Rethink About the Role of Rheumatoid Factor and Anti-citrullinated Protein Antibody in Rheumatoid Arthritis

Gut microbiome-immune interactions and their role in rheumatoid arthritis development

Objective

The primary objective is to study the impact of gut microbiota and their interactions with diverse immunological markers on the development of rheumatoid arthritis.

Methods

This study was performed in Astana, Kazakhstan, and included 77 Kazakh female patients older than 18 years, who met the American College of Rheumatology 2010 classification criteria for rheumatoid arthritis (RA), and 113 healthy controls. The DNA was extracted from fecal samples obtained from all study participants for subsequent sequencing at the 16S rRNA gene V1-V3 locus, facilitating the analysis of the gut microbiome. The Multiplex immunoassay was employed to measure the concentrations of inflammatory cytokines, chemokines, and immunoglobulins in both fecal and plasma samples.

Results

Our taxonomic analysis revealed significant differences in the composition of the gut microbiota between the healthy control cohort and the cohort with rheumatoid arthritis RA. Alpha diversity was significantly lower in the RA group. Lachnospiraceae were the most abundant taxon and found to be crucial, showing correlations with immunological markers such as IL5. Additionally, Lachnospiraceae and Oscillospiraceae exhibited the most predictable power and distinguished the composition of both study groups.

Conclusion

Our study identifies key differences in the gut microbiome of RA patients, revealing distinct microbial patterns and specific taxa abundance. We highlight potential biomarkers in immunological and bacterial pathways, offering insights into RA development and indicating possibilities for personalized treatment.

Benefits of Autoantibody Enrichment in Early Rheumatoid Arthritis: Analysis of Efficacy Outcomes in Four Pooled Abatacept Trials

INTRODUCTION

The efficacy of abatacept is enhanced in anti-citrullinated protein antibody (ACPA) and rheumatoid factor (RF)-positive versus -negative patients with rheumatoid arthritis (RA). Four early RA abatacept trials were analyzed to understand the differential impact of abatacept among patients with SeroPositive Early and Active RA (SPEAR) compared to non-SPEAR patients.

METHODS

Pooled patient-level data from AGREE, AMPLE, AVERT, and AVERT-2 were analyzed. Patients were classified as SPEAR if they were ACPA +, RF +, disease duration < 1 year, and Disease Activity Score-28 (DAS28) C-reactive protein (CRP) ≥ 3.2 at baseline; non-SPEAR otherwise. Outcomes included: American College of Rheumatology (ACR) 20/50/70 at week 24; mean change from baseline to week 24 for DAS28 (CRP), Simple Disease Activity Index (SDAI), ACR core components; DAS28 (CRP) and SDAI remission. Adjusted regression analyses among abatacept-treated patients compared SPEAR and non-SPEAR patients, and in full trial population estimating how the efficacy of abatacept versus comparators [adalimumab + methotrexate, methotrexate] was modified by SPEAR status.

RESULTS

The study included 1400 SPEAR and 673 non-SPEAR patients; most were female (79.35%), white (77.38%), and with a mean age 49.26 (SD 12.86) years old. Around half with non-SPEAR were RF + and three-quarters ACPA +. Stronger improvements from baseline to week 24 were observed in almost all outcomes for abatacept-treated SPEAR versus non-SPEAR patients or versus SPEAR patients treated with comparators. Larger improvements were observed for SPEAR patients among the abatacept-treated population, and more strongly improved efficacy among SPEAR patients for abatacept than comparators.

CONCLUSIONS

This analysis, including large patient numbers of early-RA abatacept trials, confirmed beneficial treatment effects of abatacept in patients with SPEAR versus non-SPEAR.

Benefits of bone marrow-derived mesenchymal stem cells primed with estradiol in alleviating collagen-induced arthritis

Objectives

To investigate the effects of the oestradiol (ES) pulsed bone marrow-derived mesenchymal stem cells (BM-MSC) to treat adjuvant-induced arthritis in Wistar rats.

Materials and Methods

BM-MSCs were pulsed with ES (0, 10,100, and 1000 nM) for 24 hr. RA was induced by collagen and Freund's Complete Adjuvant into the base of the tail of Wistar rats.

Results

The least effective concentration of ES that can promote potent anti-inflammatory properties in the MSC population is 100 nM. At this concentration, ES increases the inhibition of the polyclonal T lymphocyte proliferation, production of IDO, IL-10, Nitric oxide, and TGF-β, and expression of CXCR4 and CCR2 mRNA in the MSC population. Accordingly, the RA rats were treated with 2×106 MSCs or ES-pulsed MSCs (100 nM) on day 10 when all animals had developed signs of RA. ES-pulsed BM-MSCs reduced the severity of RA more profoundly than treatment with BM-MScs alone. The ability of ES-pulsed BM-MSCs to reduce symptoms and RA markers like CRP, RF, and nitric oxide was comparable to that of prednisolone. Prednisolone was more successful in reducing inflammatory cytokines than treatment with ES-pulsed BM-MSCs. ES-pulsed BM-MSCs were more successful in increasing anti-inflammatory cytokines than treatment with Prednisolone. The ability of ES-pulsed BM-MSCs to decrease the level of nitric oxide was comparable to that of prednisolone.

Conclusion

ES-pulsed BM-MSCs may be a helpful strategy in RA control.