Changing the wolf from outside: how microbiota trigger systemic lupus erythematosus

Fecal microbiota transplantation: Emerging applications in autoimmune diseases

Both genetic susceptibility and environmental factors are important contributors to autoimmune disease pathogenesis. As an environmental factor, the gut microbiome plays a crucial role in the development and progression of autoimmune diseases. Thus, strategies targeting gut microbiome alterations can potentially be used to treat autoimmune disease. Microbiota-based interventions, such as prebiotics, probiotics, dietary interventions, and fecal microbiota transplantation (FMT), have attracted growing interest as novel treatment approaches. FMT is an effective method for treating recurrent Clostridioides difficile infections; moreover, it is emerging as a promising treatment for patients with inflammatory bowel disease and other autoimmune diseases. Although the mechanisms underpinning the interaction between the gut microbiome and host are not fully understood in patients with autoimmune disease, FMT has been shown to restore altered gut microbiota composition, rebuild the intestinal microecosystem, and mediate innate and adaptive immune responses to achieve a therapeutic effect. In this review, we provide an overview of FMT and discuss how FMT can be used as a novel treatment approach for autoimmune diseases. Furthermore, we discuss recent challenges and offer future research directions.

Alterations of the gut microbiota in the lupus nephritis: a systematic review

BACKGROUND

Emerging evidence suggests that gut microbiota dysbiosis may play a critical role in the development of lupus nephritis (LN). However, the specific characteristics of the gut microbiota in individuals with LN have not been fully clarified.

METHODS

The PubMed, Web of Science, and Embase databases were systematically searched for clinical and animal studies related to the relationship between LN and gut microbiota from inception until October 1, 2023. A semiquantitative analysis was used to assess the changes in gut microbial profiles.

RESULTS

A total of 15 clinical studies were selected for analysis, which included 138 LN patients, 441 systemic lupus erythematosus patients, and 1526 healthy controls (HCs). Five different types of LN mouse models were included in 5 animal studies. The alpha diversity was decreased in LN patients compared to HCs. A significant decrease in the Firmicutes/Bacteroidetes (F/B) ratio is considered a hallmark of pathological conditions. Specifically, alterations in the abundance of the phylum Proteobacteria, genera Streptococcus and Lactobacillus, and species Ruminococcus gnavus and Lactobacillus reuteri may play a critical role in the pathogenesis of LN. Remarkably, the gut taxonomic chain Bacteroidetes-Bacteroides-Bacteroides thetaiotaomicron was enriched in LN patients, which could be a crucial characteristic of LN patients. The increased level of interleukin-6, imbalance of regulatory T cells and T helper 17 cells, and decreased level of the intestinal tight junction proteins zonula occludens-1 and claudin-1 also might be related to the pathogenesis of LN.

CONCLUSIONS

Specific changes in the abundance of gut microbiota such as decreased F/B ratio, and the level of inflammatory indicators, and markers of intestinal barrier dysfunction may play a crucial role in the pathogenesis of LN. These factors could be effective diagnostic and potential therapeutic targets for LN.

Annals of the Rheumatic Diseases collection on lupus nephritis (2019-2022): novel insights and advances in therapy

No single organ has received as much attention in systemic lupus erythematosus (SLE) as the kidneys. During the period 2019-2022, the Annals of the Rheumatic Diseases published several original papers, brief reports and letters that further elucidate the pathogenesis and advance the management of LN. A selection of representative original papers is highlighted in this review.

Microbiome landscape of lesions and adjacent normal mucosal areas in oral lichen planus patient

The pathogenesis of oral lichen planus (OLP) remains unclear, and microbial dysbiosis has been proposed to play a role in the pathogenesis of OLP. Oral mucosal swabs from 77 OLP patients and 76 healthy subjects were collected. The bacterial community among the OLP lesion, the adjacent normal mucosal, and the oral mucosal surface in healthy people were analyzed by 16S sequencing. The factor of gender and age that may affect the flora distribution of OLP patients were explored. Results indicate no significant difference in microbiota between OLP and the adjacent group. Compared with the healthy group, Neisseria, Haemophilus, Fusobacterium, Porphyromonas, Rothia, Actinomyces, and Capnocytophaga significantly increased in the OLP group. Actinomyces increased in male OLP patients, and the other six bacteria increased in female OLP patients. In female OLP patients, Lautropia and Dialister were positively correlated with age. While in male OLP patients, Moraxella, Porphyromonas, and Fusobacterium were positively correlated with age. Functional enrichment analysis suggested that abnormal energy metabolism related to ATP synthases, abnormal transport and metabolism of glycans, amino acids, and vitamins, and disorders of the local immune microenvironment might exist in OLP lesion.

