseburia inulivorans (p=0,008) y Lachnospira pectinoschiza. Entre EA vs ARe hubo diferencia a favor de EA para L. pectinoschiza (p=0,009), Ruminococcus callidus (p = 0,006), Clostridium ruminantium (p=0,031); G. formicilis (p=0,034). La diversidad y riqueza mostraron diferencias en pacientes con alta actividad para los índices de Simpson y Pielou. En alta actividad, se encontró menor enriquecimiento de Bacteroides eggerthii (p=0,0003), C. ruminantium (p= 0,026) y Alistipes putredinis (p= 0,035). El número de ASV fue superior en el grupo de anti IL-17 vs convencional (p=0.025), y una tendencia entre anti IL-17 vs anti-TNF (p=0,09). En anti TNF hubo menor proporción para C. clostridioforme (p=0,023), G. formicilis (p=0,030) y R. callidus (p= 0,003). Y en anti IL-17, Alistipes indistinctus (p= 0,012), estuvo disminuida. CONCLUSIONES: Existen diferencias en la diversidad microbiana para los subtipos de EspA. El nivel de actividad de la enfermedad es plausible para influir en la composición de microbiota fecal. El tratamiento con anti-TNFα, puede influenciar el ambiente del microbioma favoreciendo la restauración de la microbiota intestinal, mientras los anti IL-17 podrían mantener un ambiente inflamatorio.

Alterations in the cutaneous microbiome of patients with psoriasis and psoriatic arthritis reveal similarities between non-lesional and lesional skin.

OBJECTIVES: To investigate the cutaneous microbiome spanning the entire psoriatic disease spectrum, and to evaluate distinguishing features of psoriasis (PsO) and psoriatic arthritis (PsA). METHODS: Skin swabs were collected from upper and lower extremities of healthy individuals and patients with PsO and PsA. Psoriatic patients contributed both lesional (L) and contralateral non-lesional (NL) samples. Microbiota were analysed using 16S rRNA sequencing. RESULTS: Compared with healthy skin, alpha diversity in psoriatic NL and L skin was significantly reduced (p<0.05) and samples clustered separately in plots of beta diversity (p<0.05). Kocuria and Cutibacterium were enriched in healthy subjects, while Staphylococcus was enriched in psoriatic disease. Microbe-microbe association networks revealed a higher degree of similarity between psoriatic NL and L skin compared with healthy skin despite the absence of clinically evident inflammation. Moreover, the relative abundance of Corynebacterium was higher in NL PsA samples compared with NL PsO samples (p<0.05), potentially serving as a biomarker for disease progression. CONCLUSIONS: These findings show differences in diversity, bacterial composition and microbe-microbe interactions between healthy and psoriatic skin, both L and NL. We further identified bacterial biomarkers that differentiate disease phenotypes, which could potentially aid in predicting the transition from PsO to PsA.

Alterations of the Skin and Gut Microbiome in Psoriasis and Psoriatic Arthritis.

Numerous scientific studies in recent years have shown significant skin and gut dysbiosis among patients with psoriasis. A significant decrease in microbiome alpha-diversity (abundance of different bacterial taxa measured in one sample) as well as beta-diversity (microbial diversity in different samples) was noted in psoriasis skin. It has been proven that the representation of Cutibacterium, Burkholderia spp., and Lactobacilli is decreased and Corynebacterium kroppenstedii, Corynebacterium simulans, Neisseria spp., and Finegoldia spp. increased in the psoriasis skin in comparison to healthy skin. Alterations in the gut microbiome in psoriasis are similar to those observed in patients with inflammatory bowel disease. In those two diseases, the F. prausnitzii, Bifidobacterium spp., Lactobacillus spp., Parabacteroides and Coprobacillus were underrepresented, while the abundance of Salmonella sp., Campylobacter sp., Helicobacter sp., Escherichia coli, Alcaligenes sp., and Mycobacterium sp. was increased. Several research studies provided evidence for the significant influence of psoriasis treatments on the skin and gut microbiome and a positive influence of orally administered probiotics on the course of this dermatosis. Further research is needed to determine the influence of the microbiome on the development of inflammatory skin diseases. The changes in microbiome under psoriasis treatment can serve as a potential biomarker of positive response to the administered therapy.

Safety and efficacy of faecal microbiota transplantation for active peripheral psoriatic arthritis: an exploratory randomised placebo-controlled trial.

