Faculty Bibliography

OBJECTIVE:The synovial tissue pathotype may determine the treatment response in rheumatoid arthritis (RA); however, biopsies are not widely available. Synovial fluid is a promising tissue surrogate. Our purpose was to compare RA synovial fluid cell counts with histopathology and use synovial fluid to predict tissue inflammation. METHODS:Synovial fluid and tissue were collected during knee arthroplasty. Patients were stratified based on their medication treatment history. Synovial lymphocytic inflammation (SLI) was graded from low to high. Synovial fluid white blood cell (WBC) count and differentials were performed in the clinical laboratory. Descriptive statistics, correlations, receiver operating characteristic curve analysis, and multivariable regression were performed to determine the associations with tissue SLI. RESULTS:Sixty-four patients with RA had paired synovial tissue and synovial fluid data available. The mean Clinical Disease Activity Index (CDAI) score was 17.9. High tissue SLI was observed in 29 patients, and low SLI was observed in 35 patients, with roughly equal distribution among treatment groups. The mean synovial fluid WBC count was 5,661 cells/μL and was not correlated with CDAI but correlated positively with SLI and percentage polymorphonuclear cells (PMN%). Synovial fluid WBC count ≥1,400 cells/μL was sensitive (0.86) and specific (0.91) for high SLI (area under the curve 0.91). In a multivariable regression, PMN% was associated with high SLI (odds ratio [OR] 1.46 [95% confidence interval (CI) 1.14-1.85]). Synovial fluid monocyte percentage was negatively associated with high SLI (OR 0.44 [95% CI 0.27-0.73]). CONCLUSION/CONCLUSIONS:Synovial fluid WBC count is sensitive and specific for differentiating high and low lymphocytic synovial inflammation. Further analysis of the synovial fluid as it relates to the adjacent tissue in different cohorts is needed.

OBJECTIVES/OBJECTIVE:Although genetic risk factors, such as HLA-DRB1 alleles, contribute to the pathogenesis of rheumatoid arthritis (RA), the concordance rate in monozygotic (MZ) twins is low, suggesting that other factors are involved in disease development. Further, the relative contribution of nongenetic elements in identical twins has not been characterised. Here, we aimed to characterise host and microbial biomarkers of RA by studying MZ twins discordant for disease using a multiomics approach. METHODS:Eight pairs of MZ twins discordant for RA (N = 16) were enrolled in the United States (US). The gut microbiome was assessed using shotgun metagenomic sequencing. Autoantibodies, cytokines, and plasma proteins were measured in both plasma and faeces. Levels of short-chain fatty acids (SCFAs) from serum and faeces were quantified using gas chromatography mass spectrometry (GC-MS). Metagenomic data from a UK twin registry (TwinsUK) (N = 14) were used to validate findings in the US population. RESULTS:Although microbiome diversity and composition did not differ between twins, we observed a significant decrease in the SCFA-producing bacteria Blautia faecis and significantly lower concentrations of faecal butyrate and propionate in affected RA twins in the US. TwinsUK showed a similar reduction in the SCFA-producers Gemmiger formicilis and Faecalicatena fissicatena, as well as bacterial SCFA metabolism pathways. CONCLUSIONS:Multiomics biomarkers differentiate MZ twins discordant for RA. Faecal butyrate and propionate, as well as SCFA-producing bacteria, were decreased in affected twins. We found a similar decrease in SCFA-producing taxa in affected twins in a geographically distinct cohort in the UK. Our results suggest that, if further validated in larger cohorts, multiomics approaches may improve our understanding of RA pathogenesis and, potentially, contribute to more accurate diagnostics and coadjuvant therapies.

OBJECTIVES/OBJECTIVE: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: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.

INTRODUCTION:Psoriatic arthritis (PsA) is a complex, immune-mediated disease associated with skin psoriasis that, if left untreated, can lead to joint destruction. Up to 30% of patients with psoriasis progress to PsA. In most cases, psoriasis precedes synovio-entheseal inflammation by an average of 5-7 years, providing a unique opportunity for early and potentially preventive intervention in a susceptible and identifiable population. Guselkumab is an effective IL-23p19 inhibitor Food and Drug Administration (FDA-approved for treatment of moderate-to-severe psoriasis and PsA. The Preventing Arthritis in a Multicentre Psoriasis At-Risk cohort (PAMPA) study aims to evaluate the efficacy of guselkumab in preventing PsA and decreasing musculoskeletal power Doppler ultrasound (PDUS) abnormalities in a population of patients with psoriasis who are at-increased risk for PsA progression. METHODS AND ANALYSIS:The PAMPA study is a multicentre, randomised, double-blind, placebo-controlled, interventional, preventive trial comparing PDUS involvement and conversion to PsA in patients with psoriasis at-increased risk for progression treated with guselkumab compared with non-biological standard of care. The study includes a screening period, a double-blind treatment period (24 weeks) and an open-label follow-up period (72 weeks). At baseline, 200 subjects will be randomised (1:1) to receive either guselkumab 100 mg (arm 1) or placebo switching to guselkumab 100 mg starting at week 24 (arm 2). Arm 3 will follow 150 at-risk psoriasis patients who decline biological therapy and randomisation. Changes from baseline in the PDUS score at week 24 and the difference in proportion of patients transitioning to PsA at 96 weeks will be examined as the coprimary endpoints. ETHICS AND DISSEMINATION:Ethics approval for this study was granted by the coordinating centre's (NYU School of Medicine) Institutional Review Board (IRB). Each participating site received approval through their own IRBs. The findings will be shared in peer-reviewed articles and scientific conference presentations. TRIAL REGISTRATION NUMBER:NCT05004727.

