NK cell subsets define sustained remission in rheumatoid arthritis

Area of Science:

• Immunology
• Rheumatology
• Precision Medicine

Background:

• Rheumatoid arthritis (RA) is a chronic inflammatory disease managed with immunosuppressants.
• Achieving sustained remission is a goal, but flares occur due to lack of immunological remission markers.
• A precision medicine approach is needed to identify immune signatures of remission.

Purpose of the Study:

• To define peripheral blood immunological signatures of sustained remission in RA.
• To identify specific immune cell subsets associated with remission.
• To explore the role of these cells in synovial fluid and tissue.

Main Methods:

• Utilized high-dimensional phenotyping platforms to analyze peripheral blood immune cells.
• Conducted functional studies on identified NK cell subsets.
• Performed flow cytometry on synovial fluid NK cells and analyzed public single-cell RNA-Seq data of synovial tissue.

Main Results:

• Identified CD8+CD57+KIR2DL1+ NK cells as a signature of sustained RA remission.
• Discovered an NK cell subset with normal degranulation and reduced pro-inflammatory cytokine expression elevated in remission.
• Observed a deficiency of these remission-associated NK cell characteristics in synovial fluid and tissue of active RA patients.

Conclusions:

• Uncovered an immune signature of RA remission involving NK cell phenotype and function.
• These findings have implications for understanding host immunity during sustained RA remission.
• Identified potential biomarkers for operational tolerance in RA.