TCRζ^dim T cells are enriched at sites of inflammation and accumulate in PB after treatment with anti-TNF in a subset of patients. (A) A dot plot of TCRζ versus CD3ϵ expression in PB and SF T cells from a patient with RA, as determined by flow cytometry. (B) Paired PB and SF mononuclear cells from patients with active inflammatory synovitis were stained for TCRζ and analyzed by flow cytometry. Mononuclear cell suspensions were prepared from synovial tissue (ST) specimens obtained from patients with RA at joint arthroplasty. Data are expressed as percent CD3⁺TCRζ^dim T cells in each compartment. (C) The percent CD3⁺TCRζ^dim cells was determined by flow cytometry in PBLs from 17 patients with RA at baseline and 14 weeks after treatment with anti-TNF. Data were stratified according to EULAR clinical response criteria (poor, moderate, or good), defined at 30 weeks.