Immune profiling in orthopaedic diseases using mass cytometry : a narrative review of applications and future

Yosuke Susuki1, Monica Thukkaram1, Issei Shinohara1

  • 1Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, California, USA.

Insights

Mass cytometry by time-of-flight (CyTOF) reveals shared immune markers across musculoskeletal diseases like rheumatoid arthritis. This deep immune phenotyping aids in understanding disease mechanisms and guiding future research.

Area of Science:

  • Immunology
  • Orthopaedic Surgery
  • Rheumatology

Background:

  • Musculoskeletal (MSK) diseases involve complex immune mechanisms.
  • Conventional flow cytometry has limitations in multidimensional immune characterization due to spectral overlap.
  • Mass cytometry by time-of-flight (CyTOF) offers deep immune phenotyping by measuring over 40 proteins per cell.

Purpose of the Study:

  • To summarize CyTOF applications in human orthopaedic and rheumatic diseases.
  • To highlight key immune findings and shared markers identified by CyTOF.
  • To identify research gaps and guide future panel standardization for MSK immunology.

Main Methods:

  • A literature search of peer-reviewed studies (2014-2024) was conducted using PubMed, Scopus, and Web of Science.
  • Search terms included "CyTOF" and "mass cytometry".
  • Studies involving CyTOF application to human MSK disorders with immune components were included.

Main Results:

  • Twenty-two studies were included, covering rheumatoid arthritis, osteoarthritis, psoriatic arthritis, and other MSK conditions.
  • CyTOF identified disease-specific immune cell subsets, cytokine profiles, and treatment-response signatures.
  • Eight recurrent markers (PD-1, ICOS, CXCR5, CXCR4, pSTAT3, TNFRII, p16INK4a, CD180) emerged across diseases, reflecting shared inflammatory, senescence, and tissue damage pathways.

Conclusions:

  • CyTOF enables high-dimensional immune profiling in MSK diseases, providing insights into pathogenesis, treatment response, and patient stratification.
  • Broader application of CyTOF to underexplored MSK conditions is warranted.
  • A minimal eight-marker backbone could enhance panel harmonization for multicentre translational studies in orthopaedic immunology.
Abstract