ACR Meeting Abstracts

ACR Meeting Abstracts

Abstract Number: 0560

Single Cell Sequencing Analysis of Tumour Necrosis Factor Inhibitor Drug Response Reveals Enrichment of Pro-inflammatory Pathway in Non-responders and Amino Acid Metabolic Pathways in Responders

Ayantika Talukdar1, Phuong Nguyen2, Neke Ibeke3, Rohan Machhar1, Mansi Aparnathi1, Archita Srinath2, Akihiro Nakamura4, Robert Inman3, Igor Jurisica5, Proton Rahman6, Nigil Haroon7 and Sareh Keshavarazi1, 1Schroeder Arthritis Institute, University Health Network, Toronto, ON, Canada, 2University of Toronto, Toronto, ON, Canada, 3University Health Network, Toronto, ON, Canada, 4Queen's University, Kingston, ON, Canada, 5University Health Network, Toronto, Canada, 6Division of Rheumatology, Craig L. Dobbin Genetics Research Centre, Discipline of Medicine, Memorial University of Newfoundland, St. John's, Canada, 7Department of Medicine/Rheumatology, University Health Network, Schroeder Arthritis Institute, University of Toronto, Toronto, ON, Canada

Meeting: ACR Convergence 2025

Keywords: , , ,

Session Information

Date: Sunday, October 26, 2025

Title: (0554–0592) Spondyloarthritis Including Psoriatic Arthritis – Treatment Poster I

Session Type: Poster Session A

Session Time: 10:30AM-12:30PM

Background/Purpose: Ankylosing Spondylitis (AS) is a type of chronic inflammatory arthritis affecting the spine and peripheral joints. Although tumor necrosis factor inhibitors (TNFi) substantially improve symptoms, 40% fail to respond. Predictors of treatment response could help make well-informed choices about TNFi treatment at baseline, elucidate mechanism of resistance and explore potential alternative therapeutic targets for TNFi non-responders. This study aims to identify biomarkers correlating with TNFi treatment response using single cell sequencing in AS patients at baseline.

Methods: PBMCs derived from 7 biologic naïve AS patients (4 responders and 3 non-responders to TNFi treatment) were profiled using droplet-based single cell RNA sequencing technology (10X Genomics). Statistical analysis was carried out using Seurat R package (v5.2.0). The results were then validated using Nanostring nCounter gene expression assay, a highly reproducible and sensitive technique. The cytokines levels were validated using ELISA in the serum of AS patients and the protein expression of CXCR4 and CD74 were determined using flow cytometry on CD14+CD16- monocytes.

Results: As compared to responders, non-responders had a higher proportions of B cells, dendritic cells and monocytes but a lower proportion of T cells. In total PBMCs, 5020 differentially expressed genes were identified among responders and non-responders. CXCR4 and CD74 were found to be upregulated in the monocytes of non-responders which has been further validated in the validation cohort using Nanostring nCounter gene expression assay. Pathway enrichment analysis (i.e., gene set enrichment analysis) of the most significantly changed genes in each response outcome revealed that regulation of osteoclast function, innate immune response, and regulation of T cell activation pathways are among the most enriched pathways in responders. Interferon regulated genes (IRGs) expression and MHC class II regulation was upregulated in non-responders at baseline compared to responders. Upregulated expression of MIF receptor, CD74, in non-responders suggests that monocytes in these patients are activated before the start of treatment and they are involved in the formation of inflammasome, resulting in enhanced inflammatory response. This has been further confirmed by assessing the levels of inflammatory cytokines and chemokines in the serum of patients before and after TNFi treatment using ELISA. We observed that after TNFi treatment, there is a decrease in the levels of CXCL10, CCL4, IL-1b, TNFa and MIF in responders, but not in non-responders.

Conclusion: In non-responders, elevated expression of inflammatory cytokines like IL-17A and IL1b, MIF and its receptors (CXCR4 and CD74)and chemokines like CXCL8, CXCL10 even prior to the commencement of the treatment may be the crucial in preconditioning the immune system towards TNFi treatment resistance in AS patients.

Disclosures: A. Talukdar: None; P. Nguyen: None; N. Ibeke: None; R. Machhar: None; M. Aparnathi: None; A. Srinath: None; A. Nakamura: AbbVie/Abbott, 6, Novartis, 6; R. Inman: AbbVie/Abbott, 2, Janssen, 2, Novartis, 2, 5, UCB, 2, 5; I. Jurisica: None; P. Rahman: Abbott, 2, AbbVie, 2, Amgen, 2, BMS, 2, Celgene, 2, Eli Lilly, 2, Janssen, 2, 5, Novartis, 2, 5, Pfizer, 2, UCB, 2; N. Haroon: AbbVie, 2, Eli Lilly, 2, Janssen, 2, UCB, 2; S. Keshavarazi: None.

To cite this abstract in AMA style:

Talukdar A, Nguyen P, Ibeke N, Machhar R, Aparnathi M, Srinath A, Nakamura A, Inman R, Jurisica I, Rahman P, Haroon N, Keshavarazi S. Single Cell Sequencing Analysis of Tumour Necrosis Factor Inhibitor Drug Response Reveals Enrichment of Pro-inflammatory Pathway in Non-responders and Amino Acid Metabolic Pathways in Responders [abstract]. Arthritis Rheumatol. 2025; 77 (suppl 9). https://acrabstracts.org/abstract/single-cell-sequencing-analysis-of-tumour-necrosis-factor-inhibitor-drug-response-reveals-enrichment-of-pro-inflammatory-pathway-in-non-responders-and-amino-acid-metabolic-pathways-in-responders/. Accessed .

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/single-cell-sequencing-analysis-of-tumour-necrosis-factor-inhibitor-drug-response-reveals-enrichment-of-pro-inflammatory-pathway-in-non-responders-and-amino-acid-metabolic-pathways-in-responders/