Collagen Turnover Biomarkers Associate with Active Psoriatic Arthritis and Decrease with Guselkumab Treatment in a Phase 3 Clinical Trial (DISCOVER-2)

INTRODUCTION

Guselkumab, a novel interleukin-23p19 subunit monoclonal antibody, has been shown to effectively improve the diverse manifestations of active psoriatic arthritis (PsA) in two phase 3 trials (DISCOVER-1, DISCOVER-2). Serum concentrations of extracellular matrix (ECM) biomarkers at baseline and following treatment with guselkumab were evaluated in patients with active PsA, and the relationship of these biomarkers with baseline PsA characteristics and clinical response to guselkumab treatment was explored.

METHODS

Serum samples were collected at weeks 0, 4, 24, and 52 from a selected subset (N = 260) of the 739 biologic-naïve patients with PsA treated with guselkumab 100 mg every 4 or 8 weeks or placebo in DISCOVER-2. Demographically matched healthy controls (N = 76) were used for comparison. The samples were analyzed for ECM biomarkers associated with collagen degradation (C1M, C2M, C3M, C4M, C6M, C10C) and collagen formation (PRO-C1, PRO-C2, PRO-C3, PRO-C4, PRO-C6).

RESULTS

Baseline concentrations of collagen degradation biomarkers C1M, C3M, C4M, and C6M and collagen formation biomarkers PRO-C3 and PRO-C6 were significantly higher (i.e., ≥ 1.25-fold and false discovery rate adjusted p < 0.05) in PsA patients than in healthy controls. Serum C1M, C3M, C4M, and C6M levels declined from baseline in guselkumab-treated patients in both dosing regimens. In addition, guselkumab-treated ACR20 responders (≥ 20% improvement in American College of Rhematology response criteria) had significantly lower C1M levels than ACR20 nonresponders.

CONCLUSION

These data demonstrate that serum collagen biomarkers are elevated in patients with PsA compared with healthy controls and that treatment with guselkumab decreases levels of C1M, C3M, C4M, and C6M. Importantly, C1M serves as a biomarker that associates with improvement of joint signs and symptoms.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03158285.

Autoimmunity in 2019

Based on the PubMed data, we have been performing a yearly evaluation of the publications related to autoimmune diseases and immunology to ascertain the relative weight of the former in the scientific literature. It is particularly intriguing to observe that despite the numerous new avenues of immune-related mechanisms, such as cancer immunotherapy, the proportion of immunology manuscripts related to autoimmunity continues to increase and has been approaching 20% in 2019. As in the previous 13 years, we performed an arbitrary selection of the peer-reviewed articles published by the major dedicated Journals and discussed the common themes which continue to outnumber peculiarites in autoimmune diseases. The investigated areas included systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), psoriatic arthritis (PsA), autoantibodies (autoAbs), and common therapeutic avenues and novel pathogenic mechanisms for autoimmune conditions. Some examples include new pathogenetic evidence which is well represented by IL21 or P2X7 receptor (P2X7R) in SLE or the application of single-cell RNA sequencing (scRNA-seq), mass cytometry, bulk RNA sequencing (RNA-seq), and flow cytometry for the analysis of different cellular populations in RA. Cumulatively and of interest to the clinicians, a large number of findings continue to underline the importance of a strict relationship between basic and clinical science to define new pathogenetic and therapeutic developments. The therapeutic pipeline in autoimmunity continues to grow and maintain a constant flow of new molecules, as well illustrated in RA and PsA, and this is most certainly derived from the new basic evidence and the high-throughput tools applied to autoimmune diseases.

Association between periodontitis and systemic lupus erythematosus: a meta-analysis

OBJECTIVE

The objective of this study was to explore the association between periodontitis and systemic lupus erythematosus (SLE).

METHODS

To identify eligible studies, the PubMed, EMBASE and Web of Science databases were searched from inception to 19 September 2019. Associations of periodontitis, and other periodontal parameters, with SLE were assessed.

RESULTS

Ten studies involving 80,633 subjects were included in this meta-analysis. Pooled data showed a significant association between periodontitis and SLE (odds ratio=5.32, 95% confidence interval (CI) 1.69-16.78, p = 0.004). In addition, SLE patients had a higher prevalence of bleeding on probing (mean difference = 0.03, 95% CI 0.00-0.06, p = 0.02) and higher mean clinical attachment loss (mean difference = 0.69, 95% CI 0.39-1.00, p < 0.001). However, there were no significant differences between SLE and reference subjects in mean plaque index, gingival index, pocket depth or decayed, missing or filled teeth.

CONCLUSIONS

This study demonstrates a significant association between periodontitis and SLE, which indicates that avoidance of periodontitis by maintaining oral health may be a simple and economical way to prevent SLE.