Figure 5.

CD4⁺CD28^null T cells do not associate with erosive disease. Frequency of CD4⁺CD28^null T cells in paired samples of synovial fluid (left column) and peripheral blood (right column) from (a), (b) patients seronegative (ACPA^-) and seropositive (ACPA⁺) for anti-citrullinated peptide/protein antibodies, and (c), (d) patients with or without erosive disease.