OBJECTIVES: Although causality remains to be established, targeting dysbiosis of the intestinal microbiota by faecal microbiota transplantation (FMT) has been proposed as a novel treatment for inflammatory diseases. In this exploratory, proof-of-concept study, we evaluated the safety and efficacy of FMT in psoriatic arthritis (PsA). METHODS: In this double-blind, parallel-group, placebo-controlled, superiority trial, we randomly allocated (1:1) adults with active peripheral PsA (≥3 swollen joints) despite ongoing treatment with methotrexate to one gastroscopic-guided FMT or sham transplantation into the duodenum. Safety was monitored throughout the trial. The primary efficacy endpoint was the proportion of participants experiencing treatment failure (ie, needing treatment intensification) through 26 weeks. Key secondary endpoints were change in Health Assessment Questionnaire Disability Index (HAQ-DI) and American College of Rheumatology (ACR20) response at week 26. RESULTS: Of 97 screened, 31 (32%) underwent randomisation (15 allocated to FMT) and 30 (97%) completed the 26-week clinical evaluation. No serious adverse events were observed. Treatment failure occurred more frequently in the FMT group than in the sham group (9 (60%) vs 3 (19%); risk ratio, 3.20; 95% CI 1.06 to 9.62; p=0.018). Improvement in HAQ-DI differed between groups (0.07 vs 0.30) by 0.23 points (95% CI 0.02 to 0.44; p=0.031) in favour of sham. There was no difference in the proportion of ACR20 responders between groups (7 of 15 (47%) vs 8 of 16 (50%)). CONCLUSIONS: In this first preliminary, interventional randomised controlled trial of FMT in immune-mediated arthritis, we did not observe any serious adverse events. Overall, FMT appeared to be inferior to sham in treating active peripheral PsA. TRIAL REGISTRATION NUMBER: NCT03058900.

Short-Term Western Diet Intake Promotes IL-23‒Mediated Skin and Joint Inflammation Accompanied by Changes to the Gut Microbiota in Mice.

We previously showed that exposure to a high-sugar and moderate-fat diet (i.e., Western diet [WD]) in mice induces appreciable skin inflammation and enhances the susceptibility to imiquimod-induced psoriasiform dermatitis, suggesting that dietary components may render the skin susceptible to psoriatic inflammation. In this study, utilizing an IL-23 minicircle-based model with features of both psoriasiform dermatitis and psoriatic arthritis, we showed that intake of WD for 10 weeks predisposed mice not only to skin but also to joint inflammation. Both WD-induced skin and joint injuries were associated with an expansion of IL-17A‒producing γδ T cells and increased expression of T helper type 17 cytokines. After IL-23 minicircle delivery, WD-fed mice had reduced microbial diversity and pronounced dysbiosis. Treatment with broad-spectrum antibiotics suppressed IL-23‒mediated skin and joint inflammation in the WD-fed mice. Strikingly, reduced skin and joint inflammation with a partial reversion of the gut microbiota were noted when mice switched from a WD to a standard diet after IL-23 minicircle delivery. These findings reveal that a short-term WD intake‒induced dysbiosis is accompanied by enhanced psoriasis-like skin and joint inflammation. Modifications toward a healthier dietary pattern should be considered in patients with psoriatic skin and/or joint disease.

Interleukin-17 Inhibition in Spondyloarthritis Is Associated With Subclinical Gut Microbiome Perturbations and a Distinctive Interleukin-25-Driven Intestinal Inflammation.

