Clarithromycin in rheumatoid arthritis: the addition to methotrexate and low-dose methylprednisolone induces a significant additive value--a 24-month single-blind pilot study

Association Between Soluble Cell Adhesion Molecules (sP-Selectin, sE-Selectin, and sICAM-1) and Antibodies Against the Antigens of Proteus mirabilis in Rheumatoid Arthritis Patients

Objective The purpose of this study was to examine the association between the serum concentration of soluble cell adhesion molecules (CAMs) and antibodies against antigens of Proteus mirabilis (P. mirabilis) in rheumatoid arthritis (RA) patients, taking into consideration the implication of P. mirabilis in the etiopathogenesis of RA. Methods The serum levels of soluble P-selectin (sP-selectin), soluble E-selectin (sE-selectin), and soluble intercellular adhesion molecule-1 (sICAM-1) were determined by sandwich enzyme-linked immunosorbent assay (ELISA) in 59 RA patients and 36 healthy controls. Using the same ELISA method, the serum levels of class-specific antibodies against hemolysin (HpmB), urease C (UreC), and urease F (UreF) enzymes of P. mirabilis were also measured.  Results In this study, increased levels of sP-selectin and sICAM-1 were observed in RA patients, while the levels of sE-selectin were increased in comparison with healthy controls but did not present a statistically significant difference. Moreover, increased levels of antibodies against HpmB, UreC, and UreF of P. mirabilis were found. Additionally, it was observed that the sE-selectin levels presented a significant correlation with IgG antibodies against the UreF antigen (there is no corresponding antigen in human tissue) in all the RA patients. A statistically significant correlation was observed between levels of soluble CAMs and antibodies against P. mirabilis in the different subgroups. Conclusion The observed correlation between soluble CAMs and antibodies against antigens of P. mirabilis, specifically in the subgroup of biologic therapy, indicates that P. mirabilis exists and provokes refractory in the treatment of RA.

Gut microbiota in pre-clinical rheumatoid arthritis: From pathogenesis to preventing progression

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by progressive polyarthritis that leads to cartilage and bone damage. Pre-clinical RA is a prolonged state before clinical arthritis and RA develop, in which autoantibodies (antibodies against citrullinated proteins, rheumatoid factors) can be present due to the breakdown of immunologic self-tolerance. As early treatment initiation before the onset of polyarthritis may achieve sustained remission, optimize clinical outcomes, and even prevent RA progression, the pre-clinical RA stage is showing the prospect to be the window of opportunity for RA treatment. Growing evidence has shown the role of the gut microbiota in inducing systemic inflammation and polyarthritis via multiple mechanisms, which may involve molecular mimicry, impaired intestinal barrier function, gut microbiota-derived metabolites mediated immune regulation, modulation of the gut microbiota's effect on immune cells, intestinal epithelial cells autophagy, and the interaction between the microbiome and human leukocyte antigen alleles as well as microRNAs. Since gut microbiota alterations in pre-clinical RA have been reported, potential therapies for modifying the gut microbiota in pre-clinical RA, including natural products, antibiotic therapy, fecal microbiota transplantation, probiotics, microRNAs therapy, vitamin D supplementation, autophagy inducer-based treatment, prebiotics, and diet, holds great promise for the successful treatment and even prevention of RA via altering ongoing inflammation. In this review, we summarized current studies that include pathogenesis of gut microbiota in RA progression and promising therapeutic strategies to provide novel ideas for the management of pre-clinical RA and possibly preventing arthritis progression.

Arsenic trioxide modulates the composition and metabolic function of the gut microbiota in a mouse model of rheumatoid arthritis

The mechanism of rheumatoid arthritis (RA) has been widely investigated, and studies on the use of arsenic trioxide (ATO) in the treatment of RA have been reported in recent years. However, the exact mechanism of action of ATO in RA remains unclear. This study explores alterations in the gut microbiota and metabolism during ATO treatment in a mouse model of RA and provides an integrative analysis of the biomechanism. The purpose of this study was to verify whether ATO can alleviate RA by altering the gut microbiota. In this study, the mice were randomly divided into four different groups: the normal control (NC) group, the collagen-induced arthritis (CIA) group, the ATO 1.0 mg/kg/day group, and the ATO 2.0 mg/kg/day group. Fecal samples were collected. Through 16S rDNA gene sequencing and metabolomic analysis, the effect of ATO on the composition and metabolites of gut microbiota in CIA mice was investigated. The results showed that compared with NC mice, CIA mice showed differences at both the phylum level (Firmicutes and Bacteroidetes) and the genus level (Muribaculaceae_unclassified and Alistipes). Meanwhile, many metabolites were significantly changed between the two groups, including benzoic acid and (s)-2-acetolactate. However, these alterations were partially reversed in ATO-treated CIA mice. These results indicated that ATO treatment modulated gut microbiota disorder and improved fecal metabolite abnormalities. In conclusion, this study provided important evidence for alterations of the gut microbiota and metabolites and the role of these alterations in a potential novel mechanism of ATO treatment in RA.

The Gut Microbiota in Immune-Mediated Inflammatory Diseases

The collection of microbes and their genes that exist within and on the human body, collectively known as the microbiome has emerged as a principal factor in human health and disease. Humans and microbes have established a symbiotic association over time, and perturbations in this association have been linked to several immune-mediated inflammatory diseases (IMID) including inflammatory bowel disease, rheumatoid arthritis, and multiple sclerosis. IMID is a term used to describe a group of chronic, highly disabling diseases that affect different organ systems. Though a cornerstone commonality between IMID is the idiopathic nature of disease, a considerable portion of their pathobiology overlaps including epidemiological co-occurrence, genetic susceptibility loci and environmental risk factors. At present, it is clear that persons with an IMID are at an increased risk for developing comorbidities, including additional IMID. Advancements in sequencing technologies and a parallel explosion of 16S rDNA and metagenomics community profiling studies have allowed for the characterization of microbiomes throughout the human body including the gut, in a myriad of human diseases and in health. The main challenge now is to determine if alterations of gut flora are common between IMID or, if particular changes in the gut community are in fact specific to a single disease. Herein, we review and discuss the relationships between the gut microbiota and IMID.

The association between rheumatoid arthritis and periodontitis

The relationship between rheumatoid arthritis and poor oral health has been recognised for many decades. The association between periodontal infection and the risk of developing RA has been the subject of epidemiological, clinical and basic science research in recent times. Converging and reproducible evidence now makes a clear case for the role of specific periodontal infective pathogens in initiating, amplifying and perpetuating rheumatoid arthritis. The unique enzymatic properties of the periodontal pathogen Porphyromonas gingivalis and its contribution to the burden of citrullinated peptides is now well established. The impact of localized infection such as periodontitis in shaping specific anti-citrullinated peptide immune responses highlights a key area for treatment, prevention and risk assessment in rheumatoid arthritis.

Antibiotics for the treatment of rheumatoid arthritis

Antibiotic treatment for rheumatoid arthritis (RA) commenced in the 1930s with the use of sulfasalazine. Later, tetracyclines were successfully used for the treatment of RA. In double-blind and randomized studies, levofloxacin and macrolide antibiotics (including clarithromycin and roxithromycin) were also shown to be effective in the treatment of RA. There have been several reports in the literature indicating that periodontal pathogens are a possible cause of RA. Oral bacteria are one possible cause of RA. In this review, we aimed to investigate the effects of different antibiotics in RA treatment.