Background: Rheumatoid arthritis (RA) is a systemic autoimmune disease with the hallmark of persistent synovial inflammation resulting in chronic pain, cartilage and joint destruction and if untreated permanent disability of the patient. In contrast to RA, where personalized treatment strategies based on individual biomarkers are scarce, functional precision medicine (FPM), an approach to assess ex vivo drug effectiveness to assist physicians’ choice for optimal treatment selection has been pioneered and successfully employed in the field of oncology [1, 2].

Objectives: This proof-of-concept study is the systematic evaluation of high content imaging-based profiling of primary RA peripheral blood mononuclear cells (PBMCs) in combination with ex vivo drug treatment as a screening tool to enable disease stratification and functional precision medicine.

Methods: A high content, high throughput microscopy-based phenotyping pipeline for PBMCs was developed, allowing for the quantification of cell type frequencies, cell type specific morphology and intercellular interactions from RA patients (n=65) and healthy controls (HC, n=33). All samples were exposed to a curated set of RA-specific small molecules, biologicals and reference stimuli for 24h to assess ex vivo drug effects. Data on ex vivo PBMC phenotypes were integrated with information on patients’ in vivo medication and disease activity.

Results: The unbiased data from in total 6.9e8 individual cells were collected and allowed for the identification of PBMC phenotypes specific to disease activity as well as in vivo and ex vivo treatment. Global analysis of PBMC characteristics enabled clustering of patients according to disease activity, with distinct morphologic responses of T cells to proinflammatory ex vivo stimuli. Individual in vivo treatment regimens translated into altered immune cell abundances in patients with a comedication of conventional synthetic disease modifying drugs (DMARDs) when compared to HCs. The arrayed ex vivo drug perturbation allowed for the systematic characterization of drug effects, clustering by mode of action and uncovered morphologic alterations associated with biologic DMARD treatment.

Conclusion: The presented study demonstrates a first technical proof-of-concept for feasibility of a functional precision medicine approach to the ex vivo immunophenotypic characterization of RA patients.

REFERENCES: [1] Kornauth C, Pemovska T, Vladimer GI, Bayer G, Bergmann M, Eder S, et al. Functional Precision Medicine Provides Clinical Benefit in Advanced Aggressive Hematologic Cancers and Identifies Exceptional Responders. Cancer Discov. 2022;12(2):372-87.

[2] Snijder B, Vladimer GI, Krall N, Miura K, Schmolke AS, Kornauth C, et al. Image-based ex-vivo drug screening for patients with aggressive haematological malignancies: interim results from a single-arm, open-label, pilot study. Lancet Haematol. 2017;4(12):e595-e606

Acknowledgements: We thank Gregory Vladimer (now Exscientia), Berend Snijder (now ETH Zurich) and Ben Haladik for crucial conversations and help. We thank Sylvia Taxer for material handling and patient care. This work was supported by the Austrian Academy of Sciences.

Disclosure of Interests: Felix Kartnig: None declared, Michael Bonelli received grants from GSK and Galapagos, Ulrich Goldmann: None declared, Noemi Mészáros: None declared, Nikolaus Krall: None declared, Daniel Aletaha received grants, speaker fees, or consultancy fees from Abbvie, Gilead, Galapagos, Eli Lilly, Janssen, Merck, Novartis, Pfizer, Sandoz, and Sanofi, Leonhard Heinz: None declared, Giulio Superti-Furga: None declared.