OBJECTIVE: To characterize the ecological effects of biologic therapies on the gut bacterial and fungal microbiome in psoriatic arthritis (PsA)/spondyloarthritis (SpA) patients. METHODS: Fecal samples from PsA/SpA patients pre- and posttreatment with tumor necrosis factor inhibitors (TNFi; n = 15) or an anti-interleukin-17A monoclonal antibody inhibitor (IL-17i; n = 14) underwent sequencing (16S ribosomal RNA, internal transcribed spacer and shotgun metagenomics) and computational microbiome analysis. Fecal levels of fatty acid metabolites and cytokines/proteins implicated in PsA/SpA pathogenesis or intestinal inflammation were correlated with sequence data. Additionally, ileal biopsies obtained from SpA patients who developed clinically overt Crohn's disease (CD) after treatment with IL-17i (n = 5) were analyzed for expression of IL-23/Th17-related cytokines, IL-25/IL-17E-producing cells, and type 2 innate lymphoid cells (ILC2s). RESULTS: There were significant shifts in abundance of specific taxa after treatment with IL-17i compared to TNFi, particularly Clostridiales (P = 0.016) and Candida albicans (P = 0.041). These subclinical alterations correlated with changes in bacterial community co-occurrence, metabolic pathways, IL-23/Th17-related cytokines, and various fatty acids. Ileal biopsies showed that clinically overt CD was associated with expansion of IL-25/IL-17E-producing tuft cells and ILC2s (P < 0.05), compared to pre-IL-17i treatment levels. CONCLUSION: In a subgroup of SpA patients, the initiation of IL-17A blockade correlated with features of subclinical gut inflammation and intestinal dysbiosis of certain bacterial and fungal taxa, most notably C albicans. Further, IL-17i-related CD was associated with overexpression of IL-25/IL-17E-producing tuft cells and ILC2s. These results may help to explain the potential link between inhibition of a specific IL-17 pathway and the (sub)clinical gut inflammation observed in SpA.

Autoimmunity in 2018.

In the vast database of peer-reviewed articles, the number of 2018 papers published retrieved using the "autoimmunity" keyword remained unchanged compared with the brilliant results of 2017 while returning above a 5% share within the immunology field, after the brisk decrease of this ratio in 2017. As in the past 12 years, we have now searched PubMed for publications related to autoimmunity in the major immunology and autoimmunity peer-reviewed journals and provide here an arbitrary discussion of the major themes encountered. Once again, we are happy to notice that similarities between autoimmune diseases and the common mechanisms significantly outnumber differences. Some examples include data on Th17 cells, cytokines, or other mediators variably involved in the autoimmunity mechanisms such as BLIMP-1, IL-10, IFN, or NF-kB. The study of the microbiome remains central to autoimmunity development and data are being gathered in a growing number of conditions, similar to epigenetics and long non-coding RNA. In the cases of specific diseases, such as systemic lupus erythematosus, rheumatoid arthritis, or psoriatic arthritis, multiple encouraging findings underline the importance of a strict relationship between basic and clinical science to define new pathogenetic and therapeutic developments. Cumulatively, the present scenario of autoimmunity appears bright and should be regarded as one of the fastest growing in the scientific field of immunology, despite the enormous attention paid to cancer immune mechanisms. The parallel observation that the rheumatology therapeutic pipeline is second only to oncology increases the hopes that more and more patients will be satisfactorily treated in the near future.

FEATURES OF MICROBIOTA IN PSORIATIC DISEASE: FROM SKIN AND GUT PERSPECTIVES (REVIEW).

Psoriatic disease is a chronic inflammatory disease characterized by skin lesions. Psoriasis development has been associated both with genetic and environmental factors. Though skin and gut microbiota has been implicated in number of pathologies including atopic dermatitis, inflammatory bowel disease, Crohn's disease, allergy, and obesity, its role has been poorly studied in psoriatic disease, which incorporates both psoriasis and psoriatic arthritis. This literature review summarizes the most recent and major findings on microbiota features in psoriatic disease. Despite conflicting findings, psoriasis patients were frequently found to have distinct microbial composition in both skin and guts especially in the major bacterial phyla, Firmicutes, Bacteroidetes, and genus Akkermansia. Furthermore, bacterial DNA has been found in psoriatic patients both locally and systemically, and altogether suggesting a crucial role of bacteria in psoriatic disease and future studies in this field.

The gut microbiome in psoriasis and psoriatic arthritis.

This review summarizes existing research on the gut microbiome composition and function in psoriasis and psoriatic arthritis, exploring potential roles in disease pathogenesis, progression, and management. A strong relationship between skin, joint, and gastrointestinal inflammation exists, as demonstrated by an increased prevalence of psoriasis, psoriatic arthritis, and inflammatory bowel disease co-occurring together; however, the link between them has not been fully elucidated. Studies analyzing the gut microbiome in psoriasis and psoriatic arthritis reveal a unique pattern of dysbiosis. With regard to the gut microbiome's role in psoriasis and psoriatic arthritis pathogenesis, we discuss several theories including intestinal permeability, altered immune homeostasis, and imbalance of short- and medium-chain fatty acid-producing bacteria. We also discuss how the gut microbiome affects patient risk of psoriatic arthritis and other serious comorbidities, and how fecal microbes could be used clinically as therapeutic targets or markers of disease.