OBJECTIVES/OBJECTIVE:Autoantibody seroconversion has been extensively studied in the context of COVID-19 infection but data regarding post-vaccination autoantibody production is lacking. Here we aimed to determine the incidence of common autoantibody formation following mRNA COVID-19 vaccines in patients with inflammatory arthritis (IA) and in healthy controls. METHODS:Autoantibody seroconversion was measured by serum ELISA in a longitudinal cohort of IA participants and healthy controls before and after COVID-19 mRNA-based immunization. RESULTS:Overall, there was a significantly lower incidence of ANA seroconversion in participants who did not contract COVID-19 prior to vaccination compared with those who been previously infected (7.4% vs 24.1%, p= 0.014). Incidence of de novo anti-cyclic citrullinated protein (CCP) seroconversion in all participants was low at 4.9%. Autoantibody levels were typically of low titer, transient, and not associated with increase in IA flares. CONCLUSIONS:In both health and inflammatory arthritis, the risk of autoantibody seroconversion is lower following mRNA-based immunization than following natural SARS-CoV-2 infection. Importantly, seroconversion does not correlate with self-reported IA disease flare risk, further supporting the encouragement of mRNA-based COVID-19 immunization in the IA population.

Background/Purpose: The gut microbiome and its metabolites are dysregulated in rheumatoid arthritis. Short chain fatty acids (SCFAs), microbial fermentation byproducts of certain gut microbes, induce regulatory T cells (Treg) that exhibit antiinflammatory properties. Unsurprisingly, SCFA are found at reduced levels in both murine models of RA and patients. The SCFA butyrate has been shown to increase levels of gut and circulating Treg and ameliorate inflammatory arthritis in murine models. Additionally, we previously noted that SCFA supplementation in WT mice led to significant perturbations in gut bacterial composition with a significant increase in SCFA-producing commensals. Similarly, others have shown that a high-fiber diet increases circulating levels of SCFAs and decreases pro-arthritogenic cytokines (Durholz et al. Nutrients. 2020). We therefore hypothesized that butyrate supplementation may promote favorable gut microbial changes and increase tolerogenic adaptive immune response in RA patients.
Method(s): We designed an ongoing, prospective, proof-of-principle study to determine the effects of butyrate supplementation in new-onset RA (NORA) patients. First, we evaluated the effects of butyrate supplementation in healthy subjects (n=7; 1 gm 3 times daily for 14 days). Next, we evaluated the effects of butyrate on new-onset RA (n=5; 1 gm 3 times daily for 30 days) compared to methotrexate (n=20). Clinical history and joint exam were performed at baseline and follow up. Peripheral blood and fecal samples were collected at baseline and follow up for flow cytometric analysis of Treg and 16s rRNA sequencing, respectively. Wilcoxon signed-rank test was used to compare differences in Treg before and after butyrate administration.
Result(s): Although butyrate supplementation in healthy subjects did not lead to significant community changes by 7 days, it did lead to a significant increase in the percentage of circulating CD4+CD25+FoxP3+ Treg (p=0.02) followed by a significant increase in highly activated CD39+ Treg by 14 days (p < 0.0001). Gut bacterial alpha diversity (Shannon index) was significantly lower in NORA patients compared to healthy subjects at baseline (p=0.04; wilcox-test). After butyrate supplementation, NORA alpha diversity increased to levels approaching those of healthy subjects, with a modest increase in abundance of both Firmicutes and Bacteroidetes. LDA Effect Size analysis recapitulated previous studies where healthy subjects had greater abundance of SCFA producing commensals compared to NORA.
Conclusion(s): In both health and new-onset RA, butyrate supplementation is associated with changes in human gut microbiota composition and in peripheral Treg abundance and markers of Treg activation. In preliminary analyses of this ongoing prospective study, butyrate increased gut microbial diversity in NORA, suggesting that gut microbial composition may shift towards a healthier level of diversity. As seen in murine models, butyrate also increased Treg in healthy subjects. We hypothesize that, in patients, butyrate will induce modifications in gut microbial communities that favor a regulatory adaptive immune response that may ultimately lead to better clinical response