Immunophenotyping of Inclusion Body Myositis Blood T and NK Cells

Neurology. 2022 Mar 29;98(13):e1374-e1383. doi: 10.1212/WNL.0000000000200013. Epub 2022 Feb 7.


Background and objectives: To evaluate the therapeutic potential of targeting highly differentiated T cells in patients with inclusion body myositis (IBM) by establishing high-resolution mapping of killer cell lectin-like receptor subfamily G member 1 (KLRG1+) within the T and natural killer (NK) cell compartments.

Methods: Blood was collected from 51 patients with IBM and 19 healthy age-matched donors. Peripheral blood mononuclear cells were interrogated by flow cytometry using a 12-marker antibody panel. The panel allowed the delineation of naive T cells (Tn), central memory T cells (Tcm), 4 stages of effector memory differentiation T cells (Tem 1-4), and effector memory re-expressing CD45RA T cells (TemRA), as well as total and subpopulations of NK cells based on the differential expression of CD16 and C56.

Results: We found that a population of KLRG1+ Tem and TemRA were expanded in both the CD4+ and CD8+ T-cell subpopulations in patients with IBM. KLRG1 expression in CD8+ T cells increased with T-cell differentiation with the lowest levels of expression in Tn and highest in highly differentiated TemRA and CD56+CD8+ T cells. The frequency of KLRG1+ total NK cells and subpopulations did not differ between patients with IBM and healthy donors. IBM disease duration correlated with increased CD8+ T-cell differentiation.

Discussion: Our findings reveal that the selective expansion of blood KLRG1+ T cells in patients with IBM is confined to the TemRA and Tem cellular compartments.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • CD8-Positive T-Lymphocytes*
  • Humans
  • Immunologic Memory
  • Immunophenotyping
  • Killer Cells, Natural / metabolism
  • Leukocytes, Mononuclear
  • Myositis, Inclusion Body*