The Microbiome in Psoriasis and Psoriatic Arthritis: The Skin Perspective.

Psoriasis is a chronic, inflammatory immune-mediated skin disease that affects about 2% of the world's population. In 20% of patients with psoriasis, the characteristic skin lesions are accompanied by psoriatic arthritis (PsA). Psoriasis arises in genetically predisposed individuals who have a dysregulated immune response to various environmental factors. The human body is home to many microbial species, and both the skin and the gut microbiome influence the development and function of immune tissue development and function. Studies on the cutaneous microbiome show a trend toward an increased relative abundance of Streptococcus and a decreased level of Propionibacterium in patients with psoriasis compared to healthy controls. In the gut microbiome, the ratio of Firmicutes and Bacteroidetes was perturbed in psoriatic individuals compared to healthy controls. Actinobacteria was relatively underrepresented in patients with psoriasis compared to healthy individuals. A decrease in skin microbiome flora diversity seems to be a sign that a patient with psoriasis is at elevated risk for developing arthritis. Modulating the skin microbiota for therapeutic reasons can be achieved by antimicrobial (antibiotic) therapy, the application of prebiotics or probiotics, or the transplantation of an entire healthy microbial population.

The Microbiome in Psoriasis and Psoriatic Arthritis: Joints.

The microbiome is a known and established immunomodulator of many inflammatory disorders, including psoriasis and psoriatic arthritis. Microbes co-evolved with their human hosts and provide them with nutritional, metabolic, and immunologic support. An accumulating body of evidence has revealed that psoriatic diseases are characterized by a state of intestinal dysbiosis, which has been linked to a decrease in beneficial commensals and fatty acids. This has been shown in both animal models and human samples, and multiple studies have addressed the physiological and potentially pathogenic role of intestinal and cutaneous microbes in human health and disease. In this review, we discuss state-of-the-art literature in the field of the microbiome in psoriatic diseases that was presented during the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2017 annual meeting, with a special emphasis on synovio-entheseal inflammation. A better understanding of these microbe-host interactions can lead to novel diagnostic and therapeutic targets.

The Role of the Microbiome in Gut and Joint Inflammation in Psoriatic Arthritis and Spondyloarthritis.

Spondyloarthritis (SpA) encompasses a group of diseases characterized by an inflammatory arthritis involving both joints and entheses. However, extraarticular symptoms constitute a large element of the pathology and should not be underestimated. Microscopic gut inflammation is observed in 50% of patients with SpA and has been linked to disease activity, underscoring the effect of gut inflammation in SpA. In this review, we discuss the influence of gut microbiota on SpA pathogenesis. A change in microbiota composition has been linked to the development of various inflammatory arthritides, and dysbiosis is a potential factor in the pathogenesis of multiple inflammatory diseases. In this context, several groups have reported the modulatory effects of gut microbiota-derived metabolites on the effect of immune cells. The gut mucosa is populated by several types of regulatory T cells, but also some specialized unconventional innate-like T cells. These cells are predominantly found at mucosal and epithelial barrier sites, where they serve an essential role in modulating host-microbial interplay. Apart from the close association between the composition of the microbiota and inflammatory diseases, the therapeutic value of dysbiosis needs further investigation, and the identification of a causal inflammatory pathway between gut dysbiosis and musculoskeletal inflammation could revolutionize the therapeutic approach in SpA.

Preparing patients for biologic medications for dermatologic and rheumatic diseases.

Psoriasis, psoriatic arthritis, and rheumatoid arthritis are prevalent conditions that often require a team of primary care and specialist healthcare professionals for the most optimum patient outcomes. Primary care providers can facilitate referrals to dermatology and rheumatology specialists by obtaining the needed screening workup for patients who need treatment with immunosuppressive therapies. This article reviews tuberculosis screening, hepatitis screening, and vaccinations to be administered before patients begin biologic medications.

Risk of Tuberculosis Reactivation in Patients with Rheumatoid Arthritis, Ankylosing Spondylitis, and Psoriatic Arthritis Receiving Non-Anti-TNF-Targeted Biologics.

Tuberculosis (TB) still represents an important issue for public health in underdeveloped countries, but the use of antitumor necrosis factor agents (anti-TNF) for the treatment of inflammatory rheumatic disorders has reopened the problem also in countries with low TB incidence, due to the increased risk of TB reactivation in subjects with latent tuberculosis infection (LTBI). Over the last 5 years, several non-anti-TNF-targeted biologics have been licensed for the treatment of rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis. We reviewed the epidemiology of TB, the role of different cytokines and of the immune system cells involved in the immune response against TB infection, the methods to detect LTBI, and the risk of TB reactivation in patients exposed to non-anti-TNF-targeted biologics. Given the limited role exerted by the cytokines different from TNF, as expected, data from controlled trials, national registries of biologics, and postmarketing surveillance show that the risk of TB reactivation in patients receiving non-anti-TNF-targeted biologics is negligible, hence raising the question whether the screening procedures for LTBI would be necessary.

The evidence for microbiome manipulation in inflammatory arthritis.

The human body consists of millions of commensal bacteria (the microbiome), with the intestinal tract being the most prevalent site of colonization. This colonization process begins at birth, and despite numerous factors such as ageing, diet and drug use affecting the microbiome make-up, by adulthood the composition of the gut bacteria is relatively consistent across local populations. The recent advent of new scientific techniques has enabled us to explore how the microbiome affects health and, in particular, has shed light on the involvement of the microbiome in the pathogenesis of inflammatory disease. In this review we highlight the current evidence for microbiome manipulation in inflammatory arthritis in animal and human models and discuss potential therapeutics targeting the microbiome as treatment for these diseases.

Autoimmune Arthritides, Rheumatoid Arthritis, Psoriatic Arthritis, or Peripheral Spondyloarthritis Following Lyme Disease.

OBJECTIVE: To describe systemic autoimmune joint diseases that develop following Lyme disease, and to compare their clinical features with those of Lyme arthritis (LA). METHODS: We reviewed records of all adult patients referred to our LA clinic over a 13-year period, in whom we had diagnosed a systemic autoimmune joint disease following Lyme disease. For comparison, records of patients enrolled in our LA cohort over the most recent 2-year period were analyzed. Levels of IgG antibodies to Borrelia burgdorferi and to 3 Lyme disease-associated autoantigens were measured. RESULTS: We identified 30 patients who had developed a new-onset systemic autoimmune joint disorder a median of 4 months after Lyme disease (usually manifested by erythema migrans [EM]). Fifteen had rheumatoid arthritis (RA), 13 had psoriatic arthritis (PsA), and 2 had peripheral spondyloarthritis (SpA). The 30 patients typically had polyarthritis, and those with PsA or SpA often had previous psoriasis, axial involvement, or enthesitis. In the comparison group of 43 patients with LA, the usual clinical picture was monoarticular knee arthritis, without prior EM. Most of the patients with systemic autoimmune joint disorders were positive for B burgdorferi IgG antibodies, as detected by enzyme-linked immunosorbent assay, but had significantly lower titers and lower frequencies of Lyme disease-associated autoantibodies than patients with LA. Prior to our evaluation, these patients had often received additional antibiotics for presumed LA, without benefit. We prescribed antiinflammatory agents, most commonly disease-modifying antirheumatic drugs, resulting in improvement. CONCLUSION: Systemic autoimmune joint diseases (i.e., RA, PsA, SpA) may follow Lyme disease. Development of polyarthritis after antibiotic-treated EM, previous psoriasis, or low-titer B burgdorferi antibodies may provide insight into the correct diagnosis.

Gut microbiota and inflammatory joint diseases.

In most chronic inflammatory diseases, the cause remains unknown. Chronic infection is, however, among the current hypotheses. Recent technological advances have allowed in-depth studies of the gut microflora, or microbiota, which contains a vast array of organisms, most of which cannot be cultured. Inflammatory bowel disease has been associated with distinctive changes in the gut microbiota, which persist between disease flares and may play a pathogenic role. Links have been demonstrated between the gut microbiota and joint inflammation in murine models of arthritis but have received little attention in human patients. Recent work has nevertheless demonstrated substantial alterations in the gut microbiota in patients with rheumatoid arthritis, psoriatic arthritis, or spondyloarthritis, with differences across diagnoses and studies. Interestingly, some of these alterations resemble those now firmly established in inflammatory bowel disease; examples include decreased microbial diversity and lower frequencies of bacterial groups belonging to the Firmicutes phylum known to have immunoregulatory properties. These new findings open up important new horizons both for understanding disease and for developing novel biomarkers and treatment